Regeneration of mandibular bone by the implantation of cell fixed artificial periostium

到目前为止，已经尝试过注射生长因子和植入细胞来再生骨，但这些治疗形成的骨量很少。本研究试图研制一种由细胞、生长因子和载体组成的新型人工骨膜，并探索老年人骨再生的最佳条件。首先，我寻找了人造骨膜应该具备的因素。我采集了骨髓细胞，将其固定在人造骨膜中。它们具有向成骨细胞分化的能力，这种分化是通过地塞米松处理细胞来诱导的，但地塞米松是一种激素，很难用于临床治疗。有报道称I型胶原具有诱导骨髓细胞向成骨细胞分化的能力，我研究了I型胶原是否诱导了这种分化。骨钙素和骨涎蛋白基因是成骨细胞特有的基因，我发现在I型胶原凝胶中培养的骨髓细胞显示出这两个基因的高表达。接下来，我将人工骨膜植入大鼠体内，发现它在体内形成了骨。这些结果表明，我们构建的人工骨膜具有成骨的能力，可以认为人工骨膜是一种有效的下颌骨再生工具。

So far, the injection of growth factor, and implantation of cells have been attempted to regenerate bone ; however, the bone mass formed by these treatments is little. In this study, I tried to develop new artificial periostium constituted by cells, growth factors and carrier, and investigated the optimal condition for the regeneration of bone in aged peoples. First of all, I looked for the factors that the artificial periostium should have. I harvested bone marrow cells to fix into artificial periostium. They possess the ability to differentiate into osteoblasts, and this differentiation is induced by the treatment of cells by dexamethasone, but dexamethasone is a kind of hormone, and is hard to use the clinical treatment. It has been reported that type I collagen has an ability to induce the osteobrastic differentiation of bone marrow cells, and I studied whether type I collagen induced this kind of differentiation. Osteocalcin and bone sialoprotein gene are osteoblast-specific one, and I found that bone marrow cells cultured in type I collagen gel showed high expression of these genes. Next I implanted the artificial periostium in rats, and found it formed bone in vivo. These results indicate that the artificial periostum we constructed has an ability to form bone, and I clould conclude that the artificial periostum is a potent tool to regenerate the mandibular bone.