New Tool for Next-Generation Cancer Treatments using Nanodiamonds
A research team at Northwestern University has demonstrated a tool that can precisely deliver tiny doses of drug-carrying nanomaterials to individual cells.
The tool, called the Nanofountain Probe, functions in two different ways: in one mode, the probe acts like a fountain pen, wherein drug-coated nanodiamonds serve as the ink, allowing researchers to create devices by "writing" with it. The second mode functions as a single-cell syringe, permitting direct injection of biomolecules or chemicals into individual cells.
The research was led by Horacio Espinosa, professor of mechanical engineering, and Dean Ho, assistant professor of mechanical and biomedical engineering, both at the McCormick School of Engineering and Applied Science at Northwestern. Their results were recently published online in the scientific journal Small.
The probe could be used both as a research tool in the development of next-generation cancer treatments and as a nanomanufacturing tool to build the implantable drug delivery devices that will apply these treatments. The potential of nanomaterials to revolutionize drug delivery is emergent in early trials, which show their ability to moderate the release of highly toxic chemotherapy drugs and other therapeutics. This provides a platform for drug-delivery schemes with reduced side effects and improved targeting.
“This is an exciting development that complements our previous demonstrations of direct patterning of DNA, proteins and nanoparticles,” says Espinosa.
Using the Nanofountain Probe, the group injected tiny doses of nanodiamonds into both healthy and cancerous cells. This technique will help cancer researchers investigate the efficacy of new drug-nanomaterial systems as they become available.
The group also used the same Nanofountain Probes to pattern dot arrays of drug-coated nanodiamonds directly on glass substrates. The production of these dot arrays, with dots that can be made smaller than 100 nanometers in diameter, provides the proof of concept by which to manufacture devices that will deliver these nanomaterials within the body.
The work addresses two major challenges in the development and clinical application of nanomaterial-mediated drug-delivery schemes: dosage control and high spatial resolution.
In fundamental research and development, biologists are typically constrained to studying the effects of a drug on an entire cell population because it is difficult to deliver them to a single cell. To address this issue, the team used the Nanofountain Probe to target and inject single cells with a dose of nanodiamonds.
“This allows us to deliver a precise dose to one cell and observe its response relative to its neighbors,” Ho says. “This will allow us to investigate the ultimate efficacy of novel treatment strategies via a spectrum of internalization mechanisms.”
Beyond the broad research focused on developing these drug-delivery schemes, manufacturing devices to execute the delivery will require the ability to precisely place doses of drug-coated nanomaterials. Ho and colleagues previously developed a polymer patch that could be used to deliver chemotherapy drugs locally to sites where cancerous tumors have been removed. This patch is embedded with a layer of drug-coated nanodiamonds, which moderate the release of the drug. The patch is capable of controlled and sustained low levels of release over a period of months, reducing the need for chemotherapy following the removal of a tumor.
“An attractive enhancement will be to use the Nanofountain Probe to replace the continuous drug-nanodiamond films currently used in these devices with patterned arrays composed of multiple drugs,” Ho says. “This allows high-fidelity spatial tuning of dosing in intelligent devices for comprehensive treatment.”
“One of the most significant aspects of this work is the Nanofountain Probe’s ability to deliver nanomaterials coated with a broad range of drugs and other biological agents,” Espinosa says. “The injection technique is currently being explored for delivery of a wide variety of bio-agents, including DNA, viruses and other therapeutically relevant materials.”
Nanodiamonds have also proven effective in seeding the growth of diamond thin films. These diamond films have exciting applications in next-generation nanoelectronics. Here again, the ability to pattern nanodiamonds with sub-100-nanometer resolution provides inroads to realizing these devices on a mass scale. The resolution in nanodiamond patterning demonstrated by the Nanofountain Probe represents an improvement of three orders of magnitude over other reported direct-write schemes of nanodiamond patterning.
The work was supported by the National Science Foundation, the National Institutes of Health, the V Foundation for Cancer Research and the Wallace H. Coulter Foundation.
In addition to Espinosa and Ho, other authors of the paper, entitled “Nanofountain Probe-based High-resolution Patterning and Single-cell Injection of Functionalized Nanodiamonds,” are Owen Loh, Robert Lam, Mark Chen, Nicolaie Moldovan and Houjin Huang of Northwestern University.
>http://www.nanotechwire.com/news.asp?nid=7939
วันจันทร์ที่ 15 มิถุนายน พ.ศ. 2552
Drug Delivery
NanoVentures Australia
Unveils Novel Pulmonary Drug Delivery Technology
NVA’s predecessor, Nanotechnology Victoria Ltd (”NanoVic”) invested nearly $500,000 with Monash University’s Micro NanoPhysics Research Laboratory to develop and demonstrate a novel mechanism for generation of liquid aerosol drugs. The proprietary SAW (Surface Acoustic Wave) generated mechanism allows fluids to be atomised as precisely controlled droplets, making them ideal for a new generation of inhaler devices. These inhalers are likely to be very low cost, as they require very few moving parts.
Further, the SAW technology means that drugs like insulin can be delivered in fluid droplet form from an inhaler. Previous attempts to deliver insulin from an inhaler have used dry powders, which are more difficult to control, and may cause new issues for certain groups of patients.
Last month, NVA and Monash University filed for the protection of new intellectual property around their proprietary pulmonary drug delivery device. The parties hold the Australian provisional patent application 2009902063 Microfluidics apparatus for the atomisation of a liquid. In particular the team has demonstrated in vitro results with maintenance of insulin structure and function after aerosolisation, and over 70% delivery to the lungs using the test protein insulin.
There has been growing interest in the potential for the systematic delivery of drugs and therapeutic agents (e.g. peptides and proteins) via inhalation. Pulmonary drug delivery is an attractive option compared to oral administration or other invasive delivery techniques, and is particularly suited to a number of frequent-application drugs. The surface acoustic atomisation technology developed by Monash University provides for the controlled generation of aerosol particles, and is ideal for drug delivery to the deep regions of the lungs.
NVA has exclusive rights to the exploitation of the technology for potential applications in the administration of insulin and erythropoietin, as well as for the treatment of Cystic Fibrosis and Multiple Sclerosis.
The delivery device R&D program, led by Associate Professor James Friend at the Monash University Micro NanoPhysics Research Laboratory, commenced in January 2007 and is due for completion in October 2009. Dr Friend is internationally known for his leadership in the application of nanotechnology to medical devices.
NVA commercialises nanotechnologies developed by Nanotechnology Victoria Ltd (”NanoVic”), the Victorian Government funded nanotechnology accelerator which operated from 2002 to 2009. NVA has a portfolio of other technologies being positioned for commercial development, in medical therapeutics, diagnostics, advanced materials and water analysis and purification. NVA commercialises nanotechnologies developed by Nanotechnology Victoria Ltd (”NanoVic”), the Victorian Government funded nanotechnology accelerator which operated from 2002 to 2009.
>http://www.nanotechwire.com/news.asp?nid=8000
Unveils Novel Pulmonary Drug Delivery Technology
NVA’s predecessor, Nanotechnology Victoria Ltd (”NanoVic”) invested nearly $500,000 with Monash University’s Micro NanoPhysics Research Laboratory to develop and demonstrate a novel mechanism for generation of liquid aerosol drugs. The proprietary SAW (Surface Acoustic Wave) generated mechanism allows fluids to be atomised as precisely controlled droplets, making them ideal for a new generation of inhaler devices. These inhalers are likely to be very low cost, as they require very few moving parts.
Further, the SAW technology means that drugs like insulin can be delivered in fluid droplet form from an inhaler. Previous attempts to deliver insulin from an inhaler have used dry powders, which are more difficult to control, and may cause new issues for certain groups of patients.
Last month, NVA and Monash University filed for the protection of new intellectual property around their proprietary pulmonary drug delivery device. The parties hold the Australian provisional patent application 2009902063 Microfluidics apparatus for the atomisation of a liquid. In particular the team has demonstrated in vitro results with maintenance of insulin structure and function after aerosolisation, and over 70% delivery to the lungs using the test protein insulin.
There has been growing interest in the potential for the systematic delivery of drugs and therapeutic agents (e.g. peptides and proteins) via inhalation. Pulmonary drug delivery is an attractive option compared to oral administration or other invasive delivery techniques, and is particularly suited to a number of frequent-application drugs. The surface acoustic atomisation technology developed by Monash University provides for the controlled generation of aerosol particles, and is ideal for drug delivery to the deep regions of the lungs.
NVA has exclusive rights to the exploitation of the technology for potential applications in the administration of insulin and erythropoietin, as well as for the treatment of Cystic Fibrosis and Multiple Sclerosis.
The delivery device R&D program, led by Associate Professor James Friend at the Monash University Micro NanoPhysics Research Laboratory, commenced in January 2007 and is due for completion in October 2009. Dr Friend is internationally known for his leadership in the application of nanotechnology to medical devices.
NVA commercialises nanotechnologies developed by Nanotechnology Victoria Ltd (”NanoVic”), the Victorian Government funded nanotechnology accelerator which operated from 2002 to 2009. NVA has a portfolio of other technologies being positioned for commercial development, in medical therapeutics, diagnostics, advanced materials and water analysis and purification. NVA commercialises nanotechnologies developed by Nanotechnology Victoria Ltd (”NanoVic”), the Victorian Government funded nanotechnology accelerator which operated from 2002 to 2009.
>http://www.nanotechwire.com/news.asp?nid=8000
Nanotechnology
UB Scientists Develop Novel Nanotechnology
Method to Stimulate Growth of New Neurons in Adult Brain
University at Buffalo researchers have identified a new mechanism that plays a central role in adult brain stem cell development and prompts brain stem cells to differentiate into neurons.
Their discovery, known as Integrative FGFR1 Signaling (INFS), has fundamentally challenged the prevailing ideas of how signals are processed in cells during neuronal development.
The INFS mechanism is considered capable of repopulating degenerated brain areas, raising possibilities for new treatments for Parkinson’s disease, Alzheimer’s disease and other neurodegenerative disorders, and may be a promising anti-cancer therapy.
Michal Stachowiak, Ph.D., director of the Molecular and Structural Neurobiology and Gene Therapy Program at UB, lead the research team that discovered INFS.
Results of the research appear in a recent issue of Integrative Biology at http://xlink.rsc.org/?doi=B902617G.
The approach uses gene engineering and nanoparticles for gene delivery to activate the INFS mechanism directly and promote neuronal development. The INFS-targeting gene can prompt these stem cells to differentiate into neurons.
Stachowiak, UB associate professor of pathology and anatomical sciences in the UB School of Medicine and Biomedical Sciences, said the research team set out to see if it is possible to generate a wave of new neurons from stem cells and direct them to the affected areas using a mouse model.
“In this way, targeting the INFS potentially could be used to cure certain brain diseases, particularly in the case of a stroke or injuries that happen as a single episode and are not continuously attacking the brain,” he said.
“This study provides proof of concept for a novel approach to the treatment of neuronal loss by means of therapeutic gene transfer. This is a particularly attractive alternative to viral-mediated gene transfer.
“The health risks associated with using viruses to carry genes in this type of gene transfer have led to the search for safer means of gene delivery,” noted Stachowiak. “Nanotechnology offers an unprecedented advantage in enhancing the efficacy of non-viral gene delivery.”
Stachowiak and his wife, Ewa K. Stachowiak, Ph.D., research assistant professor of pathology and anatomical sciences, along with their postdoctoral fellows and graduate students, have spent more than 15 years studying the mechanisms controlling natural neurogenesis, the creation of new neurons.
Brain injuries, stroke and progressive chronic diseases such as Parkinson’s or Alzheimer’s disease result in an extensive loss of neurons, accompanied by functional deterioration in the affected brain tissue. Such neurodegenerative diseases are a major health concern, given the rising aging population worldwide.
In addition, neurodevelopmental disorders, such as autism and schizophrenia, diminish the production of neurons and disrupt the brain’s cellular structure.
“Manipulation of pre-existing adult stem cells to repopulate diseased areas of the brain holds the key towards the treatment of these neurodegenerative and, possibly, neurodevelopmental disorders,” said Michal Stachowiak.
“However, after birth, the ability of the brain’s stem cells to form the necessary new neurons normally is greatly diminished, and the mechanisms controlling natural neurogenesis are not well understood.”
The neurogenic potential of targeting INFS was described initially in cultured stem cells in vitro by the Stachowiak team. Following these initial studies, together with a team of UB chemists that included Indrajit Roy, Ph.D., Dhruba Bharali, Ph.D., and Paras N. Prasad, Ph.D., Stachowiak’s group investigated the use of organically modified silica nanoparticles as gene delivery vehicles into the stem cells of the brain in vivo.
Prasad is executive director of the UB Institute for Lasers, Photonics and Biophotonics and SUNY Distinguished Professor in the departments of Chemistry, Physics, Electrical Engineering and Medicine. Roy is an assistant research professor in the institute; Bharali was a research associate.
Injae Shin, Ph.D., an expert in genetics at Yonsei University, Seoul, Korea, in an online article on the Chemical Biology Web site, called the work “exciting.” He noted that it has the potential to treat neurological diseases, but pointed out the need for further development of gene delivery methods for the treatment of neuronal loss.
Stachowiak and colleagues currently are working on such approaches.
“Targeting the INFS mechanisms by small molecules could potentially replace the need for gene transfers and create a classical drug therapy for the neuronal loss,” said Ewa Stachowiak. “Now that we know the mechanism, we can search effectively for the means to control it.”
>http://www.nanotechwire.com/news.asp?nid=7956
Method to Stimulate Growth of New Neurons in Adult Brain
University at Buffalo researchers have identified a new mechanism that plays a central role in adult brain stem cell development and prompts brain stem cells to differentiate into neurons.
Their discovery, known as Integrative FGFR1 Signaling (INFS), has fundamentally challenged the prevailing ideas of how signals are processed in cells during neuronal development.
The INFS mechanism is considered capable of repopulating degenerated brain areas, raising possibilities for new treatments for Parkinson’s disease, Alzheimer’s disease and other neurodegenerative disorders, and may be a promising anti-cancer therapy.
Michal Stachowiak, Ph.D., director of the Molecular and Structural Neurobiology and Gene Therapy Program at UB, lead the research team that discovered INFS.
Results of the research appear in a recent issue of Integrative Biology at http://xlink.rsc.org/?doi=B902617G.
The approach uses gene engineering and nanoparticles for gene delivery to activate the INFS mechanism directly and promote neuronal development. The INFS-targeting gene can prompt these stem cells to differentiate into neurons.
Stachowiak, UB associate professor of pathology and anatomical sciences in the UB School of Medicine and Biomedical Sciences, said the research team set out to see if it is possible to generate a wave of new neurons from stem cells and direct them to the affected areas using a mouse model.
“In this way, targeting the INFS potentially could be used to cure certain brain diseases, particularly in the case of a stroke or injuries that happen as a single episode and are not continuously attacking the brain,” he said.
“This study provides proof of concept for a novel approach to the treatment of neuronal loss by means of therapeutic gene transfer. This is a particularly attractive alternative to viral-mediated gene transfer.
“The health risks associated with using viruses to carry genes in this type of gene transfer have led to the search for safer means of gene delivery,” noted Stachowiak. “Nanotechnology offers an unprecedented advantage in enhancing the efficacy of non-viral gene delivery.”
Stachowiak and his wife, Ewa K. Stachowiak, Ph.D., research assistant professor of pathology and anatomical sciences, along with their postdoctoral fellows and graduate students, have spent more than 15 years studying the mechanisms controlling natural neurogenesis, the creation of new neurons.
Brain injuries, stroke and progressive chronic diseases such as Parkinson’s or Alzheimer’s disease result in an extensive loss of neurons, accompanied by functional deterioration in the affected brain tissue. Such neurodegenerative diseases are a major health concern, given the rising aging population worldwide.
