软骨缺损严重影响关节功能，但目前临床上常用的治疗方法仍不能有效修复。生物材料的发展为软骨功能性修复带来希望，但生物材料植入体内达到功能性修复是一个多因素影响的复杂过程，只有弄清这一过程所发生的细胞和分子机制及其影响因素的关键科学问题，才能有效提高软骨组织的功能性修复效果。我们前期研究提示miR-30b通过调控靶基因SOX9影响软骨特征型胞外基质的分泌，初步探讨了miR-30b参与了软骨分化进程的调控过程。前期研究还发现，海藻酸钠/明胶复合材料适合制备成细胞打印墨水，适合间充质干细胞(mesenchymal stem cells，MSCs)的3D打印。本课题通过研究探索miR-30b通过调控Sox9修饰3D打印材料在细胞应激、低氧环境、TGF-β3诱导、Collagen Ⅱ包被、应力等内环境条件下，促进MSCs成软骨分化的作用及机制，为功能化设计生物材料能更好促软骨分化提供新思路及新策略。

Cartilage defects seriously affect joint functions, which, however, fail to be effectively repaired via the common therapies currently used in clinical practice. The development of biological materials promises a new prospect for cartilage functional repair, but biomaterial implants for functional repair prove to be a complex process involving multiple factors. Not until the key scientific issues covered in this process, including cellular and molecular mechanisms as well as their influencing factors, are clarified can the functional repair effect of cartilage tissue be effectively improved. Our previous study has suggested that miR-30b affects the secretion of characteristic cartilage extracellular matrix through regulating the target gene SOX9 and preliminarily discussed the involvement of miR-30b in the regulatory process of cartilage differentiation progress. According to findings of the previous study, the cell printing ink prepared by sodium alginate/gelatin composite material is suitable for the 3D printing of mesenchymal stem cells (MSCs). Through investigating the role and mechanism of 3D printing material modified by miR-30b-regulated Sox9 in promoting MSCs chondrogenic differentiation under different environmental conditions like cellular stress and apoptosis, hypoxia, TGF-β3 induction, Collagen II coating and stress, this paper is designed to provide a new idea and new strategy for the functional design of biological materials to better promote the cartilage differentiation.