Silver vanadate nanomaterial incorporated into heat-cured resin and coating in printed resin - Antimicrobial activity in two multi-species biofilms and wettability.

OBJECTIVES: To incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) into denture base materials: heat-cured (HC) and 3D printed (3DP) resins, at concentrations of 2.5 %, 5 %, and 10 %; and to evaluate the antimicrobial activity in two multi-species biofilm: (1) Candida albicans, Candida glabrata, and Streptococcus mutans, (2) Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus, and the wettability. METHODS: The AgVO3 was added to the HC powder, and printed samples were coated with 3DP with AgVO3 incorporated. After biofilm formation, the antimicrobial activity was evaluated by colony forming units per milliliter (CFU/mL), metabolic activity, and epifluorescence microscopy. Wettability was assessed by the contact angles with water and artificial saliva. RESULTS: In biofilm (1), HC-5 % and HC-10 % showed activity against S. mutans, HC-10 % against C. glabrata, and HC-10 % and 3DP-10 % had higher CFU/mL of C. albicans. 3DP-5 % had lower metabolic activity than the 3DP control. In biofilm (2), HC-10 % reduced S. aureus and P. aeruginosa, and HC-5 %, 3DP-2.5 %, and 3DP-5 % reduced S. aureus. 3DP incorporated with AgVO3, HC-5 %, and HC-10 % reduced biofilm (2) metabolic activity. 3DP-5 % and 3DP-10 % increased wettability with water and saliva. CONCLUSION: HC-10 % was effective against C. glabrata, S. mutans, P. aeruginosa, and S. aureus, and HC-5 % reduced S. mutans and S. aureus. For 3DP, 2.5 % and 5 % reduced S. aureus. The incorporation of AgVO3 into both resins reduced the metabolic activity of biofilms but had no effect on C. albicans. The wettability of the 3DP with water and saliva increased with the addition of AgVO3. CLINICAL SIGNIFICANCE: The incorporation of silver vanadate into the denture base materials provides antimicrobial efficacy and can prevent the aggravation of oral and systemic diseases. The incorporation of nanomaterials into printed resins is challenging and the coating is an alternative to obtain the inner denture base with antimicrobial effect.

Denture Adhesives Associated with Silver Vanadate: Antimicrobial Approach Against Multi- Species Biofilms on Acrylic Resin Surfaces.

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.

Mechanical and microbiological properties of orthodontic resin modified with nanostructured silver vanadate decorated with silver nanoparticles (ßAgVO3).

OBJECTIVE: To investigate the impact of incorporating the antimicrobial nanomaterial ß-AgVO3 into orthodontic resin, focusing on degree of conversion, surface characteristics, microhardness, adhesion properties, and antimicrobial activity. METHODS: The 3 M Transbond XT resin underwent modification, resulting in three groups (Control, 2.5% addition, 5% addition) with 20 specimens each. Fourier transform infrared spectroscopy assessed monomer conversion. Laser confocal microscopy examined surface roughness, and microhardness was evaluated using Knoop protocols. Shear strength was measured before and after artificial aging on 36 premolar teeth. Microbiological analysis against S. mutans and S. sanguinis was conducted using the agar diffusion method. RESULTS: Degree of conversion remained unaffected by time (P = 0.797), concentration (P = 0.438), or their interaction (P = 0.187). The 5% group exhibited the lowest surface roughness, differing significantly from the control group (P = 0.045). Microhardness showed no significant differences between concentrations (P = 0.740). Shear strength was highest in the control group (P < 0.001). No significant differences were observed in the samples with or without thermocycling (P = 0.759). Microbial analysis revealed concentration-dependent variations, with the 5% group exhibiting the largest inhibition halo (P < 0.001). CONCLUSIONS: Incorporating ß-AgVO3 at 2.5% and 5% concentrations led to significant differences in surface roughness, adhesion, and antimicrobial activity. Overall, resin modification positively impacted degree of conversion, surface characteristics, microhardness, and antimicrobial activity. Further research is warranted to determine clinically optimal concentrations that maximize antimicrobial benefits while minimizing adverse effects on adhesion properties. CLINICAL SIGNIFICANCE: Incorporating ß-AgVO3 into orthodontic resin could improve patient quality of life by prolonging intervention durability and reducing the impact of cariogenic microorganisms. The study's findings also hold promise for the industry, paving the way for the development of new materials with antimicrobial properties for potential applications in the health sector.

