Sea Urchin Waste Derived Collagen Scaffolds for 3D Skeletal Muscle Tissue Engineering and Myogenic Differentiation

The growing demand for sustainable biomaterials in food biotechnology and regenerative medicine has accelerated the search for alternative collagen sources beyond conventional terrestrial animals. Marine-derived collagen, particularly from underutilized biomass, represents a promising solution aligned with circular bioeconomy principles. In this study, sea urchin–derived collagen obtained from mutable collagenous tissue (MCT) was investigated as a three-dimensional (3D) scaffold for skeletal muscle tissue engineering. Two collagen-based scaffold types were evaluated: standard MCT scaffolds and methacrylated collagen hydrogels. Both were derived from sea urchin processing waste and designed to mimic the structural and biochemical features of the native extracellular matrix (ECM). In this study the murine C2C12 myoblast cell line was used as an in vitro model to assess MCT scaffold biocompatibility, cell adhesion, infiltration, and myogenic differentiation. C2C12 cells successfully adhered, proliferated, and maintained their characteristic morphology under standard culture conditions. Cell viability analysis conducted on MCT scaffold confirmed a high proportion of metabolically active cells, distributed throughout the three-dimensional structure. Histological analysis further demonstrated progressive cell infiltration over time, indicating that this scaffold possesses suitable porosity and interconnectivity to support tissue-like organization. Immunofluorescence analysis revealed sustained expression of the myogenic marker MyoD at later time points, confirming the progression of myogenic differentiation within the MCT scaffold environment. These findings indicate that the collagen-based matrices not only support cell survival but also promote differentiation toward a myogenic phenotype. The two scaffolds showed structural differences, MCT had a fibrillar architecture that provided enhanced biomimetic cues, whereas hydrogels created a more uniform microenvironment. From a sustainability perspective, the use of sea urchin waste as a collagen source supports waste valorization, reduces environmental impact, and contributes to cost-effective biomaterial production. This approach highlights the dual role of collagen as both a structural biomaterial and a functional component in food biotechnology. In conclusion, sea urchin–derived collagen scaffolds represent a promising, biocompatible, and sustainable platform for skeletal muscle tissue engineering. Their ability to support cell viability, infiltration, and differentiation underscores their potential for applications in tissue engineering, regenerative medicine, disease modeling. Future studies should focus on enhancing functional maturation through advanced culture systems and physiological stimulation.