Mesenchymal stem cells with IGF-1 and TGF- β1 in laminin gel for osteochondral defects in rabbits.

OBJECTIVE: Healing of articular cartilage is still a challenge due to its limited potential to regenerate. In the present study, we evaluated allogenic bone marrow mesenchymal stem cells (BM-MSCs) alone or in combination with growth factors, insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1) in laminin scaffolds for healing of osteochondral defects.

DESIGN: Osteochondral defects of 4mm (diameter) x 5mm (depth) were induced in the rabbit knee joints and treated with phosphate-buffered saline (PBS; control), BM-MSCs, BM-MSCs in laminin, BM-MSCs in laminin with IGF-1, or BM-MSCs in laminin with IGF-1 and TGF-β1 in 10 animals each. Gross, radiographic, scanning electron microscopic (SEM) and histologic examinations besides chondrocyte-specific genes expression by quantitative real time qPCR were carried out at 8 and 12 weeks.

RESULTS: Gross and SEM examination revealed superior morphology and surface architecture of the healing site in animals that received MSCs with IGF-1 or IGF-1 and TGF-β1. The application of laminin composites containing MSCs with IGF-1 and TGF-β1 significantly enhanced hyaline cartilage formation with improved cellular arrangement, proteoglycan deposition, clear tidemark zone and subchondral bone formation. However, regenerated tissue in defects that received only MSCs had poor tidemark zone and proteoglycans deposition Aggrecan and Coll2 expression was significantly higher in case of MSCs with growth factors.

CONCLUSION: The treatment with BM-MSCs combined with IGF-1/TGF-β1 into laminin gel scaffold might enhance the restoration of hyaline cartilage in osteochondral defect.