Identification and characterization of an ectophosphatase activity involved in Acanthamoeba castellanii adhesion to host cells.

Acanthamoeba castellanii is a free-living amoeba and an opportunistic pathogen for humans that can cause encephalitis and, more commonly, Acanthamoeba keratitis. During its life cycle, A. castellanii may present as proliferative and infective trophozoites or resistant cysts. The adhesion of trophozoites to host cells is a key first step in the pathogenesis of infection. A major virulence protein of Acanthamoeba is a mannose-binding protein (MBP) that mediates the adhesion of amoebae to cell surfaces. Ectophosphatases are ecto-enzymes that can dephosphorylate extracellular substrates and have already been described in several microorganisms. Regarding their physiological roles, there is consistent evidence that ectophosphatase activities play an important role in parasite-host interactions. In the present work, we identified and biochemically characterized the ectophosphatase activity of A. castellanii. The ectophosphatase activity is acidic, stimulated by magnesium, cobalt and nickel, and presents the following apparent kinetic parameters: Km = 2.12 ± 0.54 mM p-NPP and Vmax = 26.12 ± 2.53 nmol p-NP × h-1 × 10-6 cells. We observed that sodium orthovanadate, ammonium molybdate, sodium fluoride, and inorganic phosphate are able to inhibit ectophosphatase activity. Comparing the two stages of the A. castellanii lifecycle, ectophosphatase activity is significantly higher in trophozoites than in cysts. The ectophosphatase activity is stimulated by mannose residues and is significantly increased when trophozoites interact with LLC-MK2 cells. The inhibition of ectophosphatase by pretreatment with sodium orthovanadate also inhibits the adhesion of trophozoites to epithelial cells. These results allow us to conclude that the ectophosphatase activity of A. castellanii is somehow important for the adhesion of trophozoites to their host cells. According to our data, we believe that the activation of MBP by mannose residues triggers the stimulation of ectophosphatase activity to facilitate the adhesion process.

Visible Light Photoelectrochemical Sensor for Dopamine: Determination Using Iron Vanadate Modified Electrode.

This study reports a facile approach for constructing low-cost and remarkable electroactivity iron vanadate (Fe-V-O) semiconductor material to be used as a photoelectrochemical sensor for dopamine detection. The structure and morphology of the iron vanadate obtained by the Successive Ionic Adsorption and Reaction process were critically characterized, and the photoelectrochemical characterization showed a high photoelectroactivity of the photoanode in visible light irradiation. Under best conditions, dopamine was detected by chronoamperometry at +0.35 V vs. Ag/AgCl, achieving two linear response ranges (between 1.21 and 30.32 µmol L-1, and between 30.32 and 72.77 µmol L-1). The limits of detection and quantification were 0.34 and 1.12 µmol L-1, respectively. Besides, the accuracy of the proposed electrode was assessed by determining dopamine in artificial cerebrospinal fluid, obtaining recovery values ranging from 98.7 to 102.4%. The selectivity was also evaluated by dopamine detection against several interferent species, demonstrating good precision and promising application for the proposed method. Furthermore, DFT-based electronic structure calculations were also conducted to help the interpretation. The dominant dopamine species were determined according to the experimental conditions, and their interaction with the iron vanadate photoanode was proposed. The improved light-induced DOP detection was likewise evaluated regarding the charge transfer process.

Heteroleptic oxidovanadium(IV)-malate complex improves glucose uptake in HepG2 and enhances insulin action in streptozotocin-induced diabetic rats.

