Characterizations of Chitosan Sponges Prepared from Shrimp Shell (Penaeus monodon) and Squid Pen (Loligo formosana)

Abstract

Chitosan is a deacethylated product of chitin which is a major component of prawn shell and squid pen. Structurally, the linear polymer chains of chitin from prawn shell are arranged by anti-parallel fashion, α -form while the chains from squid pen are arranged by parallel fashion, -form. Since the compatible biopolymers exhibit anti-bacterial, anti-fungal, enhance wound healing and hemostatic activities, various forms of product have been modified to use in medical applications. Unfortunately, most of available reports were confined with the- form, but rarely information was seen for another one. Therefore, these studies aim to compare characteristics of the sponge prepared from chitosan derived from the two sources. To each source, preparation was carried out by freez-drying known properties of chitosan in acid solution at different concentration, and at different volumes. Surface study with scanning electron microscope (SEM) revealed that the sponge from prawn shell chitosan showed the higher porosity with the more compact structure than that from the squid pen. Moisture content and concentration of residual acid was influenced by amounts of chitosan used in preparation rather than source and acid volume. Solubility examination showed that all samples were soluble in neutral aqueous solution but there were sparingly soluble in buffer solution at pH around 7. However, they became insoluble after drying and sterilizing. Interestingly, the concentration of residual acid was increased in the sponge from prawn chitosan after heating whereas the opposite was found in another one. Therefore, degree of solubility as well as residual acid concentration in the sponges might be modified by optimizing drying period.