Effects of local anesthetics on yield and differentiation of synovial mesenchymal stem cells

Human synovial mesenchymal stem cells (MSCs) demonstrate high chondrogenic capacity for regenerative medicine. While ultrasound-guided collection procedures utilize local anesthetics for patient comfort, their effects on synovial MSCs remain unclear despite their known cytotoxicity to other MSC types. This study investigated whether clinically relevant concentrations of lidocaine and ropivacaine affect synovial MSC proliferation and differentiation. Human synovial tissue from eight donors undergoing knee surgery was minced and treated for 20 min with 0.5% lidocaine, 0.2% ropivacaine, or saline control. Following enzymatic digestion, cell viability and nucleated cell yield per synovial weight were assessed immediately and after a 14-day culture expansion. Trilineage differentiation capacity was evaluated through chondrogenic pellet culture, adipogenic Oil Red O staining, and calcification Alizarin Red staining. Cell viability, nucleated cell numbers per synovium weight, and cell yield after 14-day expansion showed no significant differences between treatments. Cartilage pellet weights, Oil Red O-positive adipogenic colonies, and calcification areas remained comparable across all groups. Lidocaine or ropivacaine can be safely used during ultrasound-guided synovial tissue collection without compromising therapeutic potential. These findings support the safe clinical implementation of ultrasound-guided synovial tissue harvesting using local anesthetics, reinforcing this process as a feasible and practical platform for synovial MSC-based regenerative therapies.