Amniotic Suspension Allograft and Bone Marrow Aspirate Concentrate Results in Highly Variable Proinflammatory Cytokines in a Coculture Model of Osteoarthritis

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.