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1.
Molecules ; 26(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206375

RESUMO

This research aimed to enhance the antibacterial activity of silver nanoparticles (AgNPs) synthesized from silver nitrate (AgNO3) using aloe vera extract. It was performed by means of incorporating AgNPs on an activated carbon nanoparticle (ACNPs) under ultrasonic agitation (40 kHz, 2 × 50 watt) for 30 min in an aqueous colloidal medium. The successful AgNPs synthesis was clarified with both Ultraviolet-Visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectrophotometers. The successful AgNPs-ACNPs incorporation and its particle size analysis was performed using Transmission Electron Microscope (TEM). The brown color suspension generation and UV-Vis's spectra maximum wavelength at around 480 nm confirmed the existence of AgNPs. The particle sizes of the produced AgNPs were about 5 to 10 nm in the majority number, which collectively surrounded the aloe vera extract secondary metabolites formed core-shell like nanostructure of 8.20 ± 2.05 nm in average size, while ACNPs themselves were about 20.10 ± 1.52 nm in average size formed particles cluster, and 48.00 ± 8.37 nm in average size as stacking of other particles. The antibacterial activity of the synthesized AgNPs and AgNPs-immobilized ACNPs was 57.58% and 63.64%, respectively (for E. coli); 61.25%, and 93.49%, respectively (for S. aureus). In addition, when the AgNPs-immobilized ACNPs material was coated on the cotton and polyester fabrics, the antibacterial activity of the materials changed, becoming 19.23% (cotton; E. coli), 31.73% (polyester; E. coli), 13.36% (cotton; S. aureus), 21.15% (polyester; S. aureus).


Assuntos
Antibacterianos , Carvão Vegetal , Escherichia coli/crescimento & desenvolvimento , Química Verde , Nanopartículas Metálicas/química , Prata , Staphylococcus aureus/crescimento & desenvolvimento , Têxteis , Aloe/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Carvão Vegetal/química , Carvão Vegetal/farmacologia , Extratos Vegetais/química , Prata/química , Prata/farmacologia
2.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200653

RESUMO

Cushioning and antibacterial packaging are the requirements of the storage and transportation of fruits and vegetables, which are essential for reducing the irreversible quality loss during the process. Herein, the composite of carboxymethyl nanocellulose, glycerin, and acrylamide derivatives acted as the shell and chitosan/AgNPs were immobilized in the core by using coaxial 3D-printing technology. Thus, the 3D-printed cushioning-antibacterial dual-function packaging aerogel with a shell-core structure (CNGA/C-AgNPs) was obtained. The CNGA/C-AgNPs packaging aerogel had good cushioning and resilience performance, and the average compression resilience rate was more than 90%. Although AgNPs was slowly released, CNGA/C-AgNPs packaging aerogel had an obvious antibacterial effect on E. coli and S. aureus. Moreover, the CNGA/C-AgNPs packaging aerogel was biodegradable. Due to the customization capabilities of 3D-printing technology, the prepared packaging aerogel can be adapted to more application scenarios by accurately designing and regulating the microstructure of aerogels, which provides a new idea for the development of food intelligent packaging.


Assuntos
Antibacterianos/química , Celulose/química , Embalagem de Alimentos/métodos , Géis/química , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Quitosana/química , Escherichia coli/efeitos dos fármacos , Impressão Tridimensional , Prata/química , Staphylococcus aureus/efeitos dos fármacos
3.
Int J Mol Sci ; 22(9)2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-34063704

