Biodegradable Polymer Microparticles with Tunable Shapes and Surface Textures for Enhancement of Dendritic Cell Maturation.

In this report, we present a facile approach to produce biodegradable polymeric microparticles with uniform sizes and controllable morphologies by blending hydrophobic poly(d, l-lactic--glycolide) (PLGA) and amphiphilic poly(d, l-lactic acid)--poly(ethylene glycol) (PLA--PEG) in a microfluidic chip. Microparticles with tentacular, hollow hemispherical, and Janus structures were obtained after complete evaporation of the organic solvent by manipulating the interfacial behavior of emulsion droplets and the phase separation behavior inside the droplets. The number and length of the tentacles on the surface of tentacular microparticles could be tailored by varying the initial concentration and blending ratios of the polymers. The organic solvent played an important role in controlling the morphologies of microparticles. For example, blending PLA--PEG with PLGA in dichloromethane resulted in tentacular microparticles, whereas hollow hemispherical microparticles were obtained in trichloromethane. Moreover, these microparticles with controllable shapes and surface textures have significant influence on the immune response of dendritic cells (DCs), showing a morphology-dependent enhancement of DC maturation.