Modulating drug release kinetics of PLGA microspheres by fabricating PLGA-alginate core-shell drug delivery devices with microfluidic method

Controlled drug delivery devices offer numerous advantages compared with conventional drugs. Among all the devices, PLGA microspheres are of particular interests for biocompatibility, biodegradability and easy administration. However, control of the drug release kinetics is still a major challenge due to the complex release mechanisms [1]. Recently, near zero order release were observed from PLGA microspheres / alginate beads composite devices [2]. However, such structure eliminated the easy administration property. In this study, PLGAalginate core-shell devices were developed by microfluidic method to modulate the drug release kinetics while keeping the microspheric geometry. PLGA-alginate core-shell devices were fabricated by O/W/O emulsion systems utilizing capillary microfluidic devices [3]. The resultants were characterized by SEM, microscopy, in vitro release test and MTT assay. The core-shell structure was confirmed by SEM and microscopy. The drug release kinetics of PLGA microspheres were significantly modulated by the shell layer. Initial burst was suppressed and a near zero order release was achieved when the shell layer was saturated with released drug. PLGA-alginate core-shell devices were biocompatible and may be promising tools for controlled drug delivery.