In addition, neurodevelopmental disorders, such as autism and schizophrenia, diminish the production of neurons and disrupt the brain’s cellular structure.
“Manipulation of pre-existing adult stem cells to repopulate diseased areas of the brain holds the key towards the treatment of these neurodegenerative and, possibly, neurodevelopmental disorders,” said Michal Stachowiak.
“However, after birth, the ability of the brain’s stem cells to form the necessary new neurons normally is greatly diminished, and the mechanisms controlling natural neurogenesis are not well understood.”
The neurogenic potential of targeting INFS was described initially in cultured stem cells in vitro by the Stachowiak team. Following these initial studies, together with a team of UB chemists that included Indrajit Roy, Ph.D., Dhruba Bharali, Ph.D., and Paras N. Prasad, Ph.D., Stachowiak’s group investigated the use of organically modified silica nanoparticles as gene delivery vehicles into the stem cells of the brain in vivo.
Prasad is executive director of the UB Institute for Lasers, Photonics and Biophotonics and SUNY Distinguished Professor in the departments of Chemistry, Physics, Electrical Engineering and Medicine. Roy is an assistant research professor in the institute; Bharali was a research associate.
Injae Shin, Ph.D., an expert in genetics at Yonsei University, Seoul, Korea, in an online article on the Chemical Biology Web site, called the work “exciting.” He noted that it has the potential to treat neurological diseases, but pointed out the need for further development of gene delivery methods for the treatment of neuronal loss.
Stachowiak and colleagues currently are working on such approaches.
“Targeting the INFS mechanisms by small molecules could potentially replace the need for gene transfers and create a classical drug therapy for the neuronal loss,” said Ewa Stachowiak. “Now that we know the mechanism, we can search effectively for the means to control it.”
>http://www.nanotechwire.com/news.asp?nid=7956
Drug Delivery
Combining Two Drugs in One Nanoparticle
Overcomes Multidrug Resistance
Cancer cells, like bacteria, can develop resistance to drug therapy. In fact, research suggests strongly that multidrug-resistant cancer cells that remain alive after chemotherapy are responsible for the reappearance of tumors and the poor prognosis for patients whose cancer recurs. One new approach that shows promise in overcoming such multidrug resistance is to combine two different anticancer agents in one nanoscale construct, providing a one-two punch that can prove lethal to such resistant cells. This work appears in the journal Molecular Pharmaceutics.
Mansoor Amiji, Ph.D., principal investigator of the National Cancer Institute-funded Nanotherapeutic Strategy for Multidrug Resistant Tumors Platform Partnership at Northeastern University, and postdoctoral fellow Srinivas Ganta, Ph.D., created a nanoemulsion entrapping both paclitaxel and curcumin. The former compound is a widely used anticancer agent, whereas the latter comes from the spice tumeric and has been shown to inhibit several cancer-related processes.
The investigators prepared their nanoformulation by mixing the two drugs with flaxseed oil, the emulsifier lecithin from egg yolks, and the biocompatible polymer polyethylene glycol. To help track this nanoformulation, the investigators also added a fluorescent dye to the mixture. Ultrasonification for 10 minutes produced stable, nanosize droplets that were readily taken up by tumor cells grown in culture. In addition, the nanoformulation had significant anticancer activity that surpassed that of either of the two drugs administered together or separately, particularly in multidrug-resistant cells. Biochemical assays showed that the curcumin component inhibited P-glycoprotein, which tumor cells use to excrete anticancer agents and protect themselves from the effects of those agents. Both drugs also had the effect of triggering apoptosis in the treated cells.
This work, which was detailed in the paper “Coadministration of paclitaxel and curcumin in nanoemulsion formulations to overcome multidrug resistance in tumor cells,” was supported by the NCI Alliance for Nanotechnology in Cancer, a comprehensive initiative designed to accelerate the application of nanotechnology to the prevention, diagnosis, and treatment of cancer. An abstract is available at the journal’s Web site.
>http://www.nanotechwire.com/news.asp?nid=7861
Overcomes Multidrug Resistance
Cancer cells, like bacteria, can develop resistance to drug therapy. In fact, research suggests strongly that multidrug-resistant cancer cells that remain alive after chemotherapy are responsible for the reappearance of tumors and the poor prognosis for patients whose cancer recurs. One new approach that shows promise in overcoming such multidrug resistance is to combine two different anticancer agents in one nanoscale construct, providing a one-two punch that can prove lethal to such resistant cells. This work appears in the journal Molecular Pharmaceutics.
Mansoor Amiji, Ph.D., principal investigator of the National Cancer Institute-funded Nanotherapeutic Strategy for Multidrug Resistant Tumors Platform Partnership at Northeastern University, and postdoctoral fellow Srinivas Ganta, Ph.D., created a nanoemulsion entrapping both paclitaxel and curcumin. The former compound is a widely used anticancer agent, whereas the latter comes from the spice tumeric and has been shown to inhibit several cancer-related processes.
The investigators prepared their nanoformulation by mixing the two drugs with flaxseed oil, the emulsifier lecithin from egg yolks, and the biocompatible polymer polyethylene glycol. To help track this nanoformulation, the investigators also added a fluorescent dye to the mixture. Ultrasonification for 10 minutes produced stable, nanosize droplets that were readily taken up by tumor cells grown in culture. In addition, the nanoformulation had significant anticancer activity that surpassed that of either of the two drugs administered together or separately, particularly in multidrug-resistant cells. Biochemical assays showed that the curcumin component inhibited P-glycoprotein, which tumor cells use to excrete anticancer agents and protect themselves from the effects of those agents. Both drugs also had the effect of triggering apoptosis in the treated cells.
This work, which was detailed in the paper “Coadministration of paclitaxel and curcumin in nanoemulsion formulations to overcome multidrug resistance in tumor cells,” was supported by the NCI Alliance for Nanotechnology in Cancer, a comprehensive initiative designed to accelerate the application of nanotechnology to the prevention, diagnosis, and treatment of cancer. An abstract is available at the journal’s Web site.
>http://www.nanotechwire.com/news.asp?nid=7861
Capsules encapsulated
Drug Deliver With Nanotechnology:
Capsules Encapsulated
When cells cannot carry out the tasks required of them by our bodies, the result is disease. Nanobiotechnology researchers are looking for ways to allow synthetic systems take over simple cellular activities when they are absent from the cell. This requires transport systems that can encapsulate medications and other substances and release them in a controlled fashion at the right moment.
The transporter must be able to interact with the surroundings in order to receive the signal to unload its cargo. A team led by Frank Caruso at the University of Melbourne has now developed a microcontainer that can hold thousands of individual "carrier units"—a "capsosome". These are polymer capsules in which liposomes have been embedded to form subcompartments.
Currently, the primary type of nanotransporter used for drugs is the capsule: Polymer capsules form stable containers that are semipermeable, which allows for communication with the surrounding medium. However, these are not suitable for the transport of small molecules because they can escape. Liposomes are good at protecting small drug molecules; however, they are often unstable and impermeable to substances from the environment. The Australian researchers have now combined the advantages of both systems in their capsosomes.
Capsosomes are produced by several steps. First, a layer of polymer is deposited onto small silica spheres. This polymer contains building blocks modified with cholesterol. Liposomes that have been loaded with an enzyme can be securely anchored to the cholesterol units and thus attached to the polymer film. Subsequently, more polymer layers are added and then cross-linked by disulfide bridges into a gel by means of a specially developed, very gentle cross-linking reaction. In the final step, the silica core is etched away without damaging the sensitive cargo.
Experiments with an enzyme as model cargo demonstrated that the liposomes remain intact and the cargo does not escape. Addition of a detergent releases the enzyme in a functional state. By means of the enzymatic reaction, which causes a color change of the solution, it was possible to determine the number of liposome compartments to be about 8000 per polymer capsule.
"Because the capsosomes are biodegradable and nontoxic", says Brigitte Staedler, a senior researcher in the group, "they would also be suitable for use as resorbable synthetic cell organelles and for the transport of drugs." In addition, the scientists are planning to encapsulate liposomes filled with different enzymes together and to equip them with specific "receivers" which would allow the individual cargo to be released in a targeted fashion. This would make it possible to use enzymatic reaction cascades for catalytic reaction processes.
Frank Caruso. A Microreactor with Thousands of Subcompartments: Enzyme-Loaded Liposomes within Polymer Capsules. Angewandte Chemie International
Edition, 2009, 48, No. 24, 4359-4362 DOI: 10.1002/anie.200900386
>http://www.nanotechwire.com/news.asp?nid=7944
Capsules Encapsulated
When cells cannot carry out the tasks required of them by our bodies, the result is disease. Nanobiotechnology researchers are looking for ways to allow synthetic systems take over simple cellular activities when they are absent from the cell. This requires transport systems that can encapsulate medications and other substances and release them in a controlled fashion at the right moment.
The transporter must be able to interact with the surroundings in order to receive the signal to unload its cargo. A team led by Frank Caruso at the University of Melbourne has now developed a microcontainer that can hold thousands of individual "carrier units"—a "capsosome". These are polymer capsules in which liposomes have been embedded to form subcompartments.
Currently, the primary type of nanotransporter used for drugs is the capsule: Polymer capsules form stable containers that are semipermeable, which allows for communication with the surrounding medium. However, these are not suitable for the transport of small molecules because they can escape. Liposomes are good at protecting small drug molecules; however, they are often unstable and impermeable to substances from the environment. The Australian researchers have now combined the advantages of both systems in their capsosomes.
Capsosomes are produced by several steps. First, a layer of polymer is deposited onto small silica spheres. This polymer contains building blocks modified with cholesterol. Liposomes that have been loaded with an enzyme can be securely anchored to the cholesterol units and thus attached to the polymer film. Subsequently, more polymer layers are added and then cross-linked by disulfide bridges into a gel by means of a specially developed, very gentle cross-linking reaction. In the final step, the silica core is etched away without damaging the sensitive cargo.
Experiments with an enzyme as model cargo demonstrated that the liposomes remain intact and the cargo does not escape. Addition of a detergent releases the enzyme in a functional state. By means of the enzymatic reaction, which causes a color change of the solution, it was possible to determine the number of liposome compartments to be about 8000 per polymer capsule.
"Because the capsosomes are biodegradable and nontoxic", says Brigitte Staedler, a senior researcher in the group, "they would also be suitable for use as resorbable synthetic cell organelles and for the transport of drugs." In addition, the scientists are planning to encapsulate liposomes filled with different enzymes together and to equip them with specific "receivers" which would allow the individual cargo to be released in a targeted fashion. This would make it possible to use enzymatic reaction cascades for catalytic reaction processes.
Frank Caruso. A Microreactor with Thousands of Subcompartments: Enzyme-Loaded Liposomes within Polymer Capsules. Angewandte Chemie International
Edition, 2009, 48, No. 24, 4359-4362 DOI: 10.1002/anie.200900386
>http://www.nanotechwire.com/news.asp?nid=7944
Dead or alive
Nanotechnology technique tells the difference
(Nanowerk Spotlight)
A major concern in microbiology is to determine whether a bacterium is dead or alive. This crucial question has major consequences in food industry, water supply or health care. While culture-based tests can determine whether bacteria can proliferate and form colonies, these tests are time-consuming and work poorly with certain slow-growing or non-culturable bacteria. They are not suitable for applications where real-time results are needed, e.g. in industrial manufacturing or food processing. A team of scientists in France has now discovered that living and dead cells can be discriminated with a nanotechnology technique on the basis of their cell wall nanomechanical properties. This finding is totally new and has been made possible thanks to an interdisciplinary approach which mixes physics, biology and chemistry. This work is a key stone in the understanding of bacterial cell wall behavior. "We have developed a method to probe the mechanical properties of living and dead bacteria via atomic force microscope (AFM) indentation experimentations," Aline Cerf tells Nanowerk. ". Indeed, we provide a new way to probe bacterial cell viability based on cell wall nanomechanical properties, independently from cell ability to grow on a medium or to be penetrated by a fluorescent dye." Cerf, a PhD student in the NanoBioSystems group at LAAS-CNRS, is first author of a recent paper in Langmuir ("Nanomechanical Properties of Dead or Alive Single-Patterned Bacteria") where she and collaborators from LAAS-CNRS describe their findings. "We wanted to explore the modifications that could occur in the nanomechanical properties of a single E. coli bacterium, while it is alive and while it is dead," says Etienne Dague, a researcher in the NanoBioSystems group. "To reach this goal, it has been of first importance to immobilize the living bacteria in an aqueous environment to avoid any cell wall modifications due to a drying step." Thus, in developing a technique to probe the mechanical properties of bacteria via AFM indentation experiments, the French team also came up with an immobilization method for bacteria that doesn't require a chemical fixation.
The researchers set up a fast and simple procedure – based on a conventional microcontact printing and a simple incubation technique to generate functionalized patterns so as to induce local bacteria deposition – that allowed them to produce reliable chemical patterns exhibiting different surface properties to induce selective adsorption of individual bacteria in liquid media at registered positions. "We have evidenced a selective adsorption of bacteria on these local chemical patterns, producing highly ordered arrays of single living bacteria with a success rate close to 100%," says Cerf. The team then used this controlled immobilization method to study the mechanical properties of dead or alive bacterial cell in aqueous environment. Using force spectroscopy before and after heating , they measured the Young moduli of the same cell. The cells with a damaged membrane (after heating) present a Young modulus twice as high (6.1 ? 1.5 MPa versus 3.0 ? 0.6 MPa) as that of healthy bacteria. At the same time it has been impossible to evidence a difference between the AFM images of the living and the dead cell. "We have shown that we are capable of engineering large areas with patterns of single bacteria and this will be of major interest for future applications," says Dague. "Indeed, thanks to a periodic arrangement of cells, the process consisting in measuring the nanomechanical properties of cells could possibly be automated and a tool to count live or dead bacteria could be designed."
By Michael Berger. Copyright 2009 Nanowerk LLC >http://www.nanowerk.com/spotlight/spotid=10816.php
(Nanowerk Spotlight)
A major concern in microbiology is to determine whether a bacterium is dead or alive. This crucial question has major consequences in food industry, water supply or health care. While culture-based tests can determine whether bacteria can proliferate and form colonies, these tests are time-consuming and work poorly with certain slow-growing or non-culturable bacteria. They are not suitable for applications where real-time results are needed, e.g. in industrial manufacturing or food processing. A team of scientists in France has now discovered that living and dead cells can be discriminated with a nanotechnology technique on the basis of their cell wall nanomechanical properties. This finding is totally new and has been made possible thanks to an interdisciplinary approach which mixes physics, biology and chemistry. This work is a key stone in the understanding of bacterial cell wall behavior. "We have developed a method to probe the mechanical properties of living and dead bacteria via atomic force microscope (AFM) indentation experimentations," Aline Cerf tells Nanowerk. ". Indeed, we provide a new way to probe bacterial cell viability based on cell wall nanomechanical properties, independently from cell ability to grow on a medium or to be penetrated by a fluorescent dye." Cerf, a PhD student in the NanoBioSystems group at LAAS-CNRS, is first author of a recent paper in Langmuir ("Nanomechanical Properties of Dead or Alive Single-Patterned Bacteria") where she and collaborators from LAAS-CNRS describe their findings. "We wanted to explore the modifications that could occur in the nanomechanical properties of a single E. coli bacterium, while it is alive and while it is dead," says Etienne Dague, a researcher in the NanoBioSystems group. "To reach this goal, it has been of first importance to immobilize the living bacteria in an aqueous environment to avoid any cell wall modifications due to a drying step." Thus, in developing a technique to probe the mechanical properties of bacteria via AFM indentation experiments, the French team also came up with an immobilization method for bacteria that doesn't require a chemical fixation.
