Customizing properties of ?-chitin in squid pen (gladius) by chemical treatments

The squid pen (gladius) from the Loligo vulgaris was used for preparation of ?-chitin materials characterized by different chemical, micro- and nano-structural properties that preserved, almost completely the macrostructural and the mechanical ones. The ?-chitin materials obtained by alkaline treatment showed porosity, wettability and swelling that are a function of the duration of the treatment. Microscopic, spectroscopic and synchrotron X-ray diffraction techniques showed that the chemical environment of the N-acetyl groups of the ?-chitin chains changes after the thermal alkaline treatment. As a consequence, the crystalline packing of the ?-chitin is modified, due to the intercalation of water molecules between ?-chitin sheets. Potential applications of these ?-chitin materials range from the nanotechnology to the regenerative medicine. The use of gladii, which are waste products of the fishing industry, has also important environmental implications.