RESUMEN

Aim: To develop a ß-AgVO3 gel and evaluate its physicochemical stability and antifungal activity against Candida albicans. Materials & methods: The gel was prepared from the minimum inhibitory concentration (MIC) of ß-AgVO3. The physicochemical stability was evaluated by centrifugation, accelerated stability (AS), storage (St), pH, syringability, viscosity and spreadability tests and antifungal activity by the agar diffusion. Results: The MIC was 62.5 µg/ml. After centrifugation, AS and St gels showed physicochemical stability. Lower viscosity and higher spreadability were observed for the higher ß-AgVO3 concentration and the minimum force for extrusion was similar for all groups. Antifungal effect was observed only for the ß-AgVO3 gel with 20xMIC. Conclusion: The ß-AgVO3 gel showed physicochemical stability and antifungal activity.

We used silver and vanadium to make a gel that can kill fungi in the mouth. We looked at the color of the gel, it's smell and also checked how well it lasted. The gel turned yellow and had no smell and did not spoil for at least 2 months. When we tested the gel against a type of fungus, it worked as well as another medicine called chlorhexidine, which is sold in pharmacies. But when we compared it with another medicine called nystatin, our gel was not as effective in killing the fungus.

RESUMEN

Alternatives have been sought to add an antimicrobial property to denture adhesives. This study evaluated the antimicrobial potential of adhesives associated with nanostructured silver vanadate decorated with silver nanoparticles (ß-AgVO3). Specimens in acrylic resin were treated with the adhesives associated with ß-AgVO3 (1%, 2.5%, 5% and 10%). As control, specimens treated only with Ultra Corega Cream (UCC) or Ultra Corega Powder (UCP) adhesive were used. Multispecies biofilm of Candida albicans, Candida glabrata, Streptococcus mutans and Staphylococcus aureus was evaluated by counting colony forming units per milliliter (CFU/mL), colorimetric assay and fluorescence microscopy. The data were analyzed using the two-way analysis of variance (ANOVA) and Bonferroni multiple comparisons test (α=0.05). For both adhesives, a small amount of ß-AgVO3 (1%) completely inhibited S. mutans (P⟨0.05). For the other microorganisms, there was a reduction in metabolic activity and complete inhibition in the groups with intermediate or greater amounts of nanomaterial (P⟨0.05), except for C. albicans, which was reduced (P⟨0.05) but not completely inhibited in UCP. Microscopy that showed less biofilm in the groups with ß-AgVO3 and in the UCC than UCP. Denture adhesives in powder and cream form with ß-AgVO3 showed potential antimicrobial activity against multispecies biofilm. Powder adhesive showed higher biofilm formation.

Asunto(s)

RESUMEN

Objective: The aim of this study was to evaluate the roughness, hardness, and color change of pit and fissure sealants of two commercial brands (Fluroshield ™ and Ultraseal XT ™) incorporated with nanostructured silver vanadate nanomaterial decorated with silver nanoparticles (ß-AgVO3) in concentrations (0% - control, 2.5% and 5%). Material and methods: Two commercial brands Fluroshield TM and Ultraseal XT ™ were used to make the samples with dimensions of 6 × 6 × 4 mm. The control group was made according to the manufacturer's instructions and in the groups with the addition of ß-AgVO3, the nanomaterial was added proportionally by mass at percentages of 2.5% and 5%. Roughness properties were evaluated using a 3D Laser Confocal Microscope (n = 10), Knoop microhardness by Microdurometer (n = 10), and color change by Portable Color Spectrophotometer on the CIEDE2000 system (n = 10). Data were evaluated by one-way ANOVA with Bonferroni adjustment and Tukey's mean comparison test at a 5% significance level. Results: Ultraseal XT ™ sealant roughness showed a significant difference between concentrations with the highest mean for the 5% group (P = 0.010). Regarding the hardness, both sealants showed no significant difference between the groups. Fluroshield ™ sealant showed a significant difference in ΔE00 between the control-2.5% 24.93 (3.49) and control-5% 28.41 (2.58). Conclusion: It may be concluded that the incorporation of ß-AgVO3 influenced the increase in roughness for Ultraseal XT ™ pit and fissure sealant, did not interfere with the microhardness of both sealants, and promoted a change in the color of Fluroshield ™ sealant within clinically acceptable limits.

