Visible-Light-Triggered Reactive-Oxygen-Species-Mediated Antibacterial Activity of Peroxidase-Mimic CuO Nanorods

2018 ◽  
Vol 1 (4) ◽  
pp. 1694-1704 ◽  
Author(s):  
Md. Nurul Karim ◽  
Mandeep Singh ◽  
Pabudi Weerathunge ◽  
Pengju Bian ◽  
Rongkun Zheng ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antibacterial Activity ◽  
Visible Light ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Peroxidase Mimic ◽  
Cuo Nanorods

Photoassisted Production of O2-• and H2 in Aqueous Medium Stimulated by Polythiophene in ZSM-5 Zeolite Channels

1999 ◽  
Vol 64 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Gabriel Čík ◽  
František Šeršeň ◽  
Alena Bumbálová
Keyword(s):  
Reactive Oxygen Species ◽  
Ion Exchange ◽  
Visible Light ◽  
Aqueous Medium ◽  
Exchange Reaction ◽  
Epr Spectroscopy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Water Reduction ◽  
Ion Exchange Reaction

The formation of reactive oxygen species due to irradiation by a visible light of the polythiophene deposited in ZSM-5 zeolite channels in aqueous medium has been studied. Polymerization of thiophene was carried out in zeolite channels after the ion-exchange reaction of Na+ for Fe3+. By means of EPR spectroscopy, the temporarily generated 1O2 in irradiated aqueous medium was proved. The formation of O2-• was confirmed by the reduction of Fe3+-cytochrome c. Irradiation led to the water reduction to hydrogen.

scholarly journals Photo-Responsive Supramolecular Micelles for Controlled Drug Release and Improved Chemotherapy

2020 ◽  
Vol 22 (1) ◽  
pp. 154
Author(s):  
Fasih Bintang Ilhami ◽  
Kai-Chen Peng ◽  
Yi-Shiuan Chang ◽  
Yihalem Abebe Alemayehu ◽  
Hsieh-Chih Tsai ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Drug Release ◽  
Visible Light ◽  
Cancer Cells ◽  
Laser Irradiation ◽  
Reactive Oxygen ◽  
Controlled Drug Release ◽  
Grand Challenge ◽  
Supramolecular System ◽  
Oxygen Species

Development of stimuli-responsive supramolecular micelles that enable high levels of well-controlled drug release in cancer cells remains a grand challenge. Here, we encapsulated the antitumor drug doxorubicin (DOX) and pro-photosensitizer 5-aminolevulinic acid (5-ALA) within adenine-functionalized supramolecular micelles (A-PPG), in order to achieve effective drug delivery combined with photo-chemotherapy. The resulting DOX/5-ALA-loaded micelles exhibited excellent light and pH-responsive behavior in aqueous solution and high drug-entrapment stability in serum-rich media. A short duration (1–2 min) of laser irradiation with visible light induced the dissociation of the DOX/5-ALA complexes within the micelles, which disrupted micellular stability and resulted in rapid, immediate release of the physically entrapped drug from the micelles. In addition, in vitro assays of cellular reactive oxygen species generation and cellular internalization confirmed the drug-loaded micelles exhibited significantly enhanced cellular uptake after visible light irradiation, and that the light-triggered disassembly of micellar structures rapidly increased the production of reactive oxygen species within the cells. Importantly, flow cytometric analysis demonstrated that laser irradiation of cancer cells incubated with DOX/5-ALA-loaded A-PPG micelles effectively induced apoptotic cell death via endocytosis. Thus, this newly developed supramolecular system may offer a potential route towards improving the efficacy of synergistic chemotherapeutic approaches for cancer.

Photocatalytic Degradation of 4-Chlorophenol by •OH Radicals Generated by Thiophene Oligomers Incorporated in ZSM-5 Zeolite Channels

2003 ◽  
Vol 68 (11) ◽  
pp. 2219-2230 ◽  
Author(s):  
Gabriel Čík ◽  
Milada Hubinová ◽  
František Šeršeň ◽  
Jozef Krištín ◽  
Monika Antošová
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Maleic Acid ◽  
Aqueous Suspension ◽  
Reactive Oxygen ◽  
Spin Trapping ◽  
Oh Radicals ◽  
Oxygen Species ◽  
Trapping Method

Degradation of 4-chlorophenol by reactive oxygen species was studied, the latter being generated by photo-assisted reactions of thiophene oligomers, synthesized in channels of the Na-ZSM-5 zeolite. The photoreaction was carried out in an aqueous suspension of photocatalyst, irradiated with visible light (λ > 400 nm). The spin-trapping method was used to detect the generated •OH radicals. The main products of the photodecomposition of 4-chlorophenol were found to be phenol, hydroquinone and maleic acid.

