Preparation Of ZnO/Dopamine/L-cysteine Nanocomposites And Their Surface Properties On Antibacterial Properties And Biosafety Influence

Because of its unique physical and chemical and biological characteristics,Zn O NPs has been widely concerned and studied.As a new type of multi-functional material,ZnO NPs has good antibacterial property,and osteogenesis and anticancer function.Recent years,researchers add ZnO NPs to the dental materials such as mouthwash,dental filling materials,titanium implants,Which has improved the comprehensive performance of dental materials.However,with the extensive application of ZnO NPs,there is no doubt that this material will enter our life and environment,it may endanger human health and the safety ecological environment.Therefore,it is very important that how to make use of the green environmental and simple way to modify the surface of ZnO NPs and endow it with good biocompatibility and antibacterial property.Lcysteine is an encoded amino acid which can compound protein,and it is the only one with sulfhydyl(-SH)of more than 20 kinds of natural amino acids.It has extensive detoxification in the human body,which has been widely used in medicine and food additives.This article adopts the simple method to prepare ZnO NPs with L-cysteine,and explore its antibacterial and biological safety properties,the main research content is listed as follows:(1)In this study,we combined Dopamine to ZnO NPs,then the surface active site of this compound can combined with the surface nucleophilic group of L-cysteine.Then we analyzed the physical and chemical property of the superior combined material by infrared spectroscopy,X-ray photoelectron spectroscopy,thermal Gravimetric Analyzer,transmission electron microscope,and so on.The results showed that Zn O/Dopamine/L-cysteine nano hybrid material was prepared successfully.(2)The antibacterial ability of this material against Staphylococcus aureus and Escherichia coli was evaluated by the plate colony-counting methods,and its biocompatibility was detected by CCK8 method and mouse intragastric administration.The resulted showed that ZnO/Dopamine/L-cysteine nano hybrid material expressed good dispersibility on ultrapure water,and it showed good antibacterial ability against Staphylococcus aureus and Escherichia coli at a concentration of 300 ug/ml and 100ug/ml.The results in vivo and vitro experiments showed that the cytotoxicity of ZnO/Dopamine/L-cysteine nano hybrid material to NIH 3T3 was grade 0 or?,then we found that the blood biochemical and pathological sections showed a good biocompatibility after 7days of continuous intragastric with NPs suspension(40mg/ml).It can be seen that the biological safety of the system was improved obviously,and the antibacterial property is good after the modification of nano ZnO by L-cysteine.It may be considered as a new antibacterial agent,which can be widely used in dental material.