(680f) Nonfouling Polyampholyte Hydrogels As Drug Delivery Scaffolds

Common challenges in the biomedical field are the factors of biocompatibility as well as controllable release rates in drug delivery systems.  Nonfouling materials are ideal in dealing with the issue of biocompatibility, as this category of materials possesses the ability to resist nonspecific protein adsorption, which helps to reduce the body’s natural immune system response.  However, nonfouling materials also allow for the incorporation of functional end groups, allowing for a range of uses.  Experiments were conducted on a mixed-charged polyampholyte hydrogel made of equimolar amounts of [2-(acryloyloxy)ethyl] trimethylammonium chloride (TMA, positively charged) and 2-carboxyethyl acrylate (CAA, negatively charged) monomers.  The hydrogels were pre-loaded with three different model drugs, and the rate of release was explored under different settings, including varied cross-linker concentrations, different pHs, and different salt concentrations.  Our data suggested that through manipulation of the solution’s pH and salt concentration, as well as the hydrogel’s cross-linker concentration, the rate of release of the molecules could be controlled and deviated from their corresponding controls.  Additionally, enzyme-linked immunosorbent assay data suggested that the TMA:CAA hydrogels exhibited nonfouling characteristics, which were not affected by the charge of the molecules infused into the hydrogels. Therefore polyampholyte polymers represent a promising approach for drug delivery applications.