Preparation And Application Of Novel Polydopamine-heparin/Quaternary Ammonium Salt/polyacrylamide Hydrogel

Chronic wounds are a serious problem in the current global wound disease,which has a serious impact on human life.Chronic wounds infected by bacteria and other microorganisms are one of the main factors leading to complications,and the development of antibacterial hydrogel dressings is an effective method to improve the efficiency of wound healing.Usually antibacterial hydrogels use hydrogels as carriers to encapsulate antibacterial drugs or silver nanoparticles.The abuse of antimicrobial drugs will cause the impact of drug resistance,and the biological safety of silver ions has been doubtful.Therefore,it is of great significance to develop a new type of multifunctional hydrogel dressing with antibacterial effect.In this paper,the synthesis method of free radical polymerization is used to combine dopamine(DA),heparin(HP),antibacterial agent 2-acryloyloxy-ethyl-N,Ndimethyl-6-ammonium bromide quaternary ammonium salt(AEDMHA)And acrylamide(AM)are effectively combined in the polymer network to prepare a composite hydrogel dressing that not only meets the wound's various physical properties of the dressing,but also achieves antibacterial properties and good biocompatibility.Through the series of physical and chemical performance characterization and biological performance characterization of the prepared hydrogel,the following results were obtained:(1)The polydopamine-heparin/polyacrylamide hydrogel has prepared by simple free radical polymerization.The preparation method of the hydrogel is simple,the reaction conditions are mild.The prepared hydrogel has tissue adhesion,good physical and mechanical properties,also has good water absorption and water retention ability.(2)The prepared polydopamine-heparin/polyacrylamide hydrogel was subjected to antibacterial experiments,and found that Gram-negative bacteria-(E.coil)and Gram-positive bacteria-Staphylococcus aureus(S.aureus)has a certain antibacterial effect,and good antibacterial adhesion performance;Cytotoxicity evaluation of this hydrogel,it has not toxic to mouse 3T3 fibroblasts,and has good biocompatibility.(3)The 2-acryloyloxy-ethyl-N,N-dimethyl-6-ammonium bromide quaternary ammonium salt(AEDMHA)was synthesized;AEDMHA was added to the polydopamine-heparin/polyacrylamide gel precursor system to enhance the antibacterial effect of the original gel system,polydopamine-heparin/quaternary ammonium salt/polyacrylamide hydrogel was prepared by free radical polymerization.The gel also has the advantages of tissue adhesion,good physical and mechanical properties,and good water absorption properties.(4)The prepared polydopamine-heparin/quaternary ammonium salt/polyacrylamide hydrogel was subjected to antibacterial experiment and found to have antibacterial effect on E.coil and S.aureus;It has slightly toxic to mouse 3T3 fibroblasts and has good biocompatibility.