Cationic amphiphile aggregates exhibit superior antibacterial activity than monomers.However,the antimicrobial mechanism of aggregates has not been well understood because it is difficult to distinguish and monitor ag...Cationic amphiphile aggregates exhibit superior antibacterial activity than monomers.However,the antimicrobial mechanism of aggregates has not been well understood because it is difficult to distinguish and monitor aggregate and monomer in antimicrobial process.Herein,three bola-type cationic amphiphiles with aggregation-induced emission property have been developed to show distinguishable fluorescence in their monomer and aggregate.The hydrophilicity of monomer and the stability of aggregate are finely tuned by tailoring the linkers between two quaternary ammonium end groups and tetraphenylethylene skeleton.The sensitive fluorescence switching of monomer and aggregate achieves the quantitative monitoring of dynamic interaction of three amphiphiles with bacteria.The aggregates with cationic charges first attach to bacterial surface,and the monomers subsequently dissociate from aggregates to penetrate bacterial membrane.Further,our results reveal the vital role of stability of aggregates during antimicrobial process,shedding light on the rational design of high-efficient antimicrobials.展开更多
文摘Extracts of 16 natural medicine powders {Galla chinensis,Malloti cortex,Cassiae semen,Sophorae radix,Myricae cortex,Crataegi fructus,Gambit,Mume fructus,Geranii herba,Phellodendri cortex,Coptidis rhizoma,Swertiae herba,and Cinnamomi cortex） were assayed for reactive oxygen concentrations using the peroxyoxalate chemiluminescent detection system.High luminescence intensity was observed in Galla chinensis,Geranii herba,Malloti cortex,Myricae cortex,and Cinnamomi cortex.Additional experiments identified the reactive oxygen species as hydrogen peroxide.Galla chinensis generated 2.4 × 10^（-4） mol/L hydrogen peroxide from a 1 mg/mL solution.In bacterial growth tests,Galla chinensis extract had antibacterial activity against Escherichia coli.Staphylococcus aureus,Bacteroides thetaiotaomicron,Campylobacter sputorum biovar sputorum.Streptococcus salivarius thermophilus,Lactobacillus casei,and Bifidobacterium longum infantis.This antibacterial activity was decreased by the addition of catalase.It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.
基金National Natural Science Foundation of China,Grant/Award Number:22002137Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20200920+1 种基金Beijing Natural Science Foundation,Grant/Award Number:2212013Shenzhen Key Laboratory of Functional Aggregate Materials,Grant/Award Number:ZDSYS20211021111400001。
文摘Cationic amphiphile aggregates exhibit superior antibacterial activity than monomers.However,the antimicrobial mechanism of aggregates has not been well understood because it is difficult to distinguish and monitor aggregate and monomer in antimicrobial process.Herein,three bola-type cationic amphiphiles with aggregation-induced emission property have been developed to show distinguishable fluorescence in their monomer and aggregate.The hydrophilicity of monomer and the stability of aggregate are finely tuned by tailoring the linkers between two quaternary ammonium end groups and tetraphenylethylene skeleton.The sensitive fluorescence switching of monomer and aggregate achieves the quantitative monitoring of dynamic interaction of three amphiphiles with bacteria.The aggregates with cationic charges first attach to bacterial surface,and the monomers subsequently dissociate from aggregates to penetrate bacterial membrane.Further,our results reveal the vital role of stability of aggregates during antimicrobial process,shedding light on the rational design of high-efficient antimicrobials.
