Purpose To evaluate the anti‐inflammatory and disease‐modifying potential of bone marrow aspirate concentrate (BMAC) and amniotic suspension allograft (ASA) in a chondrocyte and synovium coculture model of osteoarthritis. Methods Seventeen patients were enrolled for cartilage, synovium, and bone marrow aspirate tissue donation prior to a total knee arthroplasty. Cartilage and synovium explants were cocultured into four different groups: one baseline group, one control group (96‐hour coculture), BMAC group, and ASA group. Interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6), and tumor necrosis factor‐alpha (TNF‐α) were measured at 96 hours in the media with enzyme‐linked immunosorbent assay. Collagen type 1 α 1, Collagen type 2 α 2, Collagen type 3 α 1, aggrecan, and Cartilage Oligomeric Matrix Protein were measured in the cartilage and synovium by reverse transcription polymerase chain reaction. Safranin‐O staining were performed on all groups and scored by the modified Mankin scoring system. Results Samples treated with ASA showed a significantly lower concentration of IL‐1β when compared to control samples (11.2 ± 13.9 vs 20.2 ± 39.5 pg/mL, P = .04). Treatment with BMAC was associated with a significantly lower concentrations of IL‐6 when compared to control samples (607.32 ± 271.07 vs 767.11 ± 30.84, P = .02). No significant differences were observed in gene expression within chondrocytes and synoviocytes or for Mankin scoring between treatment and control groups. Conclusions Osteoarthritic chondrocytes and synovial tissue may respond to BMAC and ASA by a reduction in IL‐1β and IL‐6 concentrations, but short‐term cytokine responses are variable. The mechanism of response remains unknown. Clinical Relevance This study aims to reveal the mechanism of BMAC and ASA by which these biologics function in a model of an arthritic joint.
Hannon et al. (2026) studied this question.