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1.
Talanta ; 281: 126878, 2025 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39276570

RESUMO

This contribution describes the development of a simple, fast, cost-effective, and sensitive impedimetric immunosensor for quantifying bovine tuberculosis (TB) in bovine serum samples. The construction of the immunosensor involved immobilizing the purified protein derivative (PPD) of M. bovis onto a screen-printed electrode that was modified with gold nanoparticles (AuNPs) and a polypyrrole (pPy) film synthesized electrochemically. The immunosensor exhibited a linear range from 0.5 µg mL-1 to 100 µg mL-1 and achieved a limit of detection (LD) of 100 ng mL-1 for the detection of anti-M. bovis antibody. The recovery percentages obtained in bovine serum samples were excellent, ranging between 98 % and 103 %. This device presents several advantages over alternative methods for determining TB in bovine serum samples. These include direct, in situ measurement without the need for pre-treatment, utilization of small volumes, thus avoiding harmful solvents and expensive reagents, and portability. In addition, the immunosensor exhibits both physical and chemical stability, retaining effectiveness even after 30 days of modification. This allows simultaneous incubations and facilitates large-scale detection. Hence, this immunosensor presents itself as a promising diagnostic tool for detecting anti-M. bovis antibodies in bovine serum. It serves as a viable alternative to tuberculin and ELISA tests.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Ouro , Nanopartículas Metálicas , Tuberculose Bovina , Animais , Bovinos , Tuberculose Bovina/diagnóstico , Tuberculose Bovina/sangue , Tuberculose Bovina/imunologia , Ouro/química , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Mycobacterium bovis/imunologia , Polímeros/química , Pirróis/química , Eletrodos , Limite de Detecção , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia
2.
Talanta ; 281: 126714, 2025 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-39232253

RESUMO

The indiscriminate use of pesticides in agriculture demands the development of devices capable of monitoring contaminations in food supplies, in the environment and biological fluids. Simplicity, easy handling, high sensitivities, and low limits-of-detection (LOD) and quantification are some of the required properties for these devices. In this work, we evaluated the effect of incorporating gold nanoparticles into indigo carmine-doped polypyrrole during the electropolymerization of films for use as an acetylcholinesterase (AChE) enzyme-based biosensor. As proof of concept, the pesticide methyl parathion was tested towards the inhibition of AChE. The enzyme was immobilized simply by drop-casting a solution, eliminating the need for any prior surface modification. The biosensors were characterized with cyclic voltammetry, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The assays for the detection of methyl parathion with films containing polypyrrole, indigo carmine and AChE (PPy-IC-AChE) presented a sensitivity of 5.7 µA cm-2 g-1 mL and a LOD of 12 nmol L-1 (3.0 ng L-1) with a linear range from 1.3 x 10-7 mol L-1 to 1.0 x 10-5 mol L-1. The introduction of gold nanoparticles (AuNP) into the film (PPy-IC-AuNP-AChE) led to remarkable improvements on the overall performance, such as a lower redox potential for the enzymatic reaction, a 145 % increase in sensitivity (14 µA cm-2 g-1 mL), a wider detection dynamic range (from 1.3x10-7 to 1.0x10-3 mol L-1), and a very low LOD of 24 fmol L-1 (64 ag mL-1). These findings underscore the potential of using AuNPs to improve the enzymatic performance of biosensor devices.


Assuntos
Acetilcolinesterase , Técnicas Biossensoriais , Técnicas Eletroquímicas , Enzimas Imobilizadas , Ouro , Nanopartículas Metálicas , Metil Paration , Praguicidas , Polímeros , Pirróis , Ouro/química , Pirróis/química , Polímeros/química , Nanopartículas Metálicas/química , Praguicidas/análise , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Técnicas Biossensoriais/métodos , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Metil Paration/análise , Limite de Detecção
3.
An Acad Bras Cienc ; 96(4): e20240436, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39383431

RESUMO

Nanotechnology is a fast-growing field with large number of applications. Therefore, the current study, was designed to prepare Zinc Oxide nanoparticles (ZnO NPs) from A. modesta leaves extract through a cost-effective method. The prepared NPs were characterized through UV-Vis Spectroscopy (UV-Vis), Dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), scanning electron microscope (SEM), and energy dispersive X-ray (EDX). The XRD and DLS analysis revealed the hexagonal nanocrystalline nature of ZnO NPs. The FTIR results displayed multiple fictional groups and UV results confirmed its optical properties. The average size of the NPs was 68.3 nm with a band gap of 2.71 eV. The SEM images divulge a clover leaf shape of ZnO NPs. The EDX spectrum revealed the presence of zinc and oxygen. The prepared NPs showed excellent biomedical application. The highest antileishmanial activity was 68%, anti-inflammatory activity was 78%, total antioxidant capacity (TAC) was 79.1%, antibacterial potential (ZOI) 22.1 mm, and highest growth inhibition of 85 ± 2.1% against A. rabiei. The adsorption efficiency of 85.3% within 120 min was obtained. Conclusively ZnO NPs have shown potential biomedical and environmental applications and ought to be the more investigated to enhance their practical use.


