Nanotech in Medicine

The following is mostly from Scientific American February 2009 on page 48.

Because of the way it is presented in an inset with design graphics I can only share it in a slightly different form here.
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At the scale of one nanometer--one billionth of a meter--materials and devices can interact with cells and biological molecules in unique ways. The nanoscale technologies already used in research or therapies are generally betwen 10 nanometers, the size of an antibody protein, and 100 nanometers, the size of a virus. These devices and particles are being applied as sensors to detect molecules such as proteins or DNA, as imaging enhancers, and as a means to target specific tissues and deliver therapeutic agents.

.01 nanometer, 1 is glucose at .01, then antibody 10, then virus 100, then bacterium 1,000, then red blood cell 10,000, then hair diameter 100,000.

Nanowires- use sensing

How it works- Conductive wire, 10 to 20 nanometers thick, is strung across a channel through which a sample will pass. To detect proteins or DNA, probes made of complementary antibodies or DNA are attached to each wire. When a protein meets its matching antibody, it binds to the probe and changes the conductive properties of the wire, allowing the event to be detected electronically.

Cantilevers- use sensing

How it works- Molecular probes, such as single-stranded DNA, can also be attached to beams just a few nanometers thick. When exposed to a DNA sample, complementary strands bind to the probes on the cantilever, causing the beams to bend slightly. That response can be detected visually or by a change in the beams conductivity.

Quantum dots- use imaging

How it works-Nanocrystals made of inorganic elements such as cadmium or mercury encased in latex or metal respond to light by emitting fluoresence at different wavelengths and intensities depending upon their composition. Antibodies attached to the crystals can cause the dots to bind to select tissue, such as a tumor, which can then be seen by more conventional imaging devices.

Nano Shells- use tissue targeting, imaging

How it works-Solid silica nanospheres, sometimes encased in a thin layer of gold, will travel through the bloodstream with out entering most healthy tissues, but they tend to accumulate in tumor tissue. Therapeutic molecules can be attached to the spheres, or once a large number of the nanoshells accumulate in a tumor, heat delivered to the tumor will be absorbed by he spheres, killing the tissue. Depending upon their composition, nanoshells can also absorb or scatter light, enhancing tumor images made with certain forms of spectroscopy.

Nanoparticles- Use Tissue targeting, delivery

How it works- Particles composed of a variety of materials can be constructed to contain therapeutic molecules in their core and to release them at a desireable time and location. Such delivery vehicles include simple lipid shells that passively leak through tumor blood vessel walls, then slowly release a traditional chemotherapy drug into the tissue. Newer nanoparticles are more completely depsigned, including exterior elements such as antibodies to target tumor specific proteins, and materials that minimize the particles interaction with healthy tissue.

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Since all the nanoparticles are between the size of a antibody and a virus and smaller than a bacterium, red blood cell or the diameter of a hair they can go places and do things in a custom way unheard of until now except in James Bond kind of situations the last 30 years.