Diabetes mellitus, a complex and heterogeneous disease associated with hyperglycemia, is a leading cause of mortality and reduces life expectancy. Vanadium complexes have been studied for the treatment of diabetes. The effect of complex [VO(bpy)(mal)]·H2O (complex A) was evaluated in a human hepatocarcinoma (HepG2) cell line and in streptozotocin (STZ)-induced diabetic male Wistar rats conditioned in seven groups with different treatments (n = 10 animals per group). Electron paramagnetic resonance and 51V NMR analyses of complex A in high-glucose Dulbecco's Modified Eagle Medium (DMEM) revealed the oxidation and hydrolysis of the oxidovanadium(IV) complex over a period of 24 h at 37 °C to give low-nuclearity vanadates "V1" (H2VO4-), "V2" (H2V2O72-), and "V4" (V4O124-). In HepG2 cells, complex A exhibited low cytotoxic effects at concentrations 2.5 to 7.5 µmol L-1 (IC50 10.53 µmol L-1) and increased glucose uptake (2-NBDG) up to 93%, an effect similar to insulin. In STZ-induced diabetic rats, complex A at 10 and 30 mg kg-1 administered by oral gavage for 12 days did not affect the animals, suggesting low toxicity or metabolic impairment during the experimental period. Compared to insulin treatment alone, complex A (30 mg kg-1) in association with insulin was found to improve glycemia (30.6 ± 6.3 mmol L-1 vs. 21.1 ± 8.6 mmol L-1, respectively; p = 0.002), resulting in approximately 30% additional reduction in glycemia. The insulin-enhancing effect of complex A was associated with low toxicity and was achieved via oral administration, suggesting the potential of complex A as a promising candidate for the adjuvant treatment of diabetes.

Jahn-Teller Effects in a Vanadate-Stabilized Manganese-Oxo Cubane Water Oxidation Catalyst.

Heuristic rules that allow identifying the preferred mixed-valence isomers and Jahn-Teller axis arrangements in the water oxidation catalyst [(Mn4 O4 )(V4 O13 )(OAc)3 ]n- and its activated form [(Mn4 O4 )(V4 O13 )(OAc)2 (H2 O)(OH)]n- are derived. These rules are based on computing all combinatorially possible mixed-valence isomers and Jahn-Teller axis arrangements of the MnIII atoms, and associate energetic costs with some structural features, like crossings of multiple Jahn-Teller axes, the location of these axes, or the involved ligands. It is found that the different oxidation states localize on different Mn centers, giving rise to clear Jahn-Teller distortions, unlike in previous crystallographic findings where an apparent valence delocalization was found. The low barriers that connect different Jahn-Teller axis arrangements suggest that the system quickly interconverts between them, leading to the observation of averaged bond lengths in the crystal structure. We conclude that the combination of cubane-vanadate bonds that are chemically inert, cubane-acetate/water bonds that can be activated through a Jahn-Teller axis, and low activation barriers for intramolecular rearrangement of the Jahn-Teller axes plays an essential role in the reactivity of this and probably related compounds.

Inhibition of the activated sludge-associated enzyme phosphatase by transition metal oxyanions.

Organic esters of phosphoric acid and other organophosphorous compounds are enzymatically hydrolyzed during wastewater treatment by microbial phosphoesterases, especially by phosphomonoesterase (phosphatase). For physiological reasons, the enzyme is inhibited by its main inorganic reaction product, ortho-phosphate. It is known that oxyanions of transition metals, resembling the molecular topology of ortho-phosphate, e.g. vanadate and tungstate, are more potent inhibitors for microbial alkaline phosphatase than phosphate. To proof this effect for activated sludge, a multitude of samples from a communal wastewater treatment plant was exposed at pH values from 7.00 to 8.50 to tungstate, vanadate, and molybdate. Inhibition effects were determined by a sensitive fluorimetric microplate assay and characteristic parameters (IC50 and IC20 concentrations) were deduced from modelled dose-response functions. Mean inhibitor concentrations (in brackets: ranges) causing 50% inactivation (IC50) at pH 7.50 were 2.5 (1.3-4.1) µM tungstate, 2.9 (1.6-5.5) µM vanadate, and 41.4 (33.6-56.7) µM molybdate. Vanadate and tungstate concentrations between 0.6 and 0.7 µM provoked a 20% (IC20) inhibition. The inhibition efficiency of tungstate and molybdate decreased with increasing pH, whereas vanadate reacted pH independently. These results underline the necessity to consider enzyme inhibition assessing the limitations and potentials of biological wastewater treatment processes.

