Preparation Of Silver-Supported Mesoporous Silica And Its Antibacterial Properties And Biosafety

Dentin sensitivity is thought to be caused by liquid flow in dentin tubules.The dentinal sensitivity can be relieved by closing the dentinal tubule.At the same time,silver ions have a certain antibacterial effect on pathogenic bacteria in the oral.Mesoporous silica has the characteristics of large specific surface area and good adsorption.Silver-supported mesoporous silica is a potential material for the treatment of dentin sensitivity and as an oral antibacterial agent.However,Due to differences in material production methods,the characteristics of materials also show differences,and their characteristics need to be studied before clinical use.This study focuses on the following three aspects:1.Synthesis of silver-loaded mesoporous silica:first using cetyltrimethylammonium chloride(CTAC)cationic surfactant as template,tetraethyl orthosilicate(TEOS)as the silicon source,mesoporous silica(MSNs)with 3 D dendritic structure was synthesized by soft template method,and then MSNs were amino-modified to obtain amino-modified mesoporous silica(NH2-MSNs),and chemical reduction method was used to obtain silver-loaded mesoporous silica(Ag-MSNs),and Ag-MSNs were coated with different amounts of silica(SiO2)film to obtain silver-loaded mesoporous silica coated with silica(Ag-MSNs@60SiO2 and Ag-MSNs@100SiO2),and finally the synthesized materials were characterized by a projection electron microscope(TEM).The three kinds of silver-loaded mesoporous silica had good dispersibility.2.Antibacterial properties of silver-loaded mesoporous silica:The minimum inhibitory concentration(MIC)and the minimum bactericidal concentration(MBC)of Ag-MSNs,Ag-MSNs@60SiO2 and Ag-MSNs@100SiO2 against Escherichia coli and Staphylococcus aureus standard strains were tested.The MIC of Ag-MSNs@60SiO2 and Ag-MSNs@100SiO2 against E.coli was 160 ?g/mL,and the MIC against S.aureus was 320 ?g/mL,The MIC of Ag-MSNs against E.coli was 320 ? g/mL,the MIC against S.aureus was 640 ? g/mL,and the MBC of Ag-MSNs and Ag-MSNs@60SiO2 against E.coli was 640 ? g/mL,The MBC of Ag-MSNs@60SiO2 and Ag-MSNs@100SiO2 against S.aureus was 320 ?g/mL,the MBC of Ag-MSNs@100SiO2 against E.coli was 160 ?g/mL,and the MBC of Ag-MSNs against S.aureus was 1280 ?g/mL,all three materials have good antibacterial properties.3.Biosafety study of silver-loaded mesoporous silica:The cytotoxicity of NIH 3T3 cells and HGF-1 cells was tested with these three materials respectively,and the results showed that none of these three materials were cytotoxic to NIH 3T3 cells,Mild or moderate cytotoxicity to HGF-1 cells when the material concentration increases to 320 ? g/mL;The cytotoxicity of the three materials to HGF-1 was tested after 1,2,and 3 days of slow release of nanosilver.The results showed that the cytotoxicity of the three materials fluctuated slightly with the increase of the release time of nano-silver,but it was almost non-toxic to the cells at the material concentration<320 ? g/mL.The effects of three materials on the cell cycle of HGF-1 were studied.The results showed that it had almost no effect on the HGF-1 cell cycle.Conclusion:The three kinds of silver-supported mesoporous silica materials have good antibacterial properties and biosafety,especially Ag-MSNs@60SiO2 and Ag-MSNs@100SiO2,which have better antibacterial properties and biosafety and have the potential as desensitizers and oral antimicrobial materials.