Development Of A Drug-Loaded Wound Dressing Based On Glucomannan-Chitosan For Enhanced Wound Healing

The skin serves as the outermost barrier protecting animals from the physical environment,making it susceptible to injuries and damage,while secondary damage and bacterial infection caused by inadequate protection after injury also hinder the normal healing behavior of the skin.The difficulty of rapid healing of common wounds affects people’s daily lives,while severe full-thickness skin wounds expose tissue directly to the external environment and can even be life-threatening.Therefore,there is an urgent need to find suitable ways to protect skin wounds so that people can accelerate the healing process after injury and return to their daily activities.Traditional wound dressings no longer meet people’s needs.As the demand for advanced wound dressings increases,higher expectations are placed on their additional functionalities.Excellent wound dressings should not only provide physical protection to the wound area but also quickly remove tissue exudate and possess antibacterial properties.Additionally,they should intervene in the skin repair process,quickly passing through the inflammatory phase and facilitating wound healing.Injectable hydrogel wound dressings can not only absorb tissue exudate promptly due to their rapid gelation properties but also can adapt to any wound shape.In addition,the porous structure of the hydrogel allows for the carriage of various drugs,while its degradability gives it sustained release properties.With the continuous rise of antibiotic-resistant superbugs,it is becoming increasingly difficult for antibiotics to be effective.The antibacterial mechanism of zinc ions is different from that of antibiotics and it has no drug resistance,so it is suitable for advanced wound dressings.This study developed an injectable hydrogel based on glucomannan and chitosan and loaded with mesoporous zinc oxide nanoparticles as drug carriers.The characteristics,biocompatibility and antibacterial performance of the hydrogel are assessed.Subsequently,two traditional Chinese herbal molecules are loaded onto the hydrogel dressings,and a full-thickness skin injury model in rats is established to evaluate the therapeutic effects.Two parts of the study are carried out as follows:1.Injectable hydrogels based on glucomannan and chitosan were designed and loaded with mesoporous zinc oxide nanoparticles to form the wound dressing system.The self-healing properties of the hydrogels were evaluated by rheological tests;their mechanical properties were assessed by compression tests.The mesoporous structure of the mesoporous Zn O nanoparticles and their feasibility as drug carriers were determined by specific surface area testing;the slow release of Zn²⁺from the dressing system was demonstrated by inductively coupled plasma mass spectrometry;the safety of the dressing system as a wound dressing was demonstrated by biocompatibility testing;and the antibacterial properties of the dressing system were assessed by antibacterial testing.The hydrogel wound dressing system was shown to have the ability to act as a drug carrier and can be used for wound repair.2.The above hydrogel wound dressing system was loaded with two different small molecules of Chinese medicine,paeoniflorin and baicalin,and the successful loading of mesoporous zinc oxide on the two small molecules was demonstrated by UV-Vis absorption test and high performance liquid chromatography analysis.The effect of the dressing system loaded with the two small molecules on wound healing was then evaluated by establishing a whole skin wound model in SD rats,and collagen deposition at the wound site was observed by H&E staining and Masson staining.It was demonstrated that the drug-loaded wound excipient system could promote wound healing at both macro and micro levels.