Autologous bone marrow concentrate in a sheep model of osteoarthritis: new perspectives for cartilage and meniscus repair
Cell-based therapies are becoming a valuable tool to treat osteoarthritis (OA). This study investigated and compared the regenerative potential of Bone Marrow Concentrate (BMC) and Mesenchymal Stem Cells (MSC), both engineered with Hyaff®-11 (HA) for OA treatment in a sheep model.
OA was induced via unilateral medial meniscectomy. Bone marrow was aspirated from the iliac crest, followed by concentration processes or cell isolation and expansion to obtain BMC and MSC respectively. Treatments consisted of autologous BMC and MSC seeded onto HA. The regenerative potential on bone, cartilage, menisci and synovia was monitored using macroscopy, histology, immunohistochemistry and micro-computed tomography, at 12 weeks post-op. Data were analyzed using the General Linear Model with adjusted Sidak’s multiple comparison and Spearman tests.
BMC-HA treatment showed a greater repair ability in inhibiting OA progression compared to MSC-HA, leading to a reduction of inflammation in cartilage, meniscus and synovium. Indeed, the decrease of inflammation positively contributed to counteract the progression of fibrotic and hypertrophic processes, known to be involved in tissue failure. Moreover, the treatment with BMC-HA showed the best results in allowing meniscus regeneration. Minor healing effects were noticed at bone level for both cell strategies, however a down-regulation of Cross-sectional Subchondral Bone Thickness (Cs.Th) was found in both cell-treatments compared to OA group in femur.
The transplantation of BMC-HA provided the best effects in supporting regenerative processes in cartilage,meniscus and synovium and at less extent in bone. On the whole, both MSC and BMC combined with HA reduced inflammation and contributed to switch-off fibrotic and hypertrophic processes. The observed regenerative potential by BMC-HA on meniscus could open new perspectives suggesting its use not only for OA care but also for the treatment of meniscal lesions, even if further analyses are necessary to confirm its healing potential at long-term follow-up.