Research and Development for Fabrication of 3D-structured Tissue-engineered Cartilage through Nino-molecular Technologies

软骨是由运动组织和支持组织组成的主要组成部分。由于软骨组织受到创伤、老年病、炎症和先天性畸形等多种疾病的影响，软骨的再生和重建是骨科领域最重要的课题。虽然软骨组织工程作为自体软骨细胞移植已逐渐流行，但为了拓宽软骨组织工程的适应症范围，以适应终末期骨关节炎、先天性软骨畸形等更严重的软骨疾病，仍需构建三维结构的组织工程软骨。此外，纳米技术也取得了显著的进步，可以将物质控制在小于1微米的范围内，并制造出多功能的前驱分子。在本项目中，我们尝试将纳米技术应用于软骨细胞的体外增殖和构建3D结构的组织工程软骨。为了防止培养的软骨细胞去分化，3D培养是有用的。然而，3D条件下软骨细胞的增殖培养尚未见报道。在本项目中，我们尝试使用中空纤维来制作3D增殖培养系统。为了解决软骨细胞在增殖培养过程中去分化的问题，我们还研究了可溶性因子对去分化软骨细胞的再分化作用。结果表明，BMP-2、胰岛素和T3联合使用可诱导较理想的再分化。此外，我们还对合成的多肽没有交叉污染风险的支架材料和用于基因转移的功能性胶束进行了检测，这些结果将为软骨组织工程的临床应用提供有用的信息。

Cartilage is a major component that consists of motor and supportive tissues. Because the cartilaginous tissues suffer from various diseases and disorders including trauma, ageing diseases, inflammation and congenital anomaly, the regeneration and reconstruction of cartilage is the most important topic in the orthopaedic fields. Although the cartilage tissue engineering has gradually prevailed as autologous chondrocyte transplantation, 3D-structured tissue-engineered cartilage are needed in order to broaden the indication range of the cartilage tissue engineering for the more severe cartilage diseases such as end stage of osteoarthritis and congenital anomaly of cartilage. Otherwise, the nanotechnology has remarkably progressed, which can control the matter on a scale smaller than 1 micrometer and fabricate multipotent prolymers. In the present project, we attempted to apply the nanotechnology for the proliferation of chondrocytes in vitro and the fabrication of 3D-structured tissue-engineered cartilage.In order to prevent dedifferentiation of cultured chondrocytes, 3D culture is useful. However, the proliferation culture of chondrocytes under 3D condition had not been reported. In the present project, we attempted to use hollow fibers for the purpose of making the 3D proliferation culture system. We also investigated the combination of soluble factors that redifferentiate dedifferentiated chondrocytes, in order to solve the problem that the chondrocytes are dedifferentiated during the proliferation culture. As results, the combination of BMP-2, insulin and T3 was revealed to induce ideal redifferentiation. Moreover, we examined the novel materials including the scaffolds which synthetic peptides possess no risk of cross-contamination and the functional micelles for gene transfection.These results would provide useful information for the clinical application of cartilage tissue engineering.