Preparation And Characteristics Of Quaternized Chitosan-based Hydrogel Dressings For Wound Healing Applications

Skin is the largest organ of the human body and plays an important role in defense.Skin has the ability to recover itself after the injury,but it is limit.Therefore,constructing suitable wound dressings is valuable for scientific research and clinical application.Because of its unique physical and chemical properties such as water retention and mechanical adaptation,hydrogel dressings have been widely used in wound healing.However,that is the focus and difficulty of the research to construct multifunctional hydrogel dressings for improving the wound healing rate.In this work,chitosan of grafted quaternary ammonium cations and oxidized polysaccharide were used to form a hydrogel by Schiff base,encapsulating Baicalein with the antimicrobial and antioxidant property or temperature-sensitive conductive substances to prepare multifunctional hydrogel dressings.The physicochemical property of hydrogels was characterized by Fourier-transform infrared spectroscopy(FT-IR),~1H nuclear magnetic resonance(~1H NMR),X-ray diffractometer(XRD),scanning electron microscope(SEM),rheometer,ultraviolet-visible spectroscopy and so on.The cell,antibacterial and in vivo wound healing experiments were used to evaluate its biocompatibility,antimicrobial ability and wound healing results.The study experiment results were displayed following:1.In this study,2,3-epoxypropyl trimethyl ammonium chloride grafted chitosan to prepare the quaternary chitosan.By Schiff base reaction between glycidyl trimethyl ammonium chloride-graft-chitosan(QCS)and aldehyde-dextran(ODex)under physiological conditions,loading Baicalein,prepare multifunctional hydrogel wound dressings(QCS-ODex).These hydrogels with fast in situ gel-forming(<70 s),porous structure,good transparency,tissue adhesion,transmission property,free radical scavenging capacity,good self-healing behavior,and injectability,biocompatibility and inherent antibacterial.Furthermore,Baicalein could be in situ encapsulated into QCS-ODex hydrogels,further facilitating free radical scavenging and antibacterial bioactivities due to the cooperative effects between QCS-ODex and Baicalein.Thus,a series of transparent self-healing injectable hydrogels with multifunction is ideal candidates for applying to irregular and motion wounds and observing and diagnosing the healing process as wound healing dressings.2.In this study,the multifunctional hydrogels(QOP hydrogels)were prepared by Schiff base reaction between glycidyl trimethyl ammonium chloride-graft-chitosan(QCS)and oxidized sodium alginate(OSA),adding poly(N-isopropyl acrylamide)with therm-responsive property and poly(3,4-ethylene dioxythiophene)with conductivity.The hydrogel has high mechanical properties,porous structure,swell behavior,good elastic property,conductivity,adhensive,self-healing behaviours,good biocompatibility and antibacterial property and great in vivo wound healing effect.The multifunctional hydrogel dressings are potential for wound healing.