Biomedical Nanotechnology – Diagnostics and Drug Therapy

What is Biomedical Nanotechnology?

The science of nanotechnology is a relatively new science, with extensive research maturing in this field over the last two decades, involving manipulating matter on an atomic and molecular scale on the order of tens to a few hundreds of nanometers (1x10^-8 to 1x10^-9). In biomedical terms, these new micro-materials provide a broad range of applications in medicine and biological research, especially in areas such as diagnostics and drug therapy. In addition, biomedical nanotechnology holds promising potential for further developments in cancer therapy, early disease detection, and treatment efficacy evaluation by targeting ligands/antibodies to allow for targeted molecular diagnostics. Thus, nanotechnology is emerging as a truly interdisciplinary research area in biomedical science, as it is poised to make revolutionary innovations. However, much of the research done on biomedical nanotechnology shows that its application may remain more of a vision than a reality; for, extensive questioning about long-term safety and risk-benefit analysis research yields inconclusive results.

Biomedical Nanotechnology in Diagnostics

Biomedical nanotechnology has already been applied in several fields of optical molecular imaging, diagnostics, and therapeutics in areas such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). As it currently stands, more research is being done in each of these three optical imaging technologies due to their limitations and shortfalls. While MRIs are widely-used, for example, they are also non-portable, costly, and they provide weak functional contrast. In addition, biomedical nanotechnology in diagnostic tools is limited in their techniques on humans because they are either too weak or potentially harmful. For example, ballistic optical imaging techniques cannot penetrate the skin more than one millimeter due to strong optical scattering, and conventionally employed fluorescent nanoparticles have harmful side effects such as photo-bleaching and toxicity. Therefore, more research in the field of diagnostic biomedical nanotechnology is necessary to advance noninvasive imaging techniques, for the synthesis and modification of novel nanoparticles, and for treatment efficacy evaluation in both an effective and quantitative manner.

Biomedical Nanotechnology in Drug Therapy

Research has shown that nano-sized colloidal particles have the potential to be engineered to provide opportunities for site-specific delivery of drugs after injection into the general circulatory or lymphatic systems in three orders of targeting: the first-order of targeting is where the drugs are delivered via nanoparticles to a particular organ; the second-order of targeting is where nanoparticles deliver the drug to a specific cell type; and the third-order of targeting is where nanoparticles deliver the drug and direct it to a specific structure within a cell (such as the nucleus, for example). While still in the research phase, several methods for achieving nano-technological delivery have been proposed. Chemical methods involve the use of inactive compounds to release an active compound by means of an enzymatic process. On the other hand, biological methods involve targeting the drug to an antibody and directing the conjugate towards an antigen residing on the target tissue. Both methods, however, have their shortfalls and more research is necessary. With chemical methods, at the present time, there is no clear discrimination between target tissue and nontarget tissue. And, with biological approaches, it is difficult to find tissues bearing specific antigens for targeting; consequently, the conjugate may be delivered to both target and nontarget tissues with toxic side effects to untargeted areas. Therefore, more research in the field of biomedical nanotechnology in drug therapy is necessary for both the success of drug delivery and for the safety of the patient.