Drug Discovery Industry Review
Miniaturization not only saves on scarce resources, such as purified proteins, but also decreases the time, another precious commodity, involved in doing assays.
Nanotechnology involves the miniaturization of devices beyond microengineering; however, at nanoscale, materials can have quite different properties, as different physical principles, for instance, van der Wall's forces, become more dominant. Intuitive understanding of forces like friction or surface tension are not useful at the nano level. Nanostructured materials may be very much stronger and lighter than conventional bulk materials. Some nanostructured materials have new and unexpected properties, such as "quantum dots" that fluoresce at different wavelengths depending upon their size. Nanomaterials may be used to create nanodevices with defined functions.
Biomolecules such as protein and DNA are also easily exploited to make nanodevices. Like fullerenes, biomolecules generally have a carbon backbone, but one that is widely substituted with modifiable chemical groups. Because their biochemistry is well understood, DNA and proteins are being used structurally now to build nanodevices.
The favorite manufactured items used by nanotechnologists have diameters comparable to smallest objects found in nature. Six-carbon atoms lined end to end are about 1 nm in diameter. Perhaps surprisingly, the synthetic molecule, buckminster fullerene, which contains 60 carbons, has the same diameter. Despite the large molecular weight, because C60 is approximately spherical is minimal. Even so, C60 can be made to cage other molecules, including some used for medical imaging purposes. Fullerene derivatives, such as nanotubes, have smaller diameters than C60. Commercially available nanoparticles are actually quite a bit smaller than cells, about the same size as an average virus.
It is apparent that nanoscale fabrication has already reached the scale of biomolecules. The problem that remains is how to apply nanotechnology to biomedical requirements, and even more difficult, how to make it marketable. Nanoscale devices are now being used for contrast agents for imaging purposes, for bioassays, as drug delivery agents, and even as drug equivalents.