In the past few years, the marine environment has been an important source of countless multiplicity of materials with biological and chemical potential such as polysaccharides and secondary metabolites. The recent biotechnology advances has been crucial to discover, produce or transform compounds from marine sources to be incorporated as functional biomaterials or bioactive compounds (such as enzymes, bioactive peptides, biopolymers for biotechnological or pharmaceutical application). Currently, the fish processing industries generates tons of fish remains (about 75% of fish weight is discarded as skins, bones, fins, heads and scales) seen mainly as waste. These by-products can be valorized by producing materials with biomedical relevance (namely biopolymers, similar to the ones present in our organism). Fish skins are rich in collagen, namely type I collagen. This biopolymer is the most abundant protein in mammalian extracellular matrix (ECM), has an excellent biocompatibility and weak antigenicity, making it a primary resource in biomedical applications. Until now, bovine and porcine origin by-products are the common sources, but facing religious constraints and risks associated to diseases, like bovine spongiform encephalopathy (BSE), from which alternatives as marine collagen are arising. One of the actual challenges in biomedical community is the engineering of corneal tissue in cases of cornea degeneration. Cornea structure is well defined, constituted by 5 layers, being stroma the main layer, with collagen fibers oriented perpendicularly between layers, embedded in sulfated glycosaminoglycans. Corneal transplantation and delivery of limbal epithelial cells are the only solutions available but not fully satisfactory. The objective of this work will be to use biotechnological tools on marine by-products to develop a new biomedical product for corneal tissue degeneration. Codfish skins are used as raw-material for the extraction of collagen, which will be then used to produce membranes together with other polymers. The physical, chemical and biological properties of these membranes will be assessed, evaluating their performance mimicking the collagen-based native cornea stroma. Further, in vitro and in vivo assays will be performed in order to prove their biocompatibility. For in vitro assays, cornea stromal and epithelial cells from rabbit will be cultured on the developed collagen-based membranes; for in vivo tests, membranes implantation in animal model (rabbit) will be performed, using procedures well-established in the Tissue Engineering Group, Department of Histology of the University of Granada, Spain.