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1.
Water Sci Technol ; 82(5): 940-953, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33031072

RESUMO

Ag-Cu ions in cooling water may inhibit the activity of sulfate-reducing bacteria and therefore provide solutions to microbiologically induced corrosion (MIC) problems, mainly caused by Desulfovibrio sp. To investigate this, the MIC behavior of Desulfovibrio sp. on 316L stainless steel in terms of growth and extracellular polymeric substances (EPS) production was investigated in the presence of Ag-Cu ions. Laboratory-scale systems were set up with final concentrations of 0.13 ppm Ag and 0.3 ppm Cu ions, as they are the frequently used doses for cooling waters, and operated over 720 hours. The corrosion rate was evaluated by gravimetric assay, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. The growth of Desulfovibrio sp. was assessed by bacterial counting and EPS production. Ag-Cu ions in the biofilm were assessed by inductively coupled plasma - optical emission spectrometry (ICP-OES) and EDS-elemental mapping analyses. It was concluded that the ion concentrations used caused an increase in EPS production, especially of protein. The corrosion rate of the metal by Desulfovibrio sp. in the presence of ions was detected as being 29 times higher than that in the sterile medium with the ions after 720 hours. The results suggested that Desulfovibrio sp. exhibited more corrosive behavior in the presence of non-toxic concentrations of Ag-Cu ions.


Assuntos
Desulfovibrio , Aço Inoxidável , Corrosão , Íons , Prata
2.
Braz Dent J ; 31(4): 409-416, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901718

RESUMO

This study was conducted to evaluate whether antibacterial pretreatment irrigation with silver nanoparticles (SNPs) and silver diamine fluoride (SDF) has any effect on bond strength of fiber posts cemented with three types of resin cements in root canal space. Fifty-four endodontically treated maxillary central incisor roots were prepared for fiber post (FRC Postec Plus NO.3, Ivoclar Vivadent) cementation and divided into nine groups in terms of three cement types and two pretreatments with silver antibacterial agents. The cements were as follows: an etch-and-rinse cement (ER, Excite DSC/Variolink N), a self-etch cement (SE, ED Primer/Panavia F2.0), and a self-adhesive cement (SA, Panavia SA Luting Plus). For each cement, the control group was with no treatment and two experimental groups were with SNPs and SDF treatments that were used after acid-etching for ER cement and after EDTA treatment for SE and SA cements. After fiber post cementation, each bonded root was horizontally sectioned into 1-mm thickness microslices to create two slices for each root region (apical, middle and coronal) and underwent push-out bond strength (PBS) test. Data in MPa were analyzed with two-way ANOVA and Tukey test (p=0.05). The interaction of the pretreatment type and cement type was significant (p<0.001). SNPs and SDF significantly increased PBS with ER cement (p≤0.04). This positive effect was also marginally significant for SDF with SE cement (p=0.049). For SA cement, SNPs showed a significant positive effect, but SDF had a significant adverse effect on PBS (p<0.001). The effect of pretreatment with silver antibacterial agents prior to adhesive cementation of fiber posts depends on the resin cement used. Contrary to SNPs with beneficial or no significant effect on bonding for all cements, SDF exhibited a deleterious effect with self-adhesive cement.


Assuntos
Colagem Dentária , Nanopartículas Metálicas , Técnica para Retentor Intrarradicular , Antibacterianos , Dentina , Prata
3.
J Environ Sci (China) ; 97: 75-84, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933742

RESUMO

The catalytic ozonation treatment of secondary biochemical effluent for papermaking wastewater by Ag-doped nickel ferrite was investigated. Ag-doped catalysts prepared by sol-gel method were characterized, illustrating that Ag entirely entered the crystalline of NiFe2O4 and changed the surface properties. The addition of catalyst enhanced the removal efficiency of chemical oxygen demand and total organic carbon. The results of gas chromatography-mass spectrometer, ultraviolet light absorbance at 254 nm and three-dimensional fluorescence excitation-emission matrix suggested that aromatic compounds were efficiently degraded and toxic substances, such as dibutyl phthalate. In addition, the radical scavenging experiments confirmed the hydroxyl radicals acted as the main reactive oxygen species and the surface properties of catalysts played an important role in the reaction. Overall, this work validated potential applications of Ag-doped NiFe2O4 catalyzed ozonation process of biologically recalcitrant wastewater.