RESUMO

Carnivorous plants are exemplary natural sources of secondary metabolites with biological activity. However, the therapeutic antimicrobial potential of these compounds is limited due to intrinsic resistance of selected bacterial pathogens, among which Pseudomonas aeruginosa represents an extreme example. The objective of the study was to overcome the intrinsic resistance of P. aeruginosa by combining silver nanoparticles (AgNPs) with secondary metabolites from selected carnivorous plant species. We employed the broth microdilution method, the checkerboard titration technique and comprehensive phytochemical analyses to define interactions between nanoparticles and active compounds from carnivorous plants. It has been confirmed that P. aeruginosa is resistant to a broad range of secondary metabolites from carnivorous plants, i.e., naphthoquinones, flavonoids, phenolic acids (MBC = 512 µg mL-1) and only weakly sensitive to their mixtures, i.e., extracts and extracts' fractions. However, it was shown that the antimicrobial activity of extracts and fractions with a significant level of naphthoquinone (plumbagin) was significantly enhanced by AgNPs. Our studies clearly demonstrated a crucial role of naphthoquinones in AgNPs and extract interaction, as well as depicted the potential of AgNPs to restore the bactericidal activity of naphthoquinones towards P. aeruginosa. Our findings indicate the significant potential of nanoparticles to modulate the activity of selected secondary metabolites and revisit their antimicrobial potential towards human pathogenic bacteria.


Assuntos
Planta Carnívora/química , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/efeitos adversos , Antibacterianos/química , Farmacorresistência Bacteriana/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Naftoquinonas/efeitos adversos , Naftoquinonas/química , Naftoquinonas/farmacologia , Extratos Vegetais/química , Pseudomonas aeruginosa/patogenicidade , Metabolismo Secundário/efeitos dos fármacos , Prata/química , Espectrofotometria Ultravioleta
4.
Molecules ; 26(10)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34065879

RESUMO

The modification of medical devices is an area that has attracted a lot of attention in recent years; particularly, those developments which search to modify existing devices to render them antimicrobial. Most of these modifications involve at least two stages (modification of the base material with a polymer graft and immobilization of an antimicrobial agent) which are both time-consuming and complicate synthetic procedures; therefore, as an improvement, this project sought to produce antimicrobial silicone (PDMS) in a single step. Using gamma radiation as both an energy source for polymerization initiation and as a source of reducing agents in solution, PDMS was simultaneously grafted with acrylic acid and ethylene glycol dimethacrylate (AAc:EGDMA) while producing antimicrobial silver nanoparticles (AgNPs) onto the surface of the material. To obtain reproducible materials, experimental variables such as the effect of the dose, the intensity of radiation, and the concentration of the silver salt were evaluated, finding the optimal reaction conditions to obtain materials with valuable properties. The characterization of the material was performed using electronic microscopy and spectroscopic techniques such as 13C-CPMAS-SS-NMR and FTIR. Finally, these materials demonstrated good antimicrobial activity against S. aureus while retaining good cell viabilities (above 90%) for fibroblasts BALB/3T3.


Assuntos
Acrilatos/química , Antibacterianos/química , Materiais Biocompatíveis/química , Raios gama , Nanopartículas Metálicas/química , Polimerização/efeitos da radiação , Silicones/química , Prata/química , Animais , Células 3T3 BALB , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Metacrilatos/química , Camundongos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
5.
Molecules ; 26(9)2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-34063685

RESUMO

Multidrug resistant bacteria create a challenging situation for society to treat infections. Multidrug resistance (MDR) is the reason for biofilm bacteria to cause chronic infection. Plant-based nanoparticles could be an alternative solution as potential drug candidates against these MDR bacteria, as many plants are well known for their antimicrobial activity against pathogenic microorganisms. Spondias mombin is a traditional plant which has already been used for medicinal purposes as every part of this plant has been proven to have its own medicinal values. In this research, the S. mombin extract was used to synthesise AgNPs. The synthesized AgNPs were characterized and further tested for their antibacterial, reactive oxygen species and cytotoxicity properties. The characterization results showed the synthesized AgNPs to be between 8 to 50 nm with -11.52 of zeta potential value. The existence of the silver element in the AgNPs was confirmed with the peaks obtained in the EDX spectrometry. Significant antibacterial activity was observed against selected biofilm-forming pathogenic bacteria. The cytotoxicity study with A. salina revealed the LC50 of synthesized AgNPs was at 0.81 mg/mL. Based on the ROS quantification, it was suggested that the ROS production, due to the interaction of AgNP with different bacterial cells, causes structural changes of the cell. This proves that the synthesized AgNPs could be an effective drug against multidrug resistant bacteria.


