ROS Detection Research Articles

Escherichia coli foster bladder cancer cell line progression via epithelial mesenchymal transition, stemness and metabolic reprogramming

Bacteria is recognized as opportunistic tumor inhabitant, giving rise to an environmental stress that may alter tumor microenvironment, which directs cancer behavior. In vitro infection of the T24 cell line with E. coli was performed to study the bacterial impact on bladder cancer cells. EMT markers were assessed using immunohistochemistry, western blot and RT-PCR. Stemness characteristics were monitored using RT-PCR. Furthermore, the metabolic reprograming was investigated by detection of ROS and metabolic markers. A significant (p ≤ 0.001) upregulation of vimentin as well as downregulation of CK19 transcription and protein levels was reported. A significant increase (p ≤ 0.001) in the expression level of stemness markers (CD44, NANOG, SOX2 and OCT4) was reported. ROS level was elevated, that led to a significant increase (p ≤ 0.001) in UCP2. This enhanced a significant increase (p ≤ 0.001) in PDK1 to significantly downregulate PDH (p ≤ 0.001) in order to block oxidative phosphorylation in favor of glycolysis. This resulted in a significant decrease (p ≤ 0.001) of AMPK, and a significant elevation (p ≤ 0.001) of MCT1 to export the produced lactate to extracellular matrix. Thus, bacteria may induce alteration to the heterogonous tumor cell population through EMT, CSCs and metabolic reprogramming, which may improve cancer cell ability to migrate and self-renew.

Indirect Cold Atmospheric Pressure Plasma treatment on Melanoma and Fibroblast Cells

Cold atmosphere plasma has been shown as a promising technology for certain cancer treatments. In this paper, we report indirect plasma treatment using CAP discharged in cell culture medium and study the effect of identical plasma stimulated culture medium on melanoma cancer cells and fibroblast cells cultured in vitro. The results of MTT assay, migration assay, ROS detection, and alizarin red assay show that plasma-treated medium can have a strong negative effect on melanoma cancer cells compared with the control group. However, the plasma-treated medium has a less cytotoxic effect on fibroblast cells than that on melanoma cancer cells at the same treatment. This result is attributed to the production of reactive oxygen species in the plasma-treated medium to induce apoptosis and inhibit melanoma cell proliferation and further cell metastasis. According to the results, this study shows the potential of CAP plasma treatment for anti-cancer therapy.

Phototherapy and Sonotherapy of Melanoma Cancer Cells Using Nanoparticles of Selenium-Polyethylene Glycol-Curcumin as a Dual-Mode Sensitizer.

Background: As an alternative form of cancer therapy, photothermal therapy (PTT) and sonodynamic therapy (SDT) using nanomaterials are in development. Nanomaterials can act as energy absorber as well as anti-cancer agent.Objective: In this study, the effects of laser and ultrasound irradiation with Se-PEG-Cur nanoparticles were investigated on melanoma cancer.Material and Methods: In this experimental study, nanoparticles of selenium-polyethylene glycol-curcumin (Se-PEG-Cur) were synthesized, and their UV-vis absorption, particle size, zeta potential and photothermal conversion efficiency were determined. Se-PEG-Cur was then introduced as a novel 808-nm laser light absorbing agent as well as ultrasound (US) wave for treatment of C540 (B16/F10) cancer cells. Also, ROS generation in C540 (B16/F10) cancer cells was measured upon PTT and SDT using Se-PEG-Cur. Results: Mean size, zeta potential and photothermal conversion efficiency of Se-PEG-Cur were obtained as ~300 nm, 42.7 mV and 16.7%, respectively. Cell viability upon irradiation of the laser light or US waves with 100 µg mL-1 Se-PEG-Cur were decreased to 33.9 and 22.9%, respectively. Conclusion: Intracellular ROS detection indicated that dual PTT and SDT in the presence of Se-PEG-Cur induced the highest ROS production. Se-PEG-Cur was therefore introduced as an absorbing agent of both laser light and US waves for cancer treatment.

