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1.
BMC Oral Health ; 22(1): 230, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35681128

RESUMO

BACKGROUND: Preventive measures are essential during the length of orthodontic treatment to reduce the risk of decalcification and white spot lesions formation. With the evolution of procedures that enable coating of the orthodontic brackets using nanoparticles known for their good antibacterial activity, coating the brackets with nanoparticles of silver, zinc oxide and combination of silver and zinc oxide to evaluate their antibacterial effect in comparison to a control group without coating was carried out in this study. METHODS: Four groups of 12 brackets each were included in the study. The coating procedure was carried out using physical vapor deposition. The antibacterial activity was tested on Streptococcus mutans and Lactobacillus Acidophilus using colony forming count. The antibacterial activity was evaluated immediately after coating and later after 3 months. RESULTS: Brackets coated with combination of silver and zinc oxide nanoparticles had the highest ability on reduction of both Streptococcus mutans and Lactobacillus Acidophilus count followed by silver nanoparticles and then zinc oxide nanoparticles. No significant difference was found between the first and second antibacterial tests. CONCLUSION: The silver/zinc oxide nanoparticles coated brackets had the highest antibacterial effect in comparison to silver nanoparticles and zinc oxide nanoparticles individually coated brackets on Streptococcus mutans and Lactobacillus acidophilus, and all types of coatings showed enhanced antibacterial effect in comparison to the uncoated bracket. Coating of orthodontic brackets could be further assessed in clinical application to prevent decalcification.


Assuntos
Nanopartículas Metálicas , Braquetes Ortodônticos , Óxido de Zinco , Antibacterianos/farmacologia , Humanos , Lactobacillus acidophilus , Prata/farmacologia , Streptococcus mutans , Zinco , Óxido de Zinco/farmacologia
2.
Int J Mol Sci ; 23(11)2022 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-35682664

RESUMO

The synthesis of nanoparticles from noble metals has received high attention from researchers due to their unique properties and their wide range of applications. Silver nanoparticles (AgNPs), in particular, show a remarkable inhibitory effect against microorganisms and viruses. Various methods have been developed to obtain AgNPs, however the stability of such nanostructures over time is still challenging. Researchers attempt to obtain particular shapes and sizes in order to tailor AgNPs properties for specific areas, such as biochemistry, biology, agriculture, electronics, medicine, and industry. The aim of this study was to design AgNPs with improved antimicrobial characteristics and stability. Two different wet chemical routes were considered: synthesis being performed (i) reduction method at room temperatures and (ii) solvothermal method at high temperature. Here, we show that the antimicrobial properties of the obtained AgNPs, are influenced by their synthesis route, which impact on the size and shape of the structures. This work analyses and compares the antimicrobial properties of the obtained AgNPs, based on their structure, sizes and morphologies which are influenced, in turn, not only by the type or quantities of precursors used but also by the temperature of the reaction. Generally, AgNPs obtained by solvothermal, at raised temperature, registered better antimicrobial activity as compared to NPs obtained by reduction method at room temperature.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Antibacterianos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Prata/química , Prata/farmacologia
3.
Int J Mol Sci ; 23(11)2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35682703

RESUMO

The present work is a continuation of our translational research focusing on the use of silver nanoparticles (AgNPs) to solve the global problem of antibiotic resistance. In vivo fieldwork was done with 300 breeding farm cows with serous mastitis. Ex vivo assays revealed that after cow treatment with the antibiotic drug Spectromast LCTM, S.dysgalactiae susceptibility to 31 antibiotics dropped by 22.9%, but after treatment with Argovit-CTM AgNPs, it was raised by 13.1%. This was explained by the fact that the percentage of isolates with an efflux effect after Spectromast LC treatment resulted in an 8% increase, while Argovit-C-treatment caused a 19% decrease. The similarity of these results to our previous results on S. aureus isolates from mastitis cows treated with the antibiotic drug Lactobay and Argovit-CTM AgNPs was shown. So, mastitis treatments with Argovit-CTM AgNPs can partially return the activity of antibiotics towards S.dysgalactiae and S. aureus, while, in contrast, treatments with antibiotic drugs such as Spectromast LC and Lactobay enhance bacterial resistance to antibiotics. The results of this work strengthen the hope that in the future the use of AgNPs as efflux pump inhibitors will recover the activity of antibiotics, and thus will preserve the wide spectrum of antibiotics on the market.


