A biomimetic reinforced type I/II collagen and hyaluronic acid scaffold in combination with a chondral biomaterial fixation technique for large articular cartilage defect repair: A pilot pre-clinical study

Successfully repairing large articular cartilage defects remain an unmet clinical challenge. Our lab has previously developed a biomimetic mechanically reinforced type I/II collagen-hyaluronic acid (CI/II-HyA) scaffold, which was proven in vitro to effectively support a hyaline-like cartilage formation while providing mechanical properties mimicking healthy cartilage. This initial pre-clinical study aimed to elucidate the chondral regenerative capacity of this collagen-based scaffold to repair large clinically challenging articular cartilage defects in goats. Furthermore, a biomaterial-fixation technique - previously tested ex-vivo - was also assessed in vivo. Scaffolds were implanted into large cartilage defects (8 mm diameter) in a load-bearing area of goat medial femoral condyles and fixed in place using this new fixation technique with either resorbable or non-resorbable sutures. Following 6 months implantation, scaffolds showed promise to repair the large chondral defects. Macroscopic and histological evaluation showed new hyaline-like cartilage formation partially covering the defect area in 3 out of 6 cartilage defects. Moreover, microCT analysis revealed that all scaffolds showed indications of being successfully secured in the defect. Taken together, the biomimetic reinforced CI/II-HyA scaffold in combination with the innovative fixation method provides strong promise to become a viable treatment to currently limited large articular cartilage repair strategies in the clinic.