The Anti-Proliferation Activity and Mechanism of Action of K12[V18O42(H2O)]∙6H2O on Breast Cancer Cell Lines.

Polyoxometalates (POMs) are inorganic clusters that possess potential anti-bacterial, anti-viral, and anti-tumor activities. Herein, the in vitro anti-proliferation activities of K12[V18O42(H2O)]∙6H2O (V18) have been investigated on the MCF-7 and MDA-MB-231 cell lines. The results indicated that V18 could inhibit the proliferation of MCF-7 (IC50, 11.95 µM at 48 h) in a dose-dependent manner compared to the positive control, 5-fluorouracil (5-Fu, p < 0.05). The anti-proliferation activity of V18 might be mediated by arrest of the MCF-7 cells in the G2/M phase and induction of apoptosis and necrosis. Moreover, V18 can effectively quench the fluorescence of ctDNA. The binding mode between them may be groove or outside stacking binding. V18 can also effectively quench the intrinsic fluorescence of bovine serum albumin (BSA) and human serum albumin (HSA) via static quenching, and changed the conformation of BSA and HSA.

Optimizing Colorimetric Assay Based on V2O5 Nanozymes for Sensitive Detection of H2O2 and Glucose.

Nanozyme-based chemical sensing is a rapidly emerging field of research. Herein, a simple colorimetric assay for the detection of hydrogen peroxide and glucose based on the peroxidase-like activity of V2O5 nanozymes has been established. In this assay, the effects of pH, substrate, nanozyme concentrations and buffer solution have been investigated. It was found that compared with 3,3',5,5'-tetramethylbenzidine (TMB), the enzyme substrate o-phenylenediamine (OPD) seriously interfered with the H2O2 detection. Under the optimal reaction conditions, the resulting sensor displayed a good response to H2O2 with a linear range of 1 to 500 µM, and a detection limit of 1 µM at a signal-to-noise ratio of 3. A linear correlation was established between absorbance intensity and concentration of glucose from 10 to 2000 µM, with a detection limit of 10 µM. The current work presents a simple, cheap, more convenient, sensitive, and easy handling colorimetric assay.

Factor structure and measurement invariance of the Chinese version of the COVID-19 Phobia Scale in depressive symptoms sample during COVID-19 closure: An exploratory structural equation modeling approach.

The COVID-19 Phobia Scale is an instrument for measuring the phobia of coronavirus. It has a stable four-factor structure and good reliability and validity in other countries and regions. In order to expand related research, this study aims to test the reliability and validity of the COVID-19 Phobia Scale in Chinese adolescents with depressive symptoms. The C19P-SC was translated into Chinese by the method of forward and back translation and tested in 1933 Chinese adolescents with depressive symptoms. Confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM) were used to test and compare the four-factor model of the C19P-SC. Then we tested the measurement invariance of the C19P-SC across gender and time. Finally, the reliability was measured with the McDonald's omega coefficients. Consistent with previous studies, the C19P-SC showed a stable four-factor structure. The results showed that ESEM was better than CFA and more reasonable. In addition, the results of multi-group ESEM showed that the C19P-SC met the strict invariance at male and female and partial longitudinal strict invariance. The Mcdonald's omega coefficients of the C19P-SC total scale and each subscale reached the expected acceptable level. In short, the reliability and validity index of C19P-SC has reached an acceptable level, and the measurement invariance of different genders and different time points was established, but the cross-factor phenomenon of individual items was abnormal, and a further revision and testing are still needed.

Assembled Nanocomplex for Improving Photodynamic Therapy through Intraparticle Fluorescence Resonance Energy Transfer.

In recent years, one of main obstacles in a photodynamic therapy (PDT) process has been that most photosensitizers for PDT are excited by visible light with limited penetrating ability; thus most applications of PDT are for superficial treatments. One of the methods to increase the treatment depth is to introduce a two-photon-active technique into PDT, known as TP-PDT. The difficulty here is to obtain photosensitizers with a large enough two-photon absorption cross-section. In this work, an organic nanocomplex, composed of the two-photon nanoaggregate as the core and photosensitizer as the shell, has been constructed. Photosensitizers could be excited indirectly through a fluorescence resonance energy transfer (FRET) mechanism after the two-photon core was excited by a two-photon laser. The FRET efficiency was extremely high, owing to sufficient energy donors and stable energy acceptors. In this way, a photosensitizer could induce two-photon toxicity for improving the treatment depth in PDT. The nanocomplexes were prepared through a molecular assembly method, which avoided complicated reactions for synthesizing two-photon photosensitizers. The assembly method would expand the selection of photosensitizers and two-photon dyes, and endow traditional photosensitizers with a larger two-photon absorption cross-section for TP-PDT.

Nitrogen-doped graphene quantum dots coupled with photosensitizers for one-/two-photon activated photodynamic therapy based on a FRET mechanism.

A novel material with a large two-photon absorption cross-section was conjugated with a typical photosensitizer for inducing a FRET process. The photosensitizer can be excited by a one-/two-photon laser and then induced photo-toxicity in vitro and in vivo. The system presents great potential for improving treatment depth and the precision of traditional photodynamic therapy.

Influence of VO2 Nanoparticle Morphology on the Colorimetric Assay of H2O2 and Glucose.

