Study On Preparation And Performance Of Bacterial Cellulose Antibacterial Biofilm

In the medical field,the protection of wounds with damaged skin has been receiving attention,especially the infection of microbes in the wound environment,so wound dressings have become the focus of research.In a series of medical antibacterial dressings that have been developed,it is found that there are still some problems that need to be solved,such as single function and high external environment requirements.In this thesis,several bacteriostatic composite membranes were used as medical dressings.Through a series of characterization and detection methods,the composite mechanism,morphological structure and bacteriostasis of representative bacteria?E.coli?were studied,and toxic reagents were used.The cassette evaluated the biocompatibility of the composite membrane.The main contents of this paper are summarized as follows:?1?In order to increase the effect of the composite membrane on the electrical performance,the experiment was to add graphene oxide?GO?solution to Acetobacter xylinum culture medium,use bacterial cellulose to fix graphene oxide during the formation process,and further use polydopamine to fix Ag NPs,a new silver-based cellulose composite membrane was developed wound dressing?Ag-DA/BC?rGO??.This composite membrane can produce a weak current under the condition of electricity and continue to generate heat,thereby achieving the effect of accelerating wound cell migration and promoting wound healing.In addition,Ag NPs immobilized on the surface release Ag⁺,which generates a large amount of oxidized free radicals and kills bacteria.In vitro cytotoxicity tests show that Ag-DA/BC?rGO?composite membrane has excellent biocompatibility.?2?A self-assembled bacterial cellulose/chitosan silver-loaded composite membrane?Ag-DA/BC?CTS??prepared by adding a Chitosan solution to acetobacter xylinum culture medium and using the method of microbial co-growth.The SEM image shows that the silver nanoparticles on the surface of the composite film have a diameter of about 50 nm,and the distribution is relatively uniform.The addition of CTS in the composite film also makes Ag-DA/BC?CTS?have good biocompatibility and its antibacterial It is based on the composite membrane that provides the synergistic bacteriostatic effect of the protonated amino group?-NH₃⁺?and Ag⁺of CTS.?3?A silver-containing high antibacterial PVA gel composite membrane modified by bacterial cellulose?BC?modified chitosan was prepared by one-pot method.The in vitro bacteriostasis test shows that the bacteriostasis rate of the composite membrane is over 95%,and it has ideal long-lasting bacteriostasis performance.Test characterization shows that Ag NPs are evenly distributed on the surface of the composite membrane with a particle size of 50 nm,and the composite membrane has good three-dimensional structure and physical properties.Due to the addition of CTS,the composite membrane has a synergistic bacteriostatic effect of protonated amino groups?-NH₃⁺?and Ag⁺,and provides better biocompatibility.Therefore,the Ag-DA/BC?CTS?composite membrane has the field of antibacterial dressings.Very good application prospects.In summary,the three systems of the article carried out experimental work around bacterial cellulose.The prepared medical bacteriostatic wound dressing has the characteristics of long-lasting bacteriostasis,good biocompatibility and accelerated wound healing.However,there are shortcomings such as high cost and complicated process in the preparation process,which should be continuously optimized in future research.