Sol-gel derived nanosized Sr5(PO4)2SiO4 powder with enhanced in vitro osteogenesis and angiogenesis for bone regeneration applications

Bioactive glass ceramics are widely used for hard tissue repair and bone regeneration due to their most attractive properties such as biocompatibility, bioactivity and non toxicity. In this study, for the first time, sol-gel method was used to synthesize nanosized strontium phosphosilicate (SPS: Sr 5 (PO 4 ) 2 SiO 4 ) with rod shaped morphology by using CTAB as a surfactant . The obtained SPS powder was characterized by FTIR, XRD , Raman, SEM-EDS and TEM analysis. In vitro bioactivity study confirms that SPS possesses bone bonding ability by formation of amorphous apatite layer on its surface. In vitro osteogenesis and angiogenesis studies were performed on SPS powder to determine its biological responses using mBMSCs and HUVECs, respectively. The co-culture of BMSCs with different concentrations of SPS powder (50, 100, 150, 200 and 250 µg/ml) reveals that there's no any cytotoxicity effect on mBMSCs and observed good cell proliferation , alkaline phosphatase activity, calcium nodules formation, osteogenesis-related gene expressions ( alp , runx2 , col1a2 and ocn ). In addition, the angiogenesis study demonstrated that SPS powder can stimulate the cellular response of HUVECs and its gene expressions ( vegfr2 and hif1α-3 ). Therefore, these results confirm that nanosized SPS could act as promising bioceramic material for bone tissue engineering applications.