Assuntos
Ozônio , Poluentes Químicos da Água/análise , Catálise , Prata , Águas Residuárias
4.
Medicine (Baltimore) ; 99(37): e22164, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32925780

RESUMO

This study was aimed to evaluate whether silver-containing dressings were superior to other types of dressings in the treatment of venous leg ulcers (VLU) and their specific advantages.Eight databases (Cochrane Library, PubMed, Web of Science, Ovid-Medline, Wanfang, VIP, China Biology Medicine, and China National Knowledge Infrastructure) were systematically reviewed from inception to May 2019 for randomized controlled trials (RCTs). The primary outcome was complete wound healing, and the secondary outcomes included absolute wound size changes (change of cm area since baseline), relative changes (percentage change of area relative to baseline), and healing rate. Two reviewers independently evaluated the risk of bias using the Cochrane Collaboration assessment tool and extracted the data according to the predesigned table. All analyses were performed using the latest Review Manager Software (version 5.3).A total of 8 studies qualified and were included in the meta-analysis, including 1057 patients (experiment: 526, control: 531). Both complete wound healing and wound healing rates were reported in 5 studies. Two and 3 studies reported the effect of silver dressings on absolute and relative wound size changes, respectively. Most of the studies used intention-to-treat analysis.There was sufficient evidence that silver-containing dressings can accelerate the healing rate of chronic VLU and improve their healing in a short duration of time. However, compared with other dressings, clinical trials with long-term follow-up data are needed to confirm whether silver dressings have advantages regarding complete wound healing.


Assuntos
Bandagens , Úlcera da Perna/tratamento farmacológico , Prata/uso terapêutico , Cicatrização/fisiologia , Humanos , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Prata/administração & dosagem
5.
J Environ Manage ; 271: 110962, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778272

RESUMO

In this work, silver nanoparticles have been synthesized with an average particle size of 35 nm, within 90s, using microwave and Sapindus mukorossi extract as a stabilizing agent. The AgNps were surface immobilized on eggshells (ES) to obtain Ag@ES, which was characterized by UV-Vis, UV-DRS, FT-IR, ICP-OES, TGA-DSC, SEM-EDX, XRD and XPS. Its applicability as an environmental catalyst was evaluated by Cr (VI) adsorption, photocatalytic degradation of methyl orange, eriochrome black-T, methylene blue, rhodamine-B as model dyes and microbial inhibition against Staphylococcus aureus, Escherichia coli and Candida albicans. The results revealed that Ag@ES exhibited maximum adsorption capacity of 93 mg/g for Cr (VI) ion and degradation efficiency of ~90-98% for removing anionic and cationic dyes. Further, it showed a minimum inhibitory concentration of 15.6, 7.8 and 31.2 µg/mL for S. aureus, E. coli and C. albicans respectively. Moreover, the Ag@ES being a heterogeneous catalyst can be regenerated and reused without significant loss in its efficiency.


Assuntos
Nanopartículas Metálicas , Nanocompostos , Animais , Corantes , Casca de Ovo , Escherichia coli , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus , Água
6.
Zhonghua Shao Shang Za Zhi ; 36(8): 698-703, 2020 Aug 20.
Artigo em Chinês | MEDLINE | ID: mdl-32829608

