A Calcium Silicate-derived Silicate Ion Solution Improves Fat Graft Retention and Promotes Angiogenesis: An Experimental Study.

Abstract

Autologous fat grafting is hampered by poor early vascularization, leading to necrosis and unpredictable retention. Current pro-angiogenic strategies face challenges like complexity and high cost. Calcium silicate (CS) has shown promise in promoting vascular regeneration. This study aimed to determine the optimal silicate ion solution concentration for enhancing human umbilical vein endothelial cell (HUVEC) function in vitro and to verify its efficacy and mechanism in improving fat graft survival in a nude mouse model. The effects of silicate ion solution on HUVEC viability, proliferation, migration, tube formation, and VEGF expression were assessed in vitro. A fat grafting model in nude mice was used to evaluate graft retention, tissue morphology, vascular density (CD31), apoptosis, and the expression of HIF-1α and VEGF. The silicate ion solution derived from CS, at biocompatible concentrations, significantly promoted HUVEC migration, tube formation, and VEGF expression. In vivo, the CS group achieved a significantly higher graft retention rate (58.18% ± 4.24%) compared to the Control group (41.30% ± 6.09%). Histological analysis revealed improved graft integrity, reduced fibrosis, enhanced angiogenesis, and decreased apoptosis. The incorporation of CS-derived silicate ion solution into fat grafts effectively enhances early angiogenesis and improves long-term volume retention, primarily by activating VEGF-related pathways. This straightforward and innovative strategy offers a promising solution to the challenge of graft vascularization.