Preparation And Antibacterial Activities Of 2d Dual-delivery Antibacterial System GO-PEG/Ag-SD

Hospital,food preparation factory,drug processing factory and other places with strict hygiene requirements,as well as household items,like furniture and home appliances,all need to be treated with asepsis processing.But,in recent years,the drug resistance of bacteria is increasing,because of the misuse of the antibiotics,and even caused superbugs.The human's health is threatened by bacteria,so develop and prepare new and effective antibacterial materials is in emergency.The antibacterial materials can be divided into inorganic antibacterial materials and organic antibacterial materials,which have disadvantages when used alone,such as inorganic antibacterial materials have high biotoxicity and organic antibacterial materials are easy to make bacteria resistant.So,it becomes an important project to research an inorganic-organic composite antibacterial material with excellent synergistic antibacterial effects.In this thesis,Graphene Oxide?GO?with many hydroxide radicals and carboxyl groups at its surface,was prepared by the oxidation method.Then the PEGylated graphene oxide?GO-PEG?was prepared,which exhibited significantly aqueous stability and drug loading property via the surface modification and functionalization of the GO.The GO-PEG was used as a vector for silver nanoparticles?Ag NPs?and sulfadiazine?SD?to prepare the GO-PEG/Ag-SD composite materials,which synthesized by a microwave irradiation route and a facile ultrasonic self-assembly route.The antibacterial activity of the novel composite materials,GO-PEG/Ag-SD,was enhanced by over 8 times compared to that of the system lacking SD and silver sulfadiazine?SSD?.The specific research contents and results are as follows:?1?GO was prepared by the modified Hummers method with some modifications,but the materials has poor aqueous stability with low concentration,which seriously affected the antibacterial properties and applications of graphene-based composite materials.First,carboxylated graphene oxide?GO-COOH?was prepared by surface carboxylation treatment,the hydroxyl group on the surface of GO was converted into carboxyl group,which has higher reactivity.Then,hydrophilic macromolecules?PEG-OH?were introduced into carboxylated graphene oxide via ester linkages and the GO-PEG was successfully prepared.GO-PEG was found to be stable in water without precipitation for 96 days and the PEGylated graphene oxide exhibited significantly improved water stability.?2?The preparation of GO-PEG/Ag nanocomposites by a facile synthesis method via microwave irradiation,which is a rapid and green route.In this synthesis process,GO-PEG and Ag NO₃ were used as raw materials and Na OH was used as reaction accelerator.The size of Ag NPs can be easily controlled by adjusting the microwave time.The antibacterial activity of GO-PEG/Ag with different sizes of Ag NPs against E.coli and S.aureus was determined.The smaller Ag NPs showed better antibacterial activity than the larger ones,with 6.25?g/m L and 12.5?g/m L minimal inhibitory concentration?MIC?values,respectively.?3?The preparation of GO-PEG/Ag-SD nanocomposites by a facile synthesis method via ultrasonic self-assembly route.In this synthesis process,GO-PEG/Ag was used as carrier and SD was used as raw materials.The antibacterial activity of GO-PEG/Ag-SD against E.coli and S.aureus was determined,with GO-PEG/Ag and SSD as control groups.GO-PEG/Ag-SD showed better antibacterial activity with the MIC of 0.78?g/m L.These properties are attributed to the excellent synergistic antibacterial effect of GO,Ag NPs,and SD:the capping effect of GO,puncture effect of Ag NPs,and inhibitory effect of SD.A novel 2D hybrid-material-based antibacterial system with efficient antibacterial drug loading was developed via a facile,rapid,green,microwave-assisted route.The GO-PEG possessed superior water phase stability through surface hydrophilic modification.The high specific surface area of GO was utilized to efficiently load antibacterial Ag NPs and SD.The GO-PEG/Ag-SD revealed excellent antibacterial activity with a remarkably low MIC dosage?0.78?g/m L?,fast sterilization and superior efficiency.This study provides new insights into the design and fabrication of surface-modified GO and carbon materials and their 2D hybrid multifunctional materials for advanced applications including biomedical and especially antibacterial applications,broadening the design and application scope of carbon and 2D materials.