Effects of bioactive glass on proliferation, differentiation and angiogenesis of human umbilical vein endothelial cells

Abstract

OBJECTIVE To investigate the effects of phytic acid derived bioactive P2O5-SiO2-CaO gel-glasses (PSC) on the proliferation, differentiation and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. METHODS HUVECs were cultured in PSC extracts, which were prepared with endothelial cell medium (ECM) at a gradient concentration of 0.01, 0.1, 1 and 2 g/L. Cells cultured in ECM were used as the control. The effect of PSC on HUVECs proliferation was assessed on the 1st, 3rd, 5th, 7th and 10th days with (4, 5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide assay (MTT), and the optimum PSC concentration for HUVECs proliferation was used in the following experiments. The subsequent experiments were divided into two groups. The experimental group used PSC extracts to culture HUVECs (PSC group) and the control group used ECM to culture HUVECs (ECM group). Gene expression of angiogenic factors, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), was detected on the 2nd, 4th and 7th days by real-time reverse transcription-polymerase chain reaction (real-time RT-PCR). The morphology and number of tubules formation were observed at the 4th and 10th hours. Image J software was used for counting and quantitative analysis. RESULTS The results of MTT assay showed that 0.1 g/L PSC group had the most significant effect on promoting HUVECs proliferation. The optical density values of 0.1 g/L PSC group on the 5th and 7th days were significantly higher than those of the other PSC groups and the control group (P < 0.05). The result of real-time RT-PCR showed that 0.1 g/L PSC extract up-regulated the mRNA expression of VEGF and bFGF significantly (P < 0.05). On the 4th day, the gene expressions of VEGF and bFGF in PSC group were 1.59 and 1.45 times higher than those in ECM group respectively, and on the 7th day, the gene levels of VEGF and bFGF in PSC group were 1.98 and 1.37 times higher than those in ECM group respectively. The tubule formation assay showed that the maturity and density of the tubules in 0.1 g/L PSC group was much better than that in the ECM group at the 10th hour. The quantitative analysis by Image J indicated that the tubules number in PSC group (29.63±2.29) was higher than in the ECM group (20.13±2.36), with statistical significance (P < 0.05). CONCLUSION PSC showed significant promoting effects on HUVECs' proliferation, differentiation and angiogenesis in vitro.