Background: Osteoblasts are distinguished by the characteristic morphology and by the deposition of the mineralised matrix. Another characteristic is the synthesis of type I collagen and other specialized bone proteins. Since collagen has biocompatibility with bone, collagen is a poor bone graft material when used alone. Therefore, much attention has been directed to find the biomaterial that induces osteogenic progenitor cells. However, best material still remains to be developed. It is essential to clarify the molecular mechanism of osteogenesis and understand how it induces. We succeeded in developing low adhesive scaffold type I collagen (LASCol) by enzyme treatment (patent pending). In this study, we report that LASCol markedly facilitates osteogenic differentiation of rat marrow mesenchymal stem cells (rMSCs). Furthermore, we investigated the effects of bone wound healing by implanting LASCol in a defect of rat shinbone.
Methods: We obtained LASCol by the enzyme treatment of pig type I collagen. Culture dish was coated with LASCol or pepsin-treated collagen (AteloCol). MC3T3-E1 cells or rMSCs were cultured with osteogenic basal medium on each coated-dish. We observed cell morphology by using a phase-contrast microscope. We analysed the activity of mineralisation by Alizarin red S reagent to evaluate the osteogenic differentiation. Moreover, we transplanted each collagen graft into 2.5 mm critical-sized defects (CSDs) of SD rat shinbones. After 15 days, bone repair efficiency of CSDs was evaluated by HE stain and micro-CT observation.
Results: MC3T3-E1 cells formed the spheroid morphology by only culturing on the LASCol-coated dish. By adhesion to LASCol, the activity of mineralization of MC3T3-E1 and rMSCs were significantly promoted. We demonstrated that LASCol graft induces bone regeneration of rat shinbones and is more bioabsorbable material than AteloCol.
Disclosure: The authors declared no competing interests. This work was supported by Adaptable and Seamless Technology Transfer Program through target-driven R&D, Japan Science and Technology Agency (AS2414037P to K.M.).