Human placenta-derived endothelial progenitor cells: an animal-free culture system for efficient expansion.

BACKGROUND: Endothelial progenitor cells (EPCs) play a critical role in vasculogenesis and vascular repair, but their clinical application is hindered by challenges such as cell purity, quantity, and reliance on fetal bovine serum (FBS). This study developed an animal-free system for isolating, induction, and expanding EPCs from the human placenta, evaluating their potential for wound repair. METHODS: Mononuclear cells (MNCs) were isolated from full-term placenta and induced into EPCs using an animal-free medium supplemented with bFGF, IGF, and VEGF. EPCs were characterized by flow cytometry for markers CD133, CD34, and VEGFR2, while CD31 and CD45 served as negative markers. Functional assays, including Ac-LDL uptake, migration, and tube formation, confirmed EPC properties. The wound-repair potential was assessed in a mouse model. RESULTS: The induced EPCs exhibited high purity (> 95%) and expressed CD133, CD34, and VEGFR2 while being negative for CD31 and CD45. The system yielded 1 × 10⁸ EPCs from 10 g of placental tissue, demonstrating high proliferative capacity. Functional assays confirmed robust tube formation, migration, and Ac-LDL uptake in vitro. In vivo, EPCs significantly enhanced wound repair. CONCLUSIONS: In conclusion, human placenta-derived EPCs cultured in an animal-free system displayed high purity, self-renewal capacity, and functional efficacy, making them a promising cell source for therapeutic applications, particularly in wound repair.