In WWNK 6/14/2004, we reported on the promising future of nanomedicine. While the advanced technologies scientists are feverishly working on seem nothing short of miraculous, their practical application is doubtlessly years, if not decades, away. But not everything in the nanomedical sector is science fiction--what most people don't know is that some of it is already in use... or will be very soon.

In January, the Washington Post stated that "More than 60 drugs and drug delivery systems based on nanotechnology, and more than 90 medical devices or diagnostic tests, are already being tested" for clinical purposes: From quantum dots (qdots) as research tools to amphiphiles that regenerate injured nerve cells.

Detection Devices

Nano-sized bits of material, such as silicon, are being used by researchers to study the transportation capacities of proteins, DNA and other molecules within cells. Depending on the size of these quantum dots or qdots, they glow with a bright hue under ultraviolet light--2 nanometer dots shine green, 5 nm dots red, their brightness and duration of glow being vastly superior to conventional dyes. Scientists coat the qdots with a material that makes them attach to the molecule they want to track and then send them on their way by injecting them into cells in Petri dishes. Brightly colored as they are, the qdots' trails are easy to track.

Even brighter is the prospect for so-called emissive polymersomes that a team of chemists, bioengineers and medical researchers at the Universities of Pennsylvania and Minnesota have just begun to apply in living rats to spot tumors. Unlike qdots, which consist of hard matter, self-assembled polymersomes function much like the bi-layered membranes of living cells and seem to be safe for use within the body. Emitting a distinctive glow under near-infrared light, the tiny cancer scouts have allowed researchers to visualize a tumor more than one centimeter below the skin surface, "with the potential to go even deeper," according to Michael J. Therien, a professor of chemistry at Penn.

Therien claims that the new polymersome technology could render MRI-based methods obsolete, enabling optical imaging of cancer tissue that's "less costly and more accessible... and free of the harmful side effects associated with radioactivity." Since they can be tuned to respond to different wavelengths of near-infrared light, emissive polymersomes could even target multiple cancer cells simultaneously.

In PNAS' February issue, Nanosphere Inc. announced a breakthrough in the early detection of Alzheimer's as well as plans to expand the application of its new bio-barcode assays to cancer, neurodegenerative, infectious, cardiac and pulmonary diseases, which "are often diagnosed too late for optimal treatment," according to Chad Mirkin, Ph.D., professor of chemistry at Northwestern University and leader of the biomarker assay research. "We now can detect associated protein markers at much lower concentrations than conventional tests, potentially enabling earlier intervention and validation of new therapies for [Alzheimer's]." Nanosphere has made a manual version of the technology available to research laboratories, followed by an automated form later this year.

Since their discovery in the 1990s, nanotubes have shown vast potential in commercial and medical applications. Made of interwoven carbon atoms, they could soon replace conventional testing for blood sugar, cholesterol and hormone levels. A team of scientists at the University of Illinois developed the new glucose sensors that can be packed in a splinter-size capsule and painlessly implanted under the skin. Treated with the enzyme glucose oxidase and anchored to epoxy-covered material acting as an electrode contact, the amount of emitted fluorescence from the nanotubes can be used to measure the level of blood sugar via a handheld device... without spilling a drop of blood.

Repair Devices

The alternative to stem cell treatment may be a synthetic molecule, designed by researchers from the Institute of Bio-Engineering and Nanoscience in Advanced Medicine (IBNAM). According to Samuel I. Stupp, director of IBNAM and leader of the team, the new peptide amphiphiles "interact with cells of the central nervous system in ways that may help prevent the formation of the scar that is often linked to paralysis after spinal cord injury." The Washington Post reported that rats and mice that were injected with a peptide amphiphile solution, which spurs neuron growth and inhibits scar formation, were more likely to recover the ability to walk than untreated animals.

Researchers at Rice University in Houston have found a way to literally "fry" tumors within the body without invasive surgery, made possible by photo-thermal nanoshells. The nano-size gold-coated spheres are injected in the body and gather around the tumor; when exposed to near-infrared light, they heat up to 122 degrees Fahrenheit and effectively kill the tumor, leaving the surrounding tissue intact. After the procedure, the body's immune system takes care of eliminating the tiny devices. The gold nanoparticle, assure the researchers, "is biocompatible and does not demonstrate cytotoxicity to healthy cells/tissue." Reportedly, the animals the nanoshells were tested on were still cancer-free after several months.



"If you can make the world a better place by killing people in Baghdad and Fallujah, why not kill them in Tehran too? And why stop there? Why not take out a group in Paris...or Washington? Why not smother your mother-in-law or silence a rap star?"

--Bill Bonner, editor of The Daily Reckoning


Posted 02-14-2005 9:08 PM by Doug Casey
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