Reactive oxygen species formation in the transition to hypoxia in skeletal muscle

2005 ◽  
Vol 289 (1) ◽  
pp. C207-C216 ◽  
Author(s):  
Li Zuo ◽  
Thomas L. Clanton
Keyword(s):  
Reactive Oxygen Species ◽  
Skeletal Muscle ◽  
Acute Hypoxia ◽  
Low Frequency ◽  
Metabolic Stress ◽  
Reactive Oxygen ◽  
Fluorescence Signal ◽  
Oxygen Species ◽  
Peroxidase Mimic ◽  
Intracellular Ros

Many tissues produce reactive oxygen species (ROS) during reoxygenation after hypoxia or ischemia; however, whether ROS are formed during hypoxia is controversial. We tested the hypothesis that ROS are generated in skeletal muscle during exposure to acute hypoxia before reoxygenation. Isolated rat diaphragm strips were loaded with dihydrofluorescein-DA (Hfluor-DA), a probe that is oxidized to fluorescein (Fluor) by intracellular ROS. Changes in fluorescence due to Fluor, NADH, and FAD were measured using a tissue fluorometer. The system had a detection limit of 1 μM H2O2 applied to the muscle superfusate. When the superfusion buffer was changed rapidly from 95% O2 to 0%, 5%, 21%, or 40% O2, transient elevations in Fluor were observed that were proportional to the rise in NADH fluorescence and inversely proportional to the level of O2 exposure. This signal could be inhibited completely with 40 μM ebselen, a glutathione peroxidase mimic. After brief hypoxia exposure (10 min) or exposure to brief periods of H2O2, the fluorescence signal returned to baseline. Furthermore, tissues loaded with the oxidized form of the probe (Fluor-DA) showed a similar pattern of response that could be inhibited with ebselen. These results suggest that Fluor exists in a partially reversible redox state within the tissue. When Hfluor-loaded tissues were contracted with low-frequency twitches, Fluor emission and NADH emission were significantly elevated in a way that resembled the hypoxia-induced signal. We conclude that in the transition to low intracellular Po2, a burst of intracellular ROS is formed that may have functional implications regarding skeletal muscle O2-sensing systems and responses to acute metabolic stress.

scholarly journals A boronic acid-functionalized phthalocyanine with an aggregation-enhanced photodynamic effect for combating antibiotic-resistant bacteria

2020 ◽  
Vol 11 (22) ◽  
pp. 5735-5739 ◽  
Author(s):  
Eunhye Lee ◽  
Xingshu Li ◽  
Juwon Oh ◽  
Nahyun Kwon ◽  
Gyoungmi Kim ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Antibacterial Activity ◽  
Boronic Acid ◽  
Reactive Oxygen ◽  
Resistant Bacteria ◽  
Ros Generation ◽  
Oxygen Species ◽  
Photodynamic Effect ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant

A boronic acid functionalized phthalocyanine displays aggregation-enhanced reactive oxygen species (ROS) generation and excellent photodynamic antibacterial activity.

Fabrication of magnetic BaFe12O19/Ag3PO4 composites with an in situ photo-Fenton-like reaction for enhancing reactive oxygen species under visible light irradiation

2019 ◽  
Vol 9 (10) ◽  
pp. 2563-2570 ◽  
Author(s):  
Yuanguo Xu ◽  
Feiyue Ge ◽  
Meng Xie ◽  
Shuquan Huang ◽  
Junchao Qian ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Reactive Oxygen ◽  
Light Irradiation ◽  
Oh Radicals ◽  
Oxygen Species

An in situ photo-Fenton-like and magnetic recycle system, BaFe12O19/Ag3PO4 has been constructed. BaFe12O19 can catalyze the conversion of H2O2 to generate ROSs (˙O2− and ˙OH radicals) on the surface of Ag3PO4.

Mechanism of CeVO4/TiO2 Photocatalytic Degradation of VOCs under Visible Light Irradiation: Electrochemical, Photoluminescence and Active Oxygen Species Study

2012 ◽  
Vol 217-219 ◽  
pp. 853-856 ◽  
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang
Keyword(s):  
Reactive Oxygen Species ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Gas Phase ◽  
Degradation Mechanism ◽  
Active Oxygen Species ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Composite Photocatalyst ◽  
Photocatalytic Degradation Mechanism

In this paper, CeVO4/TiO2 composite photocatalyst has been characterized by photoelectrochemical and reactive oxygen species trap techniques to reveal the mechanism for photocatalytic degradation of VOCs in gas-phase. Based on the measurement of flatband of the samples and the detection of reactive oxygen species, a visible light-induced photocatalytic degradation mechanism of VOCs on CeVO4/TiO2 is proposed.

Visible light driven mesoporous Ag-embedded ZnO nanocomposites: reactive oxygen species enhanced photocatalysis, bacterial inhibition and photodynamic therapy

2017 ◽  
Vol 46 (3) ◽  
pp. 685-696 ◽  
Author(s):  
Jagriti Gupta ◽  
Jeotikanta Mohapatra ◽  
D. Bahadur
Keyword(s):  
Reactive Oxygen Species ◽  
Photodynamic Therapy ◽  
Visible Light ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Bacterial Inhibition ◽  
Visible Light Driven

The systemic diagram shows the mechanism of photocatalysis, bacterial inhibition and photodynamic therapy through the generation of reactive oxygen species.

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