The main objective of this study is to evaluate the antibacterial effect of antibacterial pho-todynamic therapy(aPDT)on Streptococcus mutans(S.mutans)biofilm model in vitro.The selection of photosensitizers is the key...The main objective of this study is to evaluate the antibacterial effect of antibacterial pho-todynamic therapy(aPDT)on Streptococcus mutans(S.mutans)biofilm model in vitro.The selection of photosensitizers is the key step for the efficacy of photodynamic therapy(PDT).However,no studies have been conducted in the oral field to compare the functional char-acteristics and application effects of PDT mediated by various photosensitizers.In this re-search,the antibacterial effect of Methylene blue(MB)/650 nm laser and Hematoporphyrin monomethyl ether(HMME)/532 nm laser on S.mutans biofilm was compared under different energy densities to provide experimental reference for the clinical application of the two PDT.The yield of lactic acid was analyzed by Colony forming unit(CFU)and spectrophotometry,and the complete biofilm activity was measured by Confocal Laser Scanning Microscopy(CLSM)to evaluate the bactericidal effect on each group.Based on the results of CFU,the bacterial colonies formed by 30.4J/cm^(2)532nm MB-aPDT group and 30.4J/cm^(2)532nm HMME-aPDT group were significantly less than those in other groups,and the bacterial colonies in HMME-aPDT group were less than those in HMME-aPDT group.Lactic acid production in all treatment groups except the photosensitizer group was statistically lower than that in the normal saline control group.The activity of bacterial plaque biofilm was significantly decreased in the two groups treated with 30.4 J/cm^(2) aPDT.Therefore,aPDT suitable for energy measurement can kill S.mutans plaque biofilm,and MB-aPDT is better than HMME-aPDT.展开更多
Antibacterial agent of activatable photosensitizer not only has the advantages of traditional photosensitizers,such as good curative effect and low resistance,but also has better selectivity for bacteria and lower tox...Antibacterial agent of activatable photosensitizer not only has the advantages of traditional photosensitizers,such as good curative effect and low resistance,but also has better selectivity for bacteria and lower toxicity to normal tissues.Limited reports of activatable photosensitizer can be used to treat drugresistant bacteria.In order to meet this challenge,we designed and synthesized an activatable photosensitizer(Ce-OHOA),which can not only selectively identify methicillin-resistant Staphylococcus aureus(MRSA)with high expression ofβ-lactamase by fluorescence imaging,but also kill MRSA with less than10 times the concentration and 10 times the irradiation dose of CySG-2 reported.Ce-OHOA not only combines the dual functions of fluorescence diagnosis and photodynamic therapy,but also selectively acts on bacteria with high expression ofβ-lactamase and has little toxicity to normal cells.We expect that the study of this activating photosensitizer will provide a new solution for antibacterial photodynamic therapy(aPDT)of drug-resistant bacteria.展开更多
Antibiotic administration is the mainstay for treating bacterial infections,but multidrug-resistant(MDR)bacteria jeopardize its effectiveness.Antimicrobial photodynamic therapy(aPDT)offers a promising strategy with le...Antibiotic administration is the mainstay for treating bacterial infections,but multidrug-resistant(MDR)bacteria jeopardize its effectiveness.Antimicrobial photodynamic therapy(aPDT)offers a promising strategy with less risk of inducing resistance,yet the lack of a suitable wearable light source limits its widespread adoption.Here,we design flexible quantum dot light-emitting diodes(F-QLEDs)for effective aPDT treatment of MDR bacteria.By simultaneous optical,thermal,and reliability management,we achieved F-QLEDs with emission spectrum matching the photosensitizer absorption,physiologically safe surface temperature(<41℃),enhanced operating lifetime(7.5X),and ambient shelf life>1 month.Subsequently,aPDT testing demonstrated a~9-log reduction of Staphylococcus aureus and~2-3 log reduction of Pseudomonas aeruginosa compared to controls.Additionally,testing with different photosensitizers confirmed F-QLED versatility for targeted aPDT.These results showcase the potent antimicrobial efficacy of F-QLEDs and their potential as wearable optical platforms for point-of-care treatment of MDR infections and broader photomedical applications.展开更多
