Biocompatibility Profile of a Unique Dual-Biomaterial Hydrogel-Based Medical Device for Intraarticular Use in Osteoarthritis

Hydrogel OA 2% is a dual-biomaterial viscoelastic implant developed for intra-articular treatment of osteoarthritis (OA). It consists of hydrolyzed bovine bone protein crosslinked with a carbohydrate, providing mechanical support and joint lubrication while maintaining biocompatibility. This study evaluated its preclinical safety in accordance with ISO 10993 and OECD Good Laboratory Practice (GLP) guidelines. Hydrogel OA 2% underwent cytotoxicity (L-929 fibroblast assay), genotoxicity (Ames and micronucleus), sensitization (guinea pig maximization), pyrogenicity (rabbit pyrogen), acute and 4-, 13-, and 26-week systemic toxicity studies (mice and rats), and intra-articular injection studies in rabbits. Histopathological and cytopathological assessments were performed at weeks 1, 4, 13, and 26 and compared with a hylan-based control gel and saline. No cytotoxic, genotoxic, sensitizing, pyrogenic, or systemic toxic effects were observed. Intra-articular administration induced minimal local reactions, with transient low-grade inflammation at week 4 resolving by week 13, where normal synovial and cartilage architecture was restored. Progressive phagocytic degradation resulted in near-complete material clearance by week 26 without pathological findings in lymph nodes or systemic organs. Chemical characterization and toxicological risk assessment further confirmed negligible biological risk.