Effects of biomimetic hydroxyapatite coatings on osteoimmunomodulation

Macrophages play a very fundamental role in bone regeneration. Changing the physicochemical properties of biomaterials to regulate the genes and protein expressions of Macrophages in vivo is of great significance to promote osteogenesis and angiogenesis in bone tissue engineering. Herein, we investigated the interaction of biomimetic hydroxyapatite coatings with macrophages and the subsequent impact on osteogenesis and angiogenesis. In this study, we found that biomimetic hydroxyapatite coating could inhibit the expression of inflammatory factors (tumor necrosis factor-α, TNF-α) while promoting bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF), thereby promoting angiogenesis of vascular endothelial cells and osteogenic differentiation of mesenchymal stem cells. This study demonstrated that biomimetic hydroxyapatite coating modified polycaprolactone (PCL) possessed an excellent osteoimmunomodulatory property and was a promising coating material for the application.