The development of functional collagen material which has a property of controlled growth factor release, and its application for tissue regeneration therapy.

近十年来，随着分子生物学和发育生物学的发展，人们认识到了大量新的基因和蛋白质及其功能，人们对利用这些知识进行再生医学临床应用的期望也越来越高。在众多的生物组织中，骨和牙齿是一种可再生的组织，其成骨机制已被研究和了解。然而，目前我们几乎没有具体的策略来为临床应用创造新骨。本研究以胶原蛋白和羟基磷灰石为原料，制备具有“生长因子控释”特性的新型功能材料，并证实不同温度下合成的羟基磷灰石具有不同的生物可吸收性和蛋白质吸附性，为临床应用创造新的成骨方法。当我们制备了吸附蛋白质的羟基磷灰石颗粒，并研究了在几种生物条件下蛋白质从这种磷灰石中的释放时，蛋白质的释放可以通过磷灰石溶解来控制。当我们将磷灰石颗粒结合到胶原凝胶中并研究这种胶原/磷灰石复合材料的生物降解性时，这种材料的降解取决于磷灰石的含量。此外，证实了磷灰石在其降解期间从复合材料中释放。这些结果表明，该复合材料具有蛋白质的控制释放的性质。

We could realize a large numbers of new genes and proteins with their functions by the advance of the molecular biology and the developmental biology during the last decade, and the people's expectation is growing towards the clinical application of the regenerative medicine by using such obtained knowledge. Bone and tooth, especially among the numerous living tissues, is expected as a regenerativable tissue in near future, because the mechanism of bone formation has well studied and understood. However, we have had few concrete strategies to create new bone for the clinical application at this point. In this study, in order to create a new methodology of generating new bone for clinical application, we tried to make a new functional material with specific property "controlled release of growth factors" by using collagen and hydroxyapatite.It was confirmed that hydroxyapatite synthesized at different temperature showed different bioabsorbability, and protein adsorption. When we prepared hydroxyapatite particles adsorbed protein and investigated the protein release from this apatite in several biologic conditions, the protein release could be controlled by apatite dissolution. When we combined apatite particles in collagen gel and investigated the biodegradation of this collagen/apatite composite material, the degradation of this material is depended on the containing amount of apatite. Moreover, it was confirmed that the apatite was released from the composite material during its degradation period. These results suggest that this composite material has a property of controlled release of protein.