RESUMO

Objective: To investigate the influence of silver ion dressing on related infections induced by inserted central venous catheter through wounds in patients with severe burn. Methods: From June 2017 to December 2018, 90 severe burn patients who were admitted to the First Hospital of Hebei Medical University and met the inclusion criteria were included in this prospectively randomized control study. According to the random number table, they were divided into silver ion dressing group (30 patients, 20 males and 10 females, aged (37.2±3.4) years), sterile dressing group (30 patients, 18 males and 12 females, aged (35.2±4.1) years), and Anerdian dressing group (30 patients, 17 males and 13 females, aged (36.3±2.6) years). After admission, the patients in three groups were treated with a 16 G single-lumen central venous catheter inserted into the subclavian vein of burn wounds, with the depth of 19 cm. The puncture points of the patients in silver ion dressing group, sterile dressing group, and Anerdian dressing group were covered with silver ion medical antibacterial dressing, sterile dressing, and sterile gauze dressing infiltrated with Anerdian skin and mucous membrane washing and disinfecting solution, respectively. The patients in three groups underwent catheter maintenance and dressing change every 12 hours. The thousand-day infection rates of catheter outlet infection and catheter-related bloodstream infection (CRBSI), catheter indwelling days, and pathogen detection of the patients in three groups were counted. Data were statistically analyzed with chi-square test, one-way analysis of variance, least significant difference test, Fisher's exact probability test, and Bonferroni correction. Results: (1) The thousand-day infection rates of catheter outlet infection of patients in sterile dressing group and Anerdian dressing group were 22.29‰ (7/314) and 20.83‰ (7/336), respectively, which were similar (P>0.05), and both were significantly higher than 1.54‰ (1/651) in silver ion dressing group (P<0.01). The thousand-day infection rates of CRBSI of patients in sterile dressing group and Anerdian dressing group were 25.48‰ (8/314) and 20.83‰ (7/336), respectively, which were similar (P>0.05), and both were significantly higher than 1.54‰ (1/651) in silver ion dressing group (P<0.01). The catheter indwelling days of patients in sterile dressing group and Anerdian dressing group were similar (P>0.05), and both were significantly shorter than the days in silver ion dressing group (P<0.01). (2) A total of 16 cases of CRBSI occurred in all the patients in 3 groups. A total of 16 pathogenic bacteria were isolated from catheter tip attachment microbial culture and blood microbial culture. The detections rates of pathogenic bacteria of patients in sterile dressing group and Anerdian dressing group were significantly higher than the rate in silver ion dressing group (P<0.05). Conclusions: For severe burn patients, the use of silver ion dressings in the maintenance of central venous catheters inserted through wounds can effectively reduce the rate of central venous catheter-related infections and extend the catheter indwelling days.


Assuntos
Queimaduras , Infecções Relacionadas a Cateter , Cateteres Venosos Centrais , Adulto , Bandagens , Feminino , Humanos , Masculino , Prata
7.
Int J Nanomedicine ; 15: 4755-4762, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753864

RESUMO

Aim: This study was conducted to evaluate the effects of three nanoparticle solutions used as dentin pretreatments on the microshear bond strength (µSBS) of a conventional glass ionomer cement (GIC) to dentin. Materials and Methods: Ninety intact human molars were used after sectioning their occlusal surfaces to expose flat dentin surfaces. The specimens were randomly assigned to nine groups (n = 10). Group A was the control group (without using the cavity disinfectant). In groups B, C, D, and E, the prepared dentin surfaces were treated with 1 cc 2% chlorhexidine (CHX), 0.1% silver nanoparticle (SNP), 0.1% titanium dioxide nanoparticle (TNP), and 0.1% zinc oxide nanoparticle (ZNP) solutions for 1 minute, respectively, before applying the conditioner. CHX, SNPs, TNPs, and ZNPs were applied for 1 minute after applying the conditioner in groups F, G, H, and I, respectively. The specimens were restored with a conventional GIC and underwent µSBS testing after 24 hours. The data were analyzed using the one-way analysis of variance and Tukey's test (p=0.05). Results: The applications of the nanoparticles (SNP, TNP, and ZNP) after the conditioner were associated with significantly greater µSBS values compared to that of the control group (p values < 0.05). Significantly higher µSBS values were observed when TNP or ZNP was applied after the conditioner compared to their applications before the conditioner (p values < 0.05). The highest µSBS values were observed when TNP was applied after the conditioner. Conclusion: Dentin pretreatment with the nanoparticles after applying the conditioner enhanced the bond strength of the GIC to dentin compared with the control group. The best results were obtained for the TNPs applied after the conditioner.


