Several materials are being studied nowadays in a tissue engineering perspective and collagen, being the most abundant protein in mammals, is certainly one of the key polymers to be considered. The most traditional sources of collagen are calf and pork skin but those sources are facing some illness-related drawbacks as well as their use being hindered by religious constrains. In this perspective, alternatives are being pursued and besides the most costly alternative of recombinant production, marine organisms are being considered. In particular, fish skins can be an important source of collagen, and being a fish-processing by-product, brings clear economic and environmental benefits [1,2]. In this work, collagen was extracted from shark (Scyliorhinus canicula) skin by treatment with acetic acid, and thus known as acid soluble collagen (ASC). The collagen was further evaluated as alternative for different biomedical applications, with focus in tissue engineering. Collagen membranes were prepared from acetic acid solutions following a solvent casting methodology and cross-linked in situ with hexamethylene diisocyanate (HMDI), to render stable structures in PBS and culture medium. The crosslinking efficiency was assessed by FTIR spectroscopy and ninhydrine assay. Moreover, membrane properties as their mechanical properties (tensile tests), wettability and degradation in the presence of collagenase were also evaluated. Collagen membranes were successfully produced, with tunable properties by changing the processing conditions, namely the ratio between HMDI and collagen and the time of crosslinking reaction, promising relevance for application as drug delivery device, wound dressing or for cell culture.

[1] Silva TH, Alves A, Ferreira BM, Oliveira JM, Reys LL, Ferreira RF, Sousa RA, Silva SS, Mano JF, and Reis RL, "Materials of marine origin: a review on polymers and ceramics of biomedical interest", International Materials Reviews, 57 (2012), 276-306.
[2] Silva T. H., Duarte A. R. C., Moreira-Silva J., Mano J. F., and Reis R. L., "Biomaterials from Marine-Origin Biopolymers", Biomimetic Approaches for Biomaterials Development, Wiley-VCH, 2012, pp. 3-24.