RESUMEN

The aim to access linked tetravanadate [V4O12]4- anion with mixed copper(II) complexes, using α-amino acids and phenanthroline-derived ligands, resulted in the formation of four copper(II) complexes [Cu(dmb)(Gly)(OH2)]2[Cu(dmb)(Gly)]2[V4O12]·9H2O (1) [Cu(dmb)(Lys)]2[V4O12]·8H2O (2), [Cu(dmp)2][V4O12]·C2H5OH·11H2O (3), and [Cu(dmp)(Gly)Cl]·2H2O (4), where dmb = 4,4'-dimethioxy-2,2'-bipyridine; Gly = glycine; Lys = lysine; and dmp = 2,9-dimethyl-1,10-phenanthroline. The [V4O12]4- anion is functionalized with mixed copper(II) units in 1 and 2; while in 3, it acts as a counterion of two [Cu(dmp)]2+ units. Compound 4 crystallized as a unit that did not incorporate the vanadium cluster. All compounds present magnetic couplings arising from Cu⋯O/Cu⋯Cu bridges. Stability studies of water-soluble 3 and 4 by UV-Vis spectroscopy in cell culture medium confirmed the robustness of 3, while 4 appears to undergo ligand scrambling over time, resulting partially in the stable species [Cu(dmp)2]+ that was also identified by electrospray ionization mass spectrometry at m/z = 479. The in vitro cytotoxicity activity of 3 and 4 was determined in six cancer cell lines; the healthy cell line COS-7 was also included for comparative purposes. MCF-7 cells were more sensitive to compound 3 with an IC50 value of 12 ± 1.2 nmol. The tested compounds did not show lipid peroxidation in the TBARS assay, ruling out a mechanism of action via reactive oxygen species formation. Both compounds inhibited cell migration at 5 µM in wound-healing assays using MCF-7, PC-3, and SKLU-1 cell lines, opening a new window to study the anti-metastatic effect of mixed vanadium-copper(II) systems.

Asunto(s)

RESUMEN

A sensitive and selective label-free photoelectrochemical (PEC) immunosensor was designed for the detection of cardiac troponin I (cTnI). The platform was based on a fluorine-doped tin oxide (FTO)-coated glass photoelectrode modified with bismuth vanadate (BiVO4) and sensitized by an electrodeposited bismuth sulfide (Bi2S3) film. The PEC response of the Bi2S3/BiVO4/FTO platform for the ascorbic acid (AA) donor molecule was approximately 1.6-fold higher than the response observed in the absence of Bi2S3. The cTnI antibodies (anti-cTnI) were immobilized on the Bi2S3/BiVO4/FTO platform surface to produce the anti-cTnI/Bi2S3/BiVO4/FTO immunosensor, which was incubated in cTnI solution to inhibit the AA photocurrent. The photocurrent obtained by the proposed immunosensor presented a linear relationship with the logarithm of the cTnI concentration, ranging from 1 pg mL-1 to 1000 ng mL-1. The immunosensor was successfully employed in artificial blood plasma samples for the detection of cTnI, with recovery values ranging from 98.0% to 98.5%.

Asunto(s)

RESUMEN

The title compound, (C4H12N5)4(C2H7N4O)2[V10O28]·4H2O, is a by-product obtained by reacting ammonium metavanadate(V), metformin hydro-chloride and acetic acid in the presence of sodium hypochlorite, at pH = 5. The crystal structure comprises a deca-vanadate(V) anion (V10O28)6- lying on an inversion centre in space group P , while cations and solvent water mol-ecules are placed in general positions, surrounding the anion, and forming numerous N-H⋯O and O-H⋯O hydrogen bonds. Metforminium (C4H12N5)+ and guanylurea (C2H7N4O)+ cations display the expected shape. Inter-estingly, in physiology the latter cation is known to be the main metabolite of the former one. The reported structure thus supports the role of sodium hypochlorite as an oxidizing reagent being able to degrade metformin hydro-chloride to form guanylurea.

