ABSTRACT
BACKGROUND:Our previous studies have shown that strontium-doped calcium polyphosphate containing low-dose strontium appears to have a significant effect on angiogenesis-related behaviors of monocultured umbilical vein endothelial cells and osteoblasts. OBJECTIVE:To investigate the effect of strontium-doped calcium polyphosphate on angiogenesis-related behaviors of umbilical vein endothelial cells and osteoblasts co-cultured, including celladhesion, spreading, proliferation, as wel as the protein secretion of vascular endothelial growth factor and basic fibroblast growth factor from co-culture system in vitro. METHODS:Human umbilical vein endothelial cells and osteoblastic cells (MG63) were utilized in this study. cells from passage 3 were used for preparation of the cel-scaffold constructs. After placed in 24-wel plate at a ratio of 2:1, human umbilical vein endothelial cells and MG63 cells were seeded onto strontium-doped calcium polyphosphate, calcium polyphosphate and hydroxyapatite scaffolds and co-cultured for 7 days. The vascular endothelial growth factor and basic fibroblast growth factor protein levels were determined through a double ligand enzyme-linked immunosorbent assay. The colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay was performed to quantify the effect of scaffolds on cellproliferation. RESULTS AND CONCLUSION:Compared with those on calcium polyphosphate and hydroxyapatite scaffolds, cells on strontium-doped calcium polyphosphate scaffolds attached and spread better with a significantly improved cellproliferation. More importantly, the vascular endothelial growth factor and basic fibroblast growth factor expressions were significantly higher in the strontium-doped calcium polyphosphate group than the other two groups (P<0.05), indicating strontium-doped calcium polyphosphate can up-regulate levels of vascular endothelial growth factor and basic fibroblast growth factor proteins.