Preparation and characteristics of a water‐soluble chitosan–heparin complex

To improve the wound‐healing ability of chitosan, heparin, known to be effective in wound healing, was complexed with water‐soluble chitosan (WSC) by chemical reaction. The chemical structure of the water‐soluble chitosan–heparin (CH) complex was analyzed, and CH complex formation was confirmed with an FTIR spectrometer. The mechanical and thermal properties of the CH complex were measured by a tensile tester and thermal analyzers (DSC and TGA). Within the heparin content up to ≈470 IU/g in the aqueous CH complex solution, the intrinsic viscosity and tensile strength of the water‐soluble CH complex gradually increased, but thermal stability slightly decreased by introducing the heparin into the WSC. When the heparin content was greater than these values (470 IU/g), the water‐insoluble CH complex, which is supposed to have a multisubstituted or crosslinked structure, precipitated in the aqueous water‐soluble CH complex solution.