新型多重仿生人工软骨的构建及其促进干细胞软骨分化的性能评价和机制研究

The bionics design of artificial cartilage in the field of articular cartilage repair has a promising prospect, and how to simulate the accurate structure and function of natural cartilage is a challenge urgently to be solved in this field. This project group has a in-depth research of physical crosslinking PLGA - HA - PVA artificial cartilage beforehand. On the basis of 3d printing technology controlling pore structure and collagen scaffold increasing the cell affinity of the material, this project puts forward a new type of multiple bionic artificial cartilage expecting to simulate artificial cartilage from aspects of material, structure and function. Subcutaneous layer of artificial cartilage, playing a role of bearing impact and lubrication, simulates subcutaneous layer of cartilage. Pressure load layer (deep layer) simulating natural transition and radiative zone of cartilage is designed to absorb shock and transfer load. In order to explore a proper artificial cartilage fitting the physiological needs of articular cartilage, mesenchymal stem cells will be inoculated into the artificial cartilage to compare chondrogenic ability among all the groups. Based on the discussion about the influence of mechanical environment, the effect of phosphorylation level of stem cell integrin on expression of Lamin-A and stem cell differentiation will be further discussed in order to provide scientific basis for the bionics design of artificial cartilage.

仿生学设计的人工软骨材料在修复关节软骨损伤领域具有良好的应用前景，如何精准仿生天然软骨的结构和功能是本领域亟待解决的科学问题。本课题组在前期对物理交联PLGA-HA-PVA人工软骨进行了深入研究的基础上，利用3D打印技术控制孔隙结构，加入胶原支架来提高材料的细胞亲和力，从而制备出一种新型多重仿生人工软骨，以期从材料、结构、功能三方面进行仿生。材料表层仿生软骨浅表层，承受冲击和磨擦；深层仿生天然软骨过渡区及辐射区，能促进软骨细胞长入，吸收震荡及传递负荷。本研究将间充质干细胞接种于上述材料内行体内外成软骨实验，比较各组成软骨能力，以探讨更加符合生理需求的仿生人工软骨材料，在此基础上，进一步探讨在材料三维力学环境影响下，干细胞整合素的活化水平对于核纤层蛋白A的表达及细胞分化方向的影响。为进一步研发接近天然软骨组织的仿生人工软骨材料提供理论依据。

仿生学设计的人工软骨材料在修复关节软骨损伤领域具有良好的应用前景，如何精准仿生天然软骨的结构和功能是本领域亟待解决的科学问题。本课题组在前期对物理交联的水凝胶结构进行了深入研究的基础上，将倒模法及3D打印技术结合，制备出一系列孔隙结构可控的HA-PVA水凝胶结构，并在其中加入COL支架来提高材料的细胞亲和力，从而制备出一系列新型COL-HA-PVA人工材料，其中HA-PVA水凝胶支架赋予材料力学强度，并通过连通孔隙维持营养物质流通，HA-PVA水凝胶孔隙内含COL微支架，可提高材料生物相容性并给种子细胞的粘附增殖提供足够场地。并通过体内外实验研究系统性评价不同结构的新型COL-HA-PVA人工材料的显微结构对软骨修复的生物学行为的影响，从而筛选出体内修复效果更佳的COL-HA-PVA水凝胶。并在此基础上，从细胞胞整合素的活化及核纤层蛋白A的表达水平，初步探究材料的三维力学结构对种子细胞分化的相关机制。本项目研究将为此类新型COL-HA-PVA水凝胶结构的进一步临床应用提供实验依据及理论指导。