Cytotoxic effect of xyloglucan and oxovanadium (IV/V) xyloglucan complex in HepG2 cells.

It is well known that the chemical structure of polysaccharides is important to their final biological effect. In this study we investigated the cytotoxic effect of xyloglucan from Copaifera langsdorffii seeds (XGC) and its complex with oxovanadium (XGC:VO) on hepatocellular carcinoma cells (HepG2). After 72 h of incubation, XGC and XGC:VO (200 µg/mL) reduced cell viability in ~20% and ~40%, respectively. At same conditions, only XGC:VO increased in ~20% the LDH enzyme release. In permeabilized cells, incubated with XGC and XGC:VO (200 µg/mL) for 72 h, NADH oxidase activity was reduced by ~45% with XGC and XGC:VO. The succinate oxidase activity was reduced by ~35% with XGC and ~65% with XGC:VO, evidencing that polysaccharide complexation with vanadium could intensify its effects on the respiratory chain. According to this result, the mitochondrial membrane potential was also reduced by ~9% for XGC and ~30% for XGC:VO, when compared to the control group. Interestingly, ATP levels were more elevated for XGC:VO in respect to XGC, probably due the enhance in glycolytic flux evidenced by increased levels of lactate. These results show that the xyloglucan complexation with oxovanadium (IV/V) potentiates the cytotoxic effect of the native polysaccharide, possibly by impairment of oxidative phosphorylation.

DNA cleavage mechanism by metal complexes of Cu(II), Zn(II) and VO(IV) with a schiff-base ligand.

Metal ions and metal complexes are important components of nucleic acid biochemistry, participating both in regulation of gene expression and as therapeutic agents. Three new transition metal complexes of copper(II), zinc(II) and oxidovanadium(IV) with a ligand derived from o-vanillin and thiophene were previously synthesized and their antitumor properties were studied in our laboratory. To elucidate some molecular mechanisms tending to explain the cytotoxic effects observed over tumor cells, we investigated the interaction of these complexes with DNA by gel electrophoresis, UV-Vis spectroscopy, docking studies and molecular dynamics simulations. Our spectroscopy and computational results have shown that all of them were able to bind to DNA, Cu(II) complex is located in the minor groove while Zn(II) and oxidovanadium(IV) complexes act as major groove binding molecules. Interestingly, only the Cu(II) complex caused double-strand DNA nicks, consistent with its higher cytotoxic activities previously observed in tumor cell lines. We propose that the DNA-complex interaction destabilize the molecule either disrupting the phosphodiester bonds or impairing DNA replication, giving those complexes strong antitumor potential.

Stability in solution and chemoprotection by octadecavanadates(IV/V) in E. coli cultures.

Two mixed-valence octadecavanadates, (NH4)2(Me4N)5[VIV12VV6O42I]·Me4NI·5H2O (V18I) and [{K6(OH2)12VIV11VV7O41(PO4)·4H2O}n] (V18P), were synthesized and characterized by single-crystal X-ray diffraction analysis and FTIR, Raman, 51V NMR, EPR and UV/Vis/NIR spectroscopies. The chemoprotective activity of V18I and V18P towards the alkylating agent diethyl sulfate was assessed in E. coli cultures. The complex V18I was nontoxic in concentrations up to 5.0 mmol L-1, while V18P presented moderate toxicity in the concentration range 0.10 - 10 mmol L-1. Conversely, a ca. 35% enhancement in culture growth as compared to cells treated only with diethyl sulfate was observed upon addition of V18I (0.10 to 2.5 mmol L-1), while the combination of diethyl sulfate with V18P increased the cytotoxicity presented by diethyl sulfate alone. 51V NMR and EPR speciation studies showed that V18I is stable in solution, while V18P suffers partial breakage to give low nuclearity oxidometalates of vanadium(V) and (IV). According to the results, the chemoprotective effect depends strongly on the direct reactivity of the polyoxidovanadates (POV) towards the alkylating agent. The reaction of diethyl sulfate with V18I apparently produces a new, rearranged POV instead of poorly-reactive breakage products, while V18P shows the formation and subsequent consumption of low-nuclearity species. The correlation of this chemistry with that of other mixed-valence polyoxidovanadates, [H6VIV2VV12O38PO4]5- (V14) and [VIV8VV7O36Cl]6- (V15), suggests a relationship between stability in solution and chemoprotective performance.

