Graphene/β-Tricalcium Phosphate Composite Scaffold Facilitates the Repairment of Cartilage Defect in Rabbit Knee Joint

Our research aims to evaluate the repairment of graphene/β-tricalcium phosphate (G/β-TCP) composite scaffold on cartilage defect in rabbit knee joints. The G/β-TCP composite material containing BMSCs was surgically implanted into the femoral condyle of a full-thickness cartilage defect model in rabbits. XRD showed that no difference in the X-ray diffraction characteristics was observed between G/β-TCP and β-TCP. The biomechanical test claimed that the graphene doped β-TCP material processed higher mechanical strength. Scanning electron microscopy showed that the surface of G/β-TCP material was smoother and the texture was denser. The scaffold combined with BMSCs was transplanted into the full-thickness cartilage defect rabbit model and the results showed that the serum CRP level increased only 1 month after implantation, and the Cr level increased at 2 months after implantation, while G/β-TCP material showed rare significant pathological changes on the liver, spleen, kidney, brain, and soft tissue around the operation, which indicated a promising biocompatibility. The expression of type I and II collagen in the cartilage tissue of G/β-TCP treated rabbits was dramatically elevated compared to β-TCP at 2 and 3 months after implantation. Collectively, the G/β-TCP composite scaffold facilitated the repairment of cartilage defects in the rabbit knee joints.