The researchers set up a fast and simple procedure – based on a conventional microcontact printing and a simple incubation technique to generate functionalized patterns so as to induce local bacteria deposition – that allowed them to produce reliable chemical patterns exhibiting different surface properties to induce selective adsorption of individual bacteria in liquid media at registered positions. "We have evidenced a selective adsorption of bacteria on these local chemical patterns, producing highly ordered arrays of single living bacteria with a success rate close to 100%," says Cerf. The team then used this controlled immobilization method to study the mechanical properties of dead or alive bacterial cell in aqueous environment. Using force spectroscopy before and after heating , they measured the Young moduli of the same cell. The cells with a damaged membrane (after heating) present a Young modulus twice as high (6.1 ? 1.5 MPa versus 3.0 ? 0.6 MPa) as that of healthy bacteria. At the same time it has been impossible to evidence a difference between the AFM images of the living and the dead cell. "We have shown that we are capable of engineering large areas with patterns of single bacteria and this will be of major interest for future applications," says Dague. "Indeed, thanks to a periodic arrangement of cells, the process consisting in measuring the nanomechanical properties of cells could possibly be automated and a tool to count live or dead bacteria could be designed."
By Michael Berger. Copyright 2009 Nanowerk LLC >http://www.nanowerk.com/spotlight/spotid=10816.php
Virus Battery
MIT researchers make virus battery
WASHINGTON, April 2 (Xinhua)
For the first time, MIT researchers have shown they can genetically engineer viruses to build both the positively and negatively charged ends of a lithium-ion battery, according to a study released on Thursday in the online edition of journal Science.
The new virus-produced batteries have the same energy capacity and power performance as state-of-the-art rechargeable batteries being considered to power plug-in hybrid cars, and they could also be used to power a range of personal electronic devices, said Angela Belcher, the MIT materials scientist who led the research team.
The new batteries could be manufactured with a cheap and environmentally benign process: The synthesis takes place at and below room temperature and requires no harmful organic solvents, and the materials that go into the battery are non-toxic.
In a traditional lithium-ion battery, lithium ions flow between a negatively charged anode, usually graphite, and the positively charged cathode, usually cobalt oxide or lithium iron phosphate. Three years ago, an MIT team led by Belcher reported that it had engineered viruses that could build an anode by coating themselves with cobalt oxide and gold and self-assembling to form a nanowire.
In the latest work, the team focused on building a highly powerful cathode to pair up with the anode, said Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering in MIT. Cathodes are more difficult to build than anodes because they must be highly conducting to be a fast electrode. However, most candidate materials for cathodes are highly insulating (non-conductive).
To achieve that, the researchers, including MIT Professor Gerbrand Ceder of materials science and Associate Professor Michael Strano of chemical engineering, genetically engineered viruses that first coat themselves with iron phosphate, then grab hold of carbon nanotubes to create a network of highly conductive material.
Because the viruses recognize and bind specifically to certain materials (carbon nanotubes in this case), each iron phosphate nanowire can be electrically "wired" to conducting carbon nanotubenetworks. Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time.
The viruses are a common bacteriophage, which infect bacteria but are harmless to humans.
The team found that incorporating carbon nanotubes increases the cathode's conductivity without adding too much weight to the battery. In lab tests, batteries with the new cathode material could be charged and discharged at least 100 times without losing any capacitance. That is fewer charge cycles than currently available lithium-ion batteries, but "we expect them to be able to go much longer," Belcher said.
The prototype is packaged as a typical coin cell battery, but the technology allows for the assembly of very lightweight, flexible and conformable batteries that can take the shape of their container.
Last week, MIT President Susan Hockfield took the prototype battery to a press briefing at the White House where she and U.S. President Barack Obama spoke about the need for federal funding to advance new clean-energy technologies.
Now that the researchers have demonstrated they can wire virus batteries at the nanoscale, they intend to pursue even better batteries using materials with higher voltage and capacitance, such as manganese phosphate and nickel phosphate, said Belcher. Once that next generation is ready, the technology could go into commercial production, she said.
source: > www.chinaview.cn
Editor: Mu Xuequan
WASHINGTON, April 2 (Xinhua)
For the first time, MIT researchers have shown they can genetically engineer viruses to build both the positively and negatively charged ends of a lithium-ion battery, according to a study released on Thursday in the online edition of journal Science.
The new virus-produced batteries have the same energy capacity and power performance as state-of-the-art rechargeable batteries being considered to power plug-in hybrid cars, and they could also be used to power a range of personal electronic devices, said Angela Belcher, the MIT materials scientist who led the research team.
The new batteries could be manufactured with a cheap and environmentally benign process: The synthesis takes place at and below room temperature and requires no harmful organic solvents, and the materials that go into the battery are non-toxic.
In a traditional lithium-ion battery, lithium ions flow between a negatively charged anode, usually graphite, and the positively charged cathode, usually cobalt oxide or lithium iron phosphate. Three years ago, an MIT team led by Belcher reported that it had engineered viruses that could build an anode by coating themselves with cobalt oxide and gold and self-assembling to form a nanowire.
In the latest work, the team focused on building a highly powerful cathode to pair up with the anode, said Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering in MIT. Cathodes are more difficult to build than anodes because they must be highly conducting to be a fast electrode. However, most candidate materials for cathodes are highly insulating (non-conductive).
To achieve that, the researchers, including MIT Professor Gerbrand Ceder of materials science and Associate Professor Michael Strano of chemical engineering, genetically engineered viruses that first coat themselves with iron phosphate, then grab hold of carbon nanotubes to create a network of highly conductive material.
Because the viruses recognize and bind specifically to certain materials (carbon nanotubes in this case), each iron phosphate nanowire can be electrically "wired" to conducting carbon nanotubenetworks. Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time.
The viruses are a common bacteriophage, which infect bacteria but are harmless to humans.
The team found that incorporating carbon nanotubes increases the cathode's conductivity without adding too much weight to the battery. In lab tests, batteries with the new cathode material could be charged and discharged at least 100 times without losing any capacitance. That is fewer charge cycles than currently available lithium-ion batteries, but "we expect them to be able to go much longer," Belcher said.
The prototype is packaged as a typical coin cell battery, but the technology allows for the assembly of very lightweight, flexible and conformable batteries that can take the shape of their container.
Last week, MIT President Susan Hockfield took the prototype battery to a press briefing at the White House where she and U.S. President Barack Obama spoke about the need for federal funding to advance new clean-energy technologies.
Now that the researchers have demonstrated they can wire virus batteries at the nanoscale, they intend to pursue even better batteries using materials with higher voltage and capacitance, such as manganese phosphate and nickel phosphate, said Belcher. Once that next generation is ready, the technology could go into commercial production, she said.
source: > www.chinaview.cn
Editor: Mu Xuequan
วันศุกร์ที่ 5 มิถุนายน พ.ศ. 2552
Your doctor's on your Web cam
The new house call: Your doctor's at the door, er, on your Web cam
Too busy to go to the doctor? Unfortunately, it's the rare one who makes house calls these days. But how about the next best thing? The Hawaii Medical Service Association (HMSA) next week is set to begin offering doctor consults via Web cam, an emerging form of telemedicine.
The association (the state's Blue Cross Blue Shield insurance provider) will offer the 10-minute Internet visits through American Well, a Boston-based company that provides video conferencing and electronic medical record-keeping to doctors and patients, the New York Times reports today. HMSA is its first customer, the Times says. “It’s a better iteration on, ‘Take two aspirin and call me in the morning,’” Robert Sussman, a family practice doctor on Oahu, tells the newspaper. “We can’t lay on the hands, but we can lay on the eyes and get a better feel" than from a simple phone consult.
Telemedicine – by Internet or phone – is touted as a convenience for folks who don’t want to wait days for a doctor’s appointment, who don’t live near a physician, and who are willing to pay out of pocket for the perk of a visit on their own schedule. The cost is a $10 co-pay for HMSA members and $45 for non-members. Proponents say doctors can take care of about half of medical problems without a face-to-face workup.
While some traditional doctors consult with regular patients by phone or email, many don’t, says Jay Parkinson, a primary-care doctor who runs the telemedicine business Hello Health in Brooklyn, N.Y. “Doctors don’t get paid for communications – only office visits and procedures,” Parkinson tells ScientificAmerican.com. “Nowadays doctors see so many patients – 30, 40, 50 patients a day. When the day is over, they can’t sit down and answer 50 emails for free.”
Hello Health's fees are based on the length and type of visit: $100-to-$200 for an office visit versus $50-to-$100 for video, instant message and phone visits. (If the latter leads to an office visit or house call, that charge is applied to the cost of the in-person exam.) A similar service, Doctokr in Vienna, Va., a suburb of Washington, D.C., also provides scaled fees for phone, office and house consults. Both businesses require patients to be seen at least once in person.
Internet-based medicine is still in its infancy, Parkinson says, and whether it’s ideally practiced via Web cam or by text-based instant messaging or email is an open question. Just 16 percent of Internet users have used a Web cam, according to a 2005 report by the Pew Internet & American Life Project.
Whatever its form, telemedicine is really best suited for relatively minor problems, Parkinson says, and to determine whether further medical attention or lab tests are needed to check out, say, swollen lymph nodes or whether a sore throat may be strep. “We target someone who communicates and transacts online, and that’s everyone under 65 these days,” he says. But, a doctor really needs "to have a [previous] relationship with someone. Otherwise, it’s sort of reckless.”
Source>Scientific American
Too busy to go to the doctor? Unfortunately, it's the rare one who makes house calls these days. But how about the next best thing? The Hawaii Medical Service Association (HMSA) next week is set to begin offering doctor consults via Web cam, an emerging form of telemedicine.
The association (the state's Blue Cross Blue Shield insurance provider) will offer the 10-minute Internet visits through American Well, a Boston-based company that provides video conferencing and electronic medical record-keeping to doctors and patients, the New York Times reports today. HMSA is its first customer, the Times says. “It’s a better iteration on, ‘Take two aspirin and call me in the morning,’” Robert Sussman, a family practice doctor on Oahu, tells the newspaper. “We can’t lay on the hands, but we can lay on the eyes and get a better feel" than from a simple phone consult.
Telemedicine – by Internet or phone – is touted as a convenience for folks who don’t want to wait days for a doctor’s appointment, who don’t live near a physician, and who are willing to pay out of pocket for the perk of a visit on their own schedule. The cost is a $10 co-pay for HMSA members and $45 for non-members. Proponents say doctors can take care of about half of medical problems without a face-to-face workup.
While some traditional doctors consult with regular patients by phone or email, many don’t, says Jay Parkinson, a primary-care doctor who runs the telemedicine business Hello Health in Brooklyn, N.Y. “Doctors don’t get paid for communications – only office visits and procedures,” Parkinson tells ScientificAmerican.com. “Nowadays doctors see so many patients – 30, 40, 50 patients a day. When the day is over, they can’t sit down and answer 50 emails for free.”
Hello Health's fees are based on the length and type of visit: $100-to-$200 for an office visit versus $50-to-$100 for video, instant message and phone visits. (If the latter leads to an office visit or house call, that charge is applied to the cost of the in-person exam.) A similar service, Doctokr in Vienna, Va., a suburb of Washington, D.C., also provides scaled fees for phone, office and house consults. Both businesses require patients to be seen at least once in person.
Internet-based medicine is still in its infancy, Parkinson says, and whether it’s ideally practiced via Web cam or by text-based instant messaging or email is an open question. Just 16 percent of Internet users have used a Web cam, according to a 2005 report by the Pew Internet & American Life Project.
Whatever its form, telemedicine is really best suited for relatively minor problems, Parkinson says, and to determine whether further medical attention or lab tests are needed to check out, say, swollen lymph nodes or whether a sore throat may be strep. “We target someone who communicates and transacts online, and that’s everyone under 65 these days,” he says. But, a doctor really needs "to have a [previous] relationship with someone. Otherwise, it’s sort of reckless.”
Source>Scientific American
Who Needs a Doctor
When There's a Robot in the House, er, Hospital? [Slide Show]A Florida trauma center tests the use of a mobile robot to deliver telemedicine
By Larry Greenemeier
Scientificamerican:December 4, 2008
Telemedicine has caught on over the past several years as an effective way to bring patients and specialists together via the magic of video conferencing. Unfortunately, most telemedicine setups require the patient to be in a room equipped with a computer, camera, microphone and monitor, so that specialists can remotely assess his or her condition. Could robots be the answer, providing both patient care and a view for specialists checking in from afar?
The William Lehman Injury Research Center (WLIRC) in Miami for a year has been experimenting with a budding type of telemedicine that uses a robot to let videoconferencing go mobile, allowing a specialist working from a remote location to see a patient (and for the patient to see the physician) from the moment he or she checks in for surgery through recovery.
A typical scenario would unfold as such: A patient is brought to the Ryder Trauma Center at the University of Miami's Jackson Memorial Hospital (where the WLIRC doctors work) by ambulance or helicopter. While the patient is en route, the trauma center checks to see if there is a specialist on site who can treat the patient's specific injuries. If there are none available and the specialist on call is unable to make it to Ryder in time, staff at the center wheel out the RP-7, made by InTouch Technologies, Inc., a Santa Barbara, Calif., medical robotics technology company. Once a specialist is located, he or she uses a laptop or PC to remotely connect via wireless broadband with the robot. After the connection is made, the specialist is able to control the robot's movement, possibly even meeting the patient at the door. From there, the specialist can autonomously drive the robot to operating rooms, intensive care units and patients' bedsides so he or she can monitor those patients as well as instruct nurses and residents.
View a slideshow of the RP-7 in action
The WLIRC doctors and physicians from the U.S. Army's Trauma Training Center (working at the Ryder Trauma Center) have been testing the RP-7, to see if the above scenario is realistic. The 200-pound, (90.7-kilogram) 67-inch- (1.7-meter-) tall metal medical man glides along on three spherical balls (rather than wheels) at a top speed of four miles (6.4 kilometers) per hour. As the Army's Web site points out, it "looks vaguely like one of the Daleks [robots] from Doctor Who with a view screen mounted on top."
Ryder is the only "level 1" trauma center in Miami–Dade County, which makes it difficult to find specialists to weigh in on all cases, particularly within the critical first 60 minutes after an injury, says Jeffrey Augenstein, WLIRC's director and the RP-7 project's principal investigator. "There is a shortage of trauma specialists in this country," he says. "You need to have a plan B to bring expertise from the outside to the point of care, where decisions often involve life and death."
Source>http://www.scientificamerican.com/article.cfm?id=robot-telemedicine
By Larry Greenemeier
Scientificamerican:December 4, 2008
Telemedicine has caught on over the past several years as an effective way to bring patients and specialists together via the magic of video conferencing. Unfortunately, most telemedicine setups require the patient to be in a room equipped with a computer, camera, microphone and monitor, so that specialists can remotely assess his or her condition. Could robots be the answer, providing both patient care and a view for specialists checking in from afar?
The William Lehman Injury Research Center (WLIRC) in Miami for a year has been experimenting with a budding type of telemedicine that uses a robot to let videoconferencing go mobile, allowing a specialist working from a remote location to see a patient (and for the patient to see the physician) from the moment he or she checks in for surgery through recovery.
A typical scenario would unfold as such: A patient is brought to the Ryder Trauma Center at the University of Miami's Jackson Memorial Hospital (where the WLIRC doctors work) by ambulance or helicopter. While the patient is en route, the trauma center checks to see if there is a specialist on site who can treat the patient's specific injuries. If there are none available and the specialist on call is unable to make it to Ryder in time, staff at the center wheel out the RP-7, made by InTouch Technologies, Inc., a Santa Barbara, Calif., medical robotics technology company. Once a specialist is located, he or she uses a laptop or PC to remotely connect via wireless broadband with the robot. After the connection is made, the specialist is able to control the robot's movement, possibly even meeting the patient at the door. From there, the specialist can autonomously drive the robot to operating rooms, intensive care units and patients' bedsides so he or she can monitor those patients as well as instruct nurses and residents.
