基质弹性调控软骨终板干细胞生物学特性及其在构建组织工程髓核中的应用

Matrix elasticity has an important impact on the behavior of stem cells, on the use of matrix elasticity which builds a " suitable " seed cells play a fundamental role of biological material is currently one of the hot issues of tissue engineering research. Stem cells also exist in the degenerated intervertebral disc , but whether disc tissue matrix elasticity play a partial role on stem cells is still unknown. Our research group has confirmed the presence of stem cells existing in degenerated cartilage endplate (CESCs), nano-scale IT-AFM (indentation type Atomic Force Microscopy) determination of degenerated cartilage endplate matrix elasticity to simulate the elastic matrix in vitro by polyacrylamide gel explore different influence of elastic matrix in the process of cartilage endplate degeneration on stem cell morphology, proliferation, differentiation and maintenance of stemness in order to impact its ability to maintain stemness in which elastic environment to build in vitro amplification system (maintained in an undifferentiated state) . Combined basis for the preliminary work of stem cells found in cartilage endplate (CESCs) into the nucleus pulposus has a good ability to repair the degeneration state of the nucleus pulposus, build adjustable elastic nucleus bracket, through the design vitro and in vivo experiments to clarify its "fit " into the nucleus elastic matrix reference value for the optimization of tissue engineering nucleus designed to lay the foundation. Studies to elucidate this subject during the cartilage endplate degeneration process impact on stem cell fating and its mechanisms , and has important implications for the optimization design of nucleus pulposus tissue engineering.

基质弹性对干细胞生物学行为有着重要影响，利用基质弹性构建"适宜"种子细胞发挥生物学作用的生物材料是目前组织工程研究的热点问题之一。退变椎间盘中亦有干细胞存在，但基质弹性是否对椎间盘组织局部干细胞发挥作用目前还不得而知。本课题组结合前期在椎间盘软骨终板中证实存在软骨终板干细胞，借助原子力显微镜测定不同退变程度软骨终板基质弹性，通过聚丙烯胺凝胶体外模拟其基质弹性，探究不同退变程度软骨终板基质弹性对软骨终板干细胞形态、增殖、分化及维持干性的影响，寻找其维持干性的"适宜"弹性环境，从而构建体外扩增系统（保持未分化状态）。同时结合前期工作基础发现软骨终板干细胞具有良好的成髓核修复能力，构建可调弹性髓核支架，通过设计体内体外实验，明确其"适宜"成髓核基质弹性参考值，为优化组织工程髓核设计奠定基础。本课题的研究对于阐明退变过程中终板干细胞的生物学作用及其机制，同时对于优化组织工程髓核设计都具有重要意义。

本课题已按计划完成了课题研究，并且取得了较好的预期效果。在实验过程中，我们完成了对人退变椎间盘软骨终板临床标本的收集及硬度测试；我们借助原子力显微镜测定不同退变程度软骨终板基质弹性，通过聚丙烯胺凝胶体外模拟其基质弹性，探究不同退变程度软骨终板基质弹性对CESCs形态、增殖、分化及维持干性的影响。进一步，我们通过体内外实验证实了CESCs在高硬度环境下具有成骨特性，并且促进软骨终板钙化，同时我们明确了硬度与CESCs钙化的调控的分子机制。本课题的研究对于阐明退变过程中软骨终板干细胞的生物学作用及其机制，同时对于未来组织工程化髓核具有较重要的科学及应用意义。