Effect of strontium-doped calcium polyphosphate on endothelial cells-derived angiogenic factor matrix metalloproteinase-2 expression / 中国组织工程研究

ABSTRACT

BACKGROUND: Strontium-doped calcium polyphosphate (SCPP), as a new repairing material, has been demonstrated to have favorable biocompatibility and biodegradability and some effects on promoting self-angiogenesis. However, the mechanism remains still unknown. OBJECTIVE: Endothelial cells were cultured with SCPP scaffolds in vitro, as well as the cell proliferation and angiogenic factor matrix metalloproteinase-2 (MMP-2) secretion were observed. DESIGN,TIME AND SETTING: A contrast study was performed at the Laboratory of Tissue Engineering of Sichuan University from September 2008 to April 2009. MATERIALS A series of calcium polyphosphate (CPP) respectively containing 1 %, 2%, 5%, 8%, and 10% Sr~(2+) were prepared.METHODS: ① Materials were plated on 24-well culture plate,and endothelial cell suspension (300 μL) were seeded on 24-well culture plate at the concentration of 3×10~7/L and cultured with 200 uL RPMI1640 culture media. Endothelial cell proliferation was observed using MTT method at days 1,3,5, and 7 after culture. ② CPP and 8% SCPP were plated on 24-well culture plate, and endothelial cell suspension (300 uL) was then incubated in 24-well culture plate at the concentration of 1x10~8/L and cultured with 600 uL RPMI1640 culture media. The morphology of endothelial cells was observed by scanning electron microscopy (SEM) at day 5 after culture.③ Endothelial cells were co-cultured with SCPP of various Sr~(2+) contents for 5 days. After confluence, cells were centrifuged to obtain supernatant. Angiogenic factor MMP-2 secretion was evaluated by ELISA assay.MAIN OUTCOME MEASURES: The proliferation and morphology of endothelial cells on SCPP and CPP were observed. The amount of endothelial cells-derived MMP-2 protein secretion was detected. RESULTS: MTT method demonstrated that the proliferation of endothelial cells on the 8% SCPP scaffold showed a higher level compared to CPP, and other SCPP groups. Scanning electron microscope results suggested that endothelial cells on 8% SCPP had a better growth status and biological activity. ELISA results indicated that angiogenic factor MMP-2 expression on the SCPP was promoted compared with that of CPP, and 8% SCPP showed the highest expression (P < 0.05). CONCLUSION: SCPP has good compatibility with endothelial cells,promoting angiogenesis and enhancing the angiogenic factor MMP-2 expression.