Nanostructured Hydrogels for the Study of Cell Adhesion Response

Our group is generally focused on the development of a new class of nanostructured hydrogels spanning a range of application areas, from next generation membrane technologies to cell and tissue growth scaffolds. The research presented here concerns the fabrication of biocompatible cell adhesion surfaces, in a greater effort to study the impact of lipoprotein concentration (number of local cell binding sites), mechanical stress, and flow stress on the behavior of adhered cells. These novel substrate-systems are expected to have broad implications in the study of diseases such as atherosclerosis, in which cell response to externally applied force fields are thought to play a critical role.

The hydrogel fabrication strategy is based on the self assembly of block copolymers comprised of polystyrene (PS) and poly(N-isopropylacrylamide) (PNIPAM). The initial aim of the project has been on the use of reversible addition fragmentation chain transfer (RAFT) polymerization technique to synthesize the constituent block copolymers. The focus has been on the kinetics of the PNIPAM polymerization reaction, by varying time, temperature and AIBN (free radical initiator source) concentration. The resultant polymers were characterized by gel permeation chromatography (GPC) and 1H nuclear magnetic resonance (NMR) to estimate correlation plots of conversion, molecular weight, and polydispersity index (PDI) as a function of reaction time, temperature, and AIBN concentration.