Assuntos
Anacardiaceae/química , Antibacterianos/farmacologia , Biofilmes , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/química , Animais , Artemia , Bactérias/efeitos dos fármacos , Química Verde , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Nanomedicina , Extratos Vegetais/farmacologia , Folhas de Planta/química , Espécies Reativas de Oxigênio , Raios Ultravioleta
6.
BMC Plant Biol ; 21(1): 260, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34090329

RESUMO

BACKGROUND: Recently, numerous investigations have been done to study graphene and silver nanoparticle in the fields of agriculture and medicine. In the present study, the green synthesis of nanoparticles with two concentrations (0, 40, 60 mM) and their effect on the molecular and biochemical biosynthesis pathway of rosmarinic acid in a new method, low cost, and safe for the environment has been investigated. The transcript levels of key genes in the rosmarinic acid biosynthesis pathway (Tyrosine aminotransferase, rosmarinic acid synthase, and phenylalanine-ammonia lyase) were studied using real-time quantitative polymerase chain reaction. Then, the rosmarinic acid content was evaluated using HPLC. RESULTS: The results showed that a concentration-dependent manner was observed in treated plants. At the biochemical level, the use of nanocomposites at concentration of 40 mM showed higher soluble carbohydrate (37%), flavonoids (21%), total phenol (35%) as well as total protein (47%) compared to the control plants. HPLC results showed that rosmarinic acid content in the treated plants with a low concentration of nanocomposite (40 mM) was more affected than plants treated with a high concentration of nanocomposite (60 mM) (26%) and also compared to other treatments. At the molecular level, the result showed that Tyrosine aminotransferase and rosmarinic acid synthase gene expression was positively correlated with both silver nanoparticle concentrations and nanocomposite treatments, but phenylalanine-ammonia lyase gene expression was positively correlated only with nanocomposite at 40 mM concentration. CONCLUDE: It can conclude that the nanocomposite at low concentration is more likely to induce molecular and biochemical parameters. And also, in the rosmarinic acid biosynthesis pathway, the Tyrosine aminotransferase -derived pathway is more efficient than the phenylalanine-ammonia lyase -derived pathway by causing a nano-elicitor. Therefore, it was concluded that studied elicitor at low concentration, can create plants with higher production capacity.


Assuntos
Cinamatos/metabolismo , Depsídeos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Grafite/química , Melissa/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/química , Microscopia Eletrônica de Varredura , Folhas de Planta/química , Folhas de Planta/ultraestrutura
7.
Int J Nanomedicine ; 16: 3555-3564, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079248

RESUMO

Purpose: A silver nanoparticle obtained by reducing salts with solid dispersion of curcumin (130 nm, 0.081 mg mL-1) was used to counteract against the toxic - edematogenic, myotoxic, and neurotoxic - effects of Philodryas olfersii venom. Methods: The edematogenic effect was evaluated by plasma extravasation in rat dorsal skin after injection of 50 µg per site of venom alone or preincubated with 1, 10, and 100 µL of AgNPs; the myotoxicity was evaluated by measuring the creatine kinase released into the organ-bath before the treatment and at the end of each experiment; and neurotoxicity was evaluated in chick biventer cervicis using the conventional myographic technique, face to the exogenous acetylcholine (ACh) and potassium chloride (KCl) added into the bath before the treatment and after each experiment. Preliminarily, a concentration-response curve of AgNPs was carried out to select the concentration to be used for neutralizing assays, which consists of neutralizing the venom-induced neuromuscular paralysis and edema by preincubating AgNPs with venom for 30 min. Results: The P. olfersii venom-induced edema (n=6) and a complete neuromuscular blockade (n=4) that includes the total and unrecovered block of ACh and KCl contractures. AgNPs produced a concentration-dependent decrease the venom-induced edema (n=6) from 223.3% to 134.4% and to 100.5% after 10 and 100 µL AgNPs-preincubation, respectively. The preincubation of venom with AgNPs (1 µL; n=6) was able to maintain 46.5 ± 10.9% of neuromuscular response under indirect stimuli, 39.2 ± 9.7% of extrinsic nicotinic receptors functioning in absence of electrical stimulus and 28.3 ± 8.1% of responsiveness to potassium on the sarcolemmal membrane. The CK release was not affected by any experimental protocol which was like control. Conclusion: AgNPs interact with constituents of P. olfersii venom responsible for the edema-forming activity and neuromuscular blockade, but not on the sarcolemma membrane-acting constituents. The protective effect of the studied AgNPs on avian preparation points out to molecular targets as intrinsic and extrinsic nicotinic receptors.


