Abstract
Objectives
Migratory cartilage-derived cells have potential autologous use in cartilage repair surgery. However, obtaining cells through arthroscopic biopsy has never been reported in subjects without osteoarthritis. This study aimed to characterize cell lines derived from cartilage obtained by arthroscopic biopsies of non-osteoarthritic volunteers.
Methods
Consent was obtained for eight volunteers undergoing routine knee arthroscopy for ligament or meniscal injury treatment, aged between 18 and 55 years, with no knee osteoarthritis. After arthroscopic inspection, 5-10 mm cartilage fragment was removed from a non-weight-bearing area on the trochlear lateral edge or intercondylar notch, using an arthroscopic gouge.Cell isolation was performed by enzymatic digestion or by explant cell migration. Protein analysis was performed to evaluate the expression of osteogenic, chondrogenic or adipogenic differentiation factors.
Results
Successful cell cultures were obtained using both methods, enzymatic digestion or cell migration from cartilage biopsy fragments, with no significant differences in stem cell markers and plasticity among cell lines. Cells obtained from both procedures have: fibroblast-like morphology, expression of CD29, CD90, and CD105 markers as well Nanog and SOX2, and can differentiate in adipocytes, chondrocytes, and osteoblasts under appropriate conditions. Cells obtained via migration exhibited lower expression of collagen I and II, and a lower collagen II/collagen I ratio, both positively associated with chondral matrix production. RUNX2 expression, an osteogenic differentiation factor, was also lower in this group. No difference was observed in levels of SOX9, key for chondrogenic differentiation, or syndecan and perlecan gene expression.
Conclusion
This study showed for the first time chondral explant migration can effectively derive cells from arthroscopic biopsies from non-osteoarthritic individuals, showing comparable and plasticity profiles. Moreover, these cells exhibit important chondrogenic markers and proteins. Further, in vivo studies are needed to better evaluate the regeneration potential of these cell lines.