THE POTENTIAL OF SEA URCHINS WASTE: ECO-FRIENDLY COLLAGEN-BASED HYDROGELS FOR TISSUE REGENERATION

Sea urchins possess unique anatomical and physiological features, such as Mutable Collagenous Tissues (MCTs), which offer eco-friendly opportunities for biomedical applications (Di Benedetto et al., 2014). Up to 90% of edible sea urchins are discarded as waste, yet their peristomal membranes remain a valuable source of MCT-derived native collagen for producing biomimetic materials. In recent years, our lab has developed collagen-based biomaterials for tissue regeneration (Di Benedetto et al., 2014; Ferrario et al., 2020), ranging from collagen scaffolds (Coll) to composites with sea urchin-derived antioxidants (Coll-PHNQs). Although these materials performed well in in vitro and in vivo models (Carolo et al., 2023; Zivelonghi et al., 2024), improvements in mechanical and ultrastructural properties were needed. Hydrogels represent a key advancement in collagen biomaterials, offering improved mechanical strength and structural fidelity through collagen network crosslinking (Leonard et al., 2024). This study aimed to develop a collagen methacrylate (CollMA) hydrogel using photo-crosslinking. Collagen was extracted from sea urchin peristomal membranes (Di Benedetto et al., 2014; Ferrario et al., 2020), methacrylated using methacrylic anhydride, and crosslinked via UV light and Irgacure®. The resulting hydrogels were analyzed for ultrastructure (SEM), degradation (PBS, collagenase), hydration, and swelling—and compared to Coll. CollMA retained its fibrillar structure and showed higher porosity, enhanced stability, and a lower enzymatic degradation rate than Coll. This marks the first development of methacrylated collagen hydrogels from sea urchins. Further studies should explore their biocompatibility and performance in real-world biomedical contexts.