Elevated ROS depress mitochondrial oxygen utilization efficiency in cardiomyocytes during acute hypoxia.

Mitochondria are important sites for the production of ATP and the generation of ROS in cells. However, whether acute hypoxia increases ROS generation in cells or affects ATP production remains unclear, and therefore, monitoring the changes in ATP and ROS in living cells in real time is important. In this study, cardiomyocytes were transfected with RoGFP for ROS detection and MitGO-Ateam2 for ATP detection, whereby ROS and ATP production in cardiomyocytes were respectively monitored in real time. Furthermore, the oxygen consumption rate (OCR) of cardiomyocytes was measured. Similar results were produced for adult and neonatal rat cardiomyocytes. Hypoxia (1% O2) reduced the basal OCR, ATP-linked OCR, and maximal OCR in cardiomyocytes compared with these OCR levels in the cardiomyocytes in the normoxic group (21% O2). However, ATP-linked OCR, normalized to maximal OCR, was increased during hypoxia, indicating that the electron leakage of complex III exacerbated the increase of ATP-linked oxygen consumption during hypoxia and vice versa. Combined with the result that cardiomyocytes expressing MitGO-Ateam2 showed a significant decrease in ATP production during hypoxia compared with that of normoxic group, acute hypoxia might depress the mitochondrial oxygen utilization efficiency of the cardiomyocytes. Moreover, cardiomyocytes expressing Cyto-RoGFP or IMS-RoGFP showed an increase in ROS generation in the cytosol and the mitochondrial intermembrane space (IMS) during hypoxia. All of these results indicate that acute hypoxia generated more ROS in complex III and increased mitochondrial oxygen consumption, leading to less ATP production. In conclusion, acute hypoxia depresses the mitochondrial oxygen utilization efficiency by decreasing ATP production and increasing oxygen consumption as a result of the enhanced ROS generation at mitochondrial complex III.

Combination of metformin and cold atmospheric plasma induces glioma cell death to associate with c-Fos.

Glioma is the most common type of brain cancer. Chemotherapy combination with surgery and radiotherapy is a standard treatment for patients. Although there are many advances in glioma therapy, the prognosis of glioma patients has not significantly been improved over the past decades. Hence, there is still an urgent need to develop a new therapy to treat glioma. Cell viability was assessed by CellTiter Blue assay; flow cytometry (FCM) was used for detecting cell apoptosis; ROS detection was detected by ROS Assay; H2O2 detection was performed by hydrogen peroxide detection kits; real-time PCR and WB were used to determine gene expression. Using the glioma cell line U251 and U87, we investigated a possible combination inhibitory effect includes metformin and cold atmospheric plasma (CAP). The combination treatment showed a synergistic inhibitory effect on cell viability, significantly inducing cell apoptosis. Furthermore, we also found H2O2 produced by CAP has an important role in the synergistic inhibitory effect, eliminating H2O2 with catalase reversed the synergistic inhibitory effect. In addition, the transcript and protein levels of c-FOS were robustly increased after co-treated with metformin and CAP. Taken together, we propose that pre-treatment of glioma cells with metformin sensitize tumor cells to CAP, which may serve as a potential therapeutic strategy for glioma.

Vigilin interacts with ER-β to protect against palmitic acid-induced granulosa cells apoptosis via inhibiting calcineurin-mediated Drp1 signaling pathway