Assuntos
Anti-Infecciosos , Compostos Fitoquímicos , Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Anti-Infecciosos/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Difração de Raios X , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Antioxidantes/farmacologia , Antioxidantes/química , Folhas de Planta/química , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas/química , Química Verde/métodos
4.
World J Microbiol Biotechnol ; 40(11): 341, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39358621

RESUMO

Drug-resistant bacteria such as Escherichia coli and Staphylococcus aureus represent a global health problem that requires priority attention. Due to the current situation, there is an urgent need to develop new, more effective and safe antimicrobial agents. Biotechnological approaches can provide a possible alternative control through the production of new generation antimicrobial agents, such as silver nanoparticles (AgNPs) and bacteriocins. AgNPs stand out for their antimicrobial potential by employing several mechanisms of action that can act simultaneously on the target cell such as the production of reactive oxygen species and cell wall rupture. On the other hand, bacteriocins are natural peptides synthesized ribosomally that have antimicrobial activity and are produced, among others, by lactic acid bacteria (LAB), whose main mechanism of action is to produce pores at the level of the cell membrane of bacterial cells. However, these agents have disadvantages. Nanoparticles also have limitations such as the tendency to form aggregates, which decreases their antibacterial activity and possible cytotoxic effects, and bacteriocins have a narrow spectrum of action, require high doses to be effective, and can be degraded by proteases. Given these limitations, nanoconjugates of these two agents have been developed that can act synergistically in the control of pathogenic bacteria resistant to antibiotics. This review focuses on knowing relevant aspects of the antibiotic resistance of E. coli and S. aureus, the characteristics of these new generation antibacterial agents, and their effect alone or forming nanoconjugates that are more effective against the multiresistant mentioned bacteria.


Assuntos
Antibacterianos , Bacteriocinas , Farmacorresistência Bacteriana Múltipla , Escherichia coli , Nanopartículas Metálicas , Nanocompostos , Prata , Staphylococcus aureus , Bacteriocinas/farmacologia , Bacteriocinas/química , Prata/farmacologia , Prata/química , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Nanocompostos/química , Testes de Sensibilidade Microbiana , Lactobacillales/metabolismo , Lactobacillales/efeitos dos fármacos
5.
World J Microbiol Biotechnol ; 40(11): 343, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39375274

RESUMO

Microalgae are susceptible to most pollutants in aquatic ecosystems and can be potentially damaged by silver nanoparticles (AgNPs). This study aims to clarify the potential consequences of Chlorella vulgaris internalizing AgNPs. The exposure of C. vulgaris to AgNPs stabilized with citrate led to the accumulation of NPs in the cell wall, increasing permeability, which allowed the entry of AgNPs and Ag + ions resulting from the dissolution of AgNPs. Ag + accumulated inside the cell could be converted into AgNPs (endogenous) due to the reducing potential of the cytoplasm. Both exogenous and endogenous AgNPs caused damage to all biological structures of the algae, as demonstrated by TEM images. This damage included the disorganization of chloroplasts, deposition of AgNPs on starch granules, and increased amounts of lipids, starch granules, exopolysaccharides, plastoglobuli, and cell diameters. These changes caused cell death by altering cell viability and interfering with organelle functions, possibly due to reactive oxygen species generated by nanoparticles, as shown in a lipid bilayer model. These findings highlight the importance of considering the exposure risks of AgNPs in a worldwide distributed chlorophyte.


