Amphiphilic networks: II. Biocompatibility and controlled drug release of poly[isobutylene‐co‐2‐(dimethylamino)ethyl methacrylate]

Abstract

Biocompatibility and diffusional characteristics of recently synthesized unique amphiphilic newtworks, i.e., copolymers of methaycryloyl‐capped polysiobutylene (MA‐PIB‐MA) with 2‐(dimethylamino)‐ethyl methacrylate (DMAEMA) have been examined. Excellent biocompatibility and biostability were obtained after 7 weeks with films containing 53–58% MA‐PIB‐MA implanted dorsally or abdominally in rats. In contras, neworks with higher or lower MA‐PIB‐MA contents showed decreased biocompatibility. These amphiphilic networks were also studied as potential implantable drug release systems. Bromophenol blue and folic acid were used as model compounds for drug release. Diffusion of these chemicals from loaded networks into water showed a marked pH dependence. Under specific well‐defined conditions (MA‐PIB‐MA/DMAEMA content, pH, time range) release was observed to be independent of time (zero‐order release).