Molecular design and cellular studies with oral insulin delivery systems

New biomaterials and carriers for transmucosal protein delivery by molecular design have been the subject of a number of studies in recent years. Of particular interest to our laboratory has been the development of a new class of poly(ethylene glycol) (PEG)-containing grafted copolymers of acrylic acid (AA) or methacrylic acid (MAA), crosslinked with a wide range of agents and containing various enabling compounds such as glycosides. In our recent work, we have shown that protein delivery of from these hydrogels can be controlled by the three-dimensional network structure as well as the conditions of the surrounding environment as such systems exhibit a reversible hydrogen bonding complexation and decomplexation. Promising new studies indicate that this class of hydrogel carriers is mucoadhesive and can be used for protein delivery. We have reported various forms of adhesive hydrogels based on poly(acrylic acid) (PAA) or poly(methacrylic acid) (PMAA) which exhibit inhibition of the degradation of proteins (including insulin and calcitonin) by proteolytic enzymes.