Objective- To evaluate the biological compatibility of differentiated stem cells embedded in poly-vinyl-alcohol (PVA) scaffolds for repair of distal femoral cartilage defect.  
Design- Experimental in vivo study.
Animals- Twelve adult male New Zealand white rabbits were used which were divided into two groups (I, II) six rabbits each.  
Procedures- Mesenchymal stem cells were isolated from humerus bone marrow of group I rabbits and were cultured and differentiated on PVA scaffolds to chondrocytes. Scanning Electron Microscopy (SEM) showed well distribution of the cells inside the scaffold. A 4 mm diameter full thickness cartilage defect was created on central region of bilateral distal femoral joint surface (patellar groove) in all rabbits. In group (I) the defects were covered with autologous differentiated MSCs-seeded scaffolds; whereas the group II rabbits were left without any treatment as control ones. One month and three months after operation, three rabbits were sacrificed from each group, randomly. Histopathologic evaluation of defects was performed with H&E and trichrome staining.
Results-  The findings showed that in the engineered cartilage with the PVA scaffold, the defects were filled with smooth, shiny white tissue macroscopically at three months after the transplantation. Despite much connective tissue formed in defect area after three months, there was no evidence of chondrocytes in control group, whereas the defects of experimental group were almost completely filled with hyaline cartilage.
Conclusion and Clinical Relevance- The results indicated there is positive possibility for partial resurfacing of cartilage defect using stem cell-seeded PVA scaffolds