The difficulty in repairing osteochondral injuries is mainly the complex gradient properties of natural osteochondral structures. This review discusses the development of various osteochondral tissue engineering scaffolds with gradient properties, including pore gradients, composition gradients, and inducing factor gradients, discusses the future research focus of gradient scaffolds and the trend of osteochondral tissue engineering, and provides ideas for their potential clinical application.
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.
Yachen Peng†, Yaling Zhuang†, Yang Liu, Hanxiang Le, Di Li, Mingran Zhang, Kai Liu, Yanbo Zhang*, Jianlin Zuo*, Jianxun Ding*
How to cite:
Y. Peng, Y. Zhuang, Y. Liu, H. Le, D. Li, M. Zhang, K. Liu, Y. Zhang, J. Zuo, J. Ding, Exploration 2023, 3, 20210043.