Controlled delivery of stromal derived factor-1α from poly lactic-co-glycolic acid core-shell particles to recruit mesenchymal stem cells for cardiac regeneration.

Stromal derived factor-1α (SDF-1α) has shown promising results in treatment of myocardial infarction (MI), via recruitment of endogenous stem cells into the injured myocardium. However, the bioactivity of this susceptible signalling chemokine is reduced significantly during the common fabrication processes of drug delivery systems, due to the exposure to organic-aqueous interfaces or elevated temperature. In this study, we developed a novel SDF-1α delivery system using coaxial electrospraying, the technique which enables fabrication of core-shell particles with minimized contact of organic-aqueous phases. The SDF-1α incorporated PLGA particles exhibited distinct core-shell structure, confirmed by transmission electron microscopy (TEM). Controlled release of SDF-1α was obtained for at least 40days, and the release rate was tailored by co-encapsulation of bovine serum albumin (BSA) into the core of the particles. The SDF-1α released from PLGA/SDF-1α and PLGA/BSA-SDF-1α particles retained its chemotactic activity, and enhanced the number of migrated mesenchymal stem cells (MSCs) by 38% and 54%, respectively, compared to basal medium used as the control. Moreover, both SDF-1α and BSA supported the proliferation of MSCs within 3days of cell culture. The SDF-1α incorporated core-shell particles developed by electrospraying technique, can be effectively employed as injectable drug delivery system for in situ cardiac regeneration.