Assuntos
Colagem Dentária , Dentina/efeitos dos fármacos , Cimentos de Ionômeros de Vidro/farmacologia , Nanopartículas Metálicas/química , Prata/farmacologia , Titânio/farmacologia , Óxido de Zinco/farmacologia , Clorexidina/farmacologia , Cimentos de Ionômeros de Vidro/química , Humanos , Teste de Materiais , Propriedades de Superfície
8.
Ecotoxicol Environ Saf ; 202: 110924, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800211

RESUMO

Fabrication of poly-(N-isopropylmethacrylamide-co-methacrylic acid) [p(NMA)] microgels to be utilized as microreactors to synthesize stable Ag nanoparticles for catalytic reductive degradation of dyes has been addressed in this work. Both p(NMA) microgel and Ag-p(NMA) hybrid microgel systems have been analyzed by Fourier transform infra-red and Dynamic light scattering, Ultraviolet-Visible spectroscopy, X-ray diffraction and Transmission electron microscopy. Catalytic activity of Ag-p(NMA) towards reductive degradation of Congo Red (CR), Methyl Orange (MO) and Alizarin Yellow (AY) was investigated under different operating conditions. Spectrophotometry was employed to check the progress of reaction while the rate constant (kapp) value of degradation reaction was determined under various conditions to optimize reaction parameters for rapid and economical degradation of these dyes. An increase in kapp value was observed by increasing feed content of dye up to a certain value that decreases again by further increment in dye concentration which reflects that catalysis follows Langmuir-Hinshelwood mechanism. A gradual increase in the kapp value was also observed with increasing quantity of hybrid microgel used as a catalyst. By comparing kapp values of degradation of aforementioned dyes, it was found that Ag-p(NMA) hybrid microgel gives better activity for MO dye degradation in comparison to catalytic degradation of CR and AY.


Assuntos
Compostos Azo/química , Nanopartículas Metálicas/química , Prata/química , Catálise , Corantes/química , Vermelho Congo/química , Hidrogéis/química , Microscopia Eletrônica de Transmissão , Polímeros/química , Espectrofotometria , Difração de Raios X
9.
Prog Orthod ; 21(1): 24, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32803386

RESUMO

BACKGROUND: The purpose of the study is to assess the antiadherent and antibacterial properties of surface-modified different orthodontic brackets with silver nanoparticles against Streptococcus mutans and Streptococcus sobrinus, using radiomarker. METHODS: In this study evaluated quantitatively the adherence of Streptococci to orthodontic brackets, 300 samples of orthodontic brackets were selected and classified in to 10 groups as follow: GIn (InVu-Roth), GIIn (System-AlexanderLTS), GIIIn (Gemini-Roth), GIVn (NuEdge-Roth), GVn (Radiance plus-Roth), GVI (InVu-Roth), GVII (System-AlexanderLTS), GVIII (Gemini-Roth), GIX (NuEdge-Roth), GX (Radiance plus-Roth). All the samples were sonicated and Streptococci were cultivated by gender. A radioactive marker (3H) was used to codify the bacteria and measure them. After that, the brackets were submerged in a radiolabelled solution, and the radiation was measured. The statistical analysis was calculated with ANOVA test (Sheffè post hoc). RESULTS: The results showed significant differences were found among the groups. GIIIn shown the lowest scores for both bacteria; in contrast, GIX for Streptococcus mutans and GVI for Streptococcus sobrinus were the highest values. CONCLUSIONS: Surface modification of orthodontic brackets with silver nanoparticles can be used to prevent the accumulation of dental plaque and the development of dental caries during orthodontic treatment.


Assuntos
Cárie Dentária , Nanopartículas Metálicas , Braquetes Ortodônticos , Ortodontia , Humanos , Prata , Streptococcus mutans , Streptococcus sobrinus
10.
Int J Nanomedicine ; 15: 4969-4990, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764930