Assuntos
Chlorella vulgaris , Nanopartículas Metálicas , Microalgas , Espécies Reativas de Oxigênio , Prata , Prata/metabolismo , Prata/farmacologia , Chlorella vulgaris/efeitos dos fármacos , Chlorella vulgaris/metabolismo , Chlorella vulgaris/crescimento & desenvolvimento , Nanopartículas Metálicas/química , Microalgas/metabolismo , Microalgas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Microscopia Eletrônica de Transmissão , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Cloroplastos/metabolismo , Cloroplastos/efeitos dos fármacos
6.
Molecules ; 29(18)2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39339417

RESUMO

This study evaluated push-out bond test (POBT), surface roughness, and antimicrobial properties against Enterococcus faecalis of bioceramic sealers supplemented with silver nanoparticles (AgNPs). The sealers tested were CeraSeal®, EndoSequence® BC SealerTM, and Bio-C® Sealer. The POBT was measured with a Universal Testing Machine, and the type of failure was evaluated with a stereomicroscope. The roughness average (Sa) and peak-valley height (Sy) values were evaluated by atomic force microscopy. The bacterial growth inhibition was evaluated using a disk diffusion test, and antimicrobial activity was determined with the plate microdilution method. The POBT showed no significant difference between sealers with and those without NPs in cervical and apical thirds (p > 0.05). In the middle third, the adhesion force was significant for Endosequence BC Sealer® (p < 0.05). The results showed that the Sa and Sy parameters, when AgNPs were added, did not show a statistically significant difference compared to the groups without nanoparticles (p > 0.05). All tested sealers showed bacterial growth inhibition, but no significant difference was found. Their efficacy, in descending order of antibacterial activity when AgNPs were added, is as follows: EndoSequence® BC SealerTM > Bio-C® Sealer > CeraSeal®. The incorporation of AgNPs into bioceramics improves antimicrobial activity without affecting mechanical properties.


Assuntos
Enterococcus faecalis , Nanopartículas Metálicas , Materiais Restauradores do Canal Radicular , Prata , Propriedades de Superfície , Prata/química , Prata/farmacologia , Nanopartículas Metálicas/química , Materiais Restauradores do Canal Radicular/química , Materiais Restauradores do Canal Radicular/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antibacterianos/farmacologia , Antibacterianos/química , Teste de Materiais , Humanos , Testes de Sensibilidade Microbiana , Cerâmica/química , Cerâmica/farmacologia , Microscopia de Força Atômica , Fosfatos de Cálcio , Combinação de Medicamentos , Óxidos , Silicatos
7.
ACS Appl Bio Mater ; 7(10): 6908-6918, 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39316373

RESUMO

The incorporation of bactericidal properties into textiles is a widely sought-after aspect, and silver nanoparticles (AgNPs) can be used for this. Here, we evaluate a strategy for incorporating AgNPs into a cotton fabric. For this purpose, a bactericidal textile coating based on a composite of AgNPs and kappa-carrageenan (k-CA) was proposed. The composite was obtained by heating the silver precursor (AgNO3) directly in k-CA solution for green synthesis and in situ AgNPs stabilization. Cotton substrates were added to the heated composite solution for surface impregnation and hydrogel film formation after cooling. Direct synthesis of AgNPs on a fabric was also tested. The results showed that the application of a coating based on k-CA/AgNPs composite can achieve more than twice the silver loading on the fabric surface compared to the textile subjected to direct AgNPs incorporation. Furthermore, silver release tests in water showed that higher Ag+ levels were reached for k-CA/AgNPs-coated cotton. Therefore, inoculation tests with the bacteria Staphylococcus aureus (SA) using the agar diffusion method showed that samples covered with the composite resulted in significantly larger inhibition halos. This indicated that the use of the composite as a coating for cotton fabric improved its bactericidal activity against SA.


Assuntos
Antibacterianos , Carragenina , Fibra de Algodão , Teste de Materiais , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Prata , Staphylococcus aureus , Prata/química , Prata/farmacologia , Carragenina/química , Carragenina/farmacologia , Nanopartículas Metálicas/química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Têxteis , Propriedades de Superfície
8.
Braz J Microbiol ; 55(3): 2727-2738, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39222218

