Guided tissue regeneration with immobilized cytokine

点击翻译按钮获取中文摘要

Bone morphogenetic protein 2(BMP-2) plays an important role in bone growth and regeneration. The creation of purified recombinant human BMP-2 (rhBMP-2) has led to advances in its potential for clinical use, however this protein is soluble and disperses soon after implantation. So rhBMP-2 can't have long time stimulation to BMP signaling cascade. To overcome this problem we reported the effects of immobilization of rhBMP-2 to succinylated type I atelocollagenThe mechanism of immobilized rhBMP-2 is based on the theories of covalent bonding between rhBMP-2 and succinylated type I atelocollagen. The immobilized rhBMP-2 binds with the receptor on the cell surface without being internalized into the cell, so it is able to transduce signals into the cell over a long period of time, achieving high efficiency in promoting cell proliferation.We investigated the effect of immobilized rhBMP-2 by the way of (a) histological findings, (b) alkaline phosphatase (ALP) activity, (c) BMP intracellular signaling cascade (Smad1, Smad5 and phospho Smad1/5/8) expression, and (d) type I collagen, osteonectin, osteopontin, ostocalcin, and Smad1/5/8 mRNA expression.Our results showed that (1) nonimmobilized and immobilized rhBMP-2 also increased the alkaline phosphatase (ALP) activity in ST2, MC3T3 and C2C12 cells. However significantly higher ALP activity was observed by the immobilized rhBMP-2 treatment. (2) Phosphorylation of Smad1/5/8 after nonimmobilized rhBMP-2 stimulation increased from 15 min after stimulation and decrease to the control revel after 6hrs, however the phosphorylation was prolonged by immobilized rhBMP-2 and its effect was detectable even after 48hrs.So we conclude that because immobilized rhBMP-2 can emphasize and prolonged the effect of rhBMP-2, immobilizing rhBMP-2 is an efficient method to increase bone induction.