Preparation And Characterization Of Antibacterial Surface Based On Polyhexamethyleneguanidine Hydrochloride

The adhesion and proliferation of bacteria on the surfaces of various man-made materials pose serious problems for health care and industrial applications.In biomedical applications,the heavy use of antibiotics can lead to bacterial resistance,making it difficult to eradicate infections associated with biofilms.Therefore,it is necessary to design surfaces with antibacterial properties to eliminate or inhibit bacterial attachment and biofilm formation.Compared with the method of releasing fungicide,grafting antibacterial groups on the surface of the film can maintain the bactericidal contact ability of bacteria on the surface for a long time without releasing toxic fungicide to the outside world.In this paper,the grafted copolymer SEBS-g-MAH was synthesized by simple solution graft method using polystyrene-b-polyethylene/butene-b-polystyrene block copolymer(SEBS)and maleic anhydrine(MAH)as the main raw materials.The structure of the graft copolymer SEBS-g-MAH was characterized by Fourier transform infrared spectroscopy(FT-IR)and hydrogen nuclear magnetic resonance spectroscopy(~1H-NMR).The obtained SEBS-g-MAH was dissolved in methyl cyclohexane,and then the membrane was prepared by the solvent-casting method to obtain MAH-SEBS-film.Next,Polyhexamethylguanidine hydrochloride(PHMG)was immobilized on the surface of MAH-SEBS-film by amidation of the terminal amino group of PHMG with the anhydrine group on the surface of MAH-SEBS-film.Besides the surface component,surface morphology and antibacterial activity of PHMG were subsequently characterized.The experimental results showed that the film had good contact killing ability against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli),and the antibacterial rates were 91.4%and 99.9%,respectively.The film has the advantages involving simple preparation,easy post-modification and excellent antibacterial properties.And it is expected to be used for surface antibacterial enhancement treatment of implanted materials in vivo.The other part of this paper takes L-malic acid as monomer,then obtains low molecular weight polymalic acid(PMA)through dehydration condensation reaction under vacuum condition by polycondensation,and then Na OH aqueous solution was added into PMA aqueous solution to prepare polymalate sodium(PMA-Na)aqueous solution(polyanion).Then,under the ultrasonic condition,the PMA-Na aqueous solution was added into PHMG aqueous solution(polycation),and then the suspension of PMA-Na/PHMG ion crosslinked microspheres(PMA-PHMG-NPs)was synthesized.By changing the ratio of polyanion and polycation,a variety of PMA-PHMG-NPs suspension was synthesized,and the particle size,morphology,antibacterial properties,cytotoxicity and other aspects of the microspheres were characterized.The results showed that when the concentration of sodium polymalate solution was 0.2 mg/m L and the concentration of PHMG solution was 0.5 mg/m L,the obtained microspheres had good antibacterial properties and low cytotoxicity,the antibacterial rate was 99.9%,the cell survival rate was 97.9%,the obtained PMA-PHMG-NPs could be used in the field of food and drug sterilization or wound treatment.