RESUMO

Due to the increasing occurrence of drug resistant urinary tract infections (UTI) among children, there is a need to investigate alternative effective treatment protocols such as nanoparticles. Flagella and fimbriae are primary factors contributing the virulence of urinary tract infecting bacteria. The aim of this study was to assess the antibacterial effects of zinc oxide nanoparticles which have been synthesized using both chemical and green methods on multi-drug resistant (MDR) uropathogenic bacteria encoding fli and fim genes and investigating their binding ability to bacterial appendage proteins. A total of 30 urine culture samples were collected from children under 2 years old diagnosed with urinary tract infection. The isolates underwent antibiotic suseptibility assessment and the isolates demonstrating MDR were subjected to molecular amplification of fimG (fimbrial) and fliD and fliT (flagellal) genes. The confirmation of cellular appendages was achieved through silver nitrate staining. The antibacterial efficacy of the synthetized nanoparticles was assessed using the micro and macrodilution methods. The successful binding of nanoparticles to bacterial appendage proteins was confirmed through mobility shift and membrane filter assays. The dimensions of chemically synthesized ZnO nanoparticles and green nanoparticles were measured at 30 nm and 85 nm, respectively, with the exhibition of hexagonal geometries. The nanoparticles synthesized through chemical and green methods exhibited minimum inhibitory concentrations (MIC) of 0.0062-0.025 g/L and 0.3 g/L, respectively. The ability of ZnO nanoparticles to bind bacterial appendage proteins and to combat MDR uropathogenic bacteria are promising for new treatment protocols against UTI in children in future.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana Múltipla , Flagelos , Infecções Urinárias , Óxido de Zinco , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Óxido de Zinco/metabolismo , Antibacterianos/farmacologia , Humanos , Infecções Urinárias/microbiologia , Infecções Urinárias/tratamento farmacológico , Flagelos/efeitos dos fármacos , Flagelos/genética , Flagelos/metabolismo , Testes de Sensibilidade Microbiana , Fímbrias Bacterianas/genética , Fímbrias Bacterianas/metabolismo , Fímbrias Bacterianas/efeitos dos fármacos , Nanopartículas/química , Lactente , Nanopartículas Metálicas/química
9.
Chemosphere ; 364: 143080, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39146989

RESUMO

Nanotechnology has brought significant advancements to agriculture through the development of engineered nanomaterials (ENPs). Silver nanoparticles (AgNPs) capped with polysaccharides have been applied in agricultural diagnostics, crop pest management, and seed priming. Hyaluronic acid (HA), a natural polysaccharide with bactericidal properties, has been considered a growth regulator for plant tissues and an inducer of systemic resistance against plant diseases. Additionally, HA has been employed as a stabilizing agent for AgNPs. This study investigated the synthesis and effects of hyaluronic acid-stabilized silver nanoparticles (HA-AgNPs) as a seed priming agent on lettuce (Lactuca sativa L.) seed germination. HA-AgNPs were characterized using several techniques, exhibiting spherical morphology and good colloidal stability. Germination assays conducted with 0.1, 0.04, and 0.02 g/L of HA-AgNPs showed a concentration-dependent reduction in seed germination. Conversely, lower concentrations of HA-AgNPs significantly increased germination rates, survival, tolerance indices, and seed water absorption compared to silver ions (Ag+). SEM/EDS indicated more significant potential for HA-AgNPs internalization compared to Ag+. Therefore, these findings are innovative and open new avenues for understanding the impact of Ag+ and HA-AgNPs on seed germination.


Assuntos
Germinação , Ácido Hialurônico , Lactuca , Nanopartículas Metálicas , Sementes , Prata , Lactuca/efeitos dos fármacos , Lactuca/crescimento & desenvolvimento , Prata/química , Prata/toxicidade , Prata/farmacologia , Germinação/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/química , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia
10.
J Mater Chem B ; 12(36): 8993-9004, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39145426

RESUMO

Among external stimuli-responsive therapy approaches, those using near infrared (NIR) light irradiation have attracted significant attention to treat bone-related diseases and bone tissue regeneration. Therefore, the development of metallic biomaterials sensitive to NIR stimuli is an important area of research in orthopaedics. In this study, we have generated in situ prism-shaped silver nanoparticles (p-AgNPs) in a biomorphic nano-holed TiO2 coating on a Ti6Al4V alloy (a-Ti6Al4V). Insertion of p-AgNPs does not disturb the periodically arranged sub-wavelength-sized unit cell on the a-Ti6Al4V dielectric structure, while they exacerbate its peculiar optical response, which results in a higher NIR reflectivity and high efficiency of NIR photothermal energy conversion suitable to bacterial annihilation. Together, these results open a promising path toward strategic bone therapeutic procedures, providing novel insights into precision medicine.