BackgroundHypercholesterolemia is one of the causes of female infertility, and as a common fatty acid in follicular fluid, palmitic acid (PA) level plays a vital role in granule cell which is closely related to the developmental potential of follicle. MethodsThe ovarian granulosa cell-like human granulosa (KGN) cell line and the immortalized normal ovarian surface epithelial cell line (IOSE80) were used to verify the effect of PA on cell viability and apoptosis by MTT and flow cytometry assay, respectively. Then mitochondria damage was confirmed by mitochondrial membrane potential, mitochondrial ROS detection assay and western blot in KGN cells. Thorough luciferase reporter assay and RIP-qPCR, the relationship between vigilin and ER-β was investigated. ResultsIn our study, PA induced mitochondrial damage-mediated cell apoptosis of KGN cells was dose-dependently, while PA shown no effects on in IOSE80 cells. Then the role of calcineurin (CnA)-mediated Drp1 signaling pathway on KGN cells was confirmed by treating with Mdivi-1 or FK506T. In addition, the changed level of vigilin and ER-β was observed in cell apoptosis of KGN cells induced by PA. By transfecting vigilin vector or ER-β vector into KGN cells, respectively, vigilin and ER-β were demonstrated to regulate the apoptosis of KGN cells. And vigilin was a binding protein of ER-β mRNA. ConclusionVigilin could interact with ER-β mRNA to promote ER-β expression. And Vigilin/ ER-β relieve the mitochondrial damage and cell apoptosis induced by PA through regulating CnA-mediated Drp1 signaling pathway, which revealed the mechanism and strategy of hypercholesterolemia in female infertility.

RETRACTED ARTICLE: STRUCTURAL INSIGHTS AND ANTI-COLON CANCER ACTIVITY OF TWO Zn(II)-BASED COORDINATION POLYMERS BASED ON CARBOXYLATE AND IMIDAZOLE CO-LIGANDS

Two new mixed-ligand coordination polymers [Zn(bdc)(bib)]n (1, H2bdc = 1,3-dicarboxybenzene, bib = 1,3-bis(imidazol-1-yl)benzene) and [Zn(NH2-bdc)(bib)]n (2, NH2–H2bdc = 2-amino-1,4-dicarboxybenzene) are successfully prepared by the reaction of zinc nitrate, N-containing and dicarboxylate ligands under the same hydrothermal conditions. The anti-viability of compounds 1 and 2 is assessed with CCK-8 against SW480 colon cancer cells. To further explore the underlying mechanism of compounds, the cell apoptosis and ROS detection are performed in this experiment.

RETRACTED ARTICLE: SYNTHESIS, CRYSTAL STRUCTURE, AND ANTI-GASTRIC CANCER ACTIVITY OF A Zn(II) COORDINATION POLYMER WITH A 4,4′-BIS(1-IMIDAZOLYL)BIPHENYL LIGAND

In this work, the rod-like 4,4′-bis(imidazol-1-yl)-biphenyl (bibp) ligand is utilized as a building block for the coordination assembly with the Zn(II) ion to produce a new Zn(II)-based coordination polymer [Zn3(bibp)2(HCOO)6](H2O)2 (1) under solvothermal conditions. Furthermore, we use the grinding method to downsize complex 1 to the nanoregion. The anti-gastric cancer activity of the compound is evaluated by the Annexin V-FITC/PI apoptosis assay in flow cytometry, and the following mechanism exploration is performed by the DCFH-DA detection assay for the ROS detection.

Ultra-small-size Astragaloside-IV loaded lipid nanocapsules eye drops for the effective management of dry age-related macular degeneration