Metforminium Decavanadate (MetfDeca) Treatment Ameliorates Hippocampal Neurodegeneration and Recognition Memory in a Metabolic Syndrome Model.

The consumption of foods rich in carbohydrates, saturated fat, and sodium, accompanied by a sedentary routine, are factors that contribute to the progress of metabolic syndrome (MS). In this way, they cause the accumulation of body fat, hypertension, dyslipidemia, and hyperglycemia. Additionally, MS has been shown to cause oxidative stress, inflammation, and death of neurons in the hippocampus. Consequently, spatial and recognition memory is affected. It has recently been proposed that metformin decavanadate (MetfDeca) exerts insulin mimetic effects that enhance metabolism in MS animals; however, what effects it can cause on the hippocampal neurons of rats with MS are unknown. The objective of the work was to evaluate the effect of MetfDeca on hippocampal neurodegeneration and recognition memory in rats with MS. Administration of MetfDeca for 60 days in MS rats improved object recognition memory (NORt). In addition, MetfDeca reduced markers of oxidative stress and hippocampal neuroinflammation. Accompanied by an increase in the density and length of the dendritic spines of the hippocampus of rats with MS. We conclude that MetfDeca represents an important therapeutic agent to treat MS and induce neuronal and cognitive restoration mechanisms.

Comparison of oral microbiome profile of polymers modified with silver and vanadium base nanomaterial by next-generation sequencing.

This study aimed to evaluate two methods of the incorporation of nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) into acrylic resin and characterize the profile of early and late microbial communities in class and family taxonomic level by pyrosequencing. The specimens were made by adding different concentrations of AgVO3 (1, 2.5, and 5%) to the heat-activated acrylic resin by two methods: vacuum spatulation (VS) and polymeric film (PF). A control group (0%) without AgVO3 was also obtained for both methods. After 24 h and 7 days of incubation in human saliva, biofilm samples were collected, DNA was extracted, and 16S rRNA genes were sequenced by the 454-Roche sequencing platform. Seventeen classes and 51 families of bacteria were identified. The abundance of Bacteroidia, Bacilli, Negativicutes, Fusobacteria and Betaproteobacteria classes decreased after 7 days of incubation, and Clostridia, Gammaproteobacteria, and unclassified bacteria increased. The Negativicutes and Betaproteobacteria classes were more abundant when the PF method was used, and Gammaproteobacteria was more abundant when VS was used. The incorporation of 5% AgVO3 promoted a reduction in the prevalence of Bacilli, Clostridia, Negativicutes, Betaproteobacteria, and unclassified bacteria, and increased Gammaproteobacteria. The addition of AgVO3 to acrylic resin altered the early and mature microbiome formed on the specimen surface, and the PF method presented a more favorable microbial profile than the VS method.

Sodium metavanadate treatment improves glycogen levels in multiple tissues in a model of metabolic syndrome caused by chronic cadmium exposure in Wistar rats.

Cadmium, one of the more hazardous environmental contaminants, has been proposed as a metabolic disruptor. Vanadium has emerged as a possible treatment for metabolic diseases. Both metals are important in public health. We aimed to investigate whether vanadium treatment is effective against metabolic disturbances caused by chronic exposure to the lowest-observable adverse effect level of cadmium. Male Wistar rats were exposed to cadmium (32.5 ppm) in drinking water for 3 months. Metabolic complications such as overweight, visceral adipose gain, hyperglycemia, impaired glucose tolerance, and dyslipidemia were detected, and low glycogen levels and steatosis were observed in the tissues. Then, the control and treated animals were subdivided and treated with a solution of 5 µM NaVO3/kg/twice a week for 2 months. The control-NaVO3 group did not show zoometric or metabolic changes. A strong interaction of NaVO3 treatment over cadmium metabolic disruption was observed. The vanadium accumulation diminished cadmium concentration in tissues. Also, vanadium interaction improved glucose homeostasis. The major effect was observed on glycogen synthesis, which was fully recovered in all tissues analyzed. Additionally, vanadium treatment prevented overweight and visceral fat accumulation, improving BMI and the percentage of fat. However, NaVO3 treatment did not have an effect on dyslipidemia or steatosis. In conclusion, this work shows that vanadium administration has a strong effect against metabolic disturbances caused by chronic cadmium exposure, observing powerful interaction on glucose homeostasis.