Assuntos
Ligas , Antibacterianos , Raios Infravermelhos , Nanopartículas Metálicas , Prata , Propriedades de Superfície , Titânio , Titânio/química , Titânio/farmacologia , Ligas/química , Ligas/farmacologia , Prata/química , Prata/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas Metálicas/química , Staphylococcus aureus/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Escherichia coli/efeitos dos fármacos , Tamanho da Partícula
11.
Bull Environ Contam Toxicol ; 113(3): 32, 2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39183240

RESUMO

Due to their broad-spectrum antimicrobial action and ease of synthesis, silver nanoparticles (AgNP) are one of the most widely used nanomaterials in different industrial and ecological areas. AgNP are released into marine ecosystems, nevertheless, their ecotoxicological effects have been overlooked. In this study, we evaluated the toxic effects of biogenic and synthesized AgNP (AgNPIBCLP11 and AgNPSINT) on sea urchin Echinometra lucunter embryos and compared them with the metal precursor silver nitrate (AgNO3). Fertilized eggs were exposed to five concentrations of the test compounds and a negative control for 48 h under controlled conditions. The IC50-48 h of AgNPIBCLP11, AgNPSINT and AgNO3 were 0.31, 4.095, and 0.01 µg L-1, evidencing that both AgNP are less toxic than AgNO3, and that AgNPSINT is less toxic than the AgNPIBCLP11. Toxicity to E. lucunter embryos could be explained by the fact that Ag affects DNA replication and induces the formation of pores in the cellular wall, leading to apoptosis.


Assuntos
Embrião não Mamífero , Nanopartículas Metálicas , Ouriços-do-Mar , Prata , Poluentes Químicos da Água , Animais , Prata/toxicidade , Nanopartículas Metálicas/toxicidade , Ouriços-do-Mar/efeitos dos fármacos , Ouriços-do-Mar/embriologia , Embrião não Mamífero/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade
12.
Braz J Biol ; 84: e280570, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39109714

RESUMO

Anthocyanins are known as an antioxidant, and their water-soluble purple-colored pigments are very nutritive. Therefore, the present study investigated the antioxidant activity of black rice anthocyanins nano-composite against infertility induced by AlCl3 in rats. Anthocyanin silver nanoparticles (An-AgNPs) were prepared by reducing black rice anthocyanin with the metallic ions. Antioxidant activity (DPPH %) of anthocyanin was determined. Also, the morphology of (An-AgNPs) was examined by scanning electron microscopy (SEM). Albino rats were divided into five groups (negative control (NC): fed on basel diet, positive control (PC): treated with AlCl3 (34 mg/kg bw) for seventy days, and three other groups treated with AlCl3 (34 mg/kg bw) + An-AgNPs at 10, 15, and 20 mg/kg, b.w/ day, respectively for seventy days. Serum testosterone, LH, FSH, and estradiol were measured. Additionally, Sperm motility, Sperm count (Testicular and Epididymal), fructose in semen, and semen quality were determined. The values of the anthocyanin component and DPPH radical scavenging activity obtained were 3603.82±6.11 mg CCE/g and 84.62±1.98, respectively. An-AgNPs shows tend to agglomerate, particles are uniform in size and shape, and the diameter of the particles ranges between 70nm to 130nm. LH, estradiol and testosterone levels increased significantly in rats treated with An-AgNPs 10, 15, 20 mg/kg b.w+ AlCl3 (34 mg/kg bw) also exhibited significantly higher sperm motility, sperm count, and daily sperm production, and decreased sperm transit rate than G2. In comparison to G2, animals treated with AlCl3 (34 mg/kg bw) + An-AgNPs 10, 15, 20 mg/kg b.w(G3 to G5) had significantly higher semen and semen quality (P 0.05). We can conclude that the An-AgNPs showed a strong effect against infertility induced by AlCl3; this represents a suitable natural supply of biological substances for medicine and anthocyanins could be considered the ideal ingredients against oxidative stress-induced infertility.


Assuntos
Cloreto de Alumínio , Compostos de Alumínio , Antocianinas , Antioxidantes , Nanopartículas Metálicas , Oryza , Ratos Wistar , Prata , Animais , Antocianinas/farmacologia , Antocianinas/análise , Masculino , Antioxidantes/farmacologia , Oryza/química , Prata/química , Infertilidade Masculina , Cloretos , Motilidade dos Espermatozoides/efeitos dos fármacos , Nanocompostos/química , Microscopia Eletrônica de Varredura , Ratos , Testosterona/sangue , Contagem de Espermatozoides , Análise do Sêmen
13.
Int J Mol Sci ; 25(15)2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39126001

RESUMO

Breast cancer is the most diagnosed type of cancer worldwide and the second cause of death in women. Triple-negative breast cancer (TNBC) is the most aggressive, and due to the lack of specific targets, it is considered the most challenging subtype to treat and the subtype with the worst prognosis. The present study aims to determine the antitumor effect of beta-D-glucose-reduced silver nanoparticles (AgNPs-G) in a murine model of TNBC, as well as to study its effect on the tumor microenvironment. In an airbag model with 4T1 tumor cell implantation, the administration of AgNPs-G or doxorubicin showed antitumoral activity. Using immunohistochemistry it was demonstrated that treatment with AgNPs-G decreased the expression of PCNA, IDO, and GAL-3 and increased the expression of Caspase-3. In the tumor microenvironment, the treatment increased the percentage of memory T cells and innate effector cells and decreased CD4+ cells and regulatory T cells. There was also an increase in the levels of TNF-α, IFN-γ, and IL-6, while TNF-α was increased in serum. In conclusion, we suggest that AgNPs-G treatment has an antitumor effect that is demonstrated by its ability to remodel the tumor microenvironment in mice with TNBC.


