Modulating the release of vascular endothelial growth factor by negative-voltage emulsion electrospinning for improved vascular regeneration

•Making VEGF-containing PLGA scaffolds via negative-voltage emulsion electrospinning.•Encapsulating VEGF in the core of core-shell structured biodegradable nanofibers.•Realizing steady and sustained release of VEGF from nanofibrous scaffolds.•Enhancing endothelial cell functions using VEGF-containing scaffolds.

Electrospun nanofibrous scaffolds providing local delivery of vascular endothelial growth factor (VEGF) have distinctive advantages for vascular tissue engineering. However, more than 90% of VEGF were normally released from scaffolds formed by conventional positive-voltage emulsion electrospinning (PVEES) within the initial 3 days. VEGF molecules bear positive charge. In this investigation, emulsion electrospinning using power supplies of different polarities was studied for producing scaffolds bearing specific electric charge. VEGF-containing poly(lactic-co-glycolic acid) scaffolds with initial potential of −87 and −202 V were formed by negative-voltage emulsion electrospinning (NVEES) at −10 and −20 kV, respectively, which enabled steady and sustained release up to 18 days, exhibiting effective modulation for VEGF release. Compared to VEGF-containing scaffolds formed by PVEES, NVEES-formed scaffolds showed superior performance in promoting endothelial cell functions.