NIR Luminescence Enhancement of YVO4:Nd Phosphor for Biological Application.

This work reports two systematic studies related to yttrium vanadate (YVO4) phosphors. The first evaluates how the annealing temperature and V5+/Y3+ molar ratio determine the emergence of a single YVO4 tetragonal phase, whereas the second concerns the optimal Nd3+ concentration to improve the infrared emission properties for bio-labelling applications. The YVO4:Nd phosphors were synthesized by adapting the non-hydrolytic sol-gel route. For the first study, samples containing different V5+/Y3+ molar ratios (1.02, 1.48, 1.71, or 3.13) were obtained. For the second study, YVO4:Nd phosphors containing different Nd3+ concentrations (1.0, 3.0, 5.0, or 10.0% in mol) were prepared. X-ray diffractometry and RAMAN spectroscopy results revealed that, regardless of the heat-treatment temperature, the V5+/Y3+ molar ratio of 1.48 was the best composition to avoid undesired phases like Y2O3 and V2O5. Photoluminescence results indicated that the sample containing 3.0% in mol of Nd3+ and annealed at 1000 °C presented the best infrared emission properties. This sample displayed an intense broad band in the ultraviolet region, which was ascribed to the VO43- charge transfer band, as well as several bands in the visible and infrared regions, which were attributed to the Nd3+ intraconfigurational f-f transitions. Regardless of the excitation wavelength (ultraviolet, visible, or near-infrared), the mean radiative lifetime was about 12.00 µs. The prepared phosphors presented absorption and emission bands in the biological window (BW) regions, which are located between 750 and 900 nm and between 1000 and 1300 nm, so they are candidates for applications in medical imaging and diagnoses.

Cyclo-tetravanadate bridged copper complexes as potential double bullet pro-metallodrugs for cancer treatment.

Over the last decade, copper and vanadium complexes have shown promising properties for the treatment of several types of cancer. In particular, Casiopeinas®, a group of copper-based complexes, has received specific attention, and their mechanism of action has been extensively studied since their structure is simple and their synthesis may be affordable. Similarly, vanadium-containing compounds in the form of complexes and simple polyoxovanadates have also been studied as antitumor agents. Here, potential prodrugs that would release the two metals, V and Cu, in usable form to act in conjunction against cancer cells are reported. The new series of Casiopeinas-like compounds are bridged by a cyclotetravanadate ion with the generic formula [Cu(N,N')(AA)]2•(V4O12), where (N,N') represent 1,10-phenanthroline and 2,2'-bipyridine, and (AA) are aminoacidate ions (Lysine and Ornithine). The compounds were characterized by elemental analysis, single-crystal X-ray diffraction and Visible, FTIR, and Raman spectroscopies, as well as 51V NMR, EPR, and Thermogravimetric Analysis. Additionally, theoretical calculations based on the Density Functional Theory (DFT) were carried out to model the compounds. Optimized structures, theoretical IR, and Raman spectra were also obtained, as well as docking analysis to test DNA interactions with the casiopeina-like complexes. The compounds may act as prodrugs by providing acting molecules that have showed potential pharmacological properties for the treatment of several types of cancer.

Microbial vanadate and nitrate reductions coupled with anaerobic methane oxidation in groundwater.

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.

