MgAl-Layered Double Hydroxide-Modified Bioceramic Scaffolds for the Potential Application in Osteochondral Defect Repair.

Due to the differences in cell types, structural composition, and mechanical properties between articular cartilage and subchondral bone, developing effective integrated repair strategy persists as a major clinical hurdle. We constructed a novel scaffold by a three-dimensional (3D) printing and surface modification method for the potential application of simultaneously promoting bone and cartilage repair. MgAl-layered double hydroxide (MgAl-LDH) nanosheets were synthesized via the hydrothermal method and then modified on β-tricalcium phosphate (β-TCP) scaffolds. The prepared composite scaffolds exhibited a uniform microstructure, suitable compressive strength, and satisfactory biocompatibility. Attributing to the released bioactive ions, MgAl-LDHs-TCP effectively supported the proliferation and attachment of rabbit bone marrow mesenchymal stem cells and chondrocytes. Furthermore, 72MgAl-LDHs-TCP scaffolds obviously promoted osteogenic differentiation, provided deposition sites for calcium salt formation, induced the formation of alkaline phosphatase, and created favorable conditions for the early-stage and end-stage osteogenic differentiation of rBMSCs. Simultaneously, attributed to the released functional ions, the prepared composite scaffolds significantly enhanced the synthetic metabolism in chondrocytes and inhibited the expression of catabolism-related genes, playing an important role in protecting arthritis chondrocytes. Overall, such prepared scaffolds may have the possible application for the simultaneous regeneration of cartilage and subchondral bone defects.