Macromolecular release using thermoresponsive hydrogels

CHED 715

Julia C. Thomas, jthomas@wellesley.edu and Nolan T. Flynn, nflynn@wellesley.edu. Department of Chemistry, Wellesley College, 21 Wellesley College Rd, Unit 7139, Wellesley, MA 02481-0271
Poly(N-isopropylacrylamide) (p(NIPAm)) is a water-loving polymer. P(NIPAm) hydrogels are thermoresponsive materials that decrease in mass (water content) upon heating. This property makes p(NIPAm) hydrogels potential drug delivery vehicles. Anionic hydrogels are created by copolymerizing NIPAm with acrylic acid (AAc), which is negatively charged at neutral pH. When gold nanostructures are synthesized within the p(NIPAm-co-AAc) matrices, the phase transition temperatures are altered. These hydrogels are then loaded with one of a variety of macromolecules with different molecule weights and charges. Spectroscopic methods are used to monitor the diffusion of the macromolecule from the hydrogel matrices. System parameters, such as size and charge state of the macromolecule, release temperature, and identity and concentration of hydrogel cross-linking agent, were investigated.