Polydimethylsiloxane(PDMS)is widely used in biomedical applications due to its biocompatibility,chemical stability,flexibility,and resistance to degradation in physiological environments.However,its intrinsic inertnes...Polydimethylsiloxane(PDMS)is widely used in biomedical applications due to its biocompatibility,chemical stability,flexibility,and resistance to degradation in physiological environments.However,its intrinsic inertness limits further(bio)functionalization,and its hydrophobic recovery compromises the longevity of conventional surface modifications.To address these challenges,we developed a nanoprecipitation method for the straight-forward colloidal deposition,covalent thermal crosslinking,and surface anchoring of a chemically tunable,biocompatible polyacrylamide with reactive hydroxyl groups,enabling further surface modifications.This polymer incorporates~6%bioinspired catechol units,introduced via an elegant one-pot Kabachnik-Fields re-action,to facilitate thermally induced network formation and enhance adhesion to plasma-activated PDMS.The resulting uniform coatings exhibited tunable dry layer thicknesses up to 44±7 nm and effectively suppressed PDMS chain rearrangement even after steam autoclaving,ensuring long-term stability in aqueous and ambient environments for at least 90 days.The bioactive post-modification potential was demonstrated in a proof-of-concept study by immobilizing the photosensitizer rose bengal at surface concentrations of 20 or 40μg cm^(-2).The coating exhibited antimicrobial activity against S.aureus,achieving a 4-log reduction(99.99%)in colony-forming units after 30 min of irra-diation at 554 nm(342 J cm^(-2)),even when bacteria were suspended in liquid,without direct surface contact.In contrast,antimicrobial activity against E.coli was only observed with minimized liquid volume,bringing the motile bacteria into close contact with the surface.This work established a straightforward and versatile strategy for the stable and bioactive functionalization of PDMS surfaces for application in non-invasive surface decontamination.展开更多
基金supported by the Construction Plan of the Tianjin Characteristic Subject Group,Oral Medical Engineering
文摘The main objective of this study is to evaluate the antibacterial effect of antibacterial pho-todynamic therapy(aPDT)on Streptococcus mutans(S.mutans)biofilm model in vitro.The selection of photosensitizers is the key step for the efficacy of photodynamic therapy(PDT).However,no studies have been conducted in the oral field to compare the functional char-acteristics and application effects of PDT mediated by various photosensitizers.In this re-search,the antibacterial effect of Methylene blue(MB)/650 nm laser and Hematoporphyrin monomethyl ether(HMME)/532 nm laser on S.mutans biofilm was compared under different energy densities to provide experimental reference for the clinical application of the two PDT.The yield of lactic acid was analyzed by Colony forming unit(CFU)and spectrophotometry,and the complete biofilm activity was measured by Confocal Laser Scanning Microscopy(CLSM)to evaluate the bactericidal effect on each group.Based on the results of CFU,the bacterial colonies formed by 30.4J/cm^(2)532nm MB-aPDT group and 30.4J/cm^(2)532nm HMME-aPDT group were significantly less than those in other groups,and the bacterial colonies in HMME-aPDT group were less than those in HMME-aPDT group.Lactic acid production in all treatment groups except the photosensitizer group was statistically lower than that in the normal saline control group.The activity of bacterial plaque biofilm was significantly decreased in the two groups treated with 30.4 J/cm^(2) aPDT.Therefore,aPDT suitable for energy measurement can kill S.mutans plaque biofilm,and MB-aPDT is better than HMME-aPDT.
