scholarly journals The Effect of Quasi-Spherical Gold Nanoparticles on Two-Photon Induced Reactive Oxygen Species for Cell Damage

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1180
Author(s):  
Jiunn-Woei Liaw ◽  
Chia-Yu Kuo ◽  
Shiao-Wen Tsai
Keyword(s):  
Reactive Oxygen Species ◽  
Gold Nanoparticles ◽  
Laser Scanning ◽  
Cell Damage ◽  
Reactive Oxygen ◽  
Laser Scanning Confocal Microscopy ◽  
Oxygen Species ◽  
A431 Cells ◽  
Two Photon ◽  
Spherical Gold Nanoparticles

The performance of quasi-spherical gold nanoparticles (GNPs) on the generation of reactive oxygen species (ROS) to cause cell damage, as irradiated by a two-photon laser, is studied. In this mechanism, hot electrons are generated from GNPs as irradiated by the two-photon laser, reacting with the molecules in the medium to produce ROS. We used laser scanning confocal microscopy with a low-fluence femtosecond Ti:Sapphire laser of 800 nm to observe the generated ROS in A431 cells, which were incubated with GNPs in advance. Subsequently, the cell morphology, cytoskeleton, and viability were investigated. In comparison with the control (no GNPs), the expression of ROS in these GNP-treated cells was enhanced after irradiation by the two-photon laser. Additionally, the disruption of cytoskeletons and the follow-up apoptosis of these GNP-treated cells are significantly increased as the number of laser shots increases. Moreover, we used N-acetyl-L-cysteine (NAC), an antioxidant, to inhibit the formation of ROS, to clarify whether the cytoskeletal disruption is caused by ROS rather than photothermal effects. Our results show that after two-photon irradiation, the ROS expression in these cells treated with GNPs plus NAC was significantly reduced. In addition, the cytoskeletal damage of these cells treated with GNPs and NAC was less than that of those treated with GNPs but without NAC; their cell viability after three days was almost the same with the control. These results illustrate that the induced ROS from the two-photon excited GNPs is the main cause of cell damage. The study may pave a way for the use of GNPs as a photosensitized therapeutic agent for two-photon photodynamic therapy on tumor treatment.

scholarly journals Rehydration of the Lichen Ramalina lacera Results in Production of Reactive Oxygen Species and Nitric Oxide and a Decrease in Antioxidants

2005 ◽  
Vol 71 (4) ◽  
pp. 2121-2129 ◽  
Author(s):  
Lior Weissman ◽  
Jacob Garty ◽  
Ayala Hochman
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Molecular Weight ◽  
Laser Scanning ◽  
Membrane Integrity ◽  
Reactive Oxygen ◽  
Laser Scanning Confocal Microscopy ◽  
Water Soluble ◽  
Low Molecular Weight ◽  
Oxygen Species

ABSTRACT Lichens are slow-growing associations of fungi and unicellular green algae or cyanobacteria. They are poikilohydric organisms whose lifestyle in many cases consists of alternating periods of desiccation, with low metabolic activity, and hydration, which induces increase in their metabolism. Lichens have apparently adapted to such extreme transitions between desiccation and rehydration, but the mechanisms that govern these adaptations are still poorly understood. In this study, the effect of rehydration on the production of reactive oxygen species and nitric oxide as well as low-molecular-weight antioxidants was investigated with the lichen Ramalina lacera. Rehydration of R. lacera resulted in the initiation of and a rapid increase in photosynthetic activity. Recovery of photosynthesis was accompanied by bursts of intracellular production of reactive oxygen species and nitric oxide. Laser-scanning confocal microscopy using dichlorofluorescein fluorescence revealed that formation of reactive oxygen species following rehydration was associated with both symbiotic partners of the lichen. The rate and extent of reactive oxygen species production were similar in the light and in the dark, suggesting a minor contribution of photosynthesis. Diaminofluorescein fluorescence, indicating nitric oxide formation, was detected only in fungal hyphae. Activities associated with rehydration did not have a deleterious effect on membrane integrity as assessed by measurement of electrolyte leakage, but water-soluble low-molecular-weight antioxidants decreased significantly.

Radiation-induced red cell damage: role of reactive oxygen species

Transfusion ◽  
1997 ◽  
Vol 37 (2) ◽  
pp. 160-165 ◽  
Author(s):  
AJ Anand ◽  
WH Dzik ◽  
A Imam ◽  
SM Sadrzadeh
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Damage ◽  
Reactive Oxygen ◽  
Red Cell ◽  
Oxygen Species ◽  
Radiation Induced

In Vitro Bacterial Cytotoxicity of CNTs: Reactive Oxygen Species Mediate Cell Damage Edges over Direct Physical Puncturing

Langmuir ◽  
2013 ◽  
Vol 30 (2) ◽  
pp. 592-601 ◽  
Author(s):  
Krishnamoorthy Rajavel ◽  
Rajkumar Gomathi ◽  
Sellamuthu Manian ◽  
Ramasamy Thangavelu Rajendra Kumar
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Damage ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Mediate Cell

Reactive Oxygen Species Influence Biofilm Formation of Acidophilic Mineral-Oxidizing Bacteria on Pyrite

2015 ◽  
Vol 1130 ◽  
pp. 118-122 ◽  
Author(s):  
Sören Bellenberg ◽  
Dieu Huynh ◽  
Laura Castro ◽  
Maria Boretska ◽  
Wolfgang Sand ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radicals ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Reactive Oxygen ◽  
Laser Scanning Microscopy ◽  
Metal Sulfides ◽  
Confocal Laser ◽  
Water Molecules ◽  
Oxygen Species

Reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), superoxide (O2-) and hydroxyl radicals (OH.) are known to be formed on the surface of metal sulfides in aqueous solution under oxic and anoxic conditions. Consequently bacteria which have not been adapted to their presence are metabolically inhibited [1], presumably due to the presence of these ROS. Pyrite-grown cells ofAcidithiobacillus ferrooxidansT, in contrast to iron (II)-grown cells, were able to oxidize iron (II)-ions or pyrite after 24 h starvation and contact with 1 mM externally added H2O2. In this study, similar results were obtained withAcidiferrobactersp. SPIII/3. However,Acidithiobacillus ferrivoransSS3 showed the highest tolerance towards contact with H2O2, whileLeptospirillum ferrooxidansDSM 2391 was most sensitive. Similar results were obtained after exposure to defined doses of gamma radiation, which cleaves water molecules and generates ROS. In this study members of the three aforementioned genera of mineral-oxidizing bacteria were compared regarding their ability to survive, colonize pyrite and to oxidize iron (II)-ions after exposure to different concentrations of H2O2. Pyrite colonization was studied after exposure to endogenous ROS formed on pyrite or after external addition of H2O2using confocal laser scanning microscopy (CLSM).

Preventing UV induced cell damage by scavenging reactive oxygen species with enzyme-mimic Au–Pt nanocomposites

Talanta ◽  
2014 ◽  
Vol 120 ◽  
pp. 262-267 ◽  
Author(s):  
Bin Xiong ◽  
Ruili Xu ◽  
Rui Zhou ◽  
Yan He ◽  
Edward S. Yeung
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Damage ◽  
Reactive Oxygen ◽  
Enzyme Mimic ◽  
Oxygen Species
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