Peng Yachen, Zhuang Yaling, Liu Yang, Le Hanxiang, Li Di, Zhang Mingran, Liu Kai, Zhang Yanbo, Zuo Jianlin, Ding Jianxun
Department of Orthopedics China-Japan Union Hospital of Jilin University Changchun P. R. China.
Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun P. R. China.
Exploration (Beijing). 2023 Jul 12;3(4):20210043. doi: 10.1002/EXP.20210043. eCollection 2023 Aug.
Repairing articular osteochondral defects present considerable challenges in self-repair due to the complex tissue structure and low proliferation of chondrocytes. Conventional clinical therapies have not shown significant efficacy, including microfracture, autologous/allograft osteochondral transplantation, and cell-based techniques. Therefore, tissue engineering has been widely explored in repairing osteochondral defects by leveraging the natural regenerative potential of biomaterials to control cell functions. However, osteochondral tissue is a gradient structure with a smooth transition from the cartilage to subchondral bone, involving changes in chondrocyte morphologies and phenotypes, extracellular matrix components, collagen type and orientation, and cytokines. Bioinspired scaffolds have been developed by simulating gradient characteristics in heterogeneous tissues, such as the pores, components, and osteochondrogenesis-inducing factors, to satisfy the anisotropic features of osteochondral matrices. Bioinspired gradient scaffolds repair osteochondral defects by altering the microenvironments of cell growth to induce osteochondrogenesis and promote the formation of osteochondral interfaces compared with homogeneous scaffolds. This review outlines the meaningful strategies for repairing osteochondral defects by tissue engineering based on gradient scaffolds and predicts the pros and cons of prospective translation into clinical practice.
修复关节软骨下骨缺损由于其复杂的组织结构和软骨细胞的低增殖能力，在自我修复方面面临着巨大挑战。传统的临床治疗方法，包括微骨折、自体/异体软骨下骨移植和基于细胞的技术，均未显示出显著疗效。因此，组织工程已被广泛探索，通过利用生物材料的天然再生潜力来控制细胞功能，以修复软骨下骨缺损。然而，软骨下骨组织是一种梯度结构，从软骨到软骨下骨呈平滑过渡，涉及软骨细胞形态和表型、细胞外基质成分、胶原类型和取向以及细胞因子的变化。通过模拟异质组织中的梯度特征，如孔隙、成分和成骨软骨生成诱导因子，已开发出仿生支架，以满足软骨下骨基质的各向异性特征。与均质支架相比，仿生梯度支架通过改变细胞生长的微环境来诱导成骨软骨生成并促进软骨下骨界面的形成，从而修复软骨下骨缺损。本综述概述了基于梯度支架的组织工程修复软骨下骨缺损的有意义策略，并预测了其在临床实践中潜在转化的利弊。