Assuntos
Mastite Bovina , Nanopartículas Metálicas , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bovinos , Resistência a Medicamentos , Feminino , Humanos , Mastite Bovina/tratamento farmacológico , Mastite Bovina/microbiologia , Testes de Sensibilidade Microbiana , Prata/farmacologia , Prata/uso terapêutico , Staphylococcus aureus , Streptococcus
4.
Int J Mol Sci ; 23(11)2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35683003

RESUMO

Bombyx mori nucleopolyhedrovirus (BmNPV) causes major economic losses in sericulture. A number of agents have been employed to treat viral diseases. Silver nanoparticles (AgNPs) have wide applications in biomedical fields due to their unique properties. The anti-BmNPV effect of AgNPs has been evaluated, however, there are insufficient studies concerning its toxicity to other organisms and the environment. We chemically synthesized biocompatible BSA-AgNPs with a diameter range of 2-4 nm and characterized their physical properties. The toxicity of AgNPs towards cells and larvae with different concentrations was examined; the results indicated a biofriendly effect on cells and larvae within specific concentration ranges. The SEM observation of the surface of BmNPV after treatment with AgNPs suggested that AgNPs could destroy the polyhedral structure, and the same result was obtained by Coomassie blue staining. Further assays confirmed the weakened virulence of AgNPs-treated BmNPV toward cells and larvae. AgNPs also could effectively inhibit the replication of BmNPV in infected cells and larvae. In summary, our research provides valuable data for the further development of AgNPs as an antiviral drug for sericulture.


Assuntos
Bombyx , Nanopartículas Metálicas , Nucleopoliedrovírus , Animais , Larva , Nanopartículas Metálicas/química , Prata/farmacologia
5.
Sci Rep ; 12(1): 9633, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688844

RESUMO

Reproductive dysfunctions (RDs) characterized by impairment in testicular parameters, and metabolic disorders such as insulin resistance and type 2 diabetes mellitus (T2DM) are on the rise among human immunodeficiency virus (HIV) patients under tenofovir disoproxil fumarate (TDF) and highly active antiretroviral therapy (HAART). These adverse effects require a nanoparticle delivery system to circumvent biological barriers and ensure adequate ARVDs to viral reservoir sites like testis. This study aimed to investigate the effect of TDF-loaded silver nanoparticles (AgNPs), TDF-AgNPs on sperm quality, hormonal profile, insulin-like growth factor 1 (IGF-1), and testicular ultrastructure in diabetic rats, a result of which could cater for the neglected reproductive and metabolic dysfunctions in HIV therapeutic modality. Thirty-six adult Sprague-Dawley rats were assigned to diabetic and non-diabetic (n = 18). T2DM was induced by fructose-streptozotocin (Frt-STZ) rat model. Subsequently, the rats in both groups were subdivided into three groups each (n = 6) and administered distilled water, TDF, and TDF-AgNP. In this study, administration of TDF-AgNP to diabetic rats significantly reduced (p < 0.05) blood glucose level (268.7 ± 10.8 mg/dL) from 429 ± 16.9 mg/dL in diabetic control and prevented a drastic reduction in sperm count and viability. More so, TDF-AgNP significantly increased (p < 0.05) Gonadotropin-Releasing Hormone (1114.3 ± 112.6 µg), Follicle Stimulating Hormone (13.2 ± 1.5 IU/L), Luteinizing Hormone (140.7 ± 15.2 IU/L), testosterone (0.2 ± 0.02 ng/L), and IGF-1 (1564.0 ± 81.6 ng/mL) compared to their respective diabetic controls (383.4 ± 63.3, 6.1 ± 1.2, 76.1 ± 9.1, 0.1 ± 0.01, 769.4 ± 83.7). Also, TDF-AgNP treated diabetic rats presented an improved testicular architecture marked with the thickened basement membrane, degenerated Sertoli cells, spermatogenic cells, and axoneme. This study has demonstrated that administration of TDF-AgNPs restored the function of hypothalamic-pituitary-gonadal axis, normalized the hormonal profile, enhanced testicular function and structure to alleviate reproductive dysfunctions in diabetic rats. This is the first study to conjugate TDF with AgNPs and examined its effects on reproductive indices, local gonadal factor and testicular ultrastructure in male diabetic rats with the potential to cater for neglected reproductive dysfunction in HIV therapeutic modality.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Infecções por HIV , Nanopartículas Metálicas , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Infecções por HIV/tratamento farmacológico , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Prata/farmacologia , Tenofovir/uso terapêutico , Testículo/metabolismo
6.
Braz J Biol ; 84: e261123, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35674603

