<i>In vivo</i> safety prediction of recombinant collagen using <i>in vitro</i> simulated degradation analysis, chronic toxicity and immunological evaluation

Protein-based biomaterials, particularly collagen-derived materials, have been widely applied in medical devices and regenerative medicine due to their excellent biocompatibility and tissue repair-promoting functions. However, the degradation of these materials <i>in vivo</i> may trigger immune responses and other physiological reactions, especially through interactions between degradation products and the immune system. To better evaluate their safety and efficacy, particularly regarding the potential immunotoxicological risks posed by degradation products, this study proposes a comprehensive evaluation framework combining degradation product simulation, immunotoxicological assessment and chronic toxicity testing, aiming to more fully identify potential risks during the degradation process. This study first simulated the degradation process <i>in vitro</i>, analyzing the compatibility of the resulting degradation products with human proteins to reveal potential molecular interaction risks. Based on this, a systematic immunotoxicological evaluation was conducted from multiple dimensions, including complement activation, humoral immunity, cellular immunity and inflammatory responses, to thoroughly assess the immunological safety of the material. Furthermore, chronic toxicity experiments confirmed the long-term biosafety and stability of the material. The results demonstrate that the established comprehensive evaluation framework provides new methodological support and reference for the <i>in vivo</i> long-term biological risk assessment. Using this framework, recombinant type III collagen was found to exhibit favorable biosafety and immunological compatibility at the molecular, immune and systemic toxicity levels.