View a slideshow of the RP-7 in action
The WLIRC doctors and physicians from the U.S. Army's Trauma Training Center (working at the Ryder Trauma Center) have been testing the RP-7, to see if the above scenario is realistic. The 200-pound, (90.7-kilogram) 67-inch- (1.7-meter-) tall metal medical man glides along on three spherical balls (rather than wheels) at a top speed of four miles (6.4 kilometers) per hour. As the Army's Web site points out, it "looks vaguely like one of the Daleks [robots] from Doctor Who with a view screen mounted on top."
Ryder is the only "level 1" trauma center in Miami–Dade County, which makes it difficult to find specialists to weigh in on all cases, particularly within the critical first 60 minutes after an injury, says Jeffrey Augenstein, WLIRC's director and the RP-7 project's principal investigator. "There is a shortage of trauma specialists in this country," he says. "You need to have a plan B to bring expertise from the outside to the point of care, where decisions often involve life and death."
Source>http://www.scientificamerican.com/article.cfm?id=robot-telemedicine
Brain Rerouting signal
Skip the Robotics: Paralyzed Limbs Come to Life
with New Connection to Brain
Rerouting signal from neuron to muscle allows the brain to move deadened limbs
By Sharon Guynup
From the February 2009
Scientific American
Scientists have forged a promising avenue in the quest to restore mobility to patients paralyzed by disease or injury. Researchers at the University of Washington devised a way to reroute signals from the brain’s motor cortex to trigger hand movement directly.
For the past decade researchers have focused on “listening to” and decoding the specific brain signals that trigger muscle movement, using a wall of computers running complex algorithms to translate that brain activity into instructions for moving a computer cursor or a robotic arm or leg.
The new approach simplifies the process. Engineers and neuroscientists restored use of a monkey’s immobilized limb by replacing the lost biological connection. “Rather than decoding intention, we’ve just established a connection and encouraged the monkey to learn how to act on it,” says Chet Moritz, a neurophysiologist, who pioneered the work with fellow Washington professor Eberhard Fetz.
They trained macaques to play a simple video game using a joystick. Then they ran a wire from a single neuron in the animals’ motor cortex to a desktop computer. The electrical impulse from that cell was amplified by the computer and transmitted along another wire to one of the primates’ arm muscles, which had been temporarily anesthetized.
Within minutes, the monkeys learned to control wrist movements with their thoughts, moving the joystick left or right to match targets on a computer screen.
The surprise, Moritz says, was that any neuron within that general region of the brain could learn to stimulate wrist muscles—regardless of whether the neuron was originally involved in that specific movement.
“Monkeys can rapidly learn to change neuron activity, in this case to generate movement, much like humans can change heart rate activity with biofeedback,” Fetz explains. This control necessitated conscious attention; making such movements subconsciously would require repetitive training, much like learning a sport.
The long-term goal is to develop a miniaturized, implantable neuroprosthetic device that would enable paralyzed patients to move their own paralyzed limbs. Fetz has already taken the next step, developing a cell phone–size neurochip that can be linked to a microprocessor, small enough for monkeys to carry implanted in their head.
Many hurdles remain. It is difficult to record from the same neuron for a long period. Within days or weeks, scar tissue walls off electrodes, interrupting transmission. Guiding electrodes to new locations with tiny motors might mitigate that problem. Providing a decades-long power supply is also a challenge. Biocompatibility is another issue; fully implanting such a system under the skin presents a huge infection risk. And crucial questions exist: Can this model be scaled up to stimulate multiple neurons that trigger multiple muscles? How flexible is the brain in reassigning new functions to neurons?
The team hopes to restore arm movements in the near term—and ultimately to restore paraplegics’ ability to walk. But clinical trials remain perhaps a decade away.
Source>http://www.scientificamerican.com/article.cfm?id=robotics-provide-hope
with New Connection to Brain
Rerouting signal from neuron to muscle allows the brain to move deadened limbs
By Sharon Guynup
From the February 2009
Scientific American
Scientists have forged a promising avenue in the quest to restore mobility to patients paralyzed by disease or injury. Researchers at the University of Washington devised a way to reroute signals from the brain’s motor cortex to trigger hand movement directly.
For the past decade researchers have focused on “listening to” and decoding the specific brain signals that trigger muscle movement, using a wall of computers running complex algorithms to translate that brain activity into instructions for moving a computer cursor or a robotic arm or leg.
The new approach simplifies the process. Engineers and neuroscientists restored use of a monkey’s immobilized limb by replacing the lost biological connection. “Rather than decoding intention, we’ve just established a connection and encouraged the monkey to learn how to act on it,” says Chet Moritz, a neurophysiologist, who pioneered the work with fellow Washington professor Eberhard Fetz.
They trained macaques to play a simple video game using a joystick. Then they ran a wire from a single neuron in the animals’ motor cortex to a desktop computer. The electrical impulse from that cell was amplified by the computer and transmitted along another wire to one of the primates’ arm muscles, which had been temporarily anesthetized.
Within minutes, the monkeys learned to control wrist movements with their thoughts, moving the joystick left or right to match targets on a computer screen.
The surprise, Moritz says, was that any neuron within that general region of the brain could learn to stimulate wrist muscles—regardless of whether the neuron was originally involved in that specific movement.
“Monkeys can rapidly learn to change neuron activity, in this case to generate movement, much like humans can change heart rate activity with biofeedback,” Fetz explains. This control necessitated conscious attention; making such movements subconsciously would require repetitive training, much like learning a sport.
The long-term goal is to develop a miniaturized, implantable neuroprosthetic device that would enable paralyzed patients to move their own paralyzed limbs. Fetz has already taken the next step, developing a cell phone–size neurochip that can be linked to a microprocessor, small enough for monkeys to carry implanted in their head.
Many hurdles remain. It is difficult to record from the same neuron for a long period. Within days or weeks, scar tissue walls off electrodes, interrupting transmission. Guiding electrodes to new locations with tiny motors might mitigate that problem. Providing a decades-long power supply is also a challenge. Biocompatibility is another issue; fully implanting such a system under the skin presents a huge infection risk. And crucial questions exist: Can this model be scaled up to stimulate multiple neurons that trigger multiple muscles? How flexible is the brain in reassigning new functions to neurons?
The team hopes to restore arm movements in the near term—and ultimately to restore paraplegics’ ability to walk. But clinical trials remain perhaps a decade away.
Source>http://www.scientificamerican.com/article.cfm?id=robotics-provide-hope
artificial Heart valve
April 25, 2009
Artificial Valves That Lend Hearts a Helping Hand
For the past five decades, artificial heart-valve designs have evolved to successfully replace natural valves, which often begin to leak or harden over time
By Amber Dance
The heart relies on four valves that act as one-way gates, controlling blood flow out of each of the heart's four chambers. The mitral valve between the two left chambers of the heart has two leaflets, or cusps; the tricuspid, pulmonary and aortic valves each have three. The leaflets swing open and shut like saloon doors with every beat, maintaining a steady blood supply. (A person's heart generally beats 80 million times a year and five to six billion times over the course of a normal lifetime, according to Irvine, Calif.–based valve producer Edwards Lifesciences.)
> Slide Show: Artificial heart valve improvements over the past 50 years
As comedian and actor Robin Williams, 57, and 83-year-old former first lady Barbara Bush found out recently, in many cases, the valves don't last a lifetime; some become leaky. Called a regurgitating valve, this allows pumped blood to wash back into the heart. Others pick up calcium from the blood, eventually becoming hardened, restricting blood flow (a condition known as stenosis). When the body does not receive enough blood, a person can experience symptoms such as shortness of breath. Aortic and mitral valves most commonly require treatment. Once symptoms such as lightheadedness and blackouts arise, a person with an untreated faulty aortic valve has a 50 percent chance of dying within six months, says Eugene Grossi, a professor of cardiothoracic surgery at New York University School of Medicine and director of cardiac surgery research.That means that for thousands of Americans, an artificial heart valve fashioned from tissue-thin flaps is all that stands between health and heart failure. About 140,000 Americans go under the knife for valve replacement or repair every year, according to Toronto-based Millennium Research Group, a firm that tracks the medical device, pharmaceutical and biotechnology industries.Doctors have developed several stand-ins for the natural tissue that can regulate blood flow without missing a beat. "Heart valves are the one device that when you get it in and it's successful, you add 10 or 15 years to their life," says Donald Bobo, vice president for heart valve therapy at Edwards Lifesciences. Edwards—along with Saint Jude Medical in Saint Paul, Minn., and Minneapolis-based Medtronic, Inc.—is a top provider of artificial valves worldwide, Bobo says. Sorin Group in Milan, Italy, also has a share in the global heart valve therapy market, estimated to be worth $1.6 billion in 2008, according to Edwards market estimates.Valve technology took off in 1958 when engineer and Edwards founder Miles "Lowell" Edwards applied his experience designing hydraulic debarking methods for the lumber industry and a fuel-injection system for World War II aircraft to the medical arena. Working with cardiothoracic surgeon Albert Starr, the two developed a valve that Starr could use in his ailing patients. Surgeons implanted the Starr-Edwards artificial valve, designed in Edward's backyard workshop, for the first time in 1960. Although that first patient died shortly after receiving the device, the second survived for 10 more years before dying from a fall off a ladder.People tried dozens of different designs in the ensuing decades, says Ajit Yoganathan, a biomedical engineer who studies valves at the Georgia Institute of Technology in Atlanta. "Most of them were developed in someone's garage or someone's basement." The technology has evolved from a caged-ball design into valves with artificial flaps, pig valves processed for human use, and hand-sewn biologic valves made from cow tissue."All of these valves have analogues in hydraulics, pipelines, aviation, automobiles," Bobo says. But the human body presents special challenges. "Blood ends up being a pretty different environment compared to oil or gas," he adds. The lipids in blood can destroy synthetic materials; tissue valves are subject to the same wear and tear and calcification that natural valves are."There is still room for improvement," such as better materials, Yoganathan says. He would also like to see small valves available to children with congenital heart defects. The next development likely to hit the U.S. market is valves that can be implanted without open heart surgery.
Source:>http://www.scientificamerican.com/article.cfm?id=artificial-heart-valves
Artificial Valves That Lend Hearts a Helping Hand
For the past five decades, artificial heart-valve designs have evolved to successfully replace natural valves, which often begin to leak or harden over time
By Amber Dance
The heart relies on four valves that act as one-way gates, controlling blood flow out of each of the heart's four chambers. The mitral valve between the two left chambers of the heart has two leaflets, or cusps; the tricuspid, pulmonary and aortic valves each have three. The leaflets swing open and shut like saloon doors with every beat, maintaining a steady blood supply. (A person's heart generally beats 80 million times a year and five to six billion times over the course of a normal lifetime, according to Irvine, Calif.–based valve producer Edwards Lifesciences.)
> Slide Show: Artificial heart valve improvements over the past 50 years
As comedian and actor Robin Williams, 57, and 83-year-old former first lady Barbara Bush found out recently, in many cases, the valves don't last a lifetime; some become leaky. Called a regurgitating valve, this allows pumped blood to wash back into the heart. Others pick up calcium from the blood, eventually becoming hardened, restricting blood flow (a condition known as stenosis). When the body does not receive enough blood, a person can experience symptoms such as shortness of breath. Aortic and mitral valves most commonly require treatment. Once symptoms such as lightheadedness and blackouts arise, a person with an untreated faulty aortic valve has a 50 percent chance of dying within six months, says Eugene Grossi, a professor of cardiothoracic surgery at New York University School of Medicine and director of cardiac surgery research.That means that for thousands of Americans, an artificial heart valve fashioned from tissue-thin flaps is all that stands between health and heart failure. About 140,000 Americans go under the knife for valve replacement or repair every year, according to Toronto-based Millennium Research Group, a firm that tracks the medical device, pharmaceutical and biotechnology industries.Doctors have developed several stand-ins for the natural tissue that can regulate blood flow without missing a beat. "Heart valves are the one device that when you get it in and it's successful, you add 10 or 15 years to their life," says Donald Bobo, vice president for heart valve therapy at Edwards Lifesciences. Edwards—along with Saint Jude Medical in Saint Paul, Minn., and Minneapolis-based Medtronic, Inc.—is a top provider of artificial valves worldwide, Bobo says. Sorin Group in Milan, Italy, also has a share in the global heart valve therapy market, estimated to be worth $1.6 billion in 2008, according to Edwards market estimates.Valve technology took off in 1958 when engineer and Edwards founder Miles "Lowell" Edwards applied his experience designing hydraulic debarking methods for the lumber industry and a fuel-injection system for World War II aircraft to the medical arena. Working with cardiothoracic surgeon Albert Starr, the two developed a valve that Starr could use in his ailing patients. Surgeons implanted the Starr-Edwards artificial valve, designed in Edward's backyard workshop, for the first time in 1960. Although that first patient died shortly after receiving the device, the second survived for 10 more years before dying from a fall off a ladder.People tried dozens of different designs in the ensuing decades, says Ajit Yoganathan, a biomedical engineer who studies valves at the Georgia Institute of Technology in Atlanta. "Most of them were developed in someone's garage or someone's basement." The technology has evolved from a caged-ball design into valves with artificial flaps, pig valves processed for human use, and hand-sewn biologic valves made from cow tissue."All of these valves have analogues in hydraulics, pipelines, aviation, automobiles," Bobo says. But the human body presents special challenges. "Blood ends up being a pretty different environment compared to oil or gas," he adds. The lipids in blood can destroy synthetic materials; tissue valves are subject to the same wear and tear and calcification that natural valves are."There is still room for improvement," such as better materials, Yoganathan says. He would also like to see small valves available to children with congenital heart defects. The next development likely to hit the U.S. market is valves that can be implanted without open heart surgery.
Source:>http://www.scientificamerican.com/article.cfm?id=artificial-heart-valves
Nanoparticles Home in on Brain Cancer
Nanoparticles Home in on Brain Cancer
By Nikhil Swaminathan
November 17, 2006
Call them laser-guided smart bombs for brain tumors. Researchers at the University of Michigan announced the testing of a drug delivery system that involves drug-toting nanoparticles and a guiding peptide to target cancerous cells in the brain. Their study finds that via this method more of the drug can be delivered to a tumor's general vicinity. They report their findings in the November 15 issue of Clinical Cancer Research.
The researchers used a pharmaceutical called Photofrin, which is photodynamic, meaning it is activated by a laser after it has entered the bloodstream. As its primary side effect, the drug renders patients photosensitive, and they must remain out of bright sunlight and even unshaded lamps for up to 30 days after receiving treatment. Despite this major drawback, Photofrin is used in the treatment of esophageal, bladder and skin cancers. But their novel delivery system, which relies on the intravenous delivery of 40-nanometer-wide particles to carry the drug, may actually avoid much of the photosensitivity, because less Photofrin circulates in the bloodstream thanks to a peptide called F3. A sequence of 31 amino acids broken off of the protein HMGN2 (high mobility group protein 2), F3 has the ability to penetrate cell membranes. "This peptide acts as a "zip code" in that it enables the binding of the nanoparticles only to blood vessels within the tumor and not normal blood vessels," says Alnawaz Rehemtulla, a radiologist and environmental health scientist who co-authored the study. F3 can detect the expression of a protein called nucleolin, which is a marker on the surface of tumor cells.
Another problem the researchers avoided was having to deliver their medicine in such a way that it could cross the blood-brain barrier, which keeps many substances from entering the brain from the bloodstream. Typical chemotherapies must penetrate this shield to treat tumors. In this case, however, the nontoxic polyacrylamide particles didn't have to cross over via the bloodstream. "The nanoparticles do not need to cross the blood-brain barrier as they were specifically designed to target the blood vessel cells within the tumor," explains radiologist Brian Ross, one of the study's authors. "The treatment should be thought of as an antivascular treatment thereby shutting off the tumor blood flow resulting in the death of the tumor cells through starvation of oxygen and energy sources."