基金financially supported by the National Natural Science Foundation of China (No.21977081)Zhejiang Provincial Natural Science of Foundation of China (No.LQ21H190006)。
文摘Antibacterial agent of activatable photosensitizer not only has the advantages of traditional photosensitizers,such as good curative effect and low resistance,but also has better selectivity for bacteria and lower toxicity to normal tissues.Limited reports of activatable photosensitizer can be used to treat drugresistant bacteria.In order to meet this challenge,we designed and synthesized an activatable photosensitizer(Ce-OHOA),which can not only selectively identify methicillin-resistant Staphylococcus aureus(MRSA)with high expression ofβ-lactamase by fluorescence imaging,but also kill MRSA with less than10 times the concentration and 10 times the irradiation dose of CySG-2 reported.Ce-OHOA not only combines the dual functions of fluorescence diagnosis and photodynamic therapy,but also selectively acts on bacteria with high expression ofβ-lactamase and has little toxicity to normal cells.We expect that the study of this activating photosensitizer will provide a new solution for antibacterial photodynamic therapy(aPDT)of drug-resistant bacteria.
基金support for this work from DoD Army STTR Award No.W911NF-22-P-0018the Florida High Tech Corridor Council(FHTCC)matching grant,and the Air Force Office of Scientific Research FA9550-20-1-0063 and FA9550-23-1-0656.
文摘Antibiotic administration is the mainstay for treating bacterial infections,but multidrug-resistant(MDR)bacteria jeopardize its effectiveness.Antimicrobial photodynamic therapy(aPDT)offers a promising strategy with less risk of inducing resistance,yet the lack of a suitable wearable light source limits its widespread adoption.Here,we design flexible quantum dot light-emitting diodes(F-QLEDs)for effective aPDT treatment of MDR bacteria.By simultaneous optical,thermal,and reliability management,we achieved F-QLEDs with emission spectrum matching the photosensitizer absorption,physiologically safe surface temperature(<41℃),enhanced operating lifetime(7.5X),and ambient shelf life>1 month.Subsequently,aPDT testing demonstrated a~9-log reduction of Staphylococcus aureus and~2-3 log reduction of Pseudomonas aeruginosa compared to controls.Additionally,testing with different photosensitizers confirmed F-QLED versatility for targeted aPDT.These results showcase the potent antimicrobial efficacy of F-QLEDs and their potential as wearable optical platforms for point-of-care treatment of MDR infections and broader photomedical applications.
基金Dr.Rolf M.Schwiete Foundationthe Federal Ministry of Education and Research,Germany(BMBFFKZ:13GW0439B)for the financial support of this work.
文摘Polydimethylsiloxane(PDMS)is widely used in biomedical applications due to its biocompatibility,chemical stability,flexibility,and resistance to degradation in physiological environments.However,its intrinsic inertness limits further(bio)functionalization,and its hydrophobic recovery compromises the longevity of conventional surface modifications.To address these challenges,we developed a nanoprecipitation method for the straight-forward colloidal deposition,covalent thermal crosslinking,and surface anchoring of a chemically tunable,biocompatible polyacrylamide with reactive hydroxyl groups,enabling further surface modifications.This polymer incorporates~6%bioinspired catechol units,introduced via an elegant one-pot Kabachnik-Fields re-action,to facilitate thermally induced network formation and enhance adhesion to plasma-activated PDMS.The resulting uniform coatings exhibited tunable dry layer thicknesses up to 44±7 nm and effectively suppressed PDMS chain rearrangement even after steam autoclaving,ensuring long-term stability in aqueous and ambient environments for at least 90 days.The bioactive post-modification potential was demonstrated in a proof-of-concept study by immobilizing the photosensitizer rose bengal at surface concentrations of 20 or 40μg cm^(-2).The coating exhibited antimicrobial activity against S.aureus,achieving a 4-log reduction(99.99%)in colony-forming units after 30 min of irra-diation at 554 nm(342 J cm^(-2)),even when bacteria were suspended in liquid,without direct surface contact.In contrast,antimicrobial activity against E.coli was only observed with minimized liquid volume,bringing the motile bacteria into close contact with the surface.This work established a straightforward and versatile strategy for the stable and bioactive functionalization of PDMS surfaces for application in non-invasive surface decontamination.
