Free-Radical Generation from Bulk Nanobubbles in Aqueous Electrolyte Solutions: ESR Spin-Trap Observation of Microbubble-Treated Water

Takahashi, Masayoshi; Shirai, Yoshihito; Sugawa, Shigetoshi

doi:10.1021/acs.langmuir.1c00469

Cited by 93 publications

(91 citation statements)

References 80 publications

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“…OUFBW was supplied by Nippon Beatty Lease Co., Ltd. Nanosui Company (Tokyo, Japan). It requires electrolytes, including sodium, calcium, magnesium, and potassium to stabilize nanobubbles [19]. Accordingly, OUFBWs were prepared by adding 6 (OUFBW6), 9 (OUFBW9), and 11 (OUFBW11) ppm ozone ultrafine bubbles to water containing electrolytes.…”

Section: Preparation Of Oufbw Solutionsmentioning

confidence: 99%

“…The ozone concentration of each solution was measured using an ozone meter (AOM-05, Sato Shoji Co., Ltd., Japan) and immediately used for subsequent investigations. Ozone-free electrolyte aqueous solution of OUFBW11, which had the highest ozone concentration among all OUFBWs, was referred to as OFEAS since the electrolyte concentration increases proportionally with the ozone concentration [19]. OFEAS and phosphate buffered saline (PBS; pH 7.2) were used as controls.…”

Section: Preparation Of Oufbw Solutionsmentioning

confidence: 99%

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Ozone ultrafine bubble water inhibits the early formation of Candida albicans biofilms

et al. 2021

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This study aimed to investigate the effect of ozone ultrafine bubble water (OUFBW) on the formation and growth of Candida albicans (C. albicans) biofilms and surface properties of denture base resins. OUFBWs were prepared under concentrations of 6 (OUFBW6), 9 (OUFBW9), and 11 ppm (OUFBW11). Phosphate buffered saline and ozone-free electrolyte aqueous solutions (OFEAS) were used as controls. Acrylic resin discs were made according to manufacturer instructions, and C. albicans was initially cultured on the discs for 1.5 h. A colony forming unit (CFU) assay was performed by soaking the discs in OUFBW for 5 min after forming a 24-h C. albicans biofilm. The discs after initial attachment for 1.5 h were immersed in OUFBW and then cultured for 0, 3, and 5 h. CFUs were subsequently evaluated at each time point. Moreover, a viability assay, scanning electron microscopy (SEM), Alamar Blue assay, and quantitative real-time polymerase chain reaction (qRT-PCR) test were performed. To investigate the long-term effects of OUFBW on acrylic resin surface properties, Vickers hardness (VH) and surface roughness (Ra) were measured. We found that OUFBW9 and OUFBW11 significantly degraded the formed 24-h biofilm. The time point CFU assay showed that C. albicans biofilm formation was significantly inhibited due to OUFBW11 exposure. Interestingly, fluorescence microscopy revealed that almost living cells were observed in all groups. In SEM images, the OUFBW group had lesser number of fungi and the amount of non-three-dimensional biofilm than the control group. In the Alamar Blue assay, OUFBW11 was found to suppress Candida metabolic function. The qRT-PCR test showed that OUFBW down-regulated ALS1 and ALS3 expression regarding cell-cell, cell-material adhesion, and biofilm formation. Additionally, VH and Ra were not significantly different between the two groups. Overall, our data suggest that OUFBW suppressed C. albicans growth and biofilm formation on polymethyl methacrylate without impairing surface properties.

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Section: Preparation Of Oufbw Solutionsmentioning

confidence: 99%

Section: Preparation Of Oufbw Solutionsmentioning

confidence: 99%

Ozone ultrafine bubble water inhibits the early formation of Candida albicans biofilms

et al. 2021

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“…The growth of bubbles is due to cavitation, which releases surface energy (Shatalov et al, 2012). It has been experimentally proven that under the action of vibration, nanobubbles are a source of reactive oxygen species (Gudkov et al, 2020;Gudkov et al, 2021;Takahashi et al, 2021). Gudkov et al (2020) showed that the relative rate of formation of hydrogen peroxide in water saturated with atmospheric gases is approximately 0.8 nM/min when exposed to the frequency of 30 Hz.…”

Section: Discussionmentioning

confidence: 99%

Vibration influence on the O2-dependent processes activity in human erythrocytes

Dotsenko

Mischenko

Taradina

2021

Regul. Mech. Biosyst.