RESUMO

Nature is gifted with a wide range of ornamental plants, which beautify and clean the nature. Due to its great aesthetic value, there is a need to protect these plants from a variety of biotic and abiotic stresses. Hibiscus rosa-sinensis (L.) is an ornamental plant and it is commonly known as China rose or shoeblack plant. It is affected by several fungal and bacterial pathogens. Current study was designed to isolate leaf spot pathogen of H. rosa-sinensis and its control using silver nanoparticles (AgNPs). Based on molecular and morphological features, the isolated leaf spot pathogen was identified as Aspergillus niger. AgNPs were synthesized in the leaf extract of Calotropis procera and characterized. UV-vis spectral analysis displayed discrete plasmon resonance bands on the surface of synthesized AgNPs, depicting the presence of aromatic amino acids. Fourier transform infrared spectroscopy (FTIR) described the presence of C-O, NH, C-H, and O-H functional groups, which act as stabilizing and reducing molecules. X-ray diffraction (XRD) revealed the average size (~32.43 nm) of AgNPs and scanning electron microscopy (SEM) depicted their spherical nature. In this study, in vitro and in vivo antifungal activity of AgNPs was investigated. In vitro antifungal activity analysis revealed the highest growth inhibition of mycelia (87%) at 1.0 mg/ml concentration of AgNPs. The same concentration of AgNPs tremendously inhibited the spread of disease on infected leaves of H. rosa-sinensis. These results demonstrated significant disease control ability of AgNPs and suggested their use on different ornamental plants.


Assuntos
Calotropis , Hibiscus , Nanopartículas Metálicas , Rosa , Antifúngicos , Calotropis/metabolismo , Hibiscus/metabolismo , Nanopartículas Metálicas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/metabolismo , Rosa/metabolismo , Prata/química , Prata/metabolismo , Prata/farmacologia
7.
Biomed Pharmacother ; 150: 113085, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35658239

RESUMO

The surface of silver nanoparticles (AgNPs) is characterized by high reactivity resulting in prooxidative and cytotoxic properties. These effects are observed both in normal and in cancer cells, which overexpress the Epidermal Growth Factor Receptor (EGFR). In our previous paper, we have demonstrated that, with the use of liposomes labeled with the Epidermal Growth Factor (EGF), it is possible to direct the toxic effect of AgNPs in EGFR-overexpressing cells. Unfortunately, the mechanism of uptake and toxicity induction by such liposomes is still unknown. Therefore, the aim of this study was to determine the impact of EGF-LipoAgNPs on certain genes related to endocytosis and toxicity induction by such liposomes in human lung (A549) and tongue (SCC-15) cancer cells. The siRNA knock-out gene method was used in this study to determine the engagement of EGFR in this process. The confocal microscopy study revealed that the number of liposomes in the cytoplasm of the A549EGFR- and SCC-15EGFR- cells was lowered by 51.99 × 103 RFU and 138.50 × 103 RFU, respectively, proving the crucial role of EGFR in the liposome uptake. Moreover, the expression of the SHH and ATM genes was significantly increased, whereas the expression of the NRF2 gene was decreased after the treatment with EGF-LipoAgNPs and native AgNPs. Furthermore, the expression of the CLTC, AP2M1, CAV1, and SH3GLB1 genes indicated that the tested liposomes are uptaken via the clathrin-dependent pathway with engagement of the AP-2 complex and endophilin in this process. Summarizing, the created targeted delivery system of AgNPs causes an increase in the prooxidative and toxic effect of such NPs and has an impact on endocytosis regulatory genes, especially those related to the clathrin-mediated endocytosis.


