Abstract:

Objective To control the stepwise release of vascular endothelial growth factor A(VEGF-A) within the microcapsules, and to analyze the effects of the microcapsules on cellular angiogenic capability. Methods VEGF-A encapsulated poly(lactic-co-glycolic acid)(PLGA) microcapsules were prepared using a method combining dual-channel coaxial injection and continuous flow technology. The release and degradation performance of the microcapsules were characterized using a phosphate-buffered saline (PBS) soaking method. The biocompatibility of the microcapsules was assessed through the CCK-8 method and Calcein-AM/PI staining method. The impact of microcapsule extract on cellular angiogenesis ability was examined by conducting cell scratch assays and tubule formation experiments. Results The microcapsules were round in shape, with their particle diameter measuring in the range of hundreds of micrometers. Microcapsules with a molecular weight(Mw)-12 ku can release a large amount of VEGF-A in the initial phase, while Mw-30 ku ones had the capacity to provide a stable, long-term, low-dose release of VEGF-A. Microcapsules of Mw-12 ku exhibited outstanding potential for enhancing the healing of cell scratch wounds in the initial phase. Moreover, within the 0-12 day period, the two types of microcapsule extracts significantly enhanced the ability of cells to form tubules in vitro. Conclusion This study successfully regulated the release profile of VEGF-A by adjusting the molecular weight of PLGA, achieving an initial rapid and substantial release of VEGF-A followed by a sustained slow release over time, while maintaining its biological activity throughout the process.

Key words: poly(lactic-co-glycolic acid) microcapsules, vascular endothelial growth factor A, controlled release, angiogenesis