ABSTRACT Background Age-related macular degeneration (AMD) is a major cause of severe visual loss in elderly people. The treatments for dry AMD (dAMD) are severely limited so far. In this work, we aim to develop an eye drop to protect retinal functions against oxidative stress and apoptosis for improving dAMD management. Methods Astragaloside-IV (ASIV) was prepared into phospholipid complex and loaded into three sizes (20, 50 and 90 nm) of ASIV lipid nanocapsules (ASIV-LNCs). The penetration and distribution of LNCs were investigated. DAMD mice model was induced by NaIO3, and therapeutic effect was evaluated by electroretinography (ERG), histological examination, apoptosis and ROS detection. Results The ocular penetration and pharmacokinetic studies corroborated the feasibility of the LNCs to reach the fundus, and ultra-small-size LNCs (ASIV-LNCs-20) had the best delivery effect. ASIV-LNCs-20 was able to decrease ROS production and reduce the apoptosis rate from 5.12% to 0.533%. ERG and H&E staining results confirmed ASIV-LNCs-20 had a good protective effect on the morphology and function of the retina. Conclusions These results suggest that ASIV-LNCs can be a promising therapy approach for dAMD, and this research also offers new possibilities for further applications of LNCs as a drug delivery system for other eye diseases. Abbreviations AMD: Age-related macular degeneration;AREDS Age-related eye disease study; ASIV: Astragaloside-IV;AUC: Area under the concentration-time curve; dAMD: Dry age-related macular degeneration; DHE: Dihydroethidium; DL: Drug Loading; DLS: Dynamic light scattering; DSC: Differential scanning calorimetry; EE: Entrapment efficiency; ELSD: Evaporative light scattering detector; ERG: Electroretinographic; H&E: Hematoxylin and Eosin; I.S.: Internal standard; LB: Langmuir-Blodgett; LNCs: Lipid nanocapsules; MCT: Medium-chain triacylglycerol; ONL: Outer nuclear layer; OPL: Outer plexiform layer; PDI: Polydispersity index; PR: Photoreceptor;ROS: Reactive oxygen species; RPE: Retinal pigment epithelium; TEM: Transmission electron microscope; wAMD: Wet age-related macular degeneration

Methyl Jasmonate Protects Microglial Cells Against β-Amyloid-Induced Oxidative Stress and Inflammation via Nrf2-Dependent HO-1 Pathway.

Backgroundβ-Amyloid (Aβ) induces oxidative stress and inflammation of microglial cells, thus leading to Alzheimer’s disease. Methyl jasmonate (MeJA) is reported to have anti-inflammatory and anti-oxidant effects. However, the potential roles of MeJA in Aβ-induced cell activities and the underlying mechanism are unclear.MethodsMicroglial cell line BV-2 was stimulated by 20 μM Aβ and/or 20 μM MeJA and then divided into four groups (control, Aβ, MeJA, and Aβ+MeJA). Cell viability was detected by MTT assay. MDA, SOD activity, and ROS were detected by fluorescence spectrophotometry and immunofluorescence assay. Nrf2 and HO-1 were detected by qRT-PCR and Western blot. Furthermore, inflammatory cytokines (p-NFκB, TLR4, TNF-α, IL-1β, and IL-6) and apoptosis factors (Bcl-2, Bax, and cl-casp-3) were detected by Western blot. TUNEL assay was applied to investigate apoptosis rate. Moreover, the mechanism of how MeJA played anti-oxidative stress and anti-inflammatory roles was investigated by silencing of Nrf2 via siRNA.ResultsThe result of MTT assay showed that MeJA improved the decreased viability of BV-2 cells induced by Aβ. The detection of MDA, SOD activity, and ROS showed the oxidative stress levels were decreased in Aβ+MeJA group compared with Aβ group. Nrf2, HO-1, and SOD were significantly up-regulated in Aβ+MeJA group compared with Aβ group (p<0.01). In contrast, inflammatory cytokines were significantly down-regulated in Aβ+MeJA group compared with Aβ group (p<0.05). Similarly, the expressions of apoptosis cytokines and TUNEL assay suggested a decreased apoptosis rate in Aβ+MeJA group compared to Aβ group (p<0.01). Finally, results of Nrf2 knockdown experiment showed down-regulations of anti-oxidative stress factors (Nrf2, HO-1 and SOD), up-regulations of inflammatory cytokines, and increased ratio of Bax to Bcl in Aβ+MeJA+si-Nrf2 group compared with Aβ+MeJA group (p<0.01).ConclusionMeJA could relieve Aβ-induced oxidative stress and inflammatory response in microglial cells by activating Nrf2/HO-1 pathway.

