The preparation of hyaluronic acid grafted pullulan polymers and their use in the formation of novel biocompatible wound healing film

A series of hyaluronic acid grafted pullulan (HA-g-Pu) polymers with different hyaluronic acid (HA) moieties degrees of substitution (DS) were synthesized and characterized by fourier transform infrared (FT-IR), proton nuclear magnetic resonance (H-1 NMR) and differential scanning calorimetry measurement (DSC). Compared to pure HA, HA-g-Pu polymers obtained better anti-enzymatic degradation ability in vitro, and the degradation rate of HA-g-Pu polymers depended on their different DS of HA moieties. The HA-g-Pu films were made of leaf-shape cascading arrangement with many small porous ranging from 0 to 100 mu m in diameter when observed by scanning electron microscopy (SEM). Therefore, HA-g-Pu films have a higher swelling ratio than that of the pullulan/or HA films. HA-g-Pu films could absorb much liquid, effectively protect the wound bed from accumulation of exudates and reduce the frequency of replacement. Moreover, the good biocompatibility of HA-g-Pu polymers were confirmed by skin irritation, cytotoxicity, cell proliferation and hemolysis test. Compared with the natural healing, the HA-g-Pu films promoted the wound healing. HA of HA-g-Pu polymers played an important role in the wound healing response. Furthermore, the HA-g-Pu polymers appeared a certain coagulation function and obtained a relative rapid hemostasis ability which might be attribute to heal wound.