Peg Hydrogel with Controlled Degradation Properties for Drug Delivery

Many drugs show promise in treating a range of diseases, but unfortunately cannot be targeted towards cells or tissues of interest. Drug delivery devices may be employed to improve the therapeutic efficacy of drugs by increasing their residence times within tissue systems or cellular microniches via sustained release. The objective of this project is to construct a novel hydrogel system that exhibits well-controlled degradation kinetics and delivers biologics over sustained timescales. We synthesize poly(ethylene glycol) (PEG)-based hydrogels using thiol-Michael addition reactions between multifunctional N-methyl-N-acryloylamide and thiol end-functionalized PEG monomers. By additionally incorporating acrylate end-functionalized PEG, we can tune hydrogel degradation (and thus encapsulate release rates) via ester hydrolysis. The synthesis of these monomers and subsequent hydrogel materials, as well as the rate of hydrogel degradation, are investigated using NMR and IR spectroscopy.  Rheological studies will later be employed to confirm the successful gelation of a three-dimensional cross-linked network and provide insight into the mechanical properties of the proposed hydrogel system. Future work on the release of bovine serum albumin (BSA), a model drug cargo, from these hydrogel matrices will be characterized via diffusion studies; this combined with diffusion modeling will enable well-controlled drug release over a range of clinically relevant timescales.