Full-thickness osteochondral defect repair using a biodegradable bilayered scaffold of porous zinc and chondroitin sulfate hydrogel

• Published in: Bioactive materials 2024-02, Vol.32, p.400-414
• Main Authors: Yang, Fan, Li, Yageng, Wang, Lei, Che, Haodong, Zhang, Xin, Jahr, Holger, Wang, Luning, Jiang, Dong, Huang, Hongjie, Wang, Jianquan
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Chondroitin sulfate hydrogel; Osteochondral regeneration; Porous Zn scaffold
• ISSN: 2452-199X; 2452-199X
• DOI: 10.1016/j.bioactmat.2023.10.014

The regeneration of osteochondral tissue necessitates the re-establishment of a gradient owing to the unique characteristics and healing potential of the chondral and osseous phases. As the self-healing capacity of hyaline cartilage is limited, timely mechanical support during neo-cartilage formation is crucial to achieving optimal repair efficacy. In this study, we devised a biodegradable bilayered scaffold, comprising chondroitin sulfate (CS) hydrogel to regenerate chondral tissue and a porous pure zinc (Zn) scaffold for regeneration of the underlying bone as mechanical support for the cartilage layer. The photocured CS hydrogel possessed a compressive strength of 82 kPa, while the porous pure Zn scaffold exhibited a yield strength of 11 MPa and a stiffness of 0.8 GPa. Such mechanical properties are similar to values reported for cancellous bone. In vitro biological experiments demonstrated that the bilayered scaffold displayed favorable cytocompatibility and promoted chondrogenic and osteogenic differentiation of bone marrow stem cells. Upon implantation, the scaffold facilitated the simultaneous regeneration of bone and cartilage tissue in a porcine model, resulting in (i) a smoother cartilage surface, (ii) more hyaline-like cartilage, and (iii) a superior integration into the adjacent host tissue. Our bilayered scaffold exhibits significant potential for clinical application in osteochondral regeneration. [Display omitted] •Biodegradable bilayered scaffold of porous zinc and chondroitin sulfate hydrogel for osteochondral defect repair.•Favorable cytocompatibility and chondrogenic and osteogenic differentiation of BMSC cells.•Pure Zn porous scaffolds can provide suitable mechanical support for cartilage regeneration.•Degradation rates of pure Zn porous scaffolds suitable for bone implants.