RESUMO

Background: Polyphenols possess antioxidant, anti-inflammatory and antimicrobial properties and have been used in the treatment of skin wounds and burns. We previously showed that tannic acid-modified AgNPs sized >26 nm promote wound healing, while tannic acid-modified AgNPs sized 13 nm can elicit strong local inflammatory response. In this study, we tested bimetallic Au@AgNPs sized 30 nm modified with selected flavonoid and non-flavonoid compounds for wound healing applications. Methods: Bimetallic Au@AgNPs were obtained by growing an Ag layer on AuNPs and further modified with selected polyphenols. After toxicity tests and in vitro scratch assay in HaCaT cells, modified lymph node assay as well as the mouse splint wound model were further used to access the wound healing potential of selected non-toxic modifications. Results: Tannic acid, gallic acid, polydatin, resveratrol, catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate and procyanidin B2 used to modify Au@AgNPs exhibited good toxicological profiles in HaCaT cells. Au@AgNPs modified with 15 µM tannic acid, 200 µM resveratrol, 200 µM epicatechin gallate, 1000 µM gallic acid and 200 µM procyanidin B2 induced wound healing in vivo and did not lead to the local irritation or inflammation. Tannic acid-modified Au@AgNPs induced epithelial-to-mesenchymal transition (EMT) - like re-epithelialization, while other polyphenol modifications of Au@AgNPs acted through proliferation and wound closure. Conclusion: Bimetallic Au@AgNPs can be used as a basis for modification with selected polyphenols for topical uses. In addition, we have demonstrated that particular polyphenols used to modify bimetallic nanoparticles may show different effects upon different stages of wound healing.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Polifenóis/química , Polifenóis/farmacologia , Prata/química , Cicatrização/efeitos dos fármacos , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Biflavonoides/química , Catequina/análogos & derivados , Catequina/química , Camundongos , Proantocianidinas/química , Taninos/química
11.
Int J Nanomedicine ; 15: 5147-5163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764942

RESUMO

Background: In the last decades, nosocomial infections caused by drug-resistant Pseudomonas aeruginosa became a common problem in healthcare facilities. Antibiotics are becoming less effective as new resistant strains appear. Therefore, the development of novel enhanced activity antibacterial agents becomes very significant. A combination of nanomaterials with different physical and chemical properties enables us to generate novel multi-functional derivatives. In this study, graphene oxide and polyvinylpyrrolidone-stabilized silver nanoparticles hybrid nanocomposite (GO-Ag HN) were synthesized. The relation between antibiotic resistance and GO-Ag HN potential toxicity to clinical P. aeruginosa strains, their antibiotic resistance, and molecular mechanisms were assessed. Methods: Chemical state, particle size distribution, and morphology of synthesized GO-Ag NH were investigated using spectroscopy and microscopy techniques (UV-Vis, FTIR, XPS, TEM, SEM, AFM). Broad-spectrum antibiotic resistance of P. aeruginosa strains was determined using E-test. Antibiotic resistance genes were identified using polymerase chain reaction (PCR). Results: In this study, the toxicity of the GO-Ag NH to the isolated clinical P. aeruginosa strains has been investigated. A high antibiotic resistance level (92%) was found among P. aeruginosa strains. The most prevalent antibiotic resistance gene among tested strains was the AMPC beta-lactamase gene (65.6%). UV-vis, FTIR, and XPS studies confirmed the formation of the silver nanoparticles on the GO nanosheets. The functionalization process occurred through the interaction between Ag nanoparticles, GO, and polyvinylpyrrolidone used for nanoparticle stabilization. SEM analysis revealed that GO nanosheets undergo partial fragmentation during hybrid nanocomposite preparation, which remarkably increases the number of sharp edges and their mediated cutting effect. TEM analysis showed that GO-Ag HN spherical Ag nanoparticles mainly 9-12 nm in size were irregularly precipitated on the GO nanosheet surface. A higher density of Ag NPs was observed in the sheets' wrinkles, corrugations, and sharp edges. This hybrid nanocomposite poses enhanced antibacterial activity against carbapenem-resistant P. aeruginosa strains through a possible synergy between toxicity mechanisms of GO nanosheets and Ag nanoparticles. With incubation time increasing up to 10 minutes, the survival of P. aeruginosa decreased significantly. Conclusion: A graphene oxide and silver nanoparticles hybrid composite has been shown to be a promising material to control nosocomial infections caused by bacteria strains resistant to most antibiotics.


