The human nervous system comprises an extremely complex network of neurons joined by synapses. When these synaptic connections fail, the nervous system does not function properly which may eventually leading to injury or disease.

Researchers at Arkansas State University have demonstrated that magnetic nanotubes coupled with nerve growth factor can help enable cells to differentiate into neurons with the possibility of repairing such damage. They noted that rat PC12 cells sent out projections called filopodia towards magnetic nanotubes incorporated with nerve growth factor and made contact with them. At the same time the nanotubes did not appear to display any toxicity. The research raises new hope for developing future treatments for neurodegenerative conditions such as Parkinson’s Disease and Alzheimer’s Disease.

Source: PhysOrg.com

Posted: January 19th, 2009 under Regenerative medicine, Nanomedicine.
Comments: none

Silk has been considered a useful material for some time for biological scaffold for some time, due to the fact that it is very strong and biocompatible. Researchers at Tuft’s University in the USA have now found that silkworm silk may also serve as an optical material for biosensors and other devices.

The team, led by Fiorenzo Omenetto, noted that a Tuft’s colleague, David Kaplan, was using the silk as a tissue engineering scaffold to build engineered corneal implants and wondered whether the material might also therefore be useful for optical devices. They found that the silk worked as well as traditional optical materials like glass and plastic and, in some cases, better, without the need for high temperature or harsh chemical processing enabling biosensing molecules such as proteins, antibodies and even enzymes to be easily attached.

The silk from the silkwork coccoons was extracted by the team into an aqueous solution providing an ideal medium into which to mix various biosensing molecules. A variety of moulds can then be used to create optical devices in different forms. A sample device incorporating haemoglobin and capable of sensing oxygen was constructed but the team believes that a whole variety of biosensing molecules could be utilised for a range of biosensing applications including glucose monitoring for diabetes, the detection of cancer markers, colour-changing sensors and sensors that can be incorporated into tissue-engineered devices to provide feedback about their performance.

Source: MIT Technology Review

Posted: January 12th, 2009 under Advanced materials, Advanced medtech, Nanomedicine.
Comments: none

Researchers at Oxford University have succeeded in creating a molecular machine that can walk along a strand of DNA and which can be powered by nearby molecules. The design improves upon earlier attempts in that the walker can move in a definite direction, rather than randomly, and that the walker can stop or start according to the amount of available fuel.

The walker comprises two connected feet made from a sequence of DNA bases that attach to complementary sequences on the DNA track. As one foot attaches, the back foot is forced to lift off. The base sequences in the feet act as catalysts to release energy from the surrounding molecules to power the device.

Although some problems remain to be overcome, such as the DNA track becoming tangled, the team has hopes that the walker could be used to transport molecular loads in a “nanofactory”.

Source: New Scientist

Posted: January 12th, 2009 under Advanced materials, Advanced medtech, Nanomedicine.
Comments: none

A Cornell University research team has used light to hold and move DNA fragments more precisely and over longer distances previously possible. The technique involves condensing and streaming photons along a special type of waveguide with channels of 60nm to 120nm, far smaller than the wavelength of the infrared laser light, 1500nm, being channeled through them. The small size of the channel condenses the light energy to scales closer to those of the DNA molecules and enhances the ability of the photons to interact with them. Because the waveguide is also a nanochannel it can trap and transport the molecules.

The team, whose work was published in Nature on 1 January 2009, hope that it will be possible to refine and develop the technique to routinely trap and move DNA strands.

Source: Science Daily

Posted: January 5th, 2009 under Physics, Nanomedicine.
Comments: none

Researchers at Stanford University and the University of
California in Santa Cruz have developed a novel detector that utilises nanoscale magnetic beads as tags for multiple cancer biomarkers with a much higher sensitivity than current assays. In their paper, published in the Proceedings of the National Academy of Sciences, the team reported detection of important biomarkers such as tumour necrosic factor alpha and cancer embryonic antigen down to concentrations as as low as 5 quadrillionths to 0.1 trillionth of a mole.

The research offers new hope of detecting some “hidden” cancers such as pancreatic, ovarian and lung cancer at a much earlier stage thereby greatly improving treatment options and prognosis for the patient.

Source: Nanowerk News

Posted: January 5th, 2009 under Nanomedicine.
Comments: none

Researchers at the Massachusetts Institute of Technology have developed a new nanoscale drug delivery system that allows the release of multiple drugs in a controlled manner. This can be important in many diseases, such as certain cancers and AIDS, where multiple drugs are used that have synergistic effects.

The delivery system is based on gold nanoparticles and infrared light and take advantage of the fact that when the nanoparticles are exposed to certain frequencies they melt and release the drug payload on their surface. However, the researchers found that different shapes of nanoparticles respond to different wavelengths of infrared light and built two shapes, “nanobones” and “nanocapsules” that melted at 1100nm and 800 nm respectively, dispersing test payloads of hundreds of strands of DNA. The researchers claim that up to four different shapes could be developed in a system, each releasing its payload at a different wavelength.

The system has considerable potential advantages in that the release can be controlled by external means rather than the release mechanism having to be engineered into the particles themselves.

Source: MIT News

Posted: January 5th, 2009 under Nanomedicine.
Comments: none