Assuntos
Colubridae , Nanopartículas Metálicas , Prata/química , Prata/farmacologia , Venenos de Serpentes/antagonistas & inibidores , Venenos de Serpentes/toxicidade , Animais , Galinhas , Creatina Quinase/metabolismo , Curcumina/química , Relação Dose-Resposta a Droga , Edema , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Neurotoxinas/antagonistas & inibidores , Neurotoxinas/toxicidade , Nervo Frênico/efeitos dos fármacos , Ratos
8.
Int J Nanomedicine ; 16: 3599-3612, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079252

RESUMO

Purpose: Vernonia amygdalina (VA) is a traditional African herbal medicine that has been reported to possess anticancer properties. However, the anticancer properties of VA silver nanoparticles have not been studied. The aim of the study was to examine and evaluate the anticancer activities of VA leaf extracts and VA silver nanoparticles on the human breast cancer cell line, MCF-7. Methods: VA leaves were extracted using sequential extraction assisted with ultrasound using three different solvents: ethanol, 50% ethanol, and deionized water. The silver nanoparticles were synthesised with VA aqueous extract. Results: The ethanol extract and VA silver nanoparticles inhibit MCF-7 cell proliferation with an average half-maximal inhibitory concentration (IC50) value of 67µg/mL and 6.11µg/mL, respectively, after 72 hours of treatment. The ethanol extract and VA silver nanoparticles also caused G1 phase cell cycle arrest, induced apoptosis and nuclear fragmentation in MCF-7 cells. Conclusion: VA ethanol extracts and VA silver nanoparticles decreased the cell viability in MCF-7 cells in a time and dose-dependent manner by inducing apoptosis and causing DNA damage. Further research is needed to elucidate the mechanism of action of VA leaf extracts and VA silver nanoparticles. This study is the first to report on the anticancer activity of VA silver nanoparticles in MCF-7 cells.


Assuntos
Nanopartículas Metálicas , Extratos Vegetais/química , Folhas de Planta/química , Prata/química , Prata/farmacologia , Vernonia/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Sintética , Dano ao DNA , Química Verde , Humanos , Células MCF-7 , Solventes/química
9.
Molecules ; 26(9)2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066875

RESUMO

The main core of wound treatment is cell growth and anti-infection. To accelerate the proliferation of fibroblasts in the wound and prevent wound infections, various strategies have been tried. It remains a challenge to obtain good cell proliferation and antibacterial effects. Here, human hair kerateine (HHK)/poly(ethylene oxide) (PEO)/poly(vinyl alcohol) (PVA) nanofibers were prepared using cysteine-rich HHK, and then, silver nanoparticles (AgNPs) were in situ anchored in the sulfur-containing amino acid residues of HHK. After the ultrasonic degradation test, HHK/PEO/PVA nanofibrous mats treated with 0.005-M silver nitrate were selected due to their relatively complete structures. It was observed by TEM-EDS that the sulfur-containing amino acids in HHK were the main anchor points of AgNPs. The results of FTIR, XRD and the thermal analysis suggested that the hydrogen bonds between PEO and PVA were broken by HHK and, further, by AgNPs. AgNPs could act as a catalyst to promote the thermal degradation reaction of PVA, PEO and HHK, which was beneficial for silver recycling and medical waste treatment. The antibacterial properties of AgNP-HHK/PEO/PVA nanofibers were examined by the disk diffusion method, and it was observed that they had potential antibacterial capability against Gram-positive bacteria, Gram-negative bacteria and fungi. In addition, HHK in the nanofibrous mats significantly improved the cell proliferation of NIH3T3 cells. These results illustrated that the AgNP-HHK/PEO/PVA nanofibrous mats exhibited excellent antibacterial activity and the ability to promote the proliferation of fibroblasts, reaching our target applications.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Proliferação de Células/efeitos dos fármacos , Queratinas Específicas do Cabelo/química , Nanopartículas Metálicas/química , Nanofibras/química , Polietilenoglicóis/química , Álcool de Polivinil/química , Prata/química , Animais , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Cabelo/química , Humanos , Ligação de Hidrogênio , Camundongos , Testes de Sensibilidade Microbiana , Células NIH 3T3 , Nitrato de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
10.
Nat Commun ; 12(1): 3331, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099682

