Drug-resistant bacteria,using their dense cell membranes as strong barrier,significantly reduce the efficacy of conventional antibacterial treatments.Phototriggered 2D catalytic nanomaterials have emerged as promising...Drug-resistant bacteria,using their dense cell membranes as strong barrier,significantly reduce the efficacy of conventional antibacterial treatments.Phototriggered 2D catalytic nanomaterials have emerged as promising candidates against drug-resistant bacteria by inducing membrane mechanical damage and generating reactive oxygen species(ROS).However,the practical antibacterial efficacy of typical 2D graphitic carbon nitride(g-C_(3)N_(4))is severely limited due to the low ROS production.Herein,we report an interfacial band-engineered lamellar heterojunctions(MnCN LHJs)through in situ Mn_(2)O_(3)growth on g-C_(3)N_(4).The charges generated in g-C_(3)N_(4)are stabilized by Mn_(2)O_(3),minimizing electron-hole recombination and boosting ROS production.Meanwhile,the photocatalytic effect of MnCN LHJs works synergistically with photothermal effects of Mn_(2)O_(3)to induce a robust“melee attack”against drug-resistant bacteria.High-resolution synchrotron radiation X-ray tomography directly visualized that MnCN LHJs possessed bacterial trapping capabilities,revealing their ability to induce mechanical damage to bacteria membrane for the first time.Additionally,MnCN LHJs can deplete endogenous glutathione,thereby enhancing ROS generation and weakening the bacterial antioxidant defense system.These combined effects achieve a remarkable bactericidal rate exceeding 98% against methicillin-resistant Staphylococcus aureus(MRSA).Notably,MnCN LHJs demonstrate prolonged retention at wound sites,helping to reduce inflammation and promote angiogenesis in infected wounds.This work not only advances interfacial band engineering approach to enhance the photocatalytic performance of g-C_(3)N_(4)but also underscores the significance of nanomaterial-bacteria interaction in design of next-generation antibacterial materials.展开更多
By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy o...By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt) were determined. The results of the test show that the electroplated deposits of zinc, cobalt, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt, silver and copper possess a distinct antibacterial capability against the growth of pathogenic bacteria tested, and that SUS304 stainless steel and chromium deposit have no antibacterial activity. The relationship between the antibacterial capability and the rest potentials of the deposits was investigated. It was found that the higher the antibacterial activity of the electroplated deposit was, the more negative the rest potential of deposit was.展开更多
Colorectal cancer(CRC)is a common digestive tract tumor worldwide.Specific microorganisms,including Fusobacterium nucleatum(F.nucleatum)and Escherichia coli(E.coli),are abundant in colonic mucosa and can promote the c...Colorectal cancer(CRC)is a common digestive tract tumor worldwide.Specific microorganisms,including Fusobacterium nucleatum(F.nucleatum)and Escherichia coli(E.coli),are abundant in colonic mucosa and can promote the cancer progression and malignancy.Therefore,a therapeutic strategy is proposed to deliver effective drugs to colorectum for both anticancer and antibacteria.Here we used thin-film dispersionmethod to encapsulate hemiprotonic phenanthroline-phenanthroline^(+)(ph-ph^(+))into nanomicelle.The results showed that the drug-loading nanomicelle had good dispersion,and the particle size was about 28 nm.In vitro assay indicated that the nanomicelle was active against CRC-related obligate and facultative anaerobes.In human CRC cells,the nanomicelle could effectively inhibit cell proliferation and induce apoptosis.In vivo distribution showed that the nanomicelle could release ph-ph^(+) mainly in the colorectum.In CRC model mice,the nanomicelle significantly reduced tumor number and volume,and decreased the bacteria load and colorectal inflammation.Together,the study identifies that the ph-ph^(+) nanomicelle has the potential to apply in treating CRC,and also suggests that anticancer combined with antimicrobial therapy would be a feasible way for CRC therapy.展开更多
Endophytic actinomycetes are considered as one of the relatively unexplored potential sources in search of antibiotic producer against antibiotic resistant pathogens. A potent strain isolated from Catharanthus roseus ...Endophytic actinomycetes are considered as one of the relatively unexplored potential sources in search of antibiotic producer against antibiotic resistant pathogens. A potent strain isolated from Catharanthus roseus that displays antibacterial potential against antibiotic resistant human pathogen Staphylococcus aureus was characterized and designated as Micrococcus yunnanensis strain rsk5. Rsk5 is capable of producing optimum antibacterial metabolites on starch casein medium at 30 °C, p H 5 and 2% Na Cl condition. The crude antibacterial agent was extracted from fermentation broth by ethyl acetate and separated by TLC using chloroform-methanol(24:1, v/v) solvent system with R f value of 0.26. It was partially purified by flash chromatography, followed by HPLC and analyzed by ultraviolet visible spectrophotometer to get absorption maxima at 208.4 nm. The ESI-MS spectra showed molecular ion peaks at m/z 472.4 [M-H], which does not match with any known antibacterial compound.展开更多
Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its an...Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its antibacterial performance. The results showthat the antibacterial rates of the specimens are above 95/100against the growth of E. coli, P. Aeruginasa, S. faecalis and S.aureus. The morphology of the silver in pores of anodized aluminum ischaracterized by transmission electron microscopy, and themicrographs indicate that silver is assembled in the form ofnanowires with a diameter of 10 nm or 25 nm. The nanowires have astructure of parallel bright stripes alternating with parallel darkstripes.展开更多
The aim of this study was to explore the potency of N. oculata extracts as antibacterial, antioxidant and antiviral on grouper Cromileptes altivelis （C. altivelis） infected by Vibrio alginolyticus （V. alginolyticus...The aim of this study was to explore the potency of N. oculata extracts as antibacterial, antioxidant and antiviral on grouper Cromileptes altivelis （C. altivelis） infected by Vibrio alginolyticus （V. alginolyticus） and Viral Nervous Necrotic （VNN）. Dilution test was used to measure antibacterial activity of N. oculata extracts. Antioxidant activity of extracts was expressed by levels of MDA （Malondialdehyde） and SOD （superoxide dismutase） in the brain and kidneys of fish. Antiviral capability of N. oculata was determined by the expression of cellular immune cells Major Histocompatibility Complex （MHC） Class I for proliferation and inhibition of VNN in blood cells with immunocytochemistry. The results showed that N. oculata extract was able to suppress the growth of V. alginolyticus at a concentration of 40%. Increasing levels of SOD and reducing level of MDA indicated that N. oculata extracts may serve as an antibacterial and antioxidant. Providing cellular response of MHC class I cell expressed on C. altive/is blood cells, N. oculata demonstrated its antiviral activity.展开更多
Sonodynamic therapy(SDT)has attracted widespread attention in treatment of implant-associated infections,one of the key factors leading to implant failure.Nevertheless,constructing efficient ultrasound-triggered coati...Sonodynamic therapy(SDT)has attracted widespread attention in treatment of implant-associated infections,one of the key factors leading to implant failure.Nevertheless,constructing efficient ultrasound-triggered coatings on implant surfaces remains a challenge.Herein,an acoustic metastructure Cu-doped defective tita-nium oxide coating(Cu-TiO_(x))with lattice strain was constructed in situ on titanium implant to realize effective sonocatalysis.The redistribution of Cu atoms broke the pristine lattice of TiO_(2)during the thermal reduction treatment to regulate its energy structure,which favored separation of electron-hole pairs generated by ultra-sound radiation to enhance the sonocatalytic generation of reactive oxygen species.In addition,the acoustic metastructure enhanced the absorption of ultrasound by Cu-TiO_(x)metastructure coating,which further promoted its sonocatalytic effect.Thus,Cu-TiO_(x)metastructure coating could efficiently eliminate Staphylococcus aureus and Escherichia coli infections under ultrasonic irradiation in 10 min.Besides,the osteogenic property of implant was significantly improved after infection clearance in vivo.This work provides a fresh perspective on the design of SDT biosurfaces based on metastructure and strain-defect engineering.展开更多
The antibacterial capability of silver loaded hydroxyapatite(HA\|Ag) in both poor nutrient phosphate buffer saline solution(PBS,pH=7.4)and nutrient rich medium,which represented two kinds of typical conditions in real...The antibacterial capability of silver loaded hydroxyapatite(HA\|Ag) in both poor nutrient phosphate buffer saline solution(PBS,pH=7.4)and nutrient rich medium,which represented two kinds of typical conditions in real life,was evaluated respectively using Escherichia coli as a model.At 0 4?mg/mL in PBS solution containing an initial cell concentration of 10\+6/mL,HA\|Ag killed all the E.coli cells in the PBS solution within 4 5?h .In a nutrient rich medium containing a cell concentration of 10\+7/mL,HA\|Ag exhibited a remarkable inhibitory effect of E.coli cells.The maximum specific growth rate in the medium containing 3?mg/mL HA\|Ag was only 0 292, 26% of that in a control sample which was 1 116,and the viable cell concentration in the former HA\|Ag medium was just 40% of that in the control.As a safe antibacterial agent,HA\|Ag powder demonstrated antibacterial efforts both in poor nutrient and in nutrient rich environment.It seems that the HA\|Ag compound hold a lot of promises for practical applications.展开更多
