Figure 1.

(A) Schematic of the osteochondral defect of the medial condyle in the knee joint, as indicated by the black circle. (B) Diagram of a bilayered PLGA scaffold. (C) Pore structure of the bilayered PLGA scaffold observed via SEM. The blue line indicates the boundary of the two layers. (D) An SEM image of BMSCs on the internal surfaces of the chondral layer of the porous scaffold after being cultured for one week. (E) Magnification of the rectangle of (D). The yellow arrows indicate cells adhered to the pore wall of the scaffold. BMSCs = bone marrow mesenchymal stem cells; PLGA = poly(lactide-co-glycolide); SEM = scanning electron microscopy.