Assuntos
Nanopartículas Metálicas , Neoplasias , Linhagem Celular Tumoral , Clatrina/metabolismo , Endocitose , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Lipossomos/farmacologia , Nanopartículas Metálicas/toxicidade , Prata/farmacologia
8.
J Hazard Mater ; 435: 128965, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35650719

RESUMO

In this paper, the antibacterial 2D covalent organic framework (COFTGTp) containing guanidyl cation was synthesized and used as a carrier to deposit AgNPs on N and O groups to form nanocomposites to avoid AgNPs aggregation and achieve excellent antibacterial effect. The Ag content in Ag/COFTGTp was 10.3% determined by ICP. TEM can clearly observe that AgNPs were uniformly dispersed in COFTGTp. Ag/COFTGTp was stable after being evenly dispersed in water with low cytotoxicity and hemolysis rate to erythrocytes. In bacteriostatic study, the minimum inhibitory concentration of Ag/COFTGTp for E. coli and S. aureus were 100 µg/mL and 50 µg/mL, respectively. Finally, the morphology of the bacteria was observed by SEM, confirmed the main sterilization by Ag/COFTGTp was destroying the cell wall of the bacteria.


Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Antibacterianos/farmacologia , Escherichia coli , Guanidina/farmacologia , Íons , Nanopartículas Metálicas/toxicidade , Estruturas Metalorgânicas/farmacologia , Prata/farmacologia , Staphylococcus aureus
9.
Int J Nanomedicine ; 17: 2629-2641, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35721271

RESUMO

Purpose: In order to overcome the inflammatory response to bacterial infection during wound healing, we have fabricated an antibacterial and anti-inflammatory wound dressing based on polysaccharide riclin and silver nanoparticles (AgNPs). Methods: The riclin-AgNPs nanocomposite was developed by borohydride method and was characterized by UV-Vis, TEM, XRD, Zeta potential, DLS. In vitro, we assessed the cumulative release, antibacterial activities and cytotoxicity. In vivo, we examined the wound healing in mice wound infection experiment and inflammatory mediators using histological observations and gene expression analysis. Results: The riclin/AgNPs nanocomposite hydrogel exhibited nanosized orbicular particles with high purity and stability. In vitro, the riclin/AgNPs showed sustained release of AgNPs, effective suppression in pathogen growth and negligible toxicity toward mammalian fibroblasts and macrophage cells. In vivo, the riclin/AgNPs treatment leads to faster and smoother growth of fresh skin with suppressed expression of inflammatory mediators. Conclusion: The reported Riclin-AgNPs nanocomposite hydrogel showed both antibacterial and anti-inflammatory functions, which induce significantly accelerated wound healing, indicating great potential as a novel attractive wound dressing material.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Bandagens , Mediadores da Inflamação , Mamíferos , Camundongos , Testes de Sensibilidade Microbiana , Nanogéis , Prata/farmacologia
10.
J Biomed Nanotechnol ; 18(3): 928-938, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35715899

RESUMO

Moniliella wahieum Y12T (M. wahieum Y12T), a fungal isolated from biodiesel caused serious biodiesel contamination and resulting in biofouling and corrosion, especially during storage. Nanoparticles (NPs) composed of silver, copper, iron, and graphene or their binary mixtures were examined as environmental inhibitors against the fungus Moniliella wahieum Y12T, a biodiesel contaminant. Exposure of M. wahieum Y12T and Escherichia coli (E. coli) to low concentrations of Ag-based nanoparticles (from 0.01 to 0.05 mg mL-1) resulted in excellent growth inhibition. The half-maximal inhibitory concentration (IC50) of M. wahieum Y12T by La2O3 NPs was 138 times greater when compared with silver (AgO). The median effective concentration (EC50) of La2O3 NPs on E. coli was 379 times more than M. wahieum Y12T. At this same concentration, E. coli was uninhibited after exposure to the NPs. However, a fluorescein diacetate analysis showed the Ag-based NPs (including AgO, AgO-Fe3O4 and GO-Cu-AgO) significantly reduced the metabolic activity for both of the compared organisms. Compared with other metal oxide NPs, AgO and AgO-Fe3O4 NPs display strong bactericidal effect with higher stability and dispersibility, with the zeta potential of -22.27 mV and poly-dispersity index (PDI) values of 0.36. These results demonstrate the broad-spectrum biological inhibition that occurs with both Ag-based bimetallic and graphene oxide nanoparticles and the combined utilization of Ag-based NPs paves a new way for inhibits the biodegradation of biodiesel.