Assuntos
Glucose , Nanopartículas Metálicas , Prata , Neoplasias de Mama Triplo Negativas , Microambiente Tumoral , Animais , Microambiente Tumoral/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia , Neoplasias de Mama Triplo Negativas/metabolismo , Prata/química , Nanopartículas Metálicas/química , Feminino , Camundongos , Glucose/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Camundongos Endogâmicos BALB C , Doxorrubicina/farmacologia , Humanos
14.
Nanotechnology ; 35(46)2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39116890

RESUMO

The translation of silver-based nanotechnology 'from bench to bedside' requires a deep understanding of the molecular aspects of its biological action, which remains controversial at low concentrations and non-spherical morphologies. Here, we present a hemocompatibility approach based on the effect of the distinctive electronic charge distribution in silver nanoparticles (nanosilver) on blood components. According to spectroscopic, volumetric, microscopic, dynamic light scattering measurements, pro-coagulant activity tests, and cellular inspection, we determine that at extremely low nanosilver concentrations (0.125-2.5µg ml-1), there is a relevant interaction effect on the serum albumin and red blood cells (RBCs). This explanation has its origin in the surface charge distribution of nanosilver particles and their electron-mediated energy transfer mechanism. Prism-shaped nanoparticles, with anisotropic charge distributions, act at the surface level, generating a compaction of the native protein molecule. In contrast, the spherical nanosilver particle, by exhibiting isotropic surface charge, generates a polar environment comparable to the solvent. Both morphologies induce aggregation at NPs/bovine serum albumin ≈ 0.044 molar ratio values without altering the coagulation cascade tests; however, the spherical-shaped nanosilver exerts a negative impact on RBCs. Overall, our results suggest that the electron distributions of nanosilver particles, even at extremely low concentrations, are a critical factor influencing the molecular structure of blood proteins' and RBCs' membranes. Isotropic forms of nanosilver should be considered with caution, as they are not always the least harmful.


Assuntos
Eritrócitos , Nanopartículas Metálicas , Soroalbumina Bovina , Prata , Prata/química , Nanopartículas Metálicas/química , Eritrócitos/metabolismo , Eritrócitos/química , Humanos , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Propriedades de Superfície , Animais , Bovinos , Coagulação Sanguínea/efeitos dos fármacos , Proteínas Sanguíneas/metabolismo , Proteínas Sanguíneas/química , Teste de Materiais
15.
ACS Appl Bio Mater ; 7(8): 5530-5540, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39093994

RESUMO

This study reports on the modification of bacterial cellulose (BC) membranes produced by static fermentation of Komagataeibacter xylinus bacterial strains with graphene oxide-silver nanoparticles (GO-Ag) to yield skin wound dressings with improved antibacterial properties. The GO-Ag sheets were synthesized through chemical reduction with sodium citrate and were utilized to functionalize the BC membranes (BC/GO-Ag). The BC/GO-Ag composites were characterized to determine their surface charge, morphology, exudate absorption, antimicrobial activity, and cytotoxicity by using fibroblast cells. The antimicrobial activity of the wound dressings was assessed against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The results indicate that the BC/GO-Ag dressings can inhibit ∼70% of E. coli cells. Our findings also revealed that the porous BC/GO-Ag antimicrobial dressings can efficiently retain 94% of exudate absorption after exposure to simulated body fluid (SBF) for 24 h. These results suggest that the dressings could absorb excess exudate from the wound during clinical application, maintaining adequate moisture, and promoting the proliferation of epithelial cells. The BC/GO-Ag hybrid materials exhibited excellent mechanical flexibility and low cytotoxicity to fibroblast cells, making excellent wound dressings able to control bacterial infectious processes and promote the fast healing of dermal lesions.


