Insulin-like growth factor-1 (IGF-1) poly (lactic-co-glycolic acid) (PLGA) microparticles - development, characterisation, and in vitro assessment of bioactivity for cardiac applications.

Aim: The aim of this study was to evaluate the formulation of a synthetic IGF-1 (pIGF-1) in PLGA microparticles (MP). Methods: Poly (lactic-co-glycolic acid) (PLGA) MPs loaded with pIGF-1 were prepared, characterised and evaluated using double emulsion solvent evaporation method. Results: Spherical MPs showed an average particle size of 2 µm, encapsulation efficiency (EE) of 67% and 50% degradation over 15 days. With a view to enhancing retention in the myocardium, the MP formulation was encapsulated in a cross-linked hyaluronic acid hydrogel. pIGF-1 released from MPs and from MPs suspended in hyaluronic acid hydrogel remained bioactive, determined by a significant increase in cellular proliferation of c-kit+ cells. Conclusion: This formulation has potential for loco-regional delivery to damaged myocardium to promote the survival of cardiomyocytes.