To test the delivery method, researchers divided 34 rats--all who received injections of cancerous cells into their brains--into different groups. Those that received no treatment or got only the laser fared poorly, dying on average within 8.5 days. Those that got Photofrin either intravenously or encapsulated in nanoparticles had a median survival time of 13 days. The group that got F3 with the Photofrin-carrying nanoparticles came through the best: they lived for, on average, 33 days; three of the five in this grouping lived for 60 days, and two of those three appeared tumor-free after six months. By using iron oxide as a contrast agent--to more easily detect where the nanoparticles ended up via MRI--the group determined that twice as much drug with the F3 peptide attached reached the tumor site--10 percent of the total amount administered--compared with when nontargeted nanoparticles were injected.
Ross says that based on the success of the study, the team is investigating if this delivery technology will work for nonphotodynamic therapies. Rehemtulla adds that if other FDA-approved chemotherapeutic agents reach their targets as successfully as Photofrin did, "then we will have developed a way to make cancer drugs more 'tumor-specific,' because they will only get into tumor vasculature and not normal vasculature. This will spare patients from normal tissue toxicity that is commonly associated with almost all chemotherapy."
Source>http://www.scientificamerican.com/article.cfm?id=nanoparticles-home-in-on
By Nikhil Swaminathan
November 17, 2006
Call them laser-guided smart bombs for brain tumors. Researchers at the University of Michigan announced the testing of a drug delivery system that involves drug-toting nanoparticles and a guiding peptide to target cancerous cells in the brain. Their study finds that via this method more of the drug can be delivered to a tumor's general vicinity. They report their findings in the November 15 issue of Clinical Cancer Research.
The researchers used a pharmaceutical called Photofrin, which is photodynamic, meaning it is activated by a laser after it has entered the bloodstream. As its primary side effect, the drug renders patients photosensitive, and they must remain out of bright sunlight and even unshaded lamps for up to 30 days after receiving treatment. Despite this major drawback, Photofrin is used in the treatment of esophageal, bladder and skin cancers. But their novel delivery system, which relies on the intravenous delivery of 40-nanometer-wide particles to carry the drug, may actually avoid much of the photosensitivity, because less Photofrin circulates in the bloodstream thanks to a peptide called F3. A sequence of 31 amino acids broken off of the protein HMGN2 (high mobility group protein 2), F3 has the ability to penetrate cell membranes. "This peptide acts as a "zip code" in that it enables the binding of the nanoparticles only to blood vessels within the tumor and not normal blood vessels," says Alnawaz Rehemtulla, a radiologist and environmental health scientist who co-authored the study. F3 can detect the expression of a protein called nucleolin, which is a marker on the surface of tumor cells.
Another problem the researchers avoided was having to deliver their medicine in such a way that it could cross the blood-brain barrier, which keeps many substances from entering the brain from the bloodstream. Typical chemotherapies must penetrate this shield to treat tumors. In this case, however, the nontoxic polyacrylamide particles didn't have to cross over via the bloodstream. "The nanoparticles do not need to cross the blood-brain barrier as they were specifically designed to target the blood vessel cells within the tumor," explains radiologist Brian Ross, one of the study's authors. "The treatment should be thought of as an antivascular treatment thereby shutting off the tumor blood flow resulting in the death of the tumor cells through starvation of oxygen and energy sources."
To test the delivery method, researchers divided 34 rats--all who received injections of cancerous cells into their brains--into different groups. Those that received no treatment or got only the laser fared poorly, dying on average within 8.5 days. Those that got Photofrin either intravenously or encapsulated in nanoparticles had a median survival time of 13 days. The group that got F3 with the Photofrin-carrying nanoparticles came through the best: they lived for, on average, 33 days; three of the five in this grouping lived for 60 days, and two of those three appeared tumor-free after six months. By using iron oxide as a contrast agent--to more easily detect where the nanoparticles ended up via MRI--the group determined that twice as much drug with the F3 peptide attached reached the tumor site--10 percent of the total amount administered--compared with when nontargeted nanoparticles were injected.
Ross says that based on the success of the study, the team is investigating if this delivery technology will work for nonphotodynamic therapies. Rehemtulla adds that if other FDA-approved chemotherapeutic agents reach their targets as successfully as Photofrin did, "then we will have developed a way to make cancer drugs more 'tumor-specific,' because they will only get into tumor vasculature and not normal vasculature. This will spare patients from normal tissue toxicity that is commonly associated with almost all chemotherapy."
Source>http://www.scientificamerican.com/article.cfm?id=nanoparticles-home-in-on
Nanocontainers Deliver Drugs
Nanocontainers Deliver Drugs Directly to Cells
By Sarah Graham
April 28, 2003
One challenge to effective drug treatment is getting the medication to exactly the right place. To that end, researchers have been investigating myriad new methods to deliver pharmaceuticals. Findings published in the current issue of the journal Science indicate that tiny nanocontainers composed of polymers may one day distribute drugs to specific spots within individual cells.
Radoslav Savic and his colleagues at McGill University tested the properties of tiny units built out of two types of polymers. The two compounds self-assemble into a spherical shape known as a micelle. One compound, which is hydrophobic (water fearing), aligns facing inwards and the other, which is hydrophilic (water loving), faces outwards. Drugs can then be loaded inside the tiny molecular globs, which measure 20 to 45 nanometers in diameter. The researchers used fluorescent labeling to track the micelles' journeys (see image). They found that the tiny containers could pass through the wall of a rat cell, but did not enter the cell's nucleus. The micelles did, however, penetrate some cell parts, such as mitochondria and the Golgi apparatus, which are important targets for drug delivery.
The scientists also determined that the micelles are very efficient at delivering their hydrophobic drug cargo once inside a cell. This property could mean that doctors may one day be able to administer smaller doses of toxic medications. "These micelles may thus be worth exploring for their potential to selectively deliver drugs to specified subcellular targets," the authors note. In an accompanying commentary, Jeffrey A. Hubbell of the University of Zurich cautions that much work remains to be done, "yet, multifunctional polymer micelles have already come a long way to reaching these ends."
Source >http://www.scientificamerican.com/article.cfm?id=nanocontainers-deliver-dr
By Sarah Graham
April 28, 2003
One challenge to effective drug treatment is getting the medication to exactly the right place. To that end, researchers have been investigating myriad new methods to deliver pharmaceuticals. Findings published in the current issue of the journal Science indicate that tiny nanocontainers composed of polymers may one day distribute drugs to specific spots within individual cells.
Radoslav Savic and his colleagues at McGill University tested the properties of tiny units built out of two types of polymers. The two compounds self-assemble into a spherical shape known as a micelle. One compound, which is hydrophobic (water fearing), aligns facing inwards and the other, which is hydrophilic (water loving), faces outwards. Drugs can then be loaded inside the tiny molecular globs, which measure 20 to 45 nanometers in diameter. The researchers used fluorescent labeling to track the micelles' journeys (see image). They found that the tiny containers could pass through the wall of a rat cell, but did not enter the cell's nucleus. The micelles did, however, penetrate some cell parts, such as mitochondria and the Golgi apparatus, which are important targets for drug delivery.
The scientists also determined that the micelles are very efficient at delivering their hydrophobic drug cargo once inside a cell. This property could mean that doctors may one day be able to administer smaller doses of toxic medications. "These micelles may thus be worth exploring for their potential to selectively deliver drugs to specified subcellular targets," the authors note. In an accompanying commentary, Jeffrey A. Hubbell of the University of Zurich cautions that much work remains to be done, "yet, multifunctional polymer micelles have already come a long way to reaching these ends."
Source >http://www.scientificamerican.com/article.cfm?id=nanocontainers-deliver-dr
New Drug Delivery
New Drug Delivery Technique Avoids NeedlesBy Sarah Graham
Hypodermic needles are the stuff of nightmares for many people, but they represent a common method for administering a variety of drugs. Patients who fear a needle prick, however, may soon have an alternative, painless way to receive medication. A new technique described today in the journal BMC Medicine uses a stream of gas to help deliver drugs through the skin with what subjects describe as the sensation of a gentle stream of air.
James Weaver of the Massachusetts Institute of Technology and his colleagues developed the novel procedure, which is known as microscission. It uses minuscule inert crystals of aluminum oxide to remove the rough outer layer of skin and create tiny holes, known as microconduits and measuring less than a quarter of a millimeter in diameter, through which medication can move. A jet of flowing gas then takes the crystals and the loosened skin away. After creating four microconduits on the inner arm of volunteers, the team applied a pad soaked in the anesthetic lidocaine. Within two minutes, the drug had worked and the subjects reported no feeling in the region.
The size and depth of the microconduits is determined by holes punched in a polymer mask laid on top of the skin. The team reports that "the onset of anesthesia takes longer in microconduits deep enough to yield blood than in shallower, nonblood producing microconduits." But deep microconduits do have some advantages. Patients suffering from diabetes, for example, often have to jab a finger to test their blood sugar; microscission could represent a less painful alternative, the team suggests.
Source>http://www.scientificamerican.com
Hypodermic needles are the stuff of nightmares for many people, but they represent a common method for administering a variety of drugs. Patients who fear a needle prick, however, may soon have an alternative, painless way to receive medication. A new technique described today in the journal BMC Medicine uses a stream of gas to help deliver drugs through the skin with what subjects describe as the sensation of a gentle stream of air.
James Weaver of the Massachusetts Institute of Technology and his colleagues developed the novel procedure, which is known as microscission. It uses minuscule inert crystals of aluminum oxide to remove the rough outer layer of skin and create tiny holes, known as microconduits and measuring less than a quarter of a millimeter in diameter, through which medication can move. A jet of flowing gas then takes the crystals and the loosened skin away. After creating four microconduits on the inner arm of volunteers, the team applied a pad soaked in the anesthetic lidocaine. Within two minutes, the drug had worked and the subjects reported no feeling in the region.
The size and depth of the microconduits is determined by holes punched in a polymer mask laid on top of the skin. The team reports that "the onset of anesthesia takes longer in microconduits deep enough to yield blood than in shallower, nonblood producing microconduits." But deep microconduits do have some advantages. Patients suffering from diabetes, for example, often have to jab a finger to test their blood sugar; microscission could represent a less painful alternative, the team suggests.
Source>http://www.scientificamerican.com
วันพฤหัสบดีที่ 4 มิถุนายน พ.ศ. 2552
Hemopurifier
Aethlon Medical is the developer of the Hemopurifier®,
A first-in-class medical device to treat infectious disease. The Hemopurifier® addresses the largest opportunity in infectious disease, the treatment of drug and vaccine resistant viruses. Regulatory and commercialization initiatives in the United States are focused on bioterror threats, while international initiatives are directed towards naturally evolving pandemic threats, and chronic infectious disease conditions including Hepatitis-C (HCV) and the Human Immunodeficiency Virus (HIV). Collaborative studies to demonstrate utility of the Hemopurifier® are being conducted with researchers at the Government of India's National Institute of Virology (NIV), The Centers for Disease Control and Prevention (CDC), The United States Army Medical Research Institute of Infectious Diseases (USAMRIID), and The Southwest Foundation for Biomedical Research (SFBR). Aethlon recently demonstrated safety of the Hemopurifier® in a 24-treatment human study and has received approval to continue further human studies at The Fortis Hospital in India. The Company has also submitted an Investigational Device Exemption (IDE) to the U.S. Food and Drug Administration (FDA) related to advancing the Hemopurifier® as a broad-spectrum treatment countermeasure against category "A" bioterror threats. Additional information on Aethlon Medical and its Hemopurifier® technology can be accessed at www.aethlonmedical.com.
