The investigators propose to develop nanoparticulate biodegradable polymeric oral delivery systems for therapeutic agents representative of hydrophobic small molecules, proteins, and genes, and will study their uptake, as further described by their abstract: """"""""Our project focuses on the development of nanoparticle-based, oral delivery systems, composed of biodegradable polymers, used to efficiently encapsulate and increase the bioavailability and uptake of three representative therapeutic agents from the most active fields of current research: small hydrophobic molecules (taxol), proteins (insulin) and genes. """"""""Although much research has been performed with the first two systems, still there is a challenge to improve the oral bioavailability of these drugs. No product is commercially available on the market, particularly for the oral delivery of peptides and proteins. The last system is the most challenging one, since very little work has been done on oral delivery of genes. """"""""Our hypothesis is that if we succeed in enhancing uptake of drug-loaded nanoparticles, then we may be able to enhance the bioavailability of each of the potential drug candidates. For taxol and insulin, we will target an increase in systemic bioavailability, while for plasmids the nature of he enhancement may be either local or systemic.""""""""