RESUMEN

Nowadays, orthovanadates are studied because of their unique properties for optoelectronic applications. In this work, the LuVO4:Eu3+, Bi3+ films were prepared by the sol-gel method, using a new simple route, and deposited by the dip-coating technique. The obtained films are transparent, fracture-free, and homogenous. The sol-gel process was monitored by Fourier-transform infrared spectroscopy (FTIR), and according to X-ray diffraction (XRD) results, the crystal structure was tetragonal, and films that were highly oriented along the (200) low-energy direction were obtained. The morphological studies by scanning electron microscopy (SEM) showed uniformly distributed circular agglomerations of rice-like particles with nanometric sizes. The luminescence properties of the films were analyzed using a fixed concentration of 2.5 at. % Eu3+ and different concentrations of Bi3+ (0.5, 1.0, and 1.5 at. %); all the samples emit in red, and it has been observed that the light yield of Eu3+ is enhanced as the Bi3+ content increases when the films are excited at 350 nm, which corresponds to the 1S0→3P1 transition of Bi3+. Therefore, a highly efficient energy transfer mechanism between Bi3+ and Eu3+ has been observed, reaching up to 71%. Finally, it was established that this energy transfer process occurs via a quadrupole-quadrupole interaction.

RESUMEN

OBJECTIVES: The present study aims to evaluate which studies evaluated the effectiveness of incorporating silver vanadate into dental materials and to analyze the influence of this incorporation on antimicrobial activity and material properties. DATA: This review was led by the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist and the JBI Briggs Reviewers Manual to answer the following question:Does the nanostructured silver vanadate decorate with silver particles present anti-microbial activity when incorporated into dental materials without altering its mechanical properties? SOURCE: An electronic search without restriction on the dates or languages was performed in PubMed/MEDLINE, Web of Science, Lilacs, Scopus, and Embase up until 2020. The search was specified and limited to the use of the words "nanostructured silver vanadate" in double quotation marks. STUDY SELECTION: The initial search resulted in 55 articles. After an initial assessment and careful reading, 15 studies published between 2014 and 2020 were included in this review. CONCLUSIONS: With the present scope review, it was possible to observe the good interaction between AgVO3 and dental materials and have a clarity that it is possible to use them in different types of materials in order to reduce the probability of infections resulting from the biofilm that is installed in them.

RESUMEN

In silico techniques helped explore the binding capacities of the SARS-CoV-2 main protease (Mpro) for a series of metalloorganic compounds. Along with small size vanadium complexes a vanadium-containing derivative of the peptide-like inhibitor N3 (N-[(5-methylisoxazol-3-yl)carbonyl]alanyl-l-valyl-N1-((1R,2Z)-4-(benzyloxy)-4-oxo-1-{[(3R)-2-oxopyrrolidin-3-yl] methyl }but-2-enyl)-l-leucinamide) was designed from the crystal structure with PDB entry code 6LU7. On theoretical grounds our consensus docking studies evaluated the binding affinities at the hitherto known binding site of Chymotrypsin-like protease (3CLpro) of SARS-CoV-2 for existing and designed vanadium complexes. This main virus protease (Mpro) has a Cys-His dyad at the catalytic site that is characteristic of metal-dependent or metal-inhibited hydrolases. Mpro was compared to the human protein-tyrosine phosphatase 1B (hPTP1B) with a comparable catalytic dyad. HPTP1B is a key regulator at an early stage in the signalling cascade of the insulin hormone for glucose uptake into cells. The vanadium-ligand binding site of hPTP1B is located in a larger groove on the surface of Mpro. Vanadium constitutes a well-known phosphate analogue. Hence, its study offers possibilities to design promising vanadium-containing binders to SARS-CoV-2. Given the favourable physicochemical properties of vanadium nuclei, such organic vanadium complexes could become drugs not only for pharmacotherapy but also diagnostic tools for early infection detection in patients. This work presents the in silico design of a potential lead vanadium compound. It was tested along with 20 other vanadium-containing complexes from the literature in a virtual screening test by docking to inhibit Mpro of SARS-CoV-2.

