Drug delivery is a very unique area in Biomedical engineering. The iterative process of testing, optimization and retesting is a fundamentally engineering approach. However, this approach is being applied to biological or biologically derived materials. This allows the knowledge gained from decades of research to be used for developing therapeutics for various diseases including cancer.

Here I have presented a few methods that are currently being explored for targeted drug delivery. However, there are many other different methods being developed as well. For instance, Dr. Erikki Ruoslahti at the Burham Institute of Medical Research is developing methods to specifically target the vasculature of tumor tissues. The Rouslahti group uses peptide screening method to identify short peptide chains that has specific affinity for tumor correlated vasculature. The goal is to destroy the vasculature and starve the tumor. Novel carriers are also being developed. The dendrimer system from Dr. Baker’s group in Univ. of Michigan is an example. The dendrimers are “grown” layer by layer allowing their size to be controller. The many branches also allow them to be conjugated to a variety of molecules simultaneously.

There is still a lot of room for further development in the area as well. For instance, new materials and mechanisms are being discovered and will contribute to the creation of new delivery schemes. For example as our understanding of cancer biology improves, more efficient and specific targeting techniques can be devised. On particular technology that has yet to be full explored is the use of aptamers. Aptamers are short strand DNA/RNA that is chosen for their folded shape. Since the variability allows almost any conformation, it is possible these can replace monoclonal antibodies. Archemix, based in Cambridge, Mass. And NascaCell in Munich are companies that hope to capitalize on this technology.