Preparation Of Functional Polysaccharide Hydrogel And Its Application In Wound Repair

Polysaccharide hydrogel is a polymer material synthesized from polysaccharide as the main raw material.It is an ideal wound dressing that has been proven to beneficial to cell regeneration,which has higher biological safety and tissue adaptability than general hydrogel wound dressings.In recent years,by adding therapeutic drugs or nano-materials into polysaccharide hydrogels to make them functional,the various of new generation of hydrogels with specific functions was constructed,and the perfect method of exploring wound healing and tissue repair has received widespread attention.In order to solve the problems of bacterial infection and excessive reactive oxygen species(ROS)in the process of wound healing,two kinds of functional polysaccharide hydrogels were prepared by adding the nanoparticles of Ag-decorated polydopamine(PDA@Ag NPs)and the organic nanomaterial of polytannic acid(PTA),and their therapeutic effects on wound healing and tissue repair in different types of wound were deeply explored.The specific research contents and conclusions are as follows:(1)Silver nanoparticles were deposited on the surface of PDA by the redox reaction between PDA and silver nitrate solution to prepare PDA@Ag NPs(35.6%),which has higher photothermal conversion efficiency than PDA(21.7%).Subsequently,CG-PDA@Ag hydrogels(CPA)were prepared by using PDA@Ag NPs as photothermic agent and cationic guar gum(CG)as cross-linking monomer.The research shows that CPA hydrogel not only has stable mechanical structure,fast self-healing ability and excellent photothermal performance,the temperature of CPA hydrogels exceeds 70℃when exposed to 808 nm near-infrared(NIR,1 W/cm~2)light for 5 minutes,but also has biosafety,hemostatic and photothermal antibacterial properties,the antibacterial rate is greater than 98%.Finally,the CPA hydrogels were filled into the infected wound of rats and exposed to NIR light for 3minutes.By taking representative pictures of the wound repair process,as well as full-thickness skin sections and immunostaining of wounds at different time periods,it was confirmed that CPA hydrogel combined with photothermal therapy can significantly promote the healing of infected wounds.The research in this chapter provides a new idea for constructing a robust PDA-based nanomaterial photothermal system for antibacterial therapy and wound healing.(2)The OG/QCS-PTA hydrogels(OQP)were prepared by using oxidizedβ-Glucan(OG)and quaternized chitosan(QCS)as reaction monomers,and PTA as functional material.The mechanical properties of OQP hydrogel was enhanced by the introduction of PTA and enabled it to obtain excellent ROS scavenging ability,with the nitrogen radical scavenging rate increasing from 7.8%to 45.3%.In addition,the OQP hydrogel not only met the biosafety standard,but also quickly stopped bleeding and reduced bacterial infections,with an antibacterial rate of about 50%.In the end,the OQP hydrogels were injected into the wounds of diabetic rats can effectively scavenge excessive ROS to reduce cell stress injury and accelerate wound healing.The research in this chapter provides a facile and convenient method for constructing ROS scavenging hydrogel dressing,which has great application potentials in the clinical treatment of diabetic wounds.