Study On Preparation Of Multifunctional Wound Dressing And Its Properties Of Hemostasis And Anti-infection

The massive bleeding and bacterial infection of the wound are the main causes of the death of the injured,so rapid hemostasis of the wound,and effective prevention and treatment of bacterial infection in the wound healing process is particularly important.In this study,a multifunctional wound dressing was prepared,which integrates rapid hemostasis,detection of bacterial infection and in situ photodynamic antibacterial therapy,which can intelligently intervene the whole process of wound treatment.The main research contents and results are as follows:(1)The cationic photosensitizer(3T-MP-BH)with low HOMO-LUMO gap value and high water solubility was designed by Gaussian,Molinspiration and ACD/Log P software.3T-MP-BH had no cytotoxicity and dual antibacterial mechanism.Under the irradiation of xenon lamp,the bactericide rate of 3T-MPBH to Pseudomonas aeruginosa was as high as 100%.(2)Porous starch graft copolymer(PSGC)was prepared from potato starch,and its water absorption was 398.80 g/g.The adhesive(TAPEC)was prepared from tannic acid and polyethylene glycol.TAPEC can be reused and its adhesive strength is 111.82 k Pa.The water absorption of PSGC and the adhesion of TAPEC are conducive to rapid hemostasis of wounds.(3)The detection layer(BC/MUG)was prepared by loading the MUG onto bacterial cellulose(BC)membrane under ultrasound.The protective antimicrobial layer(CA/3T-MP-BH)was prepared by electrospinning with cellulose acetate(CA)and 3T-MP-BH as raw materials.Bacteria-secreted ?-glucuronidase(?-GUS)can react with 4-methylumbelliferyl-?-D-glucuronide(MUG)to produce a fluorescent molecule 4-methylumbelliferone(4-MU).Therefore,BC/MUG relies on this reaction to detect Pseudomonas aeruginosa,Staphylococcus aureus and Escherichia coli,while CA/3T-MP-BH can photodynamically kill these three bacteria,with a bactericidal rate of 99%.(4)The double-layer membrane were prepared by electrospinning using BC/MUG as the receiving plate and the mixed solution of CA and 3T-MP-BH as the spinning fluid.TAPEC was used as the intermediate connecting layer,and the double-layer membrane was bonded with the hemostatic antibacterial layer to obtain the wound dressing.The wound dressing could stop the bleeding in rabbit auricular artery by 1 s,which was the result of the combined action of PSGC and TAPEC.In the mouse wound model,the wound healing rate of the mice infected with bacteria after the wound dressing photodynamic therapy was 97.33%,higher than the wound healing rate of other experimental groups,which proved that the wound dressing has the ability to treat bacterial infection.At the same time,the pathological observation of the wound and the analysis of serum inflammatory factors in mice showed that the wound dressing was biocompatible and did not cause inflammation.