หลอดสกัดเชื้อโรคในกระแสเลือด
ซานดิเอโก—(บิสิเนสไวร์)—2 พ.ย. 2549
บริษัทเอธลอน เมดิคอล อิงค์ (OTCBB:AEMD) ผู้นำในการพัฒนาอุปกรณ์รักษาโรคติดเชื้อ เปิดเผยในวันนี้ว่า นายเจมส์ เอ จอยซ์ ประธานและซีอีโอ ได้เขียนรายงานเรื่อง การรักษาโรคไข้เลือดออก (The Treatment of Dengue Hemorrhagic Fever) โดยเนื้อหาของรายงานมีดังนี้
สรุปใจความสำคัญ ไวรัสไข้เลือดออกและโรคไข้เลือดออกชนิดรุนแรง (DHF) เป็นประเด็นด้านสุขภาพระหว่างประเทศที่ยังคงไม่สามารถรักษาได้ด้วยยาต้านไวรัสแบบดั้งเดิมและการรักษาด้วยวัคซีน รายงานนี้สรุปการใช้ Aethlon Hemopurifier(TM) เป็นอุปกรณ์การรักษาแบบมีฤทธิ์กว้าง (broad-spectrum) ที่สามารถขจัดไวรัสไข้เลือดออกจากผู้ป่วยที่ติดเชื้อและมีแนวโน้มช่วยลดการอักเสบที่เกี่ยวกับโรค DHF การแพร่ระบาดของโรคไข้เลือดออกทั่วโลกได้ขยายตัวอย่างรวดเร็วในช่วงหลายสิบปีที่ผ่านมา โดยในขณะนี้โรคดังกล่่่่่าวเป็นโรคเฉพาะท้องถิ่นในกว่า 100 ประเทศ โดยองค์การอนามัยโลกระบุว่ามีการติดเชื้อโรคไข้เลือดออกจำนวนมากถึง 50 ล้านรายในแต่ละปี
ความเป็นมาของเครื่อง Hemopurifier(TM) เชื้อไวรัสจำนวนมากรวมถึงไข้เลือดออกนั้น ไม่สามารถรักษาด้วยยาต้านไวรัสหรือการรักษาด้วยวัคซีน เมื่อการรัีกษามีการพัฒนา ไวรัสต่างๆมักจะกลายพันธุ์จนดื้อต่อการรักษา ไวรัสซึ่งข้ามจากสายพันธุ์สัตว์มาสู่มนุษย์นั้นเพิ่มความท้าทายในการรักษา โดยตัวอย่างที่ผ่านมาของเชื้อโรคที่ติดต่อจากสัตว์ (zoonotic transmission) นั้น ได้แก่ HIV, SARS, West Nile, Ebola, Marburg และล่าสุดได้แก่เชื้อไวรัสไข้หวัดนกสายพันธุ์ H5N1 การดัดแปลงพันธุกรรมของไวรัสโดยมีจุดประสงค์เพื่อการรักษาโรคที่ดื้อต่อยาและวัคซีนนั้น จะลดความเป็นไปได้ของการรักษาแบบดั้งเดิม Aethlon Hemopurifier(TM) เป็นอุปกรณ์ชั้นหนึ่งที่ได้รับการออกแบบเพื่ออุดช่องโหว่ในการรักษาโรคที่ดื้อต่อยาและวัคซีน เทคโนโลยีดังกล่าวจะเพิ่มประโยชน์ของการรักษาด้วยยา และจะเป็นมาตรการรับมือขั้นแรกในกรณีที่ไม่มีการรักษาด้วยยาหรือวัคซีน เทคโนโลยีดังกล่าวรวมหลักการของการฟอกเลือดที่สร้างขึ้นในไตเทียม(hemodialysis) และการทำ plasmapheresis ด้วยการใช้สาร affinity agents ซึ่งจะจับเปลือกไวรัส (envelope viruses) ด้วยโครงสร้าง surface carbohydrate ที่มีการพัฒนาเพื่อหลบเลี่ยงภูมิคุ้มกันตามธรรมชาติ ผลก็คือ อุปกรณ์ Hemopurifier(TM) จะสามารถลดไวรัสที่ติดเชื้อและสารพิษที่เกี่ยวข้องในร่างกาย และจะเพิ่มความเป็นไปได้ที่ภูมิคุ้มกันของผู้ป่วยจะสามารถขจัดการติดเชื้อได้เอง เอธลอนได้เสร็จสิ้นการศึกษาความปลอดภัยในการรักษา 24 กรณีของอุปกรณ์ Hemopurifier(TM) ในการฟอกเลือดผู้ป่วยที่ติดเชื้อไวรัสตับอักเสบ-ซีร่วมด้วย โดยการศึกษาดังกล่าวจัดทำขึ้นที่โรงพยาบาลอะพอลโลในกรุงนิว เดลี ประเทศอินเดีย จากข้อมูลผลการศึกษาที่ได้นำไปสู่การยื่นขอยกเว้นการตรวจสอบอุปกรณ์ขั้นต้น (Investigational Device Exemption) จากสำนักงานอาหารและยา (FDA) ที่เกี่ยวกับการใช้อุปกรณ์ Hemopurifier(TM) ในสหรัฐเพื่อรักษาแบบให้ฤทธิ์กว้างต่อภัยคุกคามของอาวุธชีวภาพประเภท A และโรคไข้หวัดใหญ่ระบาด เอธลอนวางแผนที่จะดำเนินโครงการด้านการแพทย์ต่อไปในประเทศอินเดีย และได้เริ่มหารือกับสภาศูนย์วิจัยการแพทย์แห่งอินเดีย (ICMR) และหน่วยงานอื่นๆที่เกี่ยวกับการรักษาโรค DHF และโรคไวรัสอื่นๆ โดยเฉพาะในกรุงนิวเดลีแห่งเดียวนั้น ผู้ป่วย 67 คนจาก 2,640 คนที่ติดเชื้อไข้เลือดออกนับตั้งแต่ปลายเดือนก.ค.ได้เสียชีวิตแล้ว
อันตรายของโรคไข้เลือดออก DHF เป็นหนึ่งในโรคติดต่อที่ร้ายแรงที่สุดสำหรับมนุษย์ โดยการติดเชื้อ DHF ถ่ายทอดจากยุงที่มีเชื้อไวรัสไข้เลือดออก (serotypes 1- 4) โดยรูปแบบที่รุนแรงของโรคนี้ซึ่งได้แก่ Dengue Hemorrhagic Fever - Dengue Shock Syndrome (DHF/DSS) เป็นหนึ่งในสาเหตุหลักของการส่งตัวเข้ารับการรักษาในโรงพยาบาลและการเสียชีวิตของเด็กๆในภูมิภาคเอเชียโดยมีอัตราการเสียชีวิตเฉลี่ยประมาณ 17% นับตั้งแต่มีการอธิบายการศึกษาต้นกำเนิดของโรคไข้เลือดออกในปี 2487 นั้น ก็ได้มีความพยายามอย่างมากที่จะพัฒนาวัคซีน โดยเผชิญกับความท้าทายในการพัฒนาอย่างมาก ความท้าทายดังกล่าวรวมถึงข้อเท็จจริงที่ว่า การติดเชื้อไวรัสไข้เลือดออกของ subtype หนึ่งจะเพิ่มความรุนแรงของโรคที่มีสาเหตุจากการติดเชื้อของอีก subtype หนึ่ง การติดเชื้อครั้งแรกทำให้เป็นโรคไข้เลือดออกที่ไม่รุนแรง แต่การติดเชื้อที่ตามมา หากเป็นการติดเชื้อจากอีก subtype หนึ่ง จะทำให้เป็นโรคไข้เลือดออกชนิดรุนแรง (DHF/DSS) และการติดเชื้อครั้งที่สามจาก subtype ตัวที่ 3 นั้น ส่วนใหญ่มักจะทำให้เสียชีวิต นอกเหนือจากผลกระทบโดยตรงของการติดเชื้อไวรัสนั้น DHF แบบก้าวหน้าสามารถก่อให้เกิดภาวะ viral sepsis ที่นำไปสู่การผลิต cytokines ที่อันตรายจำนวนมากเกินไป และมีหลักฐานว่าอาจเกี่ยวข้องกับการสร้าง alpha และ beta interferon (IFN-alpha) รวมถึง gamma IFN (IFN-beta) ด้วย ดังนั้น การพัฒนาการรักษา DHF ที่มีประสิทธิภาพจึงยังคงเป็นเรื่องยาก
การใช้ Hemopurifier(TM) สำหรับการรักษาโรค DHF Hemopurifier(TM) ได้รับการออกแบบเพื่อแยกและจับไวรัสซึ่งทำให้่เกิดโรคและภัยคุกคามใหม่ๆของเชื้อไวรัส โดยในปัจจุบัน Hemopurifier เป็นเพียงการรักษาเดียวสำหรับโรค DHF ซึ่งมีเป้าหมายในการกำจัดไวรัสไข้เลือดออกในเวลาเดียวกันและยังช่วยลดการสร้าง cytokine ที่มากเกินไปด้วย โดยการพัฒนา Hemopurifier เพื่อการรักษา DHF นั้นสอดคล้องกัยกลยุทธ์องค์กรของเอธลอนเพื่อร่วมมือกับรัฐบาลและองค์กรเอกชนเพื่อพัฒนา Hemopurifier เป็นการรักษาที่ให้ฤทธิ์กว้างสำหรับเชื้อโรคที่ดื้อต่อยาและวัคซีนสำหรับการรักษาเฉพาะ DHF นั้น อุปกรณ์ Hemopurifier(TM) จะเป็นวิธีการแบบ extracorporeal เพื่อเพิ่มระบบภูมิคุ้มกัน โดยเพิ่มความเป็นไปได้ที่ระบบภูมิคุ้มกันตามธรรมชาติจะสามารถเอาชนะการติดเชื้อ
คุณสมบัติและการพิจารณาใช้ Hemopurifier(TM) เพื่อรักษา DHF ได้แก่
การกำจัด DHF อย่างรวดเร็ว – สาร affinity agents ที่เป็นตัวจับยึดภายใน Hemopurifier(TM) นั้นมีขีดความสามารถที่ให้ฤทธิ์กว้างในการจับเปลือกไวรัสโดยผูกเข้ากับโปรตีน glycosolated ซึ่งอยู่บนผิวหน้าของไวรัส ในกรณีของ DHF นั้น การจับไวรัสกระทำโดยตรงที่ผิวหน้า glycoproteins ซึ่งเป็น binding sites แม้ในกรณีที่ไวรัสกลายพันธุ์ ในการทดสอบเบื้องต้นนั้น สาร affinity agent ใน Hemopurifier(TM) แสดงความสามารถในการที่จะผูกกับผิวหน้าโปรตีนของเชื้อไข้เลือดออก ความสามารถที่จะกำจัดเชื้อไข้เลือดออกและชิ้นส่วนไวรัสก่อนที่จะิติดเชื้อที่เซลล์และอวัยวะนั้นมีแนวโน้มที่จะสกัดกั้นการพัฒนาของโรค โดยในส่วนที่เกี่ี่ยวกับขีดความสามารถในการออกฤทธิ์กว้างนั้น Hemopurifie แสดงให้เห็นถึงการจับเชื้อไวรัส HIV, HCV และ orthopox ที่เกี่ยวข้องกับโรคไข้ทรพิษ คณะวิจัยของสถาบันมะเร็งแห่งชาติ (NCI) และสถาบันสุขภาพแห่งชาติ (NIH) ได้บ่งชี้ว่า รูปแบบของสาร affinity agents ใน Hemopurifier นั้น มีความสามารถในการต่อต้านเชื้อไวรัสอื่นๆด้วยได้แก่ Marburg, Ebola และไข้หวัดใหญ่
การกำจัด Cytokines ในวงกว้าง – โครงสร้างของ Hemopurifier(TM) จะช่วยลดการผลิต cytokines จำนวนมากเกินไป โดยเทคนิค hemofiltration นั้นเป็นการรักษา cytokine ที่ก่อให้เกิดภาวะ sepsis มาตั้งแต่ปี 2533 แล้ว ดังนั้น Hemopurifier(TM) อาจเป็นวิธีการที่เหมาะสมที่จะช่วยลด cytokine เนื่องจากรูไฟเบอร์ของ Hemopurifier(TM) มีขนาดใหญ่พอที่จะขจัด cytokines ที่ไม่สามารถกำจัดได้ใน Hemofiltration
Aethlon Hemopurifier(TM) จะเพิ่มโอกาสในการรอดชีวิตของผู้ที่ติดเชื้อ DHF โดยการแพร่ระบาดตามฤดูกาลของโรคไข้เลือดออกกำลังดำเนินไปในภูมิภาคต่างๆทั่วโลกในขณะนี้ รวมถึงอินเดียซึ่งกำลังเกิดการติดเชื้อโรคไข้เลือดออกที่รุนแรงที่สุดนับตั้งแต่ปี 2539 ในกรณีที่ไม่มีวัคซีนและยาต้านไวรัสที่มีประสิทธิภาพ บริษัทเอธลอน เมดิคอลจะร่วมมือกับหน่วยงานด้านสุขภาพของรัฐบาลต่างๆเพื่อหาทางพัฒนา Hemopurifier(TM) เป็นทางเลือกในการรักษาสำหรับประชาชนที่ติดเชื้อ DHF
เกี่ยวกับเอธลอน เมดิคอล เอธลอน เมดิคอล ได้พัฒนาอุปกรณ์การแพทย์ชั้นหนึ่งเพื่อรักษาโรคติดเชื้อ โดยอุปกรณ์ดังกล่าวซึ่งได้แก่ Hemopurifier(TM) นั้น เป็นอุปกรณ์การรักษาที่ให้ฤทธิ์กว้างสำหรับเชื้อโรคที่ดื้อยาและวัคซีน ซึ่งเป็นโรคระบาดที่มีวิวัฒนาการตามธรรมชาติ อาทิ ไวรัสไข้หวัดนก H5N1 และโรคติดเชื้อเรื้อรัง รวมถึงไวรัสตับอักเสบ-ซี (HCV) และไวรัส Human Immunodeficiency Virus (HIV) บริษัทวิจัยระดับโลก Frost & Sullivan ได้มอบรางวัล Technology Innovation Award 2006 ให้กับ Hemopurifier(TM) สำหรับความก้าวหน้าในด้านการป้องกันทางชีวภาพ เอธลอนได้ริเริ่มการวิจัย Hemopurifier(TM) รุ่นที่ 2 ซึ่งมีเป้าหมายเพื่อจับปัจจัยการขยายตัวในการแพร่กระจายของโรคมะเร็ง
ข้อมูลเพิ่มเติมเกี่ยวกับเอธลอน เมดิคอลและเทคโนโลยี Hemopurifier(TM) นั้ั้้้นสามารถดูได้จากเว็บไซต์ www.aethlonmedical.com
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Artificial arms and hands
แนวความคิดที่จะจับเอาบางส่วนของหุ่นยนต์มาใส่ให้แก่คนที่มีสมรรถนะร่างกายต่ำกว่าคนปกติ เช่น แขนเทียม ขาเทียม ไปจนถึงมือเทียม ได้รับการตอบรับอย่างกว้างขวางจากทั้งผู้วิจัยและพัฒนา และผู้ใช้ทั่วโลก ในปี ค.ศ. 2006 โลกได้กำเนิดมนุษย์กึ่งหุ่นยนต์ทั้งเพศชายและเพศหญิงเป็นครั้งแรก ทั้งคู่ได้สูญเสียแขนจากอุบัติเหตุ คลาวเดีย มิทเชล (Claudia Mitchell) เล่าว่าในช่วงแรกที่เธอกลับมาใช้ชีวิตที่มีแขนข้างเดียว เวลาจะรับประทานกล้วย เธอต้องเอาเท้าทั้งสองจับกล้วยแล้วใช้มือขวาที่เหลืออยู่ปอกกล้วย “การปอกกล้วยเข้าปากไม่ใช่เรื่องง่ายๆ อย่างที่เคยคิด” ถึงแม้ในที่สุดเธอจะยังสามารถทำภารกิจแบบนี้ได้ มันก็มักจะทำให้อารมณ์เธอแปรปรวนทุกครั้ง แต่ตอนนี้เธอเพียงแต่เอาแขนกลมาอยู่ใกล้ๆ กล้วยแล้วพยายามคิดที่จะจับกล้วย แขนกลนั้นจะตอบสนองคำสั่งจากสมองของเธอด้วยการจับกล้วยลูกนั้น ก่อนที่เธอจะใช้มือจริงของเธอปลอกเปลือกมันออกเพื่อรับประทาน ทหารผ่านศึกพิการจากสงครามในอิรักของสหรัฐอเมริกาจำนวนหลายร้อยคน ต่างก็รอคอยการกลับไปใช้ชีวิตที่ถึงไม่ใช่แต่ก็ใกล้เคียงกับสิ่งที่เคยทำอยู่เดิม เทคโนโลยี Bionics จักเป็นความหวังให้ผู้พิการทางร่างกายทั่วโลก ได้ใช้ชีวิตเทียบเท่ากับคนธรรมดา
Bionics ไม่เพียงแต่จะสามารถนำพาอวัยวะทดแทนมาให้ผู้ที่บกพร่องทางร่างกายเท่านั้น แต่ศักยภาพของเทคโนโลยีนี้ยังสามารถ “เพิ่มเติม” ขีดความสามารถทางร่างกายส่วนบุคคลให้สูงขึ้นไปอีกได้ ศาสตราจารย์ โยชิยูกิ ซันไก (Yoshiyuki Sankai) แห่งมหาวิทยาลัยสึกุบะ ประเทศญี่ปุ่นได้ประดิษฐ์หุ่นยนต์ที่สวมใส่ได้ เรียกกันในวงการว่า Exoskeleton ซึ่งคนจะนำมาสวมไว้กับตัว จากนั้นเมื่อออกแรงยกของด้วยแขน เซ็นเซอร์จะออกคำสั่งให้กระดองกลที่ห่อแขนอยู่ออกแรงยกแทนแขนของเรา จะหุ่นยนต์ที่สวมใส่ได้ที่มีชื่อว่า HAL-5 นี้ได้ถูกสาธิตโดยการให้ผู้สวมใส่อุ้มผู้หญิงขึ้นมากลางอากาศได้อย่างที่คนอุ้มไม่รู้สึกหนักเลย กลุ่มวิจัยที่มหาวิทยาลัยแคลิฟอร์เนีย เบอร์คลีย์ ก็ไม่ยอมน้อยหน้าโดยการนำเอาเจ้า Exoskeleton นี้มาสาธิตให้ผู้สวมใส่แบกเป้ที่มีน้ำหนักเกือบ 40 กิโลกรัม เดินโชว์ไปมาเหมือนไม่มีอะไรเกิดขึ้น เพียงแค่เจ้าของชุดทำท่าจะเดิน หุ่นยนต์ที่สวมใส่อยู่นั้นก็จะออกตัวเดินทันที โดยรับน้ำหนักที่เป้หลังลงบนโครงโลหะของมัน
Bionic Man
In May 2001, working as a high-power lineman 54 year old Jesse Sullivan had a life changing event -- he was electrocuted so severely that both of his arms needed to be amputated.
Now he's the first Bionic Man on the Planet!
Bionic Man Moves Artificial Arm With BrainBreakthrough Could Change Lives Of Amputees, Patients With Spinal Cord InjuriesPOSTED: Thursday, June 23, 2005UPDATED: 4:07 pm EDT June 23, 2005CHICAGO -- Researchers have developed artificial arms that can be moved as it if they were real limbs, simply by thinking about making them move, according to Local 6 News. The world's first bionic man, Jesse Sullivan, 54, accidentally touched live wires while working as a utility lineman in Tennessee. He suffered severe burns, causing him to lose his arms.Now, Sullivan is the first to try out the most sophisticated artificial arms ever designed.Surgeons attached his arm nerves to healthy muscles in his chest.
