PEG-PLGA Core-Shell Microgels With Enhanced Drug Encapsulation And Controlled Release

Poly(lactic-co-glycolic acid) (PLGA) microspheres have been widely used for minimally invasive, local, and sustained drug delivery. However, they are often plagued by limited controllability of encapsulation efficiency, initial burst, and drug release rate. This study presents a strategy of tuning the encapsulation efficiency and drug release rate of PLGA microspheres by inducing gelation of the hollow core of the microsphere with poly(ethylene glycol) (PEG) of varying cross-linking density. The resulting PEG-PLGA core-shell microspheres displayed increased encapsulation efficiency, decreased initial burst release, and a more sustained release of protein drugs by controlling the cross-linking density of the PEG gel core. In addition, in vivo implementation of PEG-PLGA core-shell microspheres encapsulated with vascular endothelial growth factor demonstrated a significant increase in angiogenesis, while minimizing inflammation