Preparation And Properties Of Hydrogel Based On Cationic Polymer/sodium Alginate

The rapid healing of skin wounds,especially infected wounds,has been one of the hot spots for researchers in the field of healthcare.Compared with hydrogel dressings,traditional gauze,sponge and other dry dressings,its wound infiltration was poor and easy to bond with tissue.However,hydrogel dressings for healing of infected wounds also had the following drawbacks,such as lack of stable,continuous and efficient antibacterial property,poor functional stability in complex environment and inadequate adaptability to irregular wounds.In addition,it cannot be used as a multifunctional sensing platform to replace the sensory function of damaged skin and the dynamic monitoring of human health.In order to solve the above problems,we prepared different hydrogel dressings based on sodium alginate and cationic polymer through chemical/physical crosslinking strategies.Specific work was as follows:(1)The hydrogel skeleton was constructed by in-situ polymerization of cationic monomer 2-(methacryloyloxy)-N,N,N-trimethylethylamine chloride(DMC)in sodium alginate solution.Then hydrogel was functionalized by dynamic solvent replacement to improve its anti-freezing,water retention,environmental adaptability,adhesion and photothermal properties.As a wound dressing,the hydrogel showed significant antibacterial activity against both E.coli and S.aureus,and the number of residual colonies was reduced to 9 CFU.In the rat model of full-layer wound infection,it could significantly accelerate the healing of infected wound,and the wound healing rate of 14 days was 96.49%.In further multifunctional sensing tests,the hydrogel-based sensor demonstrated multimodal response to strain,pressure and temperature as well as excellent sensing stability.However,some problems still need to be solved,such as the residue of toxic molecules and the hydrogel’s poor adaptability to irregular wound shape.(2)In order to solve the problem of toxic molecule residue and hydrogel’s poor adaptability to irregular wound shape.Natural macromolecule sodium alginate was oxidized to be used as macromolecule crosslinking agent.An injectable hydrogel was prepared by its dynamic interaction with the cationic polymer polyvinyl alcohol bearing styrylpyridinium group(PVA-SBQ).The photothermal property of the hydrogel were endowed by loading polydopamine(PDA)nanoparticle.This hydrogel had the following advantages: Macromolecular hydrogel skeleton,no toxic cross-linking agent and photoinitiator residue;Injectable hydrogel has good adaptability to wound shape.At the same time,in situ photocrosslinking enhancement of the hydrogel can be achieved by utilizing the photosensitivity of PVA-SBQ.As a wound dressing,the hydrogel had excellent antibacterial property and could accelerate the healing of infected wounds,with a wound healing rate of 96.45% in 14 days.