Valorization of chitosan from squid pens and further use on the development of scaffolds for biomedical applications

Objectives: The aim of the present work is the valorization of squid pens through the production of chitosan that can be used for the development of biomedical applications. The present work is focused on !-chitin extraction from squid pens of the species Dosidicus gigas and its further conversion into chitosan. The biomedical potential of the isolated squid chitosan was assessed by processing this polymer as scaffolds for tissue engineering strategies. Methods: Alkali solution was used to deproteinized squid pens and thus isolate !-chitin, which was further converted into chitosan through a deacetylation reaction. The chitosan scaffolds were developed using a freeze-drying process, from 3% and 4% chitosan solutions in acetic acid and freezing at temperatures of -80ºC and -196ºC. Chitosan scaffolds were neutralized using two different methods: M1 – NaHO solution; and M2 – ethanol/water and NaHO solution. Morphology, Mechanical properties, degradation, cytotoxicity (L929 cells) and cellular adhesion (ATDC5 Chondrocytes like cells) of squid chitosan scaffolds were assessed and compared with the properties of scaffolds produced with commercial chitosan. Results: The morphology of scaffolds revealed a lamellar structure for all produced scaffolds, independent of the origin and concentration of chitosan. The treatment with sodium hydroxide and ethanol caused the formation of larger pores and loose of some lamellar features. Different freezing temperatures gave different pore morphology and the lower temperature a smaller pore size. The in vitro cell culture and cell adhesion studies showed that all chitosan scaffolds exhibited a non-cytotoxic effect over the mouse fibroblast-like cell line, L929 cells. Conclusions: The chitosan produced from the endoskeletons of giant squid Dosidicus Gigas has proven to be a valuable alternative to the commercial one when considering its use as biomaterial for different biomedical applications.