Structural Characterization, Molecular Docking and Protective Effect on Coronary Artery Disease of a New Nanostructured Cu(II)-Coordination Polymer by Reducing the Inflammatory Level

The development of Cu(II)-based coordination complexes as potent anticancer agents has received increasing attention in recent years. In this study, a novel Cu(II) bearing coordination polymer formulated as [Cu2(bix)(aip)2(H2O)2]n (1, bix = 1,4‐bis(imidazol‐1‐ylmethyl)benzene, H2aip = 5‐aminoisophthalic acid) has been triumphantly prepared by the reaction of Cu(NO3)2·3H2O, bix and H2aip under the hydrothermal condition. Furthermore, the ultrasonic synthesis method was used to produce the nanoscale 1 (denoted as nano 1 hereafter) with the particle size in the range of 360 nm. The protective effect of nano 1 on the coronary heart disease treatment was evaluated. Western blot was utilized to detect the relative expression of AMPK/SIRT1/NF-κB pathway, and the ROS detection was performed to measure the (reactive oxygen species) ROS level in the cells. Analysis further performed by molecular docking shows that Cu(II) complex possess the drug-like criteria indicating the anti-coronary heart disease potential.

Electrochemistry at Bimetallic Pd/Au Thin Film Surfaces for Selective Detection of Reactive Oxygen Species and Reactive Nitrogen Species.

In this work, we designed and fabricated Pd/Au bimetallic thin film electrodes with isolated Pd nanoparticles via underpotential deposition of copper on a gold substrate followed by in situ redox replace reaction in a Pd salt solution. The Pd/Au electrode was characterized by AFM and XPS as well as multiple electrochemical techniques including CV and electrochemical quartz crystal microbalance (EQCM) in sulfuric acid and phosphate buffer electrolytes. Results show that the reduction reactions of the analytes (i.e., H2O2 and 3-nitrotyrosine (3-NT)) at the Pd/Au thin film surfaces affect the nature and reactivity of Pd/Au surface electrochemistry including the adsorbed/absorbed hydrogen and/or the premonolayer palladium oxide redox processes at Pd. The EQCM experiment supports the arrangement of small size Pd nanoparticles in the Pd thin film in the presence of gold exhibits unusual properties, acting as a new physicochemical dimension between the electrode and target H2O2 and 3-NT molecules. The Pd/Au thin film was demonstrated as an extremely sensitive and selective probe for detection of common ROS and RNS (i.e., H2O2 and 3-NT). The integration of two different metallic species, Pd and Au, into a surface structure on nanoscale by exploiting their unique surface electrochemistry establishes an innovative analytical method for highly sensitive and selective detection of H2O2 and 3-NT simultaneously. This method has a general scope for detecting a broad range of redox active and nonredox active species simultaneously, which opens up new opportunities to develop new electrocatalytic materials and innovative sensing approaches.

RETRACTED ARTICLE: A porous Cu(II)-based metal-organic framework with one-dimensional hexagonal channels for solvent-free cyanosilylation and anti-ovarian cancer activity

On the basis of solvothermal reaction, a new porous Cu(II) metal-organic framework (MOF), {[(Cu(L)2(H2O)2](DMF)4)n (namely 1), can be formed via self-assembly of 3-(1H-pyrazol-4-yl)pyridine (namely HL) and Cu(II) ion in water and DMF mixed solvent. We characterized the MOF 1 via elemental analysis, powder X-ray diffraction (PXRD) and single crystal X-ray diffraction, thermogravimetric analysis (TGA) as well as Fourier-transform infrared spectra (FT-IR). In addition, MOF 1 can be used as a solvent free multiphase catalyst for cyanidation due to its open Cu(II) metal sites as well as a larger number of N atoms can be utilized as Lewis basic sites. In connection to these, the catalysis mechanism has also been discussed in detail. To explore the inhibitory function of compound 1a on Hey ovarian cancer cells viability, the CCK-8 was carried out, and the results revealed that compound 1a had good anti-cancer activity in vitro with the IC50 value of 2.81 ± 0.17 μg/mL. Besides, the anti-tumor mechanism of compound 1a was revealed by apoptosis and ROS detection, the results suggested that compound 1a anti-tumor activity owing to the inducing of cell apoptosis by increasing the ROS accumulation.