Nanozyme-based colorimetric sensors have received considerable attention due to their unique properties. The size, shape, and surface chemistry of these nanozymes could dramatically influence their sensing behaviors. Herein, a comparative study of VO2 nanoparticles with different morphologies (nanofibers, nanosheets, and nanorods) was conducted and applied to the sensitive colorimetric detection of H2O2 and glucose. The peroxidase-like activities and mechanisms of VO2 nanoparticles were analyzed. Among the VO2 nanoparticles, VO2 nanofibers exhibited the best peroxidase-like activity. Finally, a comparative quantitative detections of H2O2 and glucose were done on fiber, sheet, and rod nanoparticles. Under the optimal reaction conditions, the lower limit of detection (LOD) of the VO2 nanofibers, nanosheets, and nanorods for H2O2 are found to be 0.018, 0.266, and 0.41 mM, respectively. The VO2 nanofibers, nanosheets, and nanorods show the linear response for H2O2 from 0.025-10, 0.488-62.5, and 0.488-15.625 mM, respectively. The lower limit of detection (LOD) of the VO2 nanofibers, nanosheets, and nanorods for glucose are found to be 0.009, 0.348, and 0.437 mM, respectively. The VO2 nanofibers, nanosheets, and nanorods show the linear response for glucose from 0.01-10, 0.625-15, and 0.625-10 mM, respectively. The proposed work will contribute to the nanozyme-based colorimetric assay.

Antileukemic activity of an arsenomolybdate in the human HL-60 and U937 leukemia cells.

The antileukemic activity, mechanisms and serum albumin interactions of an arsenomolybdate, K2Na[AsMo6O21(O2CCH2NH3)3]·6H2O (1), was evaluated in the human leukemia HL-60 and U937 cells. The results indicated that 1 could inhibit the proliferation of both leukemia cell lines in a dose-dependent manner with the 50% lethal concentration (IC50) value of 8.61µM for HL-60 and 14.50µM for U937 at 24h, compare to the positive controls, all-trans retinoic acid (ATRA) with IC50 value of 20.76µM and 14.85µM,and As2O3 with IC50 value of 6.40µM and 8.75µM at 24h, respectively (P<0.05). Furthermore, the anti-leukemia activity of compound 1 might be medicated by arresting the leukemic cells in the G1 phase and inducing apoptosis via caspase-3 and bcl-2 regulatory proteins. Spectroscopic techniques results showed that the fluorescence of human serum albumin was quenched by compound 1, and the quenching mechanism was mainly static quenching. Compound 1 might be a potential medicinal candidate against acute promyelocytic leukemia.

In vitro and in vivo antifungal activities and mechanism of heteropolytungstates against Candida species.

The antifungal activities of heteropolytungstates, α-1,2,3-K6H[SiW9V3O40] (SiW-3), K13[Ce(SiW11O39)2]·17H2O (SiW-5), K13[Eu(SiW11O39)2]·25H2O (SiW-10), K6PV3W9O40 (PW-6), α-K4PVW11O40 (PW-8), were screened in 29 Candida albicans, 8 Candida glabrata, 3 Candida krusei, 2 Candida parapsilosis, 1 Candida tropicalis, and 1 Cryptococcus neoformans strains using the CLSI M27-A3 method. SiW-5 had the highest efficacy with a minimum inhibitory concentration (MIC) values of <0.2-10.2 µM in vitro. The antifungal mechanism, acute toxicity and in vivo antifungal activity of SiW-5 were then evaluated in C. albicans. The results showed that SiW-5 damaged the fungal cell membrane, reduce the ergosterol content and its main mode of action was through inhibition of ergosterol biosynthesis. Real-time PCR showed that ERG1, ERG7, ERG11 and ERG28 were all significantly upregulated by SiW-5. An acute toxicity study showed the 50% lethal dose (LD50) of SiW-5 for ICR mice was 1651.5 mg/kg. And in vivo antifungal studies demonstrated that SiW-5 reduced both the morbidity and fungal burden of mice infected with C. albicans. This study demonstrates that SiW-5 is a potential antifungal candidate against the Candida species.

BSA-binding properties and anti-proliferative effects of amino acids functionalized polyoxomolybdates.

Glycine decorated heteropolymolybdates, K2Na[AsMo6O21(O2CCH2NH3)3]·6H2O 1 and K2Na2[γ-Mo8O26(O2CCH2NH3)2]·6H2O 2, have been synthesized and evaluated for in vitro anti-proliferative effects. The identity and high purity of compounds 1 and 2 were confirmed by elemental analysis, FT-IR spectrum, UV-vis spectrum, and X-ray diffraction. Crystal data for 2: triclinic, P-1, a=9.792(2)Å, b=10.077(2)Å, c=10.351(2)Å, α=83.865(4)°, ß=71.110(4)°, γ=62.284(3)°, V=854.3(3)Å(3), Z=1, R(final)=0.0486. The inhibitory effects of 1 and 2 on human non-small cell lung cancer cell line A549 were investigated by MTT assay, nuclear staining, and the flow cytometry. It indicated that compound 1 inhibited the proliferation of A549 cells in a dose-dependent and time-dependent manner, which is more effective than the positive control, 5-fluorouracil (5-FU) (P<0.05). The staining and flow cytometry results showed that compound 1 induced the apoptosis and necrosis of A549 cells and inhibit cell proliferation, which is associated with S-phase arrest. Compound 2 showed a modest activity in a dose-dependent manner. In addition, the interaction between compound 1 and bovine serum albumin (BSA) was evaluated by spectroscopic methods. The results showed that the compound 1 effectively quenched the intrinsic fluorescence of BSA via static quenching and changed the conformation of BSA.