Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are st...Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.展开更多
Phototoxic treatments of pathogenic bacteria and fungi of trees induce oxidative damage that is preferable to toxic chemical treatment.Here,we used green methods to synthesize Chlorin e6 from chlorophyll a,which was e...Phototoxic treatments of pathogenic bacteria and fungi of trees induce oxidative damage that is preferable to toxic chemical treatment.Here,we used green methods to synthesize Chlorin e6 from chlorophyll a,which was extracted from crude silkworm excrement using concentrated(strong)alkali hydrolysis and acidification.The photosensitive bactericidal activities of the new chlorin were tested in vitro,and possible mechanisms of action are discussed.The results showed that Chlorin e6 can be lightactivated to have bactericidal activity against Escherichia coli,Bacillus subtilis and Fusarium oxysporum,but it had little bactericidal effect in the dark.This kind of chlorin compounds has great potential as a natural phototoxic antimicrobial compound to control harmful bacteria on the leaves in forestry systems.展开更多
AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in v...AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in vivo.METHODS YLG-1 is a novel photosensitizer extracted from spirulina. Its phototoxicity, cellular uptake and localization, as well as its effect on reactive oxygen species(ROS) production, apoptosis, and expression of apoptosis-associated proteins were detected in vitro. An in vivo imaging system(IVIS), the Lumina K imaging system, and mouse models of subcutaneous Panc-1-bearing tumors were exploited to evaluate the drug delivery pathway and pancreatic cancer growth in vivo.RESULTS YLG-1 was localized to the mitochondria, and the appropriate incubation time was 6 h. Under 650 nm light irradiation, YLG-1-PDT exerted a potent cytotoxic effect on pancreatic cancer cells in vitro, which could be abolished by the ROS scavenger N-acetyl-L-cysteine(NAC). The death mode caused by YLG-1-PDT was apoptosis, accompanied by upregulated Bax and cleaved Caspase-3 and decreased Bcl-2 expression. The results from the IVIS images suggested that the optimal administration route was intratumoral(IT) injection and that the best time to conduct YLG-1-PDT was 2 h post-IT injection. Consistent with the results in vitro, YLG-1-PDT showed great growth inhibition effects on pancreatic cancer cells in a mouse model.CONCLUSION YLG-1 is a potential photosensitizer for pancreatic cancer PDT via IT injection, the mechanisms of which are associated with inducing ROS and promoting apoptosis.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51708078)Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQ-MSX0815)+2 种基金Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202200542)the Chongqing Innovative Research Group Project(Grant No.CXQT21015)Foundation of Chongqing Normal University(22XLB022).
文摘Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.
基金supported by Fundamental Research Funds for the Central Universities(No.DL12BA06)Harbin Science and Technology Innovation Talent Research Special Funds(2015RAQXJ002)
文摘Phototoxic treatments of pathogenic bacteria and fungi of trees induce oxidative damage that is preferable to toxic chemical treatment.Here,we used green methods to synthesize Chlorin e6 from chlorophyll a,which was extracted from crude silkworm excrement using concentrated(strong)alkali hydrolysis and acidification.The photosensitive bactericidal activities of the new chlorin were tested in vitro,and possible mechanisms of action are discussed.The results showed that Chlorin e6 can be lightactivated to have bactericidal activity against Escherichia coli,Bacillus subtilis and Fusarium oxysporum,but it had little bactericidal effect in the dark.This kind of chlorin compounds has great potential as a natural phototoxic antimicrobial compound to control harmful bacteria on the leaves in forestry systems.
基金Supported by National Natural Science Foundation of China,No.81472844
文摘AIM To investigate the antitumor effects and underlying mechanisms of(17 R,18 R)-2-(1-hexyloxyethyl)-2-devinyl chlorine E6 trisodium salt(YLG-1)-induced photodynamic therapy(PDT) on pancreatic cancer in vitro and in vivo.METHODS YLG-1 is a novel photosensitizer extracted from spirulina. Its phototoxicity, cellular uptake and localization, as well as its effect on reactive oxygen species(ROS) production, apoptosis, and expression of apoptosis-associated proteins were detected in vitro. An in vivo imaging system(IVIS), the Lumina K imaging system, and mouse models of subcutaneous Panc-1-bearing tumors were exploited to evaluate the drug delivery pathway and pancreatic cancer growth in vivo.RESULTS YLG-1 was localized to the mitochondria, and the appropriate incubation time was 6 h. Under 650 nm light irradiation, YLG-1-PDT exerted a potent cytotoxic effect on pancreatic cancer cells in vitro, which could be abolished by the ROS scavenger N-acetyl-L-cysteine(NAC). The death mode caused by YLG-1-PDT was apoptosis, accompanied by upregulated Bax and cleaved Caspase-3 and decreased Bcl-2 expression. The results from the IVIS images suggested that the optimal administration route was intratumoral(IT) injection and that the best time to conduct YLG-1-PDT was 2 h post-IT injection. Consistent with the results in vitro, YLG-1-PDT showed great growth inhibition effects on pancreatic cancer cells in a mouse model.CONCLUSION YLG-1 is a potential photosensitizer for pancreatic cancer PDT via IT injection, the mechanisms of which are associated with inducing ROS and promoting apoptosis.
