Hydrogel composite scaffolds achieve recruitment and chondrogenesis in cartilage tissue engineering applications

Background: The regeneration and repair of articular cartilage remains a major challenge for clinicians and scientists due to the poor intrinsic healing of this tissue. Since cartilage injuries are often clinically irregular, tissue-engineered scaffolds that can be easily molded to fill cartilage defects of any shape that fit tightly into the host cartilage are needed. Method: In this study, bone marrow mesenchymal stem cell (BMSC) affinity peptide sequence PFSSTKT (PFS)-modified chondrocyte extracellular matrix (ECM) particles combined with GeIMA hydrogel were constructed. Results: In vitro experiments showed that the pore size and porosity of the solid-supported composite scaffolds were appropriate and that the scaffolds provided a three-dimensional microenvironment supporting cell adhesion, proliferation and chondrogenic differentiation. In vitro experiments also showed that GeIMA/ECM-PFS could regulate the migration of rabbit BMSCs. Two weeks after implantation in vivo, the GeIMA/ECM-PFS functional scaffold system promoted the recruitment of endogenous mesenchymal stem cells from the defect site. GeIMA/ECM-PFS achieved successful hyaline cartilage repair in rabbits in vivo, while the control treatment mostly resulted in fibrous tissue repair. Conclusion: This combination of endogenous cell recruitment and chondrogenesis is an ideal strategy for repairing irregular cartilage defects.