TECHNOLOGY: Nanoshells

At the level of nanometers, the world behaves under slightly different laws of physics from those we are used to. This can be illustrated with regard to color, the wavelength of light reflected by an object. A red piece of paper will remain red after being cut into smaller and smaller pieces until those pieces reach the level of nanometers. At this point, the interactions between “red paper” molecules begin undergo alterations which may affect the light reflected by the particles and change their perceived color.

Nanoshells are spherical nanoparticles with a silica core surrounded by a gold coat ranging from 5-20nm in thickness. By altering the thickness of the gold coat, researchers take advantage of the special laws obeyed on the nano level to change the spectrum of light absorbed most strongly by the shells. Moreover, shining light within this absorption spectra on these shells causes them to heat up and kill surrounding tissue. This phenomenon is useful for eliminating tumor cells in cancer.

The small size of these nanoshells makes it easy for researchers to administer the shells through bloodstream into the tissue of interest. Researchers may coat the nanoshells with anitbodies designed to localize to tumor cells and tune the absorption spectra of the shells to match the light most strongly absorbed in these tissues. A lab in Rice University led by Dr. Jennifer West has recently shown these nanoshells to be useful in eliminating tumor cells in (here). Nanoshells may also be tuned to scatter certain wavelengths of light. This has proven useful for imaging tumor cells and may have other uses for optical imaging as well.

TECHNOLOGY: Protein Scaffolds

A group led by Dr. Gerald E. Schneider in MIT recently published a paper which found that injecting a class of self-assembling proteins called "sapeptides" can promote nerve fiber regrowth in severed optic tracts of hamsters. The optic tract is the nerve bundle that connects that retina of the eye to the brain, and is crucial to the process by which we integrate the light that we sense into the intricate representations of the world that we experience. While the extent to which the experience of vision restored in these hamsters is unknown, the lab found that the regenerated hamsters were able to respond to and follow visual stimuli (demonstated by head movements from the hamsters).

The sapeptides are short and simple sequences of about a dozen of amino acids joined into oligopeptides. These peptides self assemble in physiological conditions to form scaffolds around damaged tissue. Though the mechanism of regeneration is unknown, these scaffolds have been shown to promote regeneration of tissue ranging from optic tract nerves to damaged pancreatic cells.

Sapeptides are interesting because of their self assembling nature and the fact that their components - simple amino acids - are easily degraded by natural physiological processes. Nothing has been tested in humans, but the possibilities of biomaterial mediated tissue regeneration are very encouraging. Imagine the potential of these scaffolds when combined with stem cell therapy...

NEWS: Let's Get Started

Today I will post my first informational post. This post will profile a new class of self-assembling protein scaffolds which can be injected into damaged tissue to promote regeneration. One lab in MIT found that injection of these "sapeptides" can result in regeneration of severed nerve fibers from the eye of hamsters, restoring vision. Just think, one day injections of these proteins may help stroke victims and Alzheimer's patients regenerate brain tissue and improve their lives.

This post will mark the start of my commitment to this blog. I hope to make 3-4 posts per week and I will provide equal coverage to the science behind nanotechnology as to the companies applying nanotechnology to better our lives.