Assuntos
Antibacterianos , Materiais Biocompatíveis , Celulose , Escherichia coli , Grafite , Teste de Materiais , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Prata , Staphylococcus aureus , Cicatrização , Grafite/química , Grafite/farmacologia , Prata/química , Prata/farmacologia , Cicatrização/efeitos dos fármacos , Celulose/química , Celulose/farmacologia , Nanopartículas Metálicas/química , Antibacterianos/química , Antibacterianos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Tamanho da Partícula , Pseudomonas aeruginosa/efeitos dos fármacos , Gluconacetobacter xylinus/química , Humanos , Camundongos , Bandagens , Animais
16.
Chemosphere ; 364: 142995, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39097114

RESUMO

This paper describes an alternative method for the in situ synthesis of gold nanoparticles (AuNPs) with a particle size of less than 3 nm, using nanoreactors formed by reverse micelles of 1,4-bis-(2-ethylhexyl) sulfosuccinate sodium (AOT) and nanoparticle stabilization with l-cysteine, which favor the preparation of nanoparticles with size and shape control, which are homogeneously dispersed (1% by weight) on the support of titanium dioxide nanowires (TNWs). To study the activity and selectivity of the prepared catalyst (AuNPs@TNWs), an aqueous solution of 40 mM glycerol was irradiated with a green laser (λ = 530 nm, power = 100 mW) in the presence of the catalyst and O2 as an oxidant at 22 °C for 6 h, obtaining a glycerol conversion of 86% with a selectivity towards hydroxypyruvic acid (HA) of more than 90%. From the control and reactions, we concluded that the Ti-OH groups promote the glycerol adsorption on the nanowires surface and the surface plasmon of the gold nanoparticles favors the selectivity of the reaction towards the hydroxypyruvic acid.


Assuntos
Glicerol , Ouro , Nanopartículas Metálicas , Nanofios , Oxirredução , Titânio , Titânio/química , Ouro/química , Nanopartículas Metálicas/química , Nanofios/química , Glicerol/química , Catálise
17.
Int J Mol Sci ; 25(16)2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39201681

RESUMO

In this study, the biosynthesis of polyhydroxyalkanoates (PHAs) was carried out using Pseudomonas putida and Pseudomonas aeruginosa. These PHAs were produced using reagent-grade glycerol and crude glycerol as the carbon sources. The objective was to compare the production of PHAs and to functionalize these polymers with silver nanoparticles to provide antibacterial properties for potential biomedical applications. The findings from the physical and chemical analyses confirmed the successful synthesis and extraction of PHAs, achieving comparable yields using both crude glycerol and reagent-grade glycerol as carbon sources across both strains. Approximately 16% higher PHAs production was obtained using Pseudomonas putida compared to Pseudomonas aeruginosa, and no significant difference was observed in the production rate of PHAs between the two carbon sources used, which means that crude glycerol could be utilized even though it has more impurities. Notably, PHAs functionalized with silver nanoparticles showed improved antibacterial effectiveness, especially those derived from reagent-grade glycerol and the Pseudomonas aeruginosa strain.


Assuntos
Antibacterianos , Glicerol , Nanopartículas Metálicas , Poli-Hidroxialcanoatos , Pseudomonas aeruginosa , Pseudomonas putida , Prata , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/metabolismo , Pseudomonas putida/metabolismo , Prata/química , Prata/farmacologia , Poli-Hidroxialcanoatos/biossíntese , Poli-Hidroxialcanoatos/química , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/biossíntese , Glicerol/química , Glicerol/metabolismo , Testes de Sensibilidade Microbiana
18.
Photodiagnosis Photodyn Ther ; 49: 104309, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39154922

RESUMO

The use of photothermal processes has been proven effective in the control of microbial infections. Simultaneously, the localized surface plasmon resonance phenomena in metallic nanoparticles have been explored as an alternative strategy to achieve highly efficient localized heating. In this work, we propose the use of selected nanoheaters to improve the efficiency of fungal photothermal inactivation of Candida albicans through size optimization of plasmonic gold nanorods. Here, the optical heating of polyethylene glycol coated gold nanorods of varying sizes is evaluated, both theoretically and experimentally. A size-dependent computational approach was applied to identify metallic nanorods with maximized thermal performance at 800 nm, followed by the experimental comparison of optimal and suboptimal nanoheaters. Comparison among samples show temperatures of up to 53.0 °C for 41×10 nm gold nanorods against 32.3 °C for 90×25 nm, a percentage increase of ∼63% in photothermal inactivation assessments. Our findings reveal that gold nanorods of 41×10 nm exhibit superior efficiency in near-infrared (800 nm) photothermal inactivation of fungi, owing to their higher light-thermal conversion efficiency. The identification of high performance metallic nanoheaters may lead to the reduction of the nanoparticle dose used in plasmonic-based procedures and decrease the laser exposure time needed to induce cell death. Moreover, our results provide insights to better exploit plasmonic nanoparticles on photothermal inactivation protocols.


