Facile Fabrication of Macroporous PLGA Microspheres via Double-Pickering Emulsion Templates

Porous poly(lactic-co-glycolic acid) (PLGA) microspheres with a well-defined pore structure are easily and effectively fabricated, from water-in-oil-in-water (W/O/W) double-Pickering emulsions formed by one-step emulsification. The water phase containing hydrophilic silica (SiO2) nanoparticles is emulsified with dichloromethane (CH2Cl2) solution of PLGA to directly obtain W/O/W double-Pickering emulsions. The influences of the PLGA concentration, composition and molecular weight, SiO2 nanoparticle concentration, and volume ratio of oil to water on the morphology structure of the double emulsions are systematically investigated. The porous PLGA microspheres are facilely produced by evaporating the CH2Cl2 and water in the double emulsions. The pore structure of the porous PLGA microspheres can be modulated simply by varying the PLGA concentration. Finally, potential mechanisms for the one-step fabrication of double-Pickering emulsions and porous PLGA microspheres are proposed. This work opens up a new and simple route to fabricate porous PLGA microspheres, which are suitable for biomedical applications.