"So now when Jess thinks, close hand, the impulse is picked up by a transmitter, and goes to his hand," doctor Todd Kuiken said. "He thinks, closes hand and it does."Sullivan's hand rotates 360 degrees, according to the report. When Sullivan's brain tells his arm to do something, it's done in seconds and he has feeling in the bionic arm. This gives me a lot of hope," Sullivan said. "I was an independent kind of guy. I didn't ask anybody for anything. If I could do it, I did it."Eventually tiny sensors in the fingertips will allow Sullivan to feel texture and temperature.Doctors at the Rehabilitation Institute of Chicago said the breakthrough could change the lives of amputees, patients with spinal cord injuries and stroke victims, according to the report.By the time it's perfected, the cost of manufacturing the bionic arm is expected to be about $6 million, according to the report.
Source>http://www.clickorlando.com/news/4643968/detail.html
Now he's the first Bionic Man on the Planet!
Bionic Man Moves Artificial Arm With BrainBreakthrough Could Change Lives Of Amputees, Patients With Spinal Cord InjuriesPOSTED: Thursday, June 23, 2005UPDATED: 4:07 pm EDT June 23, 2005CHICAGO -- Researchers have developed artificial arms that can be moved as it if they were real limbs, simply by thinking about making them move, according to Local 6 News. The world's first bionic man, Jesse Sullivan, 54, accidentally touched live wires while working as a utility lineman in Tennessee. He suffered severe burns, causing him to lose his arms.Now, Sullivan is the first to try out the most sophisticated artificial arms ever designed.Surgeons attached his arm nerves to healthy muscles in his chest.
"So now when Jess thinks, close hand, the impulse is picked up by a transmitter, and goes to his hand," doctor Todd Kuiken said. "He thinks, closes hand and it does."Sullivan's hand rotates 360 degrees, according to the report. When Sullivan's brain tells his arm to do something, it's done in seconds and he has feeling in the bionic arm. This gives me a lot of hope," Sullivan said. "I was an independent kind of guy. I didn't ask anybody for anything. If I could do it, I did it."Eventually tiny sensors in the fingertips will allow Sullivan to feel texture and temperature.Doctors at the Rehabilitation Institute of Chicago said the breakthrough could change the lives of amputees, patients with spinal cord injuries and stroke victims, according to the report.By the time it's perfected, the cost of manufacturing the bionic arm is expected to be about $6 million, according to the report.
Source>http://www.clickorlando.com/news/4643968/detail.html
Organ Repair
SCIENTISTS ARE WORKING ON A NEW WAY TO REPAIR ORGANS. THEY'RE TRYING TO BUILD REPLACEMENT PARTS USING A THREE-DIMENSIONAL PRINTER
Building Body Parts
Replacing organs or tissues with lab-created counterparts; engineered kidneys, livers and hearts. Science fiction? Not any more -- scientists are already successfully growing all kinds of organs and tissues in the lab.
All 50 Secrets of the Sequence videos have an accompanying classroom-tested lesson that encourages students to further explore the video topics. Each lesson includes background information, state and national science standards, discussion questions and answers, teacher notes and an activity that will ensure a hands-on, "minds-on" experience. To see lessons for this series, visit http://www.pubinfo.vcu.edu/secretsoft...
Regenerative Medicine
June 28, 2007 presentation by Michael Longaker for the Stanford University Office of Science Outreach's Summer Science Lecture Series.
Dr. Michael Longaker, Director or Children's Surgical Research, explains how regenerative, reparative, replacement and tissue engineering medicine represent an emerging field that holds great promise for core problems in medicine world wide.
Stanford University Office of Science Outreach:http://oso.stanford.edu
Summer Science Lecture Series:http://oso.stanford.edu/lecture_serie...
Stanford University Channel on YouTube:http://www.youtube.com/stanford
Tissue Engineering
Wyatt Andrews visits a laboratory at the Wake Forest Institute for Regenerative Medicine, where scientists like Anthony Atala, M.D., are researching new methods to grow body parts. (CBSNews.com)
Tissue Engineering and Drug Delivery System วิศวกรรมเนื้อเยื่อ (Tissue Engineering)
เป็นกระบวนการสร้างเนื้อเยื่อ (regeneration of functional tissues) เพื่อทดแทน ซ่อมแซม หรือปรับปรุงการทำงานของเนื้อเยื่อหรืออวัยวะที่สูญเสียหรือบาดเจ็บ ซึ่งโดยปกติจะไม่มีการงอกใหม่เองในมนุษย์ ได้แก่ ผิวหนังแท้ เส้นประสาท กระดูก กระดูกอ่อน กล้ามเนื้อหัวใจ เป็นต้น กระบวนการสร้างเนื้อเยื่อต้องใช้การพัฒนาความรู้ต่างๆสามด้านหลัก ได้แก่ วิศวกรรมของวัสดุ ชีววิทยาของเซลล์ และวิศวกรรมชีวเคมี โดยจะเริ่มจากการพัฒนาชีววัสดุ (วัสดุที่เข้ากับร่างกายได้ดี Biomaterials) เพื่อทำหน้าที่เป็นโครงเลี้ยงเซลล์ (scaffold) ซึ่งส่วนใหญ่นิยมใช้ชีววัสดุจากธรรมชาติ เช่น คอลลาเจน เจลาติน ไหมหรือวัสดุสังเคราะห์ขึ้น เช่น PLA PCL โครงเลี้ยงเซลล์จะถูกนำไปใช้เลี้ยงเซลล์ที่ถูกคัดแยก และขยายพันธุ์ให้มีปริมาณมากพอ แล้วการชักนำให้เปลี่ยนแปลง (differentiate) ไปเป็นเนื่อเยื่อที่ต้องการอย่างสมบูรณ์และสามารถทำงานได้ตามวัตถุประสงค์ ด้วยการควบคุมสภาวะแวดล้อมภายนอกในเครื่องปฏิกรณ์ชีวภาพ (Bioreactor) หรือในร่างกายสิ่งมีชีวิต (in vivo regeneration)
ปัจจุบันงานวิจัยในสาขานี้มีดังนี้ วิศวกรรมเนื้อเยื่อผิวหนัง วิศวกรรมเนื้อเยื่อเพื่อพัฒนากระดูกเทียมจากวัสดุชีวภาพในประเทศ วิศวกรรมเนื้อเยื่อกระดูกอ่อนจากเซลล์ต้นกำเนิด ระบบนำส่ง growth factor ในกระบวนการซ่อมสร้างเส้นประสาทส่วนปลาย การพัฒนาระบบนำส่งเมโทรเทรกเสสทางผิวหนังเพื่อรักษาโรคผิวหนังเรื้อนกวาง การพัฒนาระบบนำส่งสารสกัดจากสมุนไพรไทยที่ไม่ละลายน้ำ การสกัด ดัดแปลง และพัฒนาวัสดุทางการแพทย์จากชีววัสดุธรรมชาติ เช่น คอลลาเจน ไคโตซาน แบคทีเรียเซลลูโลส สารสกัดจากสาหร่าย ไซโครเด็กตริน การพัฒนาเครื่องปฏิกรณ์ชีวภาพเพื่อการเพิ่มจำนวนเซลล์ต้นกำเนิด
Source From>http://cubme.eng.chula.ac.th/index.php?q=research/TissueEngineeringAndDrugDeliverySystem
iPhone OS 3.0 and Medical Devices
Apple presented the blueprint for iPhone OS 3.0, the next version of their
advanced mobile platform. They showed some really cool new features for the
iPhone and iPod Touch, but particularly interesting to me was their enthusiasm about medicine and medical devices.
Telemedicine with Bluetooth
With Dyna-Vision you can monitor the ECG, SpO2, Plethysmogram, Respiration
and HRV of patients remotely and in real-time. The integrated GPRS module
transmits the signals directly to the secured Dyna-Vision Server. Doctors can
remotely access the data and analyse the ECG and SpO2 instantly and from
anywhere around the world. The patient does not have to connect the unit to
any peripheral to transmit the data. The device does this automatically by itself
Telemedicine solution
ITH Remote Presence
St. Alphonsus Regional Medical Center uses Remote Presence (RP) telemedicine solutions to provide a mechanism of extending the expertise of Saint Alphonsus specialists to multiple partnering hospitals that would otherwise lack specialty services. Additionally, this program enhances the consultative services that specialists at Saint Alphonsus are able to provide internally.
Source from
>http://www.youtube.com/watch?v=W7f1-
R3BzrM&feature=PlayList&p=3C93F8D54A13AF6C&playnext=1&playnext_from
=PL&index=1
Telemedicine
การแพทย์ทางไกลหรือ Telemedicine
ได้กลายเป็นเป้าหมายของการสาธารณะสุขยุคใหม่เสียแล้ว
จากการวิจัยพบว่า
การพบแพทย์แบบออนไลน์ หรือจะเป็นคลีนิกแพทย์ออนไลน์นั้น มีแนวโน้มว่าจะเข้ามาทดแทนการไปหาหมอแบบปกติ ที่เราต้องเดินทางไปคลีนิกหรือโรงพยาบาลที่จะมีค่าใช้จ่ายที่ค่อนข้างสูง (ในต่างประเทศ) และผู้ ป่วยหรือคนไข้ก็มีทีท่าว่า จะชอบการพบหมอแบบออนไลน์นี้เสียด้วยในปัจจุบันการแพทย์ทางไกล (Telemedicine) ได้รับการยอมรับว่าเป็นวิธีที่มีประสิทธิภาพมากที่สุด สำหรับการยกระดับการสาธารณะสุขของชุมชนห่างไกล และในชนบทรวมทั้งกลุ่มประชากรที่มีความต้องการ หรือมีข้อจำกัดบางประการ อาทิเช่นนักโทษในสถานกักกัน และแล้วการแพทย์ทางไกลก็ได้กลายเป็นเป้าหมายของการสาธารณะสุขยุคใหม่เสียแล้ว และมีแนวโน้มว่าคนไข้จะหันมาใช้บริการคลีนิกแพทย์ออนไลน์มากขึ้นเรื่อยๆ และในที่สุดก็จะเข้ามา ทดแทนการไปหาหมอแบบปกติที่ต้องเดินทาง และมีค่าใช้จ่ายสูงกว่าจากการศึกษาของมหาวิทยาลัยสแตนฟอร์ด ซึ่งมีผลการวิจัยที่ได้ศึกษาจากกลุ่มแพทย์ 282 ท่านและคนไข้มากกว่า 3,600 คนในกลุ่มตัวอย่างพบว่า การใช้เทคโนโลยีการสื่อสารแบบออนไลน์ รวมถึงอีเมล์ในการติดต่อสื่อสารระหว่างแพทย์และคนไข้ ทำให้ลดค่า ใช้จ่ายโดยเฉลี่ย ประมาณหนึ่งเหรีญสหรัฐต่อคนไข้หนึ่งคนต่อเดือน นอกจากนี้ยังพบอีกว่า
78 เปอร์เซนต์ของคนไข้และ 63 เปอร์เซนต์ของแพทย์ รู้สึกพอใจกับเทคโนโลยีสารสนเทศที่ได้นำเข้ามาใช้ในการติดต่อสื่อสารกัน และถ้าดูข้อมูลเฉพาะ จากกลุ่มแพทย์ ที่มีอายุน้อยกว่า 45 ปี จะพบว่าอัตราการยอมรับ การแพทย์แบบทางไกล และความพึงพอ
ใจในการใช้เทคโนโลยีสื่อสารนั้น พุ่งสูงขึ้นถึง 87 เปอร์เซนต์เลยทีเดียวผลลัพท์ที่ออกมา ในเชิงบวกนั้น แสดงให้เห็นถึงการยอมรับ และทัศนะความสนใจของแพทย์ที่มีต่อ เทคโนโลยี ซึ่งอาจเป็นจุดเริ่มต้นที่ทำให้ความคิดสร้างสรรค์ ในการใช้ประโยชน์จาก
เทคโนโลยีมีคุณค่ามากยิ่งขึ้น ทั้งในด้านการประหยัดเวลา และโอกาสในการดำเนินธุรกิจใหม่ๆ การพบแพทย์แบบออนไลน์ จะเป็นส่วนหนึ่งของความก้าวหน้า และเป็นจุดเปลี่ยนของวิวัฒนาการด้านสาธารณะสุข ที่จะเปลี่ยนจากการพบแพทย์ที่โรงพยาบาล และคลีนิกแพทย์ไปสู่สถานที่แห่งใหม่ ซึ่งไม่มีขีดจำกัดและสภาพแวดล้อมที่ไม่ต้องมีการเดินทางและนั่นคือที่บ้านของคนไข้เองรูปแบบการให้บริการด้านสาธารณะสุขแบบใหม่ ได้เกิดขึ้นแล้วในหลายประเทศทั่วโลก ทั้งนี้ต้องขอบคุณเทคโนโลยีสื่อสารและสารสนเทศ ที่ทำให้
ทุกสิ่งทุกอย่างเกิดขึ้นได้ในโลกอินเทอร์เน็ต ไม่ว่าเราจะอยู่ ณ ที่แห่งใดบนโลกใบนี้ ขอเพียงสามารถเชื่อมต่ออินเทอร์เน็ตได้ ก็เหมือนมีแพทย์ประจำตัวอยู่เคียงข้างตลอดเวลา
โครงการแพทย์ทางไกลผ่านดาวเทียม
source >http://hospital.moph.go.th/srisungworn/telemed01.htm
More details see>>http://www.visicu.com/products/index.h
วันศุกร์ที่ 22 พฤษภาคม พ.ศ. 2552
CNN's Dr. Sunjay Gupta on da Vinci Surgery
Researchers laud robot-guided heart surgeryBy Debra GoldschmidtCNN Medical UnitTuesday, November 19, 2002
CHICAGO (CNN) -- Robotic heart surgery using the da Vinci Surgical System has many advantages for patients and doctors, according to research presented to cardiologists at the annual Scientific Sessions of the American Heart Association on Tuesday.
Surgeons from New York Presbyterian Hospital presented the outcomes of 17 patients after having a heart defect -- called atrial septal defect -- repaired using the robot for assistance.
Of the 17 patients, 16 of them had their hearts repaired in a totally robotic operation. One patient required additional repair five days after the first surgery. The average length of stay in the hospital after the surgery was three days compared with seven to 10 days for traditional surgery. None of the patients experienced major complications.
The robotic technique requires four puncture wounds, each an inch in diameter. Surgeons use pencil-sized instruments to operate on the heart. They sit several feet away from the patient at a console where they see inside the patient on a monitor.
Lead researcher, Dr. Michael Argenziano said the success rate "proved we can do this surgery in a closed chest approach." The alternative is the traditional technique of cracking the chest -- done by a long incision, cutting the bone, and then splitting the ribs.
"The main advantage is that these patients were able to recover quickly." he said.
Patients recovering from the traditional approach usually have several inactive weeks before they're able to resume regular activity, but patients who undergo robotic surgery only spend a couple of days recovering from local wounds. Argenziano was amazed when one of his patients was able to pick up her toddler the day after her surgery.
Compared with other minimally invasive heart surgery approaches, robotic assistance allows surgeons to have better control over the surgical instruments and a better view of what they are doing.
However, there are disadvantages -- time being one of them. Robotic-assisted surgery takes nearly double the amount of time that a typical open-heart surgery takes. That means a patient is under anesthesia longer and nurses and other staff must also work longer hours.
The cost seems to be a disadvantage as well. In the short term, hospitals pay millions of dollars for the robot and the disposable instruments needed.
But Argenziano argues that although the robotic-assisted surgeries cost about $2,000 more per operation, in the end the cost comes out about even because patients are out of the hospital sooner.
Money is saved after surgery on nursing care and pain medications, he said, in addition to the societal benefits from faster recovery.
The procedure is still experimental under a U.S. Food and Drug Administration clinical trial; therefore, the robot's manufacturer picks up any costs that exceed the normal cost of heart surgery.
Seven other patients have undergone the procedure at other centers as part of the trial.