Intracellular oxidative damage due to antibiotics on gut bacteria reduced by glutathione oxidoreductase-derived antioxidant molecule GM15.

The human gut consists of > 1000 different bacterial species for the smooth functioning of the gut. In normal conditions, the antioxidant system present in cells minimize the effects of reactive oxygen species. Upon exposure to antibiotics, there is a rise in ROS level which induces oxidative stress to the cells, ultimately killing the cells. Two broad-spectrum antibiotics, streptomycin and gentamicin at a concentration of 50µM and 25µM, were treated with Bacillus subtilis SRMIST201901 (MN726522) and B. cereus SRMIST201902 (MN726923); the treatment reduced the cell counts. Considering the bacterial defense property which relies on the antioxidant mechanism, in this study, we have reported an antioxidant peptide (GM15) derived from glutathione oxidoreductase of spirulina (or called cyanobacteria) Arthrospira platensis (Ap) which reduced the intracellular oxidative stress. Cellular ROS detection was confirmed by fluorescent-associated cell sorting (FACS) using the DCFDA dye. Resazurin dye test also confirmed the activity of peptide on the growth of the Bacillus sp. Based on the results obtained, it was concluded that there was a significant (P < 0.05) reduction in the intracellular oxidative stress on treating with GM15 peptide. Overall, the study indicates the influence of antioxidant peptide on the intracellular oxidative stress, leading to the development of an antioxidant drug from glutathione oxidoreductase of A. platensis against oxidative-related stresses.

NGF and CNTF expression and regulation mechanism by miRNA in acute paralytic strabismus.

Nerve growth factor (NGF) and ciliary neurotrophic factor (CNTF) are well-known neurotrophic factors and widely used in the clinical treatment for its promotion effect on peripheral nerve regeneration. And they were also recommended for the acute paralytic strabismus treatment. However, whether the NGF and CNTF have protective effect for the extraocular muscles of acute paralytic strabismus patients is still poorly understood. In this study, we want to evaluate the biological function of NGF and CNTF on the extraocular muscle cells and reveale the regulation mechanism behind it. Firstly, the relative expression of ngf and cntf was assessed by quantitative real-time RT-PCR. Then, the influence of NGF and CNTF on the extraocular muscle cell proliferation was determined by CCK-8. The inflammatory response in muscle cells after NGF and CNTF treatment was evaluated by ELISA and ROS detection. In addition to this, the up-stream regulation of the ngf and cntf expression was also studied. The TargetScan was used for the predication of potential miRNAs targeting with ngf and cntf 30-UTR, which is soon confirmed by luciferase activity assay. all the results in this research indicated that NGF and CNTF could promote the muscle cell proliferation and inhibit the inflammatory levels, then exert protective effect on the muscle cell function. All the results in this research indicated that NGF and CNTF could promote the muscle cell proliferation and inhibit the inflammatory levels, then exert protective effect on the muscle cell function. It was conceivable that let 7-5p was the up-stream regulator of ngf and cntf, and let 7-5p might serve as a potential molecular target for acute paralytic strabismus treatment.

Anti-antioxidant impacts of circZNF609 silence in HaCaT cells through regulating miR-145

Background CircZNF609 (cZNF609) is previously revealed as an essential mediator in oxidative stress. This paper determined the role of cZNF609 in skin oxidative damage to evaluate its importance in pressure ulcer. Methods HaCaT cells treated by H2O2 were considered as a cell model of pressure ulcer. The role of cZNF609 in the model was checked by conducting CCK-8 assay, FITC-PI double-staining, ROS detection and Western blot. The downstream gene and signalling of cZNF609 were studied by utilizing qRT-PCR and Western blot. Results HaCaT cells were remarkably damaged by H2O2, as evidenced by the viability loss, apoptosis and ROS generation. It was coupled with the elevated expression of p53, p16, Bax and the activated forms of caspase-3 and PARP. Meanwhile, cZNF609 was high-expressed in response to H2O2. The oxidative stress driven by H2O2 was alleviated by transfection with cZNF609 specific siRNA. Further, the anti-antioxidant impacts of cZNF609 silence were impeded by miR-145 silence. The inhibition of JNK and p38MAPK pathways induced by cZNF609 silence was impeded by miR-145 silence. Conclusion The protective function of cZNF609 silence in H2O2-injured HaCaT cells was revealed in vitro. Silence of cZNF609 exhibited its impact possibly through regulating miR-145, and JNK and p38MAPK pathways.

