Nanophase Polyaiticglycolic Acid/Hydroxyapatite Composite and Mesenchymal Stem Cells in Rat Cartilage Regeneration

Objective: To repair rat cartilage defects using nanophase PLGA/HA (polyaiticglycolic acid/hydroxyapatite) composite and mesenchymal stem cells. Method: Rat bone marrow mesenchymal stem cells (BMSCs) were obtained from bone marrow of 12-week-old male Sprague-Dawley rats. After 15 days of primary culture, almost completely confluent, the cells were subcultured. Then, MSCs were cultured on PLGA/HA composite. All animals underwent bilateral knee joint surgery with a drill to introduce 36 cartilage defects in the distal femurs. The cartilage defect in the left femur was filled with PLGA/HA composite cultured with MSCs; this group was designated as the experimental group (n = 18). The cartilage defect on the right femur was not filled; this group was designated as the control group (n = 18). Histological and immunohistochemical evaluation was performed to evaluate the effect of the cartilage repair. Result:The defects created in the experimental group were repaired by newborn cartilage after 12 weeks. The defects created in the control group were repaired by fibrous tissue with no cartilage or cartilaginous extracellular matrices after 12 weeks. Conclusion: The nanophase PLGA/HA composite has a fibrous structure with high porosity and can serve as a type of tissue engineering scaffold applicable to the repair of cartilage defects. The PLGA/HA composite incorporated with MSCs was successful in repairing cartilage defects.