Assuntos
Grafite , Nanopartículas Metálicas , Antibacterianos/farmacologia , Bactérias , Biocombustíveis , Cobre , Escherichia coli , Fungos , Grafite/farmacologia , Nanopartículas Metálicas/toxicidade , Óxidos , Prata/farmacologia
11.
J Biomed Nanotechnol ; 18(3): 796-806, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35715900

RESUMO

The novel multifunctional electrospun textiles were fabricated by incorporating sheet-like kaolinite and silver nanoparticles (AgNps) into a polyurethane (PU) textile by using electrostatic spinning to promote wound-healing process. Threedimensional network of PU electrospun textiles offered an appropriate framework for loading kaolinite nanosheets and AgNps. Moreover, the kaolinite nanosheets healed bleeding wounds by accelerating plasma absorption, increasing blood cell concentrations, and stimulating coagulation factors. Furthermore, the AgNps killed microbes by destroying the cell membrane, while the deleterious effects were controlled by incorporation into the electrospun textile. The therapeutic effects of multifunctional electrospun textile in treating full-thickness abdominal wall defect were explored. The wound healing process could be accelerated via the textile by restoring the abdominal physiological environment, reducing the inflammatory response, and promoting collagen deposition, angiogenesis, and epithelization.


Assuntos
Nanopartículas Metálicas , Prata , Antibacterianos/farmacologia , Caulim/farmacologia , Nanopartículas Metálicas/uso terapêutico , Poliuretanos/farmacologia , Prata/farmacologia , Têxteis , Cicatrização
12.
Int J Med Mushrooms ; 24(6): 79-93, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35695640

RESUMO

Lichens produce a myriad of bioactive compounds that can be exploited as reducing and capping agents in the green process of synthesizing nanoparticles. In this study, we exploit a simple, environmentally safe method for synthesizing silver nanoparticles (AgNPs), using aqueous extracts of three lichen species (Lobaria pulmonaria, Ramalina farinacea, and Evernia prunastri) for the first time. Characterization showed that the three lichen species selected could be perfectly suitable as reducing agents to produce AgNPs. First, ultraviolet-visible spectroscopy confirmed the presence of metallic silver with a maximum absorbance at 425 nm. Second, Fourier transform infrared spectroscopy analysis confirmed the chemical compounds involved in reduction. Third, the elemental composition of AgNPs was illustrated by energy dispersive X-ray spectroscopy. Finally, scanning electron microscopy images displayed the size and shape of biosynthesized particles. The prepared extracts containing AgNPs showed high contents of phenolic compounds and high antioxidant activities on three assays (DPPH, ferric reducing power, and chelating power). Moreover, since bacteria are developing resistance to many common antibiotics, AgNPs produced in an environmentally safe method are an interesting replacement. The antibacterial assessment revealed more effective activity against Gram-negative than Gram-positive bacteria and a bactericidal effect against all strains tested. In this study, we present a pioneering evaluation of acetylcholinesterase inhibition by lichen-based AgNPs. The three extracts exhibited strong enzyme inhibition, with IC50 values of 3.46 ± 0.09, 3.59 ± 0.02, and 4.34 ± 0.03 mg/mL for L. pulmonaria, R. farinacea, and E. prunastri, respectively. The green approach presented would encourage the nontoxic production of AgNPs, suggesting pharmaceutical applications.


Assuntos
Líquens , Nanopartículas Metálicas , Acetilcolinesterase , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Prata/química , Prata/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Braz J Biol ; 84: e261262, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35703629

