January 1, 1970 (Vol. , No. )
Ever since watching “The Fantastic Voyage” as a kid, the notion of microscopic humans travelling throughout the body as a repair squad has captured my imagination. And, like much of science fiction, it is grounded in a reality that today is working its way towards the clinic – sans minuscule humans, of course.
The recent American Association of Physicists in Medicine (AAPM) meeting in Anaheim, California highlighted two of the most recent incarnations of nanotechnology. In one, researchers at Johns Hopkins are developing a method to deliver chemotherapy only to the cancerous cells using nanoparticles. Radiologist George Sgouros, M.D., speaking at that meeting, explained he and his team bound tumor-targeting antibodies to liposomes to create immunoliposomes. These immunoliposomes deliver their payload of alpha particle emitters directly to the targeted cells without harming adjacent normal cells, thereby avoiding the systemic toxicity that plagues chemotherapy. Preclinical work has shown the large doses of radionucleides have significantly extended the life of mice with a very aggressive form of metastatic breast cancer and must less toxicity.
Also at that meeting, biologist Yue-Wern Huang, Ph.D., at the Missouri University of Science and Technology discussed his work merging quantum dots with protein transduction domains (PTD). The combination penetrates the cellular membrane before releasing its payload of quantum dots, which can help diagnose tumors and monitor proteins, medicine, DNA or other molecules.
Quantum dots — fluorescent semiconductor nanocrystals in this case — maintain their fluorescence longer, have a longer half-life and are more resistant to degradation than traditional fluorescent dyes, making them more effective as a diagnostic tool. In early work, encapsulated cadmium is attached to PTDs and placed in cell culture where, in 60 minutes, they populate the cultures 10 times faster than systems without the PTDs, Dr. Huang reported.
Nanotechnology has a host of potential applications in biomedicine, allowing therapeutics and monitoring devices to be delivered at the cellular level. Currently, most of these projects are in preclinical stages, but their results are showing great potential. They’re worth keeping an eye on. I plan to.