RESUMEN

The title compound, (NH4)4(C4H12N5)2[V10O28]·6H2O, crystallizes with the deca-vanadate anion placed on an inversion centre in space group P . This anion is surrounded by a first shell of ammonium cations and water mol-ecules, forming efficient N-H⋯O and O-H⋯O hydrogen bonds. A second shell includes metforminium monocations with a twisted geometry, also forming numerous inter-molecular hydrogen bonds. The complex three-dimensional network of non-covalent inter-actions affords a crystal structure in which the cations and anions are densely packed.

RESUMEN

The present work reports the degradation of 4-nitrophenol using BiVO4/CuO hybrid material synthesized by the precipitation of BiVO4 in the presence of CuO. Morphological and structural characterizations were performed using X-ray diffraction and scanning electronic microscopy coupled to energy dispersive X-ray spectroscopy. Through the calculation of the Kubelka-Munk function applied to diffuse reflectance spectrophotometry data, the hybrid material presented absorption edge of 1.85 eV. The formation of p-n heterojunction between BiVO4 and CuO renders the hybrid material suitable for the construction of a photoanode employed in hydroxyl radical generation. UV-vis spectrophotometry and high-performance liquid chromatography experiments were performed in order to monitor the degradation of 4-nitrophenol and the formation of secondary products. Additional information regarding the hybrid material was obtained through ion chromatography and total organic carbon analyses. The application of BiVO4/CuO-based photocatalyzer led to a 50.2% decrease in total organic carbon after the degradation of 4-nitrophenol. Based on the results obtained in the study, BiVO4/CuO has proved to be a promising material suitable for the removal of recalcitrant compounds in water treatment plants.

RESUMEN

Vanadate contaminant in groundwater receives increasing attentions, but little is known on its biogeochemical transformation with gaseous electron donors. This study investigated bio-reduction of vanadate coupled with anaerobic methane oxidation and its relationship with nitrate reduction. Results showed 95.8 ±â€¯3.1% of 1 mM vanadate was removed within 7 days using methane as the sole electron donor. Tetravalent vanadium compounds were the main reduction products, which precipitated naturally in groundwater environment. The introduction of nitrate inhibited vanadate reduction, though both were reduced in parallel. Accumulations of volatile fatty acids (VFAs) were observed from methane oxidation. Preliminary microbial community structure and metabolite analyses indicated that vanadate was likely reduced via Methylomonas coupled with methane oxidation or through synergistic relationships between methane oxidizing bacteria and heterotrophic vanadate reducers with VFAs served as the intermediates.

Asunto(s)

RESUMEN

The crystal structure of (NH4)2V3O8 has been reported twice using single-crystal X-ray data [Theobald et al. (1984 ▸). J. Phys. Chem. Solids, 45, 581-587; Range et al. (1988 ▸). Z. Naturforsch. Teil B, 43, 309-317]. In both cases, the orientation of the ammonium cation in the asymmetric unit was poorly defined: in Theobald's study, the shape and dimensions were constrained for NH4 +, while in Range's study, H atoms were not included. In the present study, we collected a highly redundant data set for this ternary oxide, at 0.61 Šresolution, using Ag Kα radiation. These accurate data reveal that the NH4 + cation is disordered by rotation around a non-crystallographic axis. The rotation axis coincides with one N-H bond lying in the mirror m symmetry element of space-group type P4bm, and the remaining H sites were modelled over two disordered positions, with equal occupancy. It therefore follows that the NH4 + cations filling the space available in the (001) layered structure formed by (V3O8)2- ions do not form strong N-H⋯O hydrogen bonds with the mixed-valent oxidovanadate(IV,V) anions. This feature could have consequences for the Li-ion inter-calation properties of this material, which is used as a cathode for supercapacitors.

RESUMEN

In this study, the performance evaluation of lanthanum compounds as corrosion inhibitors of vanadium salts was performed. The inhibitors tested were lanthanum acetate and La2O3. The performance of the inhibitors was tested using sodium metavanadate (NaVO3) as a corrosive medium at 700, 800, and 900 °C. The corrosion inhibitory effect was evaluated on the corrosion process of 304H stainless steel. The corrosion rate of the steel was determined by the mass loss technique after 100 h of immersion in the corrosive salt with and without the addition of the corrosion inhibitor. The results show that lanthanum compounds act as corrosion inhibitors of vanadium salts. The inhibitory effect increases by increasing the concentration and tends to decrease when increasing the test temperature. Lanthanum compounds act as excellent corrosion inhibitors due to their ability to stabilize vanadium cations. Vanadium is stabilized by forming a new compound, lanthanum vanadate (LaVO4), with a melting point much higher than the compounds formed when Mg or Ni compounds are used as corrosion inhibitors.