RESUMO

Promising bioactivities of silver nanoparticles SNP urged researchers of different specialties to evaluate their field-respective activities. Bioactivity towards agricultural pests were the subject of limited publications. In the current study, SNP were synthesized and miticidal activity was evaluated towards old world date mite Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae) and an associated predatory mite Neoseiulus barkeri Hughes (Phytoseiidae). Under laboratory conditions, SNP displayed significantly higher activity towards O. afrasiaticus (LC50 was 39.7 µg/mL) than N. barkeri (LC50 was 1587.9 µg/mL) which accounts for about 40 folds of selectivity against the pest. SNP exhibited ovicidal activity against laid eggs of O. afrasiaticus (LC50 was 67.8 µg/mL). In field, SNP (at 216 µg/mL) achieved slightly higher efficiency than in laboratory study, 86.5% of population reduction of O. afrasiaticus was achieved and only 18.5% of N. barkeri population was affected. SNP suppressed hatching of 57.1% of laid eggs of O. afrasiaticus. Residues of silver were determined using ICP-OES spectrometry. Initial residues reached 1.83 µg/mL after application then declined with time passing. Estimated daily intake (EDI) reached 1.28 µg/kg/day, calculated for the highest residues obtained and the highest consumption rate of date in the world. Hazard index (Hi) was 0.17 in average. The obtained level of residues appeared to be safe in terms of acute and chronic toxicity references.


Assuntos
Nanopartículas Metálicas , Ácaros , Phoeniceae , Tetranychidae , Animais , Nanopartículas Metálicas/toxicidade , Controle Biológico de Vetores , Comportamento Predatório , Medição de Risco , Prata/farmacologia
14.
An Acad Bras Cienc ; 94(2): e20201661, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35703691

RESUMO

This study aimed to estimate the allelopathic intensity of four Asteraceae invasive plant species (IPS), including Conyza canadensis (L.) Cronq., Erigeron annuus (L.) Pers., Bidens pilosa (L.), and Aster subulatus Michx., by testing the effect of leaf extracts on the seed germination and seedling growth (SGe and SGr) of lettuce (Lactuca sativa L.) in combination with two particle sizes of silver nanoparticles. These four IPS decreased the germination of lettuce seeds but increased the growth of lettuce seedlings. The allelopathic intensity of the four IPS decreased in the following order: B. pilosa > C. canadensis > E. annuus > A. subulatus. Silver nanoparticles decreased the SGe and SGr of lettuce. The 20 nm silver nanoparticles affected the competition intensity for water and the absorption of inorganic salts by lettuce more intensively than the 80 nm nanoparticles. Silver nanoparticles intensify the allelopathic intensity of the four invasive plant species on the SGe and SGr of lettuce. The allelopathic intensity of B. pilosa was higher than that of the other three IPS when they were polluted with silver nanoparticles. Thus, silver nanoparticles could facilitate the invasion process of the four IPS, particularly B. pilosa, via an increase in the intensity of allelopathy.


Assuntos
Asteraceae , Nanopartículas Metálicas , Alelopatia , Germinação , Espécies Introduzidas , Alface , Extratos Vegetais/farmacologia , Plântula , Prata/farmacologia
15.
World J Microbiol Biotechnol ; 38(7): 119, 2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35644864

RESUMO

Long-term antibiotic treatment results in the spread of multi-drug resistance in Pseudomonas aeruginosa that complicates treatment. Anti-virulence agents can be viewed as alternative options that cripple virulence factors of the bacteria to facilitate their elimination by the host immunity. The use of nanoparticles in the inhibition of P. aeruginosa virulence factors is a promising strategy. This study aims to study the effect of metformin (MET), metformin nano emulsions (MET-NEs), silver metformin nano emulsions (Ag-MET-NEs) and silver nanoparticles (AgNPs) on P. aeruginosa virulence factors' expression. The phenotypic results showed that MET-NEs had the highest virulence inhibitory activity. However, concerning RT-PCR results, all tested agents significantly decreased the expression of quorum sensing regulatory genes of P. aeruginosa; lasR, lasI, pqsA, fliC, exoS and pslA, with Ag-MET-NEs being the most potent one, however, it failed to protect mice from P. aeruginosa pathogenesis. MET-NEs showed the highest protective activity against pseudomonal infection in vivo. Our findings support the promising use of nano formulations particularly Ag-MET-NEs as an alternative against multidrug resistant pseudomonal infections via inhibition of virulence factors and quorum sensing gene expression.