With natural polyphenol compound tannic acid(TA)as the ingredient,copper tannate(CuTA)nanolayer material was formed by self-assembly under the conditions of heating and copper ion.Copper ion and tannic acid could coor...With natural polyphenol compound tannic acid(TA)as the ingredient,copper tannate(CuTA)nanolayer material was formed by self-assembly under the conditions of heating and copper ion.Copper ion and tannic acid could coordinate to form Cu-O-C structure which was similar to the Fe-N-C structure of natural heme enzymes.In addition,the obtained CuTA nanomaterial possessed excellent peroxidase-like catalytic activity and stability.Based on this excellent enzymatic activity,CuTA nanomaterials could be used for colorimetric detection of hydrogen peroxide with a smartphone and decomposition of organic dyes.Based on the structural characteristics and catalytic activity,the copper tannate nanozymes could also serve as potential antibacterial reagents to effectively inhibit the growth of gram-negative and positive bacteria in a low hydrogen peroxide level.This work may promote the exploration of novel peroxidase mimetics and broaden the applications of nanozymes.展开更多
Bone defects have serious economic and clinical impacts;however,despite improvements in bone defect management,the range of clinical outcomes remains limited.A variety of biomaterials have been used to treat complex b...Bone defects have serious economic and clinical impacts;however,despite improvements in bone defect management,the range of clinical outcomes remains limited.A variety of biomaterials have been used to treat complex bone defects.However,final bone repair outcomes may be adversely affected by poor osteogenic capacity and risk of infection.Consequently,therapeutic methods are required that reduce bacterial contamination and increase the use of osteogenic biomaterials.Herein,we report the preparation of poly(lactic acid-coglycolic acid)(PLGA)microspheres coloaded with magnesium(Mg^(2+))and gallium(Ga^(3+))ions(Mg-Ga@PLGA),which can fill irregular bone defects and show good biosafety.During in vitro testing,Mg-Ga@PLGA not only showed a synergistic effect on promoting osteogenic differentiation but also inhibited osteoclastic differentiation.Moreover,we found that Mg-Ga@PLGA demonstrated an antibacterial effect.During in vivo testing,Mg Ga@PLGA exhibited strong in situ osteogenic ability.In conclusion,Mg-Ga@PLGA has good potential for treating bone defects at risk of infection.展开更多
基金financially supported by the National Basic Research Program of China(Nos.2022YFA1603701,2024YFC2310502,and 2024YFC2310503)the National Natural Science Foundation of China(Nos.22422403,82341044,and 22027810)+1 种基金the New Cornerstone Science Foundation(No.NCI202318)the Basic Science Center Project of the National Natural Science Foundation of China(No.22388101).
文摘Drug-resistant bacteria,using their dense cell membranes as strong barrier,significantly reduce the efficacy of conventional antibacterial treatments.Phototriggered 2D catalytic nanomaterials have emerged as promising candidates against drug-resistant bacteria by inducing membrane mechanical damage and generating reactive oxygen species(ROS).However,the practical antibacterial efficacy of typical 2D graphitic carbon nitride(g-C_(3)N_(4))is severely limited due to the low ROS production.Herein,we report an interfacial band-engineered lamellar heterojunctions(MnCN LHJs)through in situ Mn_(2)O_(3)growth on g-C_(3)N_(4).The charges generated in g-C_(3)N_(4)are stabilized by Mn_(2)O_(3),minimizing electron-hole recombination and boosting ROS production.Meanwhile,the photocatalytic effect of MnCN LHJs works synergistically with photothermal effects of Mn_(2)O_(3)to induce a robust“melee attack”against drug-resistant bacteria.High-resolution synchrotron radiation X-ray tomography directly visualized that MnCN LHJs possessed bacterial trapping capabilities,revealing their ability to induce mechanical damage to bacteria membrane for the first time.Additionally,MnCN LHJs can deplete endogenous glutathione,thereby enhancing ROS generation and weakening the bacterial antioxidant defense system.These combined effects achieve a remarkable bactericidal rate exceeding 98% against methicillin-resistant Staphylococcus aureus(MRSA).Notably,MnCN LHJs demonstrate prolonged retention at wound sites,helping to reduce inflammation and promote angiogenesis in infected wounds.This work not only advances interfacial band engineering approach to enhance the photocatalytic performance of g-C_(3)N_(4)but also underscores the significance of nanomaterial-bacteria interaction in design of next-generation antibacterial materials.