RESUMEN

Introduction: The aim of this study was adding the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) (0, 2.5, 5, and 10%) to the endodontic sealers AH-Plus, Sealer 26 and Endomethasone N, and evaluate the antimicrobial activity, solubility and pH. Methods and Materials: The antimicrobial activity of freshly mixed sealers (n=10) and set sealers (n=9) against Enterococcus faecalis (E. faecalis) was evaluated by colony forming units per milliliter and epifluorescence microscopy. Solubility (n=9) and pH (n=10), 6 and 24 h and 7, 14, and 30 days were also evaluated. The Kruskal-Wallis and Dunn's post-test were applied for the antimicrobial activity of fresh sealers. ANOVA and Tukey's post-test was used for set sealers and solubility, and Friedman's two-way analysis of variance for pH (α=0.05). Results: The fresh sealers inhibited E. faecalis. Set Sealer 26 (5 and 10% AgVO3) and Endomethasone N (2.5, 5, and 10% AgVO3) presented higher activity then the corresponding controls. Modification with AgVO3 did not influence the solubility of AH Plus and Sealer 26, but Endomethasone N (5%) presented reduced solubility. The AH-Plus groups showed acidic pH, and Sealer 26, basic pH after 30 days. Endomethasone N (5 and 10% AgVO3) presented statistical difference compared to 0% (P<0.05). Conclusion: In this in vitro study all fresh sealers and set Sealer 26 (5 and 10%) and Endomethasone N (2.5, 5, and 10%) presented higher antimicrobial activity than controls. The modification with 5% and 10% AgVO3 decreased solubility and pH of Endomethasone N, but did not affect the other groups.

RESUMEN

The aim of this study was to evaluate the antitumor efficiency of chemotherapy with cisplatin alone and incorporated into europium(III)-doped yttrium vanadate nanoparticles functionalized with 3­chloropropyltrimethoxysilane with folic acid and without folic acid in a syngeneic mouse melanoma model. Histopathological, biochemical and genotoxic analyses of treated animals were performed to assess the toxicity of treatments. The treatment of the animals with cisplatin alone and the nanoparticles functionalized with cisplatin at a dose of 5 mg/kg b.w. for 5 days reduced tumor weight about 86% and 65%, respectively. Histopathological analysis showed lower mean frequency of mitoses in tumor tissue of the groups receiving cisplatin alone (90% reduction) and the nanoparticles functionalized with cisplatin (70% reduction) compared to the tumor control group. A reduction in body and liver weight and an increase in serum creatinine and urea levels were observed in animals treated with CDDP, but not in those receiving the nanoparticles functionalized with cisplatin. Genotoxicity assessment by the comet assay revealed lower frequencies of DNA damage in animals treated with the nanoparticles functionalized with cisplatin (mean score = 140.80) compared to those treated with cisplatin alone (mean score = 231.80). Marked toxic effects were observed in animals treated with cisplatin alone, while treatment with the nanoparticles functionalized with cisplatin showed no toxicity. Moreover, folic acid in the inorganic nanoparticles reduced the genotoxicity of cisplatin in the bone marrow micronucleus test (10 ±â€¯1.4 and 40 ±â€¯0.0 micronucleus, respectively). These results demonstrate the antitumor efficiency and significantly reduced systemic toxicity of the nanoparticles compared to CDDP.

Asunto(s)

RESUMEN

Silver vanadates have been widely investigated because of their many interesting properties and their potential use in several applications. In addition to this, a large number of groups have investigated silver vanadates in the form of nanostructures. Here, we address first the synthesis and properties of nanosilver vanadate. Different techniques, such as precipitation, thermal decomposition, hydrothermal treatment, and sol-gel, are among the methods that have been employed for the controlled synthesis of silver vanadate. The use of nanosilver vanadate for the development of novel electronic devices, catalysts, and antibacterial agents for industry and biomedical applications will then be discussed. In this sense, the present review highlights the major advances regarding the synthesis, properties and applications of nanostructured silver vanadates.