Argenziano said they've had no trouble finding patients willing to try the experimental surgery because of the faster recovery time. He added that the surgeons can have the patient's chest open in one minute's time should they suddenly need to convert to traditional surgery -- something they haven't had to do.
In another trial, Argenziano and other surgeons are using the robot to perform closed-chest coronary bypass surgery.
Last week the FDA gave approval for the robot to be used for mitral valve repair surgery. This is the first robotic heart surgery to be granted clearance by the FDA.
The da Vinci Surgical System is made by California-based Intuitive Surgical Systems. There are 132 systems in hospitals worldwide and nearly 100 are in U.S. hospitals.
Source>http://archives.cnn.com/2002/HEALTH/11/19/heart.robots/index.html
Robotic-Assisted Prostate Surgery
The da Vinci? Surgical SystemLearn about the newest da Vinci Surgical System:
Read moreThe da Vinci Surgical System consists of an ergonomically designed surgeon’s console, a patient-side cart with four interactive robotic arms, the high-performance InSite? Vision System and proprietary EndoWrist? Instruments. Powered by state-of-the-art robotic technology, the surgeon’s hand movements are scaled, filtered and seamlessly translated into precise movements of the EndoWrist Instruments. The net result: an intuitive interface with breakthrough surgical capabilities.
Details>>http://www.intuitivesurgical.com/products/davinci_surgicalsystem/index.aspx
Da Vinci Surgical System
From Wikipedia, the free encyclopedia
Da Vinci Surgical System Manufacturer Intuitive Surgical Type Robotic surgery Units sold 1,032 units worldwide
The da Vinci Surgical System is a robotic surgical system made by Intuitive Surgical and designed to facilitate complex surgery using a minimally invasive approach. The system is controlled by a surgeon from a console. It is commonly used for prostatectomies and increasingly for cardiac valve repair and gynecologic surgical procedures.
Overview
The da Vinci System consists of a surgeon’s console that is typically in the same room as the patient and a patient-side cart with four interactive robotic arms controlled from the console. Three of the arms are for tools that hold objects, act as a scalpel, scissors, bovie, or unipolar or dipolar electrocautery instruments. The fourth arm is for an endoscopic camera with two lenses that gives the surgeon full stereoscopic vision from the console. The surgeon sits at the console and looks through two eye holes at a 3-D image of the procedure, meanwhile maneuvering the arms with two foot pedals and two hand controllers. The da Vinci System scales, filters and translates the surgeon's hand movements into more precise micro-movements of the instruments, which operate through small incisions in the body.
According to the manufacturer, the da Vinci System is called "da Vinci" in part because Leonardo da Vinci invented the first robot. The artist Leonardo also used anatomical accuracy and three-dimensional details to bring his works to life.
To perform a procedure, the surgeon uses the console’s master controls to maneuver the patient-side cart’s three or four robotic arms (depending on the model), which secures the instruments and a high-resolution endoscopic camera. The instruments’ jointed-wrist design exceeds the natural range of motion of the human hand; motion scaling and tremor reduction further interpret and refine the surgeon’s hand movements. The da Vinci System incorporates multiple, redundant safety features designed to minimize opportunities for human error when compared with traditional approaches. At no time is the surgical robot in control or autonomous; it operates on a "Master:Slave" relationship, the surgeon being the "Master" and the robot being the "Slave."
The da Vinci System has been designed to improve upon conventional laparoscopy, in which the surgeon operates while standing, using hand-held, long-shafted instruments, which have no wrists. With conventional laparoscopy, the surgeon must look up and away from the instruments, to a nearby 2D video monitor to see an image of the target anatomy. The surgeon must also rely on his/her patient-side assistant to position the camera correctly. In contrast, the da Vinci System’s ergonomic design allows the surgeon to operate from a seated position at the console, with eyes and hands positioned in line with the instruments. To move the instruments or to reposition the camera, the surgeon simply moves his/her hands.
By providing surgeons with superior visualization, enhanced dexterity, greater precision and ergonomic comfort, the da Vinci Surgical System makes it possible for more surgeons to perform minimally invasive procedures involving complex dissection or reconstruction. For the patient, a da Vinci procedure can offer all the potential benefits of a minimally invasive procedure, including less pain, less blood loss and less need for blood transfusions. Moreover, the da Vinci System can enable a shorter hospital stay, a quicker recovery and faster return to normal daily activities.
The robot costs on average $1.3 million in addition to several hundred thousand dollars of annual maintenance fees. Surgical procedures performed with the robot take longer than traditional ones. Critics have pointed out that hospitals have a hard time recovering the cost and that most clinical data does not support the claim of improved patient outcomes
Drug delivery
Drug delivery is a process, during which pharmaceutical compounds are delivered to humans or animals. Methods of delivery include several routs, such as oral, nasal, pneumonial, rectal and several others. In order to work effectively, the drug needs to work in a controlled manner, which would control the circulation of the drug in the body. Targeted delivery occurs when the drug remains active within a specified territory of the body. Targeted drug delivery is especially important in cases, when the drug needs to affect a malicious turmoil, such as in cancerous tissues.
Doctors all over the world are trying to find new methods for more effective drug development and drug delivery. One of the most successful methods developed in recent years is nanotechnology. This mechanism, which controls small-scale matter, makes it possible for drugs to permeate trough cell walls. The methods of nanotechnology play a very important role in pharma industry: health organizations manufacture more efficient drugs, released in a controlled manner in order to reach the target areas of the patients' body.
Drug development aims to find more effective drugs, which would cure or ameliorate symptoms of illness or medical condition. Drug development is required to establish the chemical properties of new compounds, their stability and chemical makeup. The process of drug development also involves the need to fit the regulatory requirements of drug licensing authorities. Pharmaceutical companies, which produce different medications, develop new methods of targeted drug delivery. Nanotechnology, developed in recent years may provide a breakthrough technique of drug delivery.
Submitted by Natalie Halimi - Content Editor in Internet Marketing Company - Inter-Dev http://www.inter-dev.co.il/en/ Drug delivery, drug development - http://www.docoop.com/
Doctors all over the world are trying to find new methods for more effective drug development and drug delivery. One of the most successful methods developed in recent years is nanotechnology. This mechanism, which controls small-scale matter, makes it possible for drugs to permeate trough cell walls. The methods of nanotechnology play a very important role in pharma industry: health organizations manufacture more efficient drugs, released in a controlled manner in order to reach the target areas of the patients' body.
Drug development aims to find more effective drugs, which would cure or ameliorate symptoms of illness or medical condition. Drug development is required to establish the chemical properties of new compounds, their stability and chemical makeup. The process of drug development also involves the need to fit the regulatory requirements of drug licensing authorities. Pharmaceutical companies, which produce different medications, develop new methods of targeted drug delivery. Nanotechnology, developed in recent years may provide a breakthrough technique of drug delivery.
Submitted by Natalie Halimi - Content Editor in Internet Marketing Company - Inter-Dev http://www.inter-dev.co.il/en/ Drug delivery, drug development - http://www.docoop.com/
วันพฤหัสบดีที่ 21 พฤษภาคม พ.ศ. 2552
Release of neurological drugs
Drug Delivery Systems
Markets and Applications for Nanotechnology Derived Drug Delivery Systems
Background
The most promising aspect of pharmaceuticals and medicine as it relates to nanotechnology is currently drug delivery. In the words of LaVan and Langer: ‘It is likely that the pharmaceutical industry will transition from a paradigm of drug discovery by screening compounds to the purposeful engineering of targeted molecules.’
Reasons Why the Drug Delivery Market is Rapidly Expanding
At present, there are 30 main drug delivery products on the market. The total annual income for all of these is approximately US$33 billion with an annual growth of 15% (based on global product revenue). Two major drivers are primarily responsible for this increase in the market. First, present advances in diagnostic technology appear to be outpacing advances in new therapeutic agents. Highly detailed information from a patient is becoming available, thus promoting much more specific use of pharmaceuticals. Second, the acceptance of new drug formulations is expensive and slow, taking up to 15 years to obtain accreditation of new drug formulas with no guarantee of success.
How Drug Companies are Reacting to this Expansion
In response, some companies are trying to hurry the long clinical phase required in Western medicine. However, powerful incentives remain to investigate new techniques that can more effectively deliver or target existing drugs (Saxl, 2000). In addition, many of these new tools will have foundation in current techniques: a targeted molecule may simply add spatial or temporal resolution to an existing assay. Thus, although many potential applications are envisaged, the actual near future products are not much more than better research tools or aids to diagnosis. These are summarised in the following three tables.
More details see >> AZoNanotechnology Article
Biosciences and Biomedical Engineering
Demand for interdisciplinary laboratories for physiology research by undergraduate students in biosciences and biomedical engineering
Kari L. Clase1, Patrick W. Hein2 and Nancy J. Pelaez
1 Department of Industrial Technology and Bindley Bioscience Center, West Lafayette, Indiana
2 Department of Basic Medical Sciences and Weldon School of Biomedical Engineering, West Lafayette, Indiana
3 Department of Biological Sciences, Purdue University, West Lafayette, Indiana
Address for reprint requests and other correspondence: K. L. Clase, Dept. of Industrial Technology, Bindley Bioscience Center, Purdue Univ., West Lafayette, IN 47907
(e-mail: klclase@purdue.edu)
Abstract
Physiology as a discipline is uniquely positioned to engage undergraduate students in interdisciplinary research in response to the 2006–2011 National Science Foundation Strategic Plan call for innovative transformational research, which emphasizes multidisciplinary projects. To prepare undergraduates for careers that cross disciplinary boundaries, students need to practice interdisciplinary communication in academic programs that connect students in diverse disciplines. This report surveys policy documents relevant to this emphasis on interdisciplinary training and suggests a changing role for physiology courses in bioscience and engineering programs. A role for a physiology course is increasingly recommended for engineering programs,
but the study of physiology from an engineering perspective might differ from the study of physiology as a basic science. Indeed, physiology laboratory courses provide an arena where biomedical engineering and bioscience students can apply knowledge from both fields while cooperating in multidisciplinary teams under specified technical constraints. Because different problem-solving approaches are used by students of engineering and bioscience, instructional
innovations are needed to break down stereotypes between the disciplines and create an educational environment where interdisciplinary teamwork is used to bridge differencesKey words: laboratory education; engineering education; physiology education; design thinking
>More information:
Kari L. Clase1, Patrick W. Hein2 and Nancy J. Pelaez
1 Department of Industrial Technology and Bindley Bioscience Center, West Lafayette, Indiana
2 Department of Basic Medical Sciences and Weldon School of Biomedical Engineering, West Lafayette, Indiana
3 Department of Biological Sciences, Purdue University, West Lafayette, Indiana
Address for reprint requests and other correspondence: K. L. Clase, Dept. of Industrial Technology, Bindley Bioscience Center, Purdue Univ., West Lafayette, IN 47907
(e-mail: klclase@purdue.edu)
Abstract
Physiology as a discipline is uniquely positioned to engage undergraduate students in interdisciplinary research in response to the 2006–2011 National Science Foundation Strategic Plan call for innovative transformational research, which emphasizes multidisciplinary projects. To prepare undergraduates for careers that cross disciplinary boundaries, students need to practice interdisciplinary communication in academic programs that connect students in diverse disciplines. This report surveys policy documents relevant to this emphasis on interdisciplinary training and suggests a changing role for physiology courses in bioscience and engineering programs. A role for a physiology course is increasingly recommended for engineering programs,
but the study of physiology from an engineering perspective might differ from the study of physiology as a basic science. Indeed, physiology laboratory courses provide an arena where biomedical engineering and bioscience students can apply knowledge from both fields while cooperating in multidisciplinary teams under specified technical constraints. Because different problem-solving approaches are used by students of engineering and bioscience, instructional
innovations are needed to break down stereotypes between the disciplines and create an educational environment where interdisciplinary teamwork is used to bridge differencesKey words: laboratory education; engineering education; physiology education; design thinking
>More information:
Advances in Biomedical Engineering
Advances in Biomedical Engineering
Linda G. Griffith, PhD; Alan J. Grodzinsky, ScD
JAMA. 2001;285:556-561.
The most visible contributions of biomedical engineering to clinical practice involve instrumentation for diagnosis, therapy, and rehabilitation. Cell and tissue engineering also have emerged as clinical realities. In the next 25 years, advances in electronics, optics, materials, and miniaturization will accelerate development of more sophisticated devices for diagnosis and
therapy, such as imaging and virtual surgery. The emerging new field of bioengineering—engineering based in the science of molecular cell biology—will greatly expand the scope of biomedical engineering to tackle challenges in molecular and genomic medicine.
Author Affiliations: Division of Bioengineering and Environmental Health, Departments of Electrical (Dr Grodzinsky), Mechanical (Dr Grodzinsky), and Chemical Engineering (Dr Griffith),Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge.
> More Informations :
Linda G. Griffith, PhD; Alan J. Grodzinsky, ScD
JAMA. 2001;285:556-561.
The most visible contributions of biomedical engineering to clinical practice involve instrumentation for diagnosis, therapy, and rehabilitation. Cell and tissue engineering also have emerged as clinical realities. In the next 25 years, advances in electronics, optics, materials, and miniaturization will accelerate development of more sophisticated devices for diagnosis and
therapy, such as imaging and virtual surgery. The emerging new field of bioengineering—engineering based in the science of molecular cell biology—will greatly expand the scope of biomedical engineering to tackle challenges in molecular and genomic medicine.
Author Affiliations: Division of Bioengineering and Environmental Health, Departments of Electrical (Dr Grodzinsky), Mechanical (Dr Grodzinsky), and Chemical Engineering (Dr Griffith),Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge.
> More Informations :
วันอังคารที่ 12 พฤษภาคม พ.ศ. 2552
Lab on a chip
Lab on a chip mimics brain chemistry
February 12th, 2008 Johns Hopkins researchers from the Whiting School of Engineering and the School of Medicine have devised a micro-scale tool – a lab on achip – designed to mimic the chemical complexities of the brain. The system should help scientists better understand how nerve cells in the brain work together to form the nervous system.
AmpliChip CYP450 Test – www.AmpliChip.us
Roche Diagnostics US Official Site FDA cleared CYP450 Test
A report on the work appears as the cover story in the February 2008 issue of the British journal Lab on a Chip. ”The chip we’ve developed will make xperiments on nerve cells more simple to conduct and to control,” says Andre Levchenko, Ph.D., associate professor of biomedical engineering at the Johns Hopkins Whiting School of Engineering and faculty affiliate of the Institute for NanoBioTechnology. Nerve cells decide which direction to grow by sensing both the chemical cues flowing through their environment as well as those attached to the surfaces that surround them. The chip, which is made of a plastic-like substance and covered with a glass lid, features a system of channels and wells that allow researchers to control the flow of specific chemical cocktails around single nerve cells.
“It is difficult to establish ideal experimental conditions to study how neurons react to growth signals because so much is happening at once that sorting out nerve cell connections is hard, but the chip, designed by experts in both brain chemistry and engineering, offers a sophisticated way to sort things out,” says Guo-li Ming,
M.D.,Ph.D., associate professor of neurology at the Johns Hopkins School of Medicine and Institute for Cell Engineering.
In experiments with their chip, the researchers put single nerve cells, or rons,onto the chip then introduced specific growth signals (in the form of hemicals).They found that the growing neurons turned and grew toward higher concentrations of certain chemical cues attached to the chip’s surfaces, as well as to signaling molecules free-flowing in solution.
When researchers subjected the neurons to conflicting signals (both surface bound and cues in solution), they found that the cells turned randomly, suggesting that cells do not choose one signal over the other. This,according to Levchenko,supports the prevailing theory that one cue can elicit different responses depending on
a cell’s surroundings. “The ability to combine several different stimuli in the chip resembles a more realistic environment that nerve cells will encounter in the living animal,” Ming says.This in turn will make future studies on the role of neuronal cells in development and regeneration more accurate and complete.
Source: Johns Hopkins Medical Institutions
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