Assuntos
Candida albicans , Ouro , Nanopartículas Metálicas , Nanotubos , Candida albicans/efeitos dos fármacos , Nanotubos/química , Ouro/química , Ouro/farmacologia , Nanopartículas Metálicas/química , Ressonância de Plasmônio de Superfície , Raios Infravermelhos , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Fotoquimioterapia/métodos , Terapia Fototérmica/métodos
19.
Braz J Microbiol ; 55(3): 2789-2796, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39023813

RESUMO

Acinetobacter baumannii is a bacteria associated with nosocomial infections and outbreaks, difficult to control due to its antibiotic resistance, ability to survive in adverse conditions, and biofilm formation adhering to biotic and abiotic surfaces. Therefore, this study aimed to evaluate the antibiofilm activity of biogenic silver nanoparticle (Bio-AgNP) and polymyxin B alone and combined in biofilms formed by isolates of carbapenem-resistant A. baumannii (CR-Ab). In the biofilm formation inhibition assay, CR-Ab strains were exposed to different concentrations of the treatments before inducing biofilm formation, to determine the ability to inhibit/prevent bacterial biofilm formation. While in the biofilm rupture assay, the bacterial biofilm formation step was previously carried out and the adhered cells were exposed to different concentrations of the treatments to evaluate their ability to destroy the bacterial biofilm formed. All CR-Ab isolates and ATCC® 19606™ used in this study are strong biofilm formers. The antibiofilm activity of Bio-AgNP and polymyxin B against CR-Ab and ATCC® 19606™ demonstrated inhibitory and biofilm-disrupting activity. When used in combination, Bio-AgNP and polymyxin B inhibited 4.9-100% of biofilm formation in the CR-Ab isolates and ATCC® 19606™. Meanwhile, when Bio-AgNP and polymyxin B were combined, disruption of 6.8-77.8% of biofilm formed was observed. Thus, antibiofilm activity against CR-Ab was demonstrated when Bio-AgNP was used alone or in combination with polymyxin B, emerging as an alternative in the control of CR-Ab strains.


Assuntos
Acinetobacter baumannii , Antibacterianos , Biofilmes , Carbapenêmicos , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Polimixina B , Prata , Biofilmes/efeitos dos fármacos , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/fisiologia , Polimixina B/farmacologia , Prata/farmacologia , Prata/química , Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Carbapenêmicos/farmacologia , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/tratamento farmacológico , Humanos , Sinergismo Farmacológico , Farmacorresistência Bacteriana
20.
J Drug Target ; 32(9): 1086-1100, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38980282

RESUMO

Cost-effective strategies for the treatment of chronic wounds must be developed. The green synthesis of gold nanoparticles (GNPs) it is possible to guarantee a lower toxicity in biological tissues and greater safety of applicability, in addition to adding the effects of nanoparticles (NPs) to those of extracts. The objective of this study was to evaluate the effects of treatment with biosynthesized GNPs in a chronic wound model. Wistar rats were distributed into 7 groups: Acute Wound (AW); Chronic wound (CW); CW + GNPs-Açaí; CW + GNPs-DB; CW + AV-GNPs; CW + SafGel®; CW + 660 nm laser. The chronic injury model was induced with topically applied Resiquimod for 6 days. Treatments were then initated on the fourteenth day after the last application of Resiquimod and carried out daily for ten days. The proposed therapies with GNPs were able to significantly reduce the inflammatory score and increase the rate of wound contraction. In histology, there was a reduction in the inflammatory infiltrate and increased gene expression of fibronectin and type III collagen, mainly in the CW + AV-GNPs group. The therapies were able to reduce pro-inflammatory cytokines, increase anti-inflammatory cytokines, and reduce oxidative stress. The results demonstrated that the effects of GNPs appear to complement those of the extracts, thereby enhancing the tissue repair process.


Assuntos
Modelos Animais de Doenças , Ouro , Química Verde , Imidazóis , Nanopartículas Metálicas , Ratos Wistar , Cicatrização , Animais , Ouro/química , Ouro/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Ratos , Imidazóis/administração & dosagem , Imidazóis/farmacologia , Cicatrização/efeitos dos fármacos , Química Verde/métodos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Doença Crônica , Citocinas/metabolismo
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