Evaluating the effects of vanadyl sulfate on biomarkers of oxidative stress and inflammation in renal tissue of rats with diabetes type 2

Vanadyl sulfate (VS) is an ingredient in some food supplements and experimental drugs. This study was designed to assay the effects of VS on biomarkers of oxidative stress and inflammation in renal tissue of rats with diabetes type 2. 30 male Wistar rats were divided into three equal groups as follow: non-diabetics, non-treated diabetics and VS-treated diabetics. Diabetes type 2 has been induced through high fat diet and fructose in the animals. Diabetic rats were treated with 25 mg/kgBW of VS in water for 12 weeks. At the end of study, glucose and insulin were measured using commercially available kits in serum and biomarkers of oxidative stress and inflammation in renal homogenates of animals were measured by related methods. Compared to controls, glucose and insulin were increased significantly in non-treated diabetic rats (p-value <0.05) that showed the induction of diabetes type 2 in rats. The results showed that in VS-treated diabetic rats compared to the non-treated diabetic group, vanadyl sulfate significantly reduced the glucose and insulin secretion and changed renal inflammatory and oxidative markers, except protein carbonyl so that we couldn't find any significant changes. Our study showed that vanadyl supplementation had positive effects on oxidative stress and inflammation biomarkers in kidney of diabetic rats

Influence of AgVO3 incorporation on antimicrobial properties, hardness, roughness and adhesion of a soft denture liner.

The objective of this in vitro study was to investigate the effect of nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) on antimicrobial activity, hardness, roughness, and adhesion of a soft denture liner. The antimicrobial efficacy of the Trusoft (Boswoth) liner incorporated with different concentrations of AgVO3 against Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, and Staphyloccocus aureus (n = 5) was evaluated by the agar diffusion method. Roughness, hardness, and adhesion properties were also evaluated. The data were analyzed by analysis of variance (ANOVA) and Tukey's multiple comparison test with significance at the p < 0.05 level. At concentrations of 1 and 2.5%, AgVO3 incorporation was effective only against E. faecalis, and at 5 and 10%, against E. faecalis, P. aeruginosa, and C. albicans. None of the concentrations was effective against S. aureus. A decrease in hardness was found for the 1, 2.5, and 10% AgVO3 concentrations (p < 0.001) and at 5%, hardness was not affected. None of the concentrations affected the roughness of the material. A significant increase in tensile values was observed between the liner and heat-curing acrylic resin for 2.5% (p < 0.001) and 10% (p = 0.042) concentrations. AgVO3 incorporation to a soft denture liner promoted antimicrobial activity against E. faecalis, P. aeruginosa, and C. albicans without affecting roughness, maintaining the hardness properties recommended for soft and extra soft liners, and improving the adhesion between the liner and the acrylic resin used for dentures.

Endodontic Sealers Modified with Silver Vanadate: Antibacterial, Compositional, and Setting Time Evaluation.

The incorporation of nanoparticles into endodontic sealers aims at increasing antimicrobial activity of the original material. Aim. The aim of this study is to incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3, at 2.5%, 5%, and 10%) into three endodontic sealers and evaluate the antibacterial activity of freshly sealers, surface topography and chemical composition, and setting time. Material and Methods. The AgVO3 was incorporated into AH Plus, Sealer 26, and Endomethasone N at concentrations 0%, 2.5%, 5%, and 10% (in mass). The antibacterial activity of freshly sealers was assessed by direct contact with Enterococcus faecalis and CFU/mL count (n=10), surface topography, and chemical composition were measured by SEM/EDS, and the setting time was measured by Gillmore needle (n=10). The Kruskal-Wallis and Dunn statistical tests were applied (α=0.05). Results. All groups of sealers evaluated inhibited E. faecalis (p>0.05). The incorporation of AgVO3 altered the atomic proportions between components of the endodontic sealers, and the percentage of silver (Ag) and vanadium (V) increased proportionally to the concentrations of AgVO3. Topography analysis showed differences in components distribution on the surface of the specimens. The sealers incorporated with AgVO3 of AH Plus presented a lower setting time than the control group (p<0.05). For Sealer 26 and Endomethasone N, the incorporation of AgVO3 increased the setting time in relation to control group (p<0.05). Conclusions. The modification of endodontic sealers by AgVO3 increased the atomic percentage of Ag and V proportionally to the concentration of the nanomaterial and changed the atomic percentage of the sealer components and setting times. It cannot be affirmed that the AgVO3 promote differences in the antimicrobial activity of freshly sealers, and further investigations of the antimicrobial activity of the set sealers should be carried out.