Effect of TGF-β1 transfected dental pulp derived mesenchymal stem cells on ın vivo cartilage regeneration.

OBJECTIVES: This study aimed to investigate the effect of TGF-β1-transfected dental pulp-derived mesenchymal stem cells (DP-MSCs) on the regeneration of osteochondral defects in rabbit knee joints. MATERIALS AND METHODS: A total of 32 New Zealand white rabbits (3-4 months old, 2-3 kg) were randomly divided into four groups (n=8 per group). Osteochondral defects were surgically created in the distal femoral articular cartilage of three experimental groups, while the control group remained untreated. Group 2 received an intra-articular injection of 0.5 ml sterile saline. Group 3 was administered 0.5 ml of saline containing 3×10(6) DP-MSCs. Group 4 received 3×10(6) TGF-β1-transfected DP-MSCs suspended in 0.5 ml of saline. After six weeks, animals were euthanized, and femoral joints were harvested. Tissue sections (5 μm) were analyzed histologically using hematoxylin-eosin, Masson's trichrome, and Toluidine blue staining, as well as immunohistochemical methods. RESULTS: Histological analysis revealed increased fibrous cartilage in the DP-MSC group compared to the saline group, with some irregular hyaline cartilage regions and dispersed chondrocytes. The TGF-β1+DP-MSC group demonstrated a more significant improvement, characterized by enhanced hyaline cartilage formation and a more organized tissue architecture. CONCLUSION: TGF-β1 transfection enhances the chondrogenic potential of mesenchymal stem cells by stimulating reparative cellular mechanisms and promoting the formation of hyaline cartilage, thereby facilitating more effective tissue regeneration. These findings suggest that this strategy holds considerable potential for clinical application in cartilage repair and regeneration.