RESUMEN

Molecular Co4 O4 cubane water oxidation catalysts were combined with BiVO4 electrodes for photoelectrochemical (PEC) water splitting. The results show that tuning the substituent groups on cobalt cubane allows the PEC properties of the final molecular catalyst/BiVO4 hybrid photoanodes to be tailored. Upon loading a new cubane complex featuring alkoxy carboxylato bridging ligands (1 h) on BiVO4 , an AM 1.5G photocurrent density of 5 mA cm-2 at 1.23 V vs. RHE for water oxidation was obtained, the highest photocurrent for undoped BiVO4 photoanodes. A high solar-energy conversion efficiency of 1.84 % was obtained for the integrated photoanode, a sixfold enhancement over that of unmodified BiVO4 . These results and the high surface charge separation efficiency support the role of surface-modified molecular catalysts in improving PEC performance and demonstrate the potential of molecule/semiconductor hybrids for efficient artificial photosynthesis.

RESUMEN

OBJECTIVE: The purpose of this study was evaluate, for the first time, the impact of incorporation of nanostructured silver vanadate (ß-AgVO3) in antibiofilm and mechanical properties of dental acrylic resins (poly(methyl methacrylate), PMMA). DESIGN: The ß-AgVO3 was synthesized and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and microanalysis (SEM/EDS). Resins specimens were prepared with 0-10% wt.% ß-AgVO3 and characterized by SEM, XRD and optical microscopy. The antibiofim activity of the samples against Candida albicans and Streptococcus mutans was investigated by XTT reduction test, colony-forming units (CFUs), and confocal laser scanning microscopy (CLSM). The flexural strength, hardness, and surface roughness of the samples containing ß-AgVO3 were compared with the pure PMMA matrix. RESULTS: The incorporation of 10% ß-AgVO3 significantly reduced the metabolic activity of C. albicans and S. mutans (p<0.05). There was a reduction in microbial load (CFU/mL) of microorganisms for the different concentrations used (p<0.05), which was confirmed by confocal microscopy. The addition of ß-AgVO3 did not change the mechanical properties of hardness and surface roughness of the resins (p>0.05). However, flexural strength decreased with the addition of amounts greater than 1% (p<0.05). CONCLUSIONS: ß-AgVO3 additions in dental acrylic resin may have an impact on inhibition of biofilm of main microorganisms associated with dental prostheses. However, the viability of clinical use should be evaluated in function of changed promoted in some mechanical properties.

Asunto(s)

RESUMEN

Two heterometallic deca-vanadate(V) compounds, bis-(tetra-methyl-ammonium) deca-aquadi-µ4-oxido-tetra-µ3-oxido-hexa-deca-µ2-oxido-hexa-oxidodimang-anese(II)-deca-vanadate(V) penta-hydrate, (Me4N)2[V10O28{Mn(H2O)5}2]·5H2O, A, and bis-{[tris-(hy-droxy-meth-yl)meth-yl]ammonium} deca-aquadi-µ4-oxido-tetra-µ3-oxido-hexa-deca-µ2-oxido-hexa-oxidodimanganese(II)deca-vanadate(V) dihydrate, [NH3C(CH2OH)3]2[V10O28{Mn(H2O)5}2]·2H2O, B, have been synthesized under mild reaction conditions in an aqueous medium. Both polyanions present two [Mn(OH2)5](2+) complex units bound to the deca-vanadate cluster through oxide bridges. In A, the deca-vanadate unit has 2/m symmetry, whereas in B it has twofold symmetry. Apart from this, the main differences between A and B rest on the organic cations, tetra-methyl-ammonium and [tris-(hy-droxy-meth-yl)meth-yl]ammonium, respectively, and on the number and arrangement of the water mol-ecules of crystallization. In both compounds, the H atoms from the coordinating water mol-ecules participate in extensive three-dimensional hydrogen-bonding networks, which link the cluster units both directly and through solvent mol-ecules and, in B, through the 'tris-' cation hydroxyl groups. The cation in B also participates in N-H⋯O hydrogen bonds. A number of C-H⋯O inter-actions are also observed in both structures.