Biofunctionalized Chondrogenic Shape-Memory Ternary Scaffolds for Efficient Cell-Free Cartilage Regeneration

Abstract

Cartilage defect repair remains a great clinical challenge due to the limited self-regeneration capacity of cartilage tissue. Surgical treatment of injured cartilage is rather difficult due to the narrow space in the articular cavity and irregular defect area. Herein, we designed and fabricated chondrogenic and physiological-temperature-triggered shape-memory ternary scaffolds for cell-free cartilage repair, where the poly (glycerol sebacate) (PGS) networks ensured good elasticity and shape recovery, crystallized poly (1,3-propylene sebacate) (PPS) acted as switchable phase, and immobilized bioactive kartogenin (KGN) endowed the scaffold with chondrogenic capacity. The resultant scaffolds exhibited excellent shape-memory properties with shape-memory fixed ratio of 97.6% and recovered ratio of 96.8% at 37 °C for PPS/PGS/KGN-100, indicating a good potential for minimally invasive implantation. The scaffolds gradually degraded in Dulbecco's phosphate-buffered saline and released KGN up to 12 weeks in vitro. In addition, the scaffolds promoted chondrogenic differentiation while inhibiting osteogenic differentiation of bone marrow-derived mesenchymal stem cells in a concentration-dependent manner. Consequently, the PPS/PGS/KGN-100 scaffolds efficiently stimulated the formation of an overlying layer of hyaline cartilage mimicking the characteristic architecture of native articular cartilage even in the absence of exogenous growth factors and seeded cells. This study provides much inspiration for future research on cartilage tissue engineering.