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The early signs of vibration effects on the human body are microcirculation and transcapillary metabolism disorders, accompanied by disruption of the supply to and utilization of oxygen in the tissues and organs. However, there are few experimental studies aimed at finding targets of vibration in cells and determining the action mechanism of vibration. In in vitro experiments, human erythrocytes in buffer solution were exposed to low-frequency vibration (frequency range 8–32 Hz, amplitudes 0.5–0.9 mm) for 3 hours. The dynamics of the accumulation of membrane-bound catalase and hemoglobin and the distribution of ligand hemoglobin in the membrane-bound fraction were studied as the indicators of functional activity of cells. The choice of these indicators is justified by the participation of catalase and hemoglobin in O2-dependent cellular reactions as a part of protein complexes. Since pО2 is a trigger of conformational transitions in the hemoglobin molecule, simultaneously with oxygen transport, hemoglobin signals to different metabolic systems about oxygen conditions in the environment. The studies revealed that in the conditions of vibration, the activity of membrane-associated catalase increased by 40–50% in the frequency range of 12–24 Hz (amplitude 0.5 ± 0.04 mm), by 20–30% in the amplitude of 0.9 mm, but after about 100–120 min exposure the enzyme activity decreased even below the control level. There was a dose-dependent accumulation of membrane-bound hemoglobin during exposure to vibration. In the membrane-bound fraction of hemoglobin, oxyhemoglobin had the highest content (60–80%), while the content of methemoglobin varied 5–20%. During vibrations in the frequency range 12–28 Hz, 0.5 mm, we recorded 10–30% increase in oxyhemoglobin. With increase in the vibration amplitude (0.9 mm) in the frequency range of 16–32 Hz, constant content of oxyhemoglobin was noted at the beginning of the experiment, which tended to decrease during the last exposure time. Frequency of 32 Hz caused increase in the deoxyhemoglobin content in the membrane-bound fraction. The content of methemoglobin (metHb) in erythrocytes significantly increased during exposure to the frequency range of 12–24 Hz, with the amplitude of 0.5 mm (1.3–2.4 times). During the exposure to frequencies of 28 and 32 Hz, we observed the transition of methemoglobin to hemichrome. The content of methemoglobin in the cells was lower and decreased at the end of the experiment when the vibration amplitude was 0.9 mm. In these experimental conditions, no increase in hemichrome content in the membrane-bound fraction was recorded. Therefore, the degree of binding of catalase and hemoglobin with the membrane of erythrocytes that were exposed to vibration and the changes in the content of ligand forms in the composition of membrane-bound hemoglobin are dose-dependent. Low-frequency vibration initiates O2-dependent processes in erythrocytes. Targets of such an influence are nanobubbles of dissolved air (babstons), retained on the surface of erythrocytes due to Coulomb interactions, capable of coagulation and increase in size under the action of vibration. At first, the consequences of these processes are increase in oxygen content in the surface of erythrocytes, and then decrease as a result of degassing. Thus, increase in oxygen content on the surface initiates redox reactions, whereas decrease in oxygen content leads to reconstruction of metabolic processes oriented at overcoming hypoxia.

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“…When the nanobubbles were broken, there was a possibility to produce radicals. Takahashi et al, 2021, reported that •OH was generated from the collapsing microbubbles, including oxygen with 2 vol% ozone in 1 mM FeSO4 aqueous solution under strongly acidic conditions without ultrasound or a large pressure difference [25]. The following Section 3.5 will report and discuss the experimental results on radical observation as a function of solution pH.…”

Section: Number Of Nanobubblesmentioning

confidence: 98%

“…Moreover, the microbubbles on ozonized water indicated the production of •OH by the collapse of the microbubbles [24]. In 2021, they reported that •OH was generated from the collaps-ing microbubbles under strongly acidic conditions without any dynamic stimulus such as ultrasound or a large pressure difference [25]. Liu et al, 2016 reported that •OH and superoxide ion (•O 2 − ) can be produced in an aqueous solution with bulk nanobubbles, and investigated the germination processes for plant seeds [26].…”

Section: Introductionmentioning

confidence: 99%

Stability and Free Radical Production for CO2 and H2 in Air Nanobubbles in Ethanol Aqueous Solution

Han

Kurokawa²,

Matsui³

et al. 2022

Nanomaterials

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In this study, 8% hydrogen (H2) in argon (Ar) and carbon dioxide (CO2) gas nanobubbles was produced at 10, 30, and 50 vol.% of ethanol aqueous solution by the high-speed agitation method with gas. They became stable for a long period (for instance, 20 days), having a high negative zeta potential (−40 to −50 mV) at alkaline near pH 9, especially for 10 vol.% of ethanol aqueous solution. The extended Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory was used to evaluate the nanobubble stability. When the nanobubble in ethanol alkaline aqueous solution changed to an acidic pH of around 5, the zeta potential of nanobubbles was almost zero and the decrease in the number of nanobubbles was identified by the particle trajectory method (Nano site). The collapsed nanobubbles at zero charge were detected thanks to the presence of few free radicals using G-CYPMPO spin trap reagent in electron spin resonance (ESR) spectroscopy. The free radicals produced were superoxide anions at collapsed 8%H2 in Ar nanobubbles and hydroxyl radicals at collapsed CO2 nanobubbles. On the other hand, the collapse of mixed CO2 and H2 in Ar nanobubble showed no free radicals. The possible presence of long-term stable nanobubbles and the absence of free radicals for mixed H2 and CO2 nanobubble would be useful to understand the beverage quality.

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Free-Radical Generation from Bulk Nanobubbles in Aqueous Electrolyte Solutions: ESR Spin-Trap Observation of Microbubble-Treated Water

Cited by 93 publications

References 80 publications

Ozone ultrafine bubble water inhibits the early formation of Candida albicans biofilms

Ozone ultrafine bubble water inhibits the early formation of Candida albicans biofilms

Vibration influence on the O2-dependent processes activity in human erythrocytes

Stability and Free Radical Production for CO2 and H2 in Air Nanobubbles in Ethanol Aqueous Solution

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