Assuntos
Farmacorresistência Bacteriana/genética , Grafite/química , Grafite/farmacologia , Nanopartículas Metálicas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Prata/química , Antibacterianos/química , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos
13.
Mar Pollut Bull ; 158: 111421, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753205

RESUMO

Microplastics are causing serious environmental threats worldwide. To evaluate the current state of microplastics pollution, 28 sediment samples were examined for microplastics and plastic debris contamination along Silver Beach, Southern India. Visual identification followed by FT-IR spectroscopy was used to estimate the overall distribution and characterization of plastic debris. The results reveal that white-colored (44%) and irregularly-shaped (82%) plastics are prevalent in the study area. Moreover, the dominant polymer in the study area is polyvinyl chloride (79%) followed by polyethylene (14%) and nylon (7%). Based on size fractions, mesoplastics are widely distributed in the beach sediments (65%), followed by microplastics (18%) and macroplastics (17%). The regional sources of plastic debris are tourism and fishing activities followed by storm water runoff through the Gadilam river and wave-induced deposition through high tides. Strict policy measures need to be implemented in recreational beaches like Silver beach to reduce plastic pollution.


Assuntos
Plásticos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Sedimentos Geológicos , Índia , Microplásticos , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Resíduos/análise
14.
Aquat Toxicol ; 227: 105582, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32823071

RESUMO

While it is likely that ENPs may occur together with other contaminants in nature, the combined effects of exposure to both ENPs and environmental contaminants are not studied sufficiently. In this study, we investigated the acute and sublethal toxicity of PVP coated silver nanoparticles (AgNP) and ionic silver (Ag+; administered as AgNO3) to the marine copepod Calanus finmarchicus. We further studied effects of single exposures to AgNPs (nominal concentrations: low 15 µg L-1 NPL, high 150 µg L-1 NPH) or Ag+ (60 µg L-1), and effects of co-exposure to AgNPs, Ag+ and the water-soluble fraction (WSF; 100 µg L-1) of a crude oil (AgNP + WSF; Ag++WSF). The gene expression and the activity of antioxidant defense enzymes SOD, CAT and GST, as well as the gene expression of HSP90 and CYP330A1 were determined as sublethal endpoints. Results show that Ag+ was more acutely toxic compared to AgNPs, with 96 h LC50 concentrations of 403 µg L-1 for AgNPs, and 147 µg L-1 for Ag+. Organismal uptake of Ag following exposure was similar for AgNP and Ag+, and was not significantly different when co-exposed to WSF. Exposure to AgNPs alone caused increases in gene expressions of GST and SOD, whereas WSF exposure caused an induction in SOD. Responses in enzyme activities were generally low, with significant effects observed only on SOD activity in NPL and WSF exposures and on GST activity in NPL and NPH exposures. Combined AgNP and WSF exposures caused slightly altered responses in expression of SOD, GST and CYP330A1 genes compared to the single exposures of either AgNPs or WSF. However, there was no clear pattern of cumulative effects caused by co-exposures of AgNPs and WSF. The present study indicates that the exposure to AgNPs, Ag+, and to a lesser degree WSF cause an oxidative stress response in C. finmarchicus, which was slightly, but mostly not significantly altered in combined exposures. This indicated that the combined effects between Ag and WSF are relatively limited, at least with regard to oxidative stress.


Assuntos
Copépodes/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Petróleo/toxicidade , Prata/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Copépodes/genética , Copépodes/metabolismo , Interações Medicamentosas , Expressão Gênica/efeitos dos fármacos , Íons , Nanopartículas Metálicas/química , Estresse Oxidativo/genética , Água do Mar/química , Prata/química , Solubilidade , Testes de Toxicidade Aguda , Testes de Toxicidade Subaguda , Poluentes Químicos da Água/química
15.
Int J Nanomedicine ; 15: 5345-5360, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801693