Structural insights and anti-colon cancer activity of two Zn(II)-based coordination polymers based on the carboxylate and imidazole coligands

Two new mixed-ligand coordination polymers [Zn(bdc)(bib)]n (1, H2bdc = 1,3-dicarboxy­benzene, bib = 1,3-bis(imidazol-1-yl)benzene) and [Zn(NH2-bdc)(bib)]n (2, NH2—H2bdc = 2-amino-1,4-dicarboxybenzene) are successfully prepared by the reaction of zinc nitrate, N-containing and dicarboxylate ligands under the same hydrothermal conditions. The anti-viability of compounds 1 and 2 is assessed with CCK-8 against SW480 colon cancer cells. To further explore the underlying mechanism of compounds, the cell apoptosis and ROS detection are performed in this experiment.

Implications of dichlorofluorescein photoinstability for detection of UVA-induced oxidative stress in fibroblasts and keratinocyte cells.

Although the dichlorofluorescein (DCF) assay is widely used to detect the production of UVA-induced ROS, the photostability and phototoxicity of the probe after UVA irradiation remains controversial and the experimental conditions often vary across studies, making it difficult to compare results from different studies. This study aimed to evaluate the suitability of the DCF assay for detection of UVA-induced ROS in human cells after UVA irradiation. Human primary fibroblasts (HPF) and HaCaT cells were loaded with 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) (2, 10, and 50 μM) for 10 and 30 min, before and after exposure to UVA radiation (5-50 J cm-2). Fluorescence was recorded immediately or 30 min after irradiation using three different techniques: microplate reading, flow cytometry, and confocal scanning microscopy. Cell viability was assessed by flow cytometry before and after UVA exposure. A UVA-dose-dependent increase in ROS was observed at 5-50 μM DCFDA, and the magnitude of the fluorescent signal was affected by RPMI medium, as well as DCFDA loading concentration and incubation period. However, higher concentrations of DCFDA compromised the viability of both HaCaT and HPF cells after UVA irradiation. The most sensitive and reliable combination for the ROS assay was pre-incubation with 10 μM DCFDA for 30 min in PBS. Reading the fluorescence 30 min after UVA irradiation diminished the emission signal, as did the DCFDA post-incubation. In conclusion, this single-point DCF assay allowed reproducible and sensitive UVA-induced ROS detection in HaCaT and HPF cells without compromising the cell viability or morphology.

Self-assembled reduced graphene oxide–cerium oxide nanocomposite@cytochromechydrogel as a solid electrochemical reactive oxygen species detection platform

A new dimension for the selective detection of short-lived ROS by an electroactive reduced graphene oxide–cerium oxide nanocomposite@cytochromechydrogel.

Synthesis, crystal structure and anti-gastric cancer activity of a Zn(II) coordination polymer with a 4,4'-bis(1-imidazolyl)biphenyl ligand

In this work, the rod-like 4,4¢-bis(imidazol-1-yl)-biphenyl (bibp) ligand is utilized as a building block for the coordination assembly with the Zn(II) ion to produce a new Zn(II)-based coordination polymer [Zn3(bibp)2(HCOO)6](H2O)2 (1) under solvothermal conditions. Furthermore, we use the grinding method to downsize complex 1 to the nanoregion. The anti-gastric cancer activity of the compound is evaluated by the Annexin V-FITC/PI apoptosis assay in flow cytometry, and the following mechanism exploration is performed by the DCFH-DA detection assay for the ROS detection.