文摘By way of bactericidal halo test, the antibacterial performance of various electroplated deposits (cobalt, zinc, copper, silver, gold, nickel, chromium, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt) were determined. The results of the test show that the electroplated deposits of zinc, cobalt, cobalt-containing alloy of nickel, and nickel-containing alloy of cobalt, silver and copper possess a distinct antibacterial capability against the growth of pathogenic bacteria tested, and that SUS304 stainless steel and chromium deposit have no antibacterial activity. The relationship between the antibacterial capability and the rest potentials of the deposits was investigated. It was found that the higher the antibacterial activity of the electroplated deposit was, the more negative the rest potential of deposit was.
基金supported by National Natural Science Foundation of China(No.82073830)Chongqing Natural Science Foundation(No.CSTB2022NSCQ-MSX1328).
文摘Colorectal cancer(CRC)is a common digestive tract tumor worldwide.Specific microorganisms,including Fusobacterium nucleatum(F.nucleatum)and Escherichia coli(E.coli),are abundant in colonic mucosa and can promote the cancer progression and malignancy.Therefore,a therapeutic strategy is proposed to deliver effective drugs to colorectum for both anticancer and antibacteria.Here we used thin-film dispersionmethod to encapsulate hemiprotonic phenanthroline-phenanthroline^(+)(ph-ph^(+))into nanomicelle.The results showed that the drug-loading nanomicelle had good dispersion,and the particle size was about 28 nm.In vitro assay indicated that the nanomicelle was active against CRC-related obligate and facultative anaerobes.In human CRC cells,the nanomicelle could effectively inhibit cell proliferation and induce apoptosis.In vivo distribution showed that the nanomicelle could release ph-ph^(+) mainly in the colorectum.In CRC model mice,the nanomicelle significantly reduced tumor number and volume,and decreased the bacteria load and colorectal inflammation.Together,the study identifies that the ph-ph^(+) nanomicelle has the potential to apply in treating CRC,and also suggests that anticancer combined with antimicrobial therapy would be a feasible way for CRC therapy.
基金supported by United Grant Commission, Pune, India (Grant no. 47-1328/10) for financial support
文摘Endophytic actinomycetes are considered as one of the relatively unexplored potential sources in search of antibiotic producer against antibiotic resistant pathogens. A potent strain isolated from Catharanthus roseus that displays antibacterial potential against antibiotic resistant human pathogen Staphylococcus aureus was characterized and designated as Micrococcus yunnanensis strain rsk5. Rsk5 is capable of producing optimum antibacterial metabolites on starch casein medium at 30 °C, p H 5 and 2% Na Cl condition. The crude antibacterial agent was extracted from fermentation broth by ethyl acetate and separated by TLC using chloroform-methanol(24:1, v/v) solvent system with R f value of 0.26. It was partially purified by flash chromatography, followed by HPLC and analyzed by ultraviolet visible spectrophotometer to get absorption maxima at 208.4 nm. The ESI-MS spectra showed molecular ion peaks at m/z 472.4 [M-H], which does not match with any known antibacterial compound.
文摘Aluminum specimens were anodized in a sulfuric acid bath, thensilver was electrodeposited in pores of the anodized aluminum byusing alternating current. The anodized aluminum with depositedsilver was tested for its antibacterial performance. The results showthat the antibacterial rates of the specimens are above 95/100against the growth of E. coli, P. Aeruginasa, S. faecalis and S.aureus. The morphology of the silver in pores of anodized aluminum ischaracterized by transmission electron microscopy, and themicrographs indicate that silver is assembled in the form ofnanowires with a diameter of 10 nm or 25 nm. The nanowires have astructure of parallel bright stripes alternating with parallel darkstripes.
文摘The aim of this study was to explore the potency of N. oculata extracts as antibacterial, antioxidant and antiviral on grouper Cromileptes altivelis （C. altivelis） infected by Vibrio alginolyticus （V. alginolyticus） and Viral Nervous Necrotic （VNN）. Dilution test was used to measure antibacterial activity of N. oculata extracts. Antioxidant activity of extracts was expressed by levels of MDA （Malondialdehyde） and SOD （superoxide dismutase） in the brain and kidneys of fish. Antiviral capability of N. oculata was determined by the expression of cellular immune cells Major Histocompatibility Complex （MHC） Class I for proliferation and inhibition of VNN in blood cells with immunocytochemistry. The results showed that N. oculata extract was able to suppress the growth of V. alginolyticus at a concentration of 40%. Increasing levels of SOD and reducing level of MDA indicated that N. oculata extracts may serve as an antibacterial and antioxidant. Providing cellular response of MHC class I cell expressed on C. altive/is blood cells, N. oculata demonstrated its antiviral activity.
