A Comparison of the Properties of Mesenchymal Stem Cells Derived from Different Synovial Sources: A Systematic Review

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation into different cellular lineages, including adipocytes, chondrocytes, and osteocytes. This makes them strong candidates for repairing degenerative joint conditions such as osteoarthritis, in which native cartilage lacks repair capacity. The synovium is an attractive MSC source, with synovial MSCs demonstrating superior chondrogenic and proliferative potential compared to those from bone marrow or adipose tissue. The synovial joint is a heterogeneous environment, and MSCs can be isolated from the membrane, fluid, different histological subtypes of fibrous and adipose synovium, and different anatomical regions of synovium. This systematic review assesses whether MSCs from different synovial sources possess distinct properties. 2312 papers were identified, of which 10 met the inclusion and exclusion criteria and were included in the final review. Significant differences were identified in proliferation characteristics, immunophenotype and differentiation potential. Proximity to vasculature appeared to correlate with proliferation and differentiation potential, and MSCs from the synovial membrane may have superior proliferative characteristics compared to those from synovial fluid. More work is required to fully characterise these differences and understand their underlying molecular bases, but these findings may help inform the choice of MSC source for regenerative therapies.