Artificial periodontal ligament with honey-comb structure using tissue engineering

本项目的目的是利用组织工程技术在种植体周围和牙周组织缺损处构建人工牙周膜。要形成具有功能的牙周膜，可能需要提供以下条件：首先，种植体或残牙周围的有机干细胞增殖，并通过这些细胞合成胶原。其次，这些增殖细胞必须根据周围环境分化为牙周韧带成纤维细胞、牙骨质母细胞或成骨细胞，最后这些细胞合成胶原纤维、牙骨质或骨。首先，我们考察了成骨细胞在蛋白质固定化表面的行为。经血浆表面修饰后，纤维连接蛋白、成纤维细胞生长因子和骨形态发生蛋白-2被固定。大鼠骨髓细胞在纤维连接蛋白和成纤维细胞生长因子固定化表面获得的成骨细胞数量较对照表面增多。碱…骨形态发生蛋白2固定化的细胞表面有更多的NE磷酸酶活性和骨钙素mRNA的表达。这些结果表明，经O2等离子体处理后，蛋白质可以固定到基质中，生物材料周围的成骨细胞可以通过将蛋白质固定到种植体上来控制。然后，我们分析了表面修饰为帕米磷酸酯(PAM)、含氮双膦酸盐(N-BP)、纯钛种植体和钙离子固定钛种植体周围体内新骨形成的数量。静脉注射荧光标记技术观察新骨形成情况。1周后，PAM固定的种植体周围形成的新骨多于钙固定的纯钛种植体周围的新骨。3周后可见新生骨形成。4周后，BP固定种植体周围的新骨形成明显多于钙离子种植体和纯钛种植体周围。新型N-BP修饰的钛表面可刺激种植体周围的新骨形成，这可能有助于种植体治疗的成功。此外，氧等离子体处理将SVA固定在牙种植体表面，促进了骨组织/种植体界面的成骨，提示氧等离子体修饰能够固定钛种植体表面合适的蛋白质，促进牙周韧带样组织的增殖。较少

The purpose of this project was to create the artificial periodontal ligament around the dental implant and periodontal defect using tissue engineering. To create the functional periodontal ligament might be necessary to provide following conditions : first, proliferation of organic stem cells around the dental implant or residual tooth and synthesize the collagen by these cells. Second, these proliferating cells have to differentiate into periodontal ligament fibroblast, cementblast or osteoblast depending on the surrounding situation, and finally these cells synthesis collagen fiber, cementum, or bone. First of all, we examined the osteogenic cell behavior on protein immobilized surface. Following plasma surface modification, fibronectin, fibroblast growth factor (FGF), and bone morphogenetic protein-2 (BMP) were immobilized. The number of osteogenic cells obtained from rat bone marrow adhering to fibronectin and FGF immobilized surface increased compared with control surface. Alkali … More ne phosphatase activity and osteocalcin mRNA expression of these cells on the BMP2 immobilized surface was greater than that of control groups. From these results, it is suggested that protein can be immobilized to a substratum after treatment with O2 plasma and that the osteogenic cells surrounding a biomaterial can be controlled by the immobilization of protein to the implant.Then we analyzed the quantity of new bone formed in vivo around calcium-immobilized titanium implants with surfaces modified using pamidronate (PAM), a nitrogen-containing bisphosphonate (N-BP), implants of pure titanium, and titanium implants immobilized with calcium ions. New bone formation was visualized using fluorescent labeling with intravenous injection. After 1 week, more new bone formed around the PAM-immobilized implant than around the calcium-immobilized and pure titanium implants. The was also seen with the new bone formation after 3 weeks. After 4 weeks, significantly more new bones were formed around the BP-immobilized implant than around the calcium ion-implanted and pure titanium implants. The new N-BP-modified titanium surface stimulates new bone formation around the implant, which might contribute to the success of implant therapy. Furthermore, immobilization of SVA onto dental implants using O2 plasma treatment resulted to promote osteogenesis at thae bone tissue/implant interface.These findings suggested that oxygen plasma modificantion was able to immobilize the proper proteins on the titanium implant, and contribute to proliferate the periodontal ligament like tissue. Less