Molecular Mechanisms During Constructing The Tissue Engineered Bone And Periosteum

Objective to research the molecular mechanisms of interaction between human osteoblasts and bio-derived materials, detect the important genes' expressions of osteoblasts, and predict the safety and effect of tissue engineered bone and periosteum as bone graft substitutes. Methods Using fetal osteoblasts to contract tissue engineered bone and periosteum with the bio-derived materials, and culture 2, 4, 6, 8, 10 days in vitro. Real-time PCR analysis indicated the expressions of Cbfa-1, osterix, collagen I, osteocalcin and integrinα5β1 mRNA which were presented in osteoblasts with bio-derived materials. The osteoblasts which grew in culture dishes were used as control.Results ①The expression of Cbfal in bio-derived bone group was higher than it in Group bio-derived film and control, especially at the late-stage of culture (P<0.05). In bio-derived bone, osteoblasts expressed higher Cbfal at the 2nd day and 8th day when compared to the other times (P<0.05). On bio-derived films, Cbfal decreased during the middle of culture, and was higher at the 2nd day and 10th day. ②The change of osterix was consistent with. Cbfal in Group bio-derived bone and control, while increased with time in Group bio-derived film.. In bio-derived bone, the expression of osterix was higher during the early-stage and late-stage culture than other times (P<0.05). ③ Both in the two experimental group, collagen I showed "up-down"regulation, while kept steadily in control. ④During the 2nd day to 6th day, osteoclacin showed down-regulated first and return to normal then in all three groups. But at the late-stage of culture, the expression of osteocalcin increases on bio-derived film, kept normal in bio-derived bone and decreased in control. ⑤Integrinα5β1 didn't express at the early-stage but did in control. Conclusions ①The impotant genes could been expressed normally by osteoblasts after integrating with bio-derived scaffolds. ②Cbfal was higherly expressed and consistent with osterix in bio-derived bone, which indicated the bio-derived bone, as skeleton tissue engineering scaffolds, was benefit to keep the osteoblast's phenotype and differentiation with osteoinductive ability. ③ The osteoblast could enter proliferation stage favorably and the scaffold materials had no effects on it. Bio-derived bone also supply more space for cells to proliferate.④The bio-derived materials promote osteoblasts adhension but fibronectin was not essential to adhension for osteoblasts.