基金support from the National Natural Science Foundation of China(52450110)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2024C03080)Science and Technology Commission of Shanghai Municipality(24ZR1475600)are acknowledged.
文摘Sonodynamic therapy(SDT)has attracted widespread attention in treatment of implant-associated infections,one of the key factors leading to implant failure.Nevertheless,constructing efficient ultrasound-triggered coatings on implant surfaces remains a challenge.Herein,an acoustic metastructure Cu-doped defective tita-nium oxide coating(Cu-TiO_(x))with lattice strain was constructed in situ on titanium implant to realize effective sonocatalysis.The redistribution of Cu atoms broke the pristine lattice of TiO_(2)during the thermal reduction treatment to regulate its energy structure,which favored separation of electron-hole pairs generated by ultra-sound radiation to enhance the sonocatalytic generation of reactive oxygen species.In addition,the acoustic metastructure enhanced the absorption of ultrasound by Cu-TiO_(x)metastructure coating,which further promoted its sonocatalytic effect.Thus,Cu-TiO_(x)metastructure coating could efficiently eliminate Staphylococcus aureus and Escherichia coli infections under ultrasonic irradiation in 10 min.Besides,the osteogenic property of implant was significantly improved after infection clearance in vivo.This work provides a fresh perspective on the design of SDT biosurfaces based on metastructure and strain-defect engineering.
文摘The antibacterial capability of silver loaded hydroxyapatite(HA\|Ag) in both poor nutrient phosphate buffer saline solution(PBS,pH=7.4)and nutrient rich medium,which represented two kinds of typical conditions in real life,was evaluated respectively using Escherichia coli as a model.At 0 4?mg/mL in PBS solution containing an initial cell concentration of 10\+6/mL,HA\|Ag killed all the E.coli cells in the PBS solution within 4 5?h .In a nutrient rich medium containing a cell concentration of 10\+7/mL,HA\|Ag exhibited a remarkable inhibitory effect of E.coli cells.The maximum specific growth rate in the medium containing 3?mg/mL HA\|Ag was only 0 292, 26% of that in a control sample which was 1 116,and the viable cell concentration in the former HA\|Ag medium was just 40% of that in the control.As a safe antibacterial agent,HA\|Ag powder demonstrated antibacterial efforts both in poor nutrient and in nutrient rich environment.It seems that the HA\|Ag compound hold a lot of promises for practical applications.
基金Financial support was provided by the Natural Science Foundation of jiangsu(grant No.BK20200764)the Key Technologies R&D Program of Henan(grant No.212102310231).
文摘With natural polyphenol compound tannic acid(TA)as the ingredient,copper tannate(CuTA)nanolayer material was formed by self-assembly under the conditions of heating and copper ion.Copper ion and tannic acid could coordinate to form Cu-O-C structure which was similar to the Fe-N-C structure of natural heme enzymes.In addition,the obtained CuTA nanomaterial possessed excellent peroxidase-like catalytic activity and stability.Based on this excellent enzymatic activity,CuTA nanomaterials could be used for colorimetric detection of hydrogen peroxide with a smartphone and decomposition of organic dyes.Based on the structural characteristics and catalytic activity,the copper tannate nanozymes could also serve as potential antibacterial reagents to effectively inhibit the growth of gram-negative and positive bacteria in a low hydrogen peroxide level.This work may promote the exploration of novel peroxidase mimetics and broaden the applications of nanozymes.
基金supported by grants from the National Natural Science Foundation of China(Nos.31971106,BWS21L013,and 21WS09002).
文摘Bone defects have serious economic and clinical impacts;however,despite improvements in bone defect management,the range of clinical outcomes remains limited.A variety of biomaterials have been used to treat complex bone defects.However,final bone repair outcomes may be adversely affected by poor osteogenic capacity and risk of infection.Consequently,therapeutic methods are required that reduce bacterial contamination and increase the use of osteogenic biomaterials.Herein,we report the preparation of poly(lactic acid-coglycolic acid)(PLGA)microspheres coloaded with magnesium(Mg^(2+))and gallium(Ga^(3+))ions(Mg-Ga@PLGA),which can fill irregular bone defects and show good biosafety.During in vitro testing,Mg-Ga@PLGA not only showed a synergistic effect on promoting osteogenic differentiation but also inhibited osteoclastic differentiation.Moreover,we found that Mg-Ga@PLGA demonstrated an antibacterial effect.During in vivo testing,Mg Ga@PLGA exhibited strong in situ osteogenic ability.In conclusion,Mg-Ga@PLGA has good potential for treating bone defects at risk of infection.
