Synthesis and characterization of hydrophobically modified chitosan

Abstract

The aim of this paper was to prepare and evaluate the feasibility of hydrophobically modified chitosan for hemostatic use. Chitosan was grafted with different branched chains by schiff reaction with salicylaldehyde and dodecyl aldehyde and followed by reductive amination with NaBH 4 . Elemental analysis was carried out to calculate the degree of substitution (DS) for NH 2 . Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests were used to confirm the composition and structure of modified chitosan products. Rheological experiments were performed to evaluate the ability of fluids including modified chitosan and its mixtures with heparinized blood to form gels. Dynamic blood coagulation experiments were tested to compare the hemostatic property of chitosan with its derivatives in vitro. The results demonstrated that orhto-hydroxytoluene and dodecyl were grafted into the backbone of chitosan successfully and the crystallity of chitosan was changed sligtly. Although the DS of ortho-hydroxytoluene chitosan was higher than that of dodecyl chitosan, the later had better gel-forming ability and lower absorbency at specific wavelength of haemoglobin. Dodecyl chitosan had great potential as an ideal candidate for local hemostasis.