Bionanotechnology in Drug Delivery

Nanotechnology is an emerging field that could potentially make a major impact to human health. Nanomaterials promise to revolutionize medicine and are increasingly used in drug delivery or tissue engineering applications.National Science Foundation and the National Nanotechnology Initiative define nanotechnology as understanding and control of matter at dimensions of 1–100 nm where unique phenomena enable novel applications.Nanomaterials and devices provide unique opportunities to advance medicine. The application of nanotechnology to medicine is referred to as “nanomedicine” or “nanobiomedicine” and could impact diagnosis, monitoring, and treatment of diseases as well as control and understanding of biological systems.

Nanobiotechnology in Drug delivery

              Controlled drug-delivery strategies have made a dramatic impact in medicine. Nanoscale materials can be used as drug delivery vehicles to develop highly selective and effective therapeutic and diagnostic modalities. There are a number of advantages with nanoparticles in comparison to microparticles. For example, nanoscale particles can travel through the blood stream without sedimentation or blockage of the microvasculature. Small nanoparticles can circulate in the body and penetrate tissues such as tumors. In addition, nanoparticles can be taken up by the cells through natural means such as endocytosis. Nanoparticles have already been used to deliver drugs to target sites for cancer therapeutics or deliver imaging agents for cancer diagnostics.

              In order to control the targeted drug delivery of intravenously delivered nanoparticles, nanoparticle interactions with other cells, such as macrophages must be controlled. Various approaches have been developed to control these interactions, ranging from changing the size of the particle to changing nanoparticle surface properties. To remove nonspecific protein adhesion and decrease uptake by macrophages, nanoparticles can be functionalized using protein replant materials, such as poly(ethylene glycol) (PEG) and polysaccharides. To target nanoparticles to the desired tissues, a number of methods have been developed. Aptamers, a class of DNA- or RNA-based ligands, may overcome some of the limitations associated with antibody- and peptide-based drug delivery. Aptamers have been conjugated to nanoparticles to generate nanoparticles that can target prostate cancer cells.

            Current research in targeting the delivery of nanoparticles involves validating the in vivo efficacy of the various targeting approaches and developing  methods of enhancing the targeting of the particles without side effects. Future generations of nanoparticles promise to not only deliver drugs to the desired sites within the body, but to do so in a temporally regulated manner. For example, nanoparticles have recently been generated that can be used to sequentially deliver drugs to cancer cells so that each drug is delivered at the proper time to induce cell death as well as to prevent angiogenesis. It is envisioned that the development of “smart” nanoparticles could be a powerful means of further enhancing the functionality of these nanoparticles.