Preparation of Crosslinked Poly(lactic acid-co-glycidyl methacrylate) Microspheres by Phase Inversion Emulsification

Abstract

Biodegradable/biocompatible microspheres have been prepared from poly(lactic acid-co-glycidyl methacrylate), P(LA-co-GMA), copolymers by a phase inversion emulsification (PIE) process. As the copolymer contains unsaturated functional groups, this can be crosslinked by employing thermo-curing reaction. Effects of co-surfactant concentrations and the aqueous phase addition rate on efficiency of the particle formation are evaluated. The addition of sodium dodecyl sulfate (SDS) co-surfactant at slow rates leads to narrow size distribution and higher stability of the microspheres, due to formation of effective structures of polyvinyl alcohol (PVA) surfactant and SDS at the oil/aqueous interface. The resulting microspheres are spherical shape with rough wrinkled surface morphology and bimodal particles size distribution at 1 and 10 mm. Curable behavior of the microspheres are also investigated. The semi-crystalline particles consist of network structure with high gel content of 50%, as the crosslinking efficiency is promoted by mixing the copolymers and the initiator homogeneously in droplets covered by the surfactant molecules. These microspheres with tunable properties can be applied in many fields, especially in cosmetic and biomedical applications.