Sprayable hydroxypropyl chitin/collagen extract of Ampelopsis brevipedunculata hydrogel accelerates wound healing

Objective: Keeping a wound moist can allow effective and rapid healing, and it can control the formation of scabs, thereby allowing cell proliferation and epithelial formation. When regularly changing a dressing, thermosensitive hydrogel as a moist dressing does not cause a secondary wound from adhesion. The main aim of this study was to evaluate the effect of a new sprayable thermosensitive hydrogel on wound healing. Method: The hydrophobic N -acetyl group of chitin was removed by microwave reaction with lye until the degree of acetylation was 60%, followed by reaction with propylene oxide to obtain hydroxypropyl chitin (HPCH) with a degree of substitution of 40%. After mixing HPCH with fish scale collagen (FSC), a thermosensitive hydrogel with a gel temperature of 26.5degree celsius was obtained. Ampelopsis brevipedunculata extracts (ABE), which have been found to accelerate wound repair and improve healing, were added. HPCH/ FSC is not toxic to the mouse L929 cell line and forms a hydrogel at body surface temperature. It can be easily sprayed on a wound. The HPCH/FSC has a three-dimensional network porous structure with a swelling ratio of 10.95:1 and a water vapour transmission rate of 2386.03 +/- 228.87g/m(2)/day; it can facilitate the penetration of water and air, and promote absorption of wound exudate. Wound repair was performed on five Sprague-Dawley rats. Each rat had three wounds, which were treated with medical gauze, HPCH/FSC and HPCH/FSC/ABE, respectively. Results: The wounds in the HPCH/FSC/ABE group recovered the fastest in vivo, the mature wound site was smoother, the re-epithelialisation was even and thicker, and the angiogenesis developed rapidly to the mature stage. Conclusion: In this study, HPCH/FSC/ABE thermosensitive hydrogel was shown to effectively accelerate wound healing and was convenient for practical application. Declaration of interest: The authors received financial support from the NTUT-MMH Joint Research Program under NTUTMMH-No.110-02, Mackay Memorial Hospital (MMH-108-111) and Ministry of Science and Technology MOST 109-2622-E-027-030-. The authors have no conflicts of interest to declare.