Microtechnologies and Nanotechnologies in Drug Delivery

My interest in developing drug delivery systems started during my postdoctoral career with the late Judah Folkman, as we attempted to isolate the first inhibitor of angiogenesis (blood vessel growth). To do so, it was critical to develop a bioassay for angiogenesis inhibitors, nearly all of which were macromolecules. We conceived of using a rabbit cornea assay where we could directly visualize blood vessel growth [1] through an ophthalmic microscope. It was critical to have a very small biocompatible controlled release polymer system that would not cause inflammation in the cornea, and that could also deliver macromolecules (e.g. peptides, proteins, and nucleic acids). However, everyone including Paul Florey, a Nobel prize winner in chemistry, told Dr. Folkman this couldn’t be done—large molecules couldn’t slowly leak out of a polymer. [2]