Assuntos
Nanopartículas Metálicas , Metformina , Animais , Emulsões , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Camundongos , Pseudomonas aeruginosa , Prata/farmacologia , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
16.
Sci Rep ; 12(1): 9452, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676412

RESUMO

Pseudomonas aeruginosa (P. aeruginosa) is an important opportunistic pathogen that is responsible for many clinical infections in both animals and humans. This study aimed to detect the prevalence of P. aeruginosa in dairy farm's that possess a great importance to dairy industry where it shares in milk spoilage. Evaluation of the efficacy of commonly used disinfectants to control the pathogen in dairy environment and finding a way to overcome high resistance to the used agents. Samples (n = 250) were collected from different environmental components, milk, and milkers' hands. Pathogens were isolated, biofilm was detected and their sensitivity against two commonly used disinfectants and against silver nanoparticles and Virokill AgNPs at different concentrations and contact times were tested. The pathogen significantly prevailed in milk samples (70.0%, P < 0.001). 50 out 74 isolates were biofilm-forming that was significantly obtained from environment (71.8%, P < 0.001). P. aeruginosa showed variable degree of resistance to tested disinfectants but it was significantly sensitive to Virokill AgNPs (200/1000) mg/l at exposure time 24 h (P < 0.001). It was concluded that using Virokill AgNPs in regular sanitation and disinfection of dairy farms, this helps the control of P. aeruginosa subsequently increasing milk quality and improving dairy industry and protecting human health.


Assuntos
Desinfetantes , Nanopartículas Metálicas , Animais , Antibacterianos/farmacologia , Biofilmes , Desinfetantes/farmacologia , Fazendas , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Prata/farmacologia
17.
Molecules ; 27(11)2022 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-35684436

RESUMO

Metal-organic frameworks (MOFs), which have become popular in recent years as excellent carriers of drugs and biomimetic materials, have provided new research ideas for fighting pathogenic bacterial infections. Although various antimicrobial metal ions can be added to MOFs with physical methods, such as impregnation, to inhibit bacterial multiplication, this is inefficient and has many problems, such as an uneven distribution of antimicrobial ions in the MOF and the need for the simultaneous addition of large doses of metal ions. Here, we report on the use of MIL-101(Fe)@Ag with efficient metal-ion release and strong antimicrobial efficiency for co-sterilization. Fe-based MIL-101(Fe) was synthesized, and then Ag+ was uniformly introduced into the MOF by the substitution of Ag+ for Fe3+. Scanning electron microscopy, powder X-ray diffraction (PXRD) Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to investigate the synthesized MIL-101(Fe)@Ag. The characteristic peaks of MIL-101(Fe) and silver ions could be clearly seen in the PXRD pattern. Comparing the diffraction peaks of the simulated PXRD patterns clearly showed that MIL-101(Fe) was successfully constructed and silver ions were successfully loaded into MIL-101(Fe) to synthesize an MOF with a bimetallic structure, that is, the target product MIL-101(Fe)@Ag. The antibacterial mechanism of the MOF material was also investigated. MIL-101(Fe)@Ag exhibited low cytotoxicity, so it has potential applications in the biological field. Overall, MIL-101(Fe)@Ag is an easily fabricated structurally engineered nanocomposite with broad-spectrum bactericidal activity.


Assuntos
Anti-Infecciosos , Estruturas Metalorgânicas , Nanocompostos , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Contenção de Riscos Biológicos , Íons , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Prata/farmacologia
18.
Cells ; 11(9)2022 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-35563885

RESUMO

Wheat is vulnerable to numerous diseases; on the other hand, silver nanoparticles (AgNPs) exhibit a sterilizing action. To understand the combined effects of AgNPs with nicotinate and potassium nitrate (KNO3) for plant growth and sterilization, a gel- and label-free proteomics was performed. Root weight was promoted by the treatment of AgNPs mixed with nicotinate and KNO3. From a total of 5557 detected proteins, 90 proteins were changed by the mixture of AgNPs, nicotinate, and KNO3; among them, 25 and 65 proteins increased and decreased, respectively. The changed proteins were mainly associated with redox and biotic stress in the functional categorization. By immunoblot analysis, the abundance of glutathione reductase/peroxiredoxin and pathogen-related protein three significantly decreased with the mixture. Furthermore, from the changed proteins, the abundance of starch synthase and lipoxygenase significantly increased and decreased, respectively. Through biochemical analysis, the starch contents increased with the mixture. The application of esculetin, which is a lipoxygenase inhibitor, increased the weight and length of the root. These results suggest that the AgNPs mixed with nicotinate and KNO3 cause positive effects on wheat seedlings by regulating pathogen-related protein and reactive-oxygen species scavenging. Furthermore, increasing starch and decreasing lipoxygenase might improve wheat growth.


