Microfluidic preparation of monodisperse PLGA-PEG/PLGA microspheres with controllable morphology for drug release.

Monodisperse biodegradable polymer microspheres show broad applications in drug delivery and other fields. In this study, we developed an effective method that combines microfluidics with interfacial instability to prepare monodispersed poly(lactic--glycolic acid)--polyethylene glycol (PLGA-PEG)/poly(lactic--glycolic acid) (PLGA) microspheres with tailored surface morphology. By adjusting the mass ratio of PLGA-PEG to PLGA, the concentration of stabilizers and the type of PLGA, we generated microspheres with various unique folded morphologies, such as "fishtail-like", "lace-like" and "sponge-like" porous structures. Additionally, we demonstrated that risperidone-loaded PLGA-PEG/PLGA microspheres with these folded morphologies significantly enhanced drug release, particularly in the initial stage, by exhibiting a logarithmic release profile. This feature could potentially address the issue of delayed release commonly observed in sustained-release formulations. This study presents a straightforward yet effective approach to construct precisely engineered microspheres offering enhanced control over drug release dynamics.