RESUMO

Background: Soft corals have been endorsed as a plentiful source of bioactive compounds with promising anti-inflammatory activities; therefore, exploring their potential as source of anti-inflammatory metabolites has stimulated a growing research interest. Purpose: To investigate the anti-inflammatory potential of the soft coral, Nephthea sp., in its bulk and silver nanostructure. Metabolomics analysis of Nephthea sp., followed by molecular docking studies, was also conducted in order to explore and predict the secondary metabolites that might provide its inhibitory actions on inflammation. Materials and Methods: The petroleum ether and ethyl acetate fractions were used to synthesize silver nanoparticles. The prepared silver nanoparticles were characterized through UV-vis spectrophotometric, transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR) analyses. Testing for the anti-inflammatory activity was performed against COX-1 and COX-2. Furthermore, liquid chromatography-mass spectrometry (LC-MS) based metabolomics analysis and molecular docking were also applied. Results: A variety of secondary metabolites were identified, among them, sesquiterpenes were found to prevail. The petroleum ether and acetone fractions of Nephthea sp. showed the highest COX-2 inhibitory activities, possibly attributable to their substantial contents of terpenoids. Additionally, the green synthesized silver nanoparticles of both the petroleum ether and ethyl acetate fractions of Nephthea sp. demonstrated higher anti-COX-2 properties. Conclusion: The obtained results showed the effectiveness of non-targeted metabolomics technique in metabolic profiling of Nephthea sp., helping the search for new bioactive metabolites in future chemical studies on this soft coral. The interesting anti-inflammatory potential of the tested extracts and their nanoparticles could also be relevant to the development of new, effective anti-inflammatory agents.


Assuntos
Antozoários/metabolismo , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Nanopartículas Metálicas/química , Prata/química , Alcanos/química , Animais , Antozoários/química , Anti-Inflamatórios/síntese química , Ciclo-Oxigenase 1/química , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Química Verde , Humanos , Metabolômica , Simulação de Acoplamento Molecular , Metabolismo Secundário , Sesquiterpenos/análise , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Ecotoxicol Environ Saf ; 204: 111070, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32763567

RESUMO

Silver nanoparticles (AgNPs) are widely used as antimicrobial agents and resulted in their accumulation in environment. The purpose of this study was to investigate the detailed molecular mechanisms underlying AgNP-induced lung cellular senescence which has been proposed as a pathogenic driver of chronic lung disease. Herein, we demonstrate that exposure to AgNPs elevates multiple senescence biomarkers in lung cells, with cell cycle arrest in the G2/M phase, and potently activates genes of the senescence-associated secretory phenotype (SASP) in human fetal lung fibroblast cell line MRC5. Fluorescence-based assay also reveals that apoptosis induced by AgNPs is associated with senescence. Furthermore, we show that AgNPs cause premature senescence through an increase in transcription factor nuclear factor kappa B (NF-κB), cyclooxygenase-2 (COX2) expression and over-production of prostaglandin E2 (PGE2) in lung cells. Inhibition of COX2 reduces AgNPs-induced senescence to a normal level. Moreover, AgNPs also induce upregulation of COX2 and accelerate lung cellular senescence in vivo and cause mild fibrosis in the lung tissue of mice. Taken together, our studies support a critical role of AgNPs in the induction of lung cellular senescence via the upregulation of the COX2/PGE2 intracrine pathway, and suggest the adverse effects to the human respiratory system.


Assuntos
Senescência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Pulmão/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Prata/metabolismo
18.
Int J Nanomedicine ; 15: 4351-4362, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606682

RESUMO

Purpose: The present study synthesized silver nanoparticles (AgNPs) using the aqueous extract of a traditional medicinal product consisting of an oleoresin (a combination of macromolecules of carbohydrates and proteins) exuded from the rhizome of the plant Ferula foetida (asafoetida gum) and evaluated its biological properties. Materials and Methods: The silver nanoparticles synthesized using asafoetida gum (As-AgNPs) were characterized using UV/Vis spectroscopy, fourier infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM) and EADX. The cytotoxicity and antimicrobial activity As-AgNPs were evaluated against MCF-7 cell lines and selected microbial pathogens, respectively. Results: The synthesized silver nanoparticles were crystalline in nature with a spherical shape. The average particle size was 5.6-8.6 nm. The cytotoxicity of the synthesized As-AgNPs was evaluated against MCF-7 cell lines, and the As-AgNPs were found to be effective in inhibiting the multiplication of cancer cells. The As-AgNPs exhibited significant antimicrobial activity towards E. coli, K. pneumoniae and C. albicans. The MIC of the synthesized As-AgNPs was 7.80 µg/mL for E. coli ATCC 25922, Salmonella sp. WS50- and S. typhi; 15.60 µg/mL for S. typhimurium and S. aureus WS10, and 31.20 µg/mL for K. pneumoniae and S. aureus ATCC 43300-MRSA. In addition, MIC values of 15.60 µg/mL for C. albicans ATCC8436 and 31.20 µg/mL for C. krusei ATCC6258 were obtained. Conclusion: As asafoetida is a good traditional medicine, its involvement in the synthesis of AgNPs led the silver nanoparticles to exhibit good cytotoxic and antimicrobial effects.