Assuntos
Compostos Inorgânicos , Nanopartículas Metálicas , Niacina , Compostos Inorgânicos/farmacologia , Lipoxigenases , Nanopartículas Metálicas/química , Niacina/farmacologia , Proteômica , Prata/farmacologia , Amido , Triticum
19.
Cells ; 11(9)2022 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-35563888

RESUMO

Guided tissue regeneration and guided bone regeneration membranes are some of the most common products used for bone regeneration in periodontal dentistry. The main disadvantage of commercially available membranes is their lack of bone cell stimulation and easy bacterial colonization. The aim of this work was to design and fabricate a new membrane construct composed of electrospun poly (D,L-lactic acid)/poly (lactic-co-glycolic acid) fibers sonocoated with layers of nanoparticles with specific properties, i.e., hydroxyapatite and bimetallic nanocomposite of zinc oxide-silver. Thus, within this study, four different variants of biomaterials were evaluated, namely: poly (D,L-lactic acid)/poly (lactic-co-glycolic acid) biomaterial, poly(D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano hydroxyapatite biomaterial, poly (D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano zinc oxide-silver biomaterial, and poly (D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano hydroxyapatite/nano zinc oxide-silver biomaterial. First, it was demonstrated that the wettability of biomaterials-a prerequisite property important for ensuring desired biological response-was highly increased after the sonocoating process. Moreover, it was indicated that biomaterials composed of poly (D,L-lactic acid)/poly (lactic-co-glycolic acid) with or without a nano hydroxyapatite layer allowed proper osteoblast growth and proliferation, but did not have antibacterial properties. Addition of a nano zinc oxide-silver layer to the biomaterial inhibited growth of bacterial cells around the membrane, but at the same time induced very high cytotoxicity towards osteoblasts. Most importantly, enrichment of this biomaterial with a supplementary underlayer of nano hydroxyapatite allowed for the preservation of antibacterial properties and also a decrease in the cytotoxicity towards bone cells, associated with the presence of a nano zinc oxide-silver layer. Thus, the final structure of the composite poly (D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano hydroxyapatite/nano zinc oxide-silver seems to be a promising construct for tissue engineering products, especially guided tissue regeneration/guided bone regeneration membranes. Nevertheless, additional research is needed in order to improve the developed construct, which will simultaneously protect the biomaterial from bacterial colonization and enhance the bone regeneration properties.


Assuntos
Nanopartículas Metálicas , Óxido de Zinco , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Durapatita/farmacologia , Osteoblastos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Prata/farmacologia , Óxido de Zinco/farmacologia
20.
Sci Rep ; 12(1): 7193, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35505071

RESUMO

The current Coronavirus Disease 19 (COVID-19) pandemic has exemplified the need for simple and efficient prevention strategies that can be rapidly implemented to mitigate infection risks. Various surfaces have a long history of antimicrobial properties and are well described for the prevention of bacterial infections. However, their effect on many viruses has not been studied in depth. In the context of COVID-19, several surfaces, including copper (Cu) and silver (Ag) coatings have been described as efficient antiviral measures that can easily be implemented to slow viral transmission. In this study, we detected antiviral properties against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) on surfaces, which were coated with Cu by magnetron sputtering as thin Cu films or as Cu/Ag ultrathin bimetallic nanopatches. However, no effect of Ag on viral titers was observed, in clear contrast to its well-known antibacterial properties. Further enhancement of Ag ion release kinetics based on an electrochemical sacrificial anode mechanism did not increase antiviral activity. These results clearly demonstrate that Cu and Ag thin film systems display significant differences in antiviral and antibacterial properties which need to be considered upon implementation.


Assuntos
COVID-19 , Prata , Antibacterianos/química , Antibacterianos/farmacologia , Antivirais/farmacologia , Cobre/química , Cobre/farmacologia , Humanos , SARS-CoV-2 , Prata/química , Prata/farmacologia
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