Investigating the comparative effect of conditioned medium from mesenchymal stem cells and fibroblast cells on articular cartilage defects

Mesenchymal stem cell-secreted factors play influential roles in proliferation, differentiation, and chondrogenesis. This study was designed to examine the ameliorative effects of conditioned medium (CM) from stem cells, fibroblasts, and platelet rich plasma (PRP) on articular cartilage defects in a rat model. A cartilage defect (2 mm in diameter) was created in the intercondylar notch of the femur. Forty adult male Wistar rats were divided into eight groups: intact, sham, and untreated, DMEM, stem cells, stem cell conditioned medium, fibroblast conditioned medium, and PRP. Conditioned medium, PRP, and stem cells were administered as a single dose intra-articularly immediately after surgery and closure of the joint capsule. At the end of the 4th week, cartilage repair was assessed by histopathological assays. Microscopy data showed that defects in the stem cell-conditioned medium group repaired tissue better in terms of cartilage layer formation, thickness, collagen deposition and glycosaminoglycan synthesis compared to defects in the stem cell, fibroblast-conditioned medium, and PRP groups. In terms of angiogenesis, the fibroblast-conditioned medium group outperformed the other groups. Based on histological findings, stem cell conditioned medium yields superior results to fibroblast conditioned medium and PRP treatment in creating hyalinelike repair tissue. The effectiveness of the role of conditioned medium compared to cell therapy may only be due to the type and amount of growth factors present in them.