Assuntos
Anti-Infecciosos/farmacologia , Ferula/química , Nanopartículas Metálicas/química , Gomas Vegetais/química , Prata/farmacologia , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Células MCF-7 , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Extratos Vegetais/química , Staphylococcus aureus/efeitos dos fármacos , Difração de Raios X
19.
Environ Sci Pollut Res Int ; 27(28): 35828-35836, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32601878

RESUMO

In this work, titanium dioxide nanoparticles (TiO2 NPs) and modified TiO2 NPs with silver (Ag) or platinum (Pt) dopant were developed through photodeposition method for the NOx conversion into nitric acid (HNO3) under visible light irradiation. The formed photocatalysts TiO2, Ag/TiO2, and Pt/TiO2 nanocomposites were characterized by utilizing TEM, SEM, energy-dispersive X-ray analysis (EDX), XRD, UV/visible diffuse reflectance spectroscopy (UV-Vis DRS), and FT-IR. It had been investigated that an enhancement within the conversion of NOx into HNO3 was increased from 34.3 to 78.3% for Ag/TiO2 and from 35.2 to 78.5% for Pt/TiO2 under visible light irradiation conditions at room temperature for less than 2 h. The photodegradation rate order of NOx under visible light irradiation is Pt/TiO2 ~ Ag/TiO2 > TiO2. A possible mechanism for the catalytic conversion of NOx gases has been proposed, which depends on the photogeneration of electrons and holes after the excitation of nanocatalysts under visible radiation that promoted superoxide and hydroxyl ions, which can depredate NOx gases. This approach of NOx photocatalytic conversion is characterized by its chemical stability, low cost, high efficiency, simple operation, and strong durability than traditional methods.


Assuntos
Nanopartículas , Platina , Catálise , Luz , Óxidos de Nitrogênio , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Titânio
20.
Sci Total Environ ; 741: 140341, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615428

RESUMO

The frequent harmful algae blooms (HABs) in eutrophic waters pose serious threats to the water environment and health of human beings and animals. In this study, a new type of photocatalytic coating was prepared by loading Ag2CO3-N:GO (AGON) on the polyurethane sponge modified by silica sol via a dip coating method for the photocatalytic inactivation of Microcystis aeruginosa (M. aeruginosa) and degradation of Microcystin-LR (MC-LR). The factors including photocatalyst loading dosage, natural organic matter (NOM), and alkalinity were studied. The effects on the physiological characteristics of M. aeruginosa and reactive oxygen species (ROS) were also investigated to reveal the photocatalytic inactivation mechanisms. The results showed that the AGON coating-4 (the initial concentration of AGON suspension used for loading is 4 g/L) exhibited the optimum photocatalytic performance under visible light, which can completely remove chlorophyll a after 5 h of irradiation. And the NOM and alkalinity in water have relatively negative effects on the photocatalytic inactivation of algae. The prepared AGON coating also exhibited excellent photocatalytic performance in the degradation of MC-LR under visible light. It only needed 20, 60 and 120 min to completely degrade 0.1, 0.3 and 0.5 mg/L MC-LR, respectively. However, the mixed systems of algae and MC-LR required a longer time to achieve photocatalytic degradation. The O2- were the predominant reactive oxygen species, causing the damage of cell membranes and walls and the leakage of cellular content, which eventually led to the irreversible damage to algal cells. What's more, the coating can be reused several times due to its good cyclability and stability. Therefore, the AGON coating has promising prospects for the treatment of algal blooms in eutrophic waters.


Assuntos
Microcystis , Prata , Animais , Clorofila A , Proliferação Nociva de Algas , Luz , Microcistinas
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