RESUMO

The rapid emergence of drug resistant Staphylococcus aureus (S. aureus) poses a serious threat to public health globally. Silver (Ag)-based antimicrobials are promising to combat antibiotic resistant S. aureus, yet their molecular targets are largely elusive. Herein, we separate and identify 38 authentic Ag+-binding proteins in S. aureus at the whole-cell scale. We then capture the molecular snapshot on the dynamic action of Ag+ against S. aureus and further validate that Ag+ could inhibit a key target 6-phosphogluconate dehydrogenase through binding to catalytic His185 by X-ray crystallography. Significantly, the multi-target mode of action of Ag+ (and nanosilver) endows its sustainable antimicrobial efficacy, leading to enhanced efficacy of conventional antibiotics and resensitization of MRSA to antibiotics. Our study resolves the long-standing question of the molecular targets of silver in S. aureus and offers insights into the sustainable bacterial susceptibility of silver, providing a potential approach for combating antimicrobial resistance.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Nanopartículas Metálicas/química , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Cristalografia por Raios X , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Fosfogluconato Desidrogenase/efeitos dos fármacos , Proteômica , Prata/química , Nitrato de Prata , Infecções Estafilocócicas
11.
Food Chem ; 360: 130002, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33975071

RESUMO

The European Food Safety Authority has published a guidance regarding risk assessment of nanomaterials in food and feed. Following these recommendations, an in vitro gastrointestinal digestion has been applied to study the biopersistence of TiO2 and Ag NPs in standards, molluscs and surimi. TiO2 NPs standards and TiO2 NPs/ TiO2 microparticles from E171 were not found to be degraded. Ag NPs proved to be more degradable than TiO2 NPs, but the biopersistence rates were higher than 12%, which means that Ag NPs are also biopersistent. Findings for seafood are quite similar to those obtained for TiO2 NPs and Ag NPs standards, although the calculation of the biopersistence rate proposed by the EFSA was not found to be straightforward for foodstuff (the use of the NPs concentration in the sample instead of the NPs concentration at initial time (sample mixed with the gastric solution before enzymatic hydrolysis) has been proposed.


Assuntos
Nanopartículas Metálicas/química , Prata/química , Titânio/química , Humanos , Hidrólise , Nanopartículas Metálicas/toxicidade , Medição de Risco
12.
Food Chem ; 360: 130006, 2021 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33984559

RESUMO

In this paper, a novel ratiometric electrochemical sensor for carbendazim (CBZ) detection was constructed by a composite of MXene@Ag nanoclusters and amino-functionalized multi-walled carbon nanotubes (MXene@AgNCs/NH2-MWCNTs). The Ag nanoclusters (AgNCs) embedded in the MXene not only could inhibit the aggregation of MXene flakes and enhance the electrocatalytic ability, but also serve as an internal reference probe for the ratiometric electrochemical detection. Moreover, the introduction of NH2-MWCNTs can further improve the electrochemical signals of CBZ and Ag, resulting in the enhanced signal amplification and higher sensitivity. Based on these characteristics of the MXene@AgNCs/NH2-MWCNTs composite, the proposed sensor exhibits a favorable linear relationship between ICBZ/IAgNCs and the concentration of CBZ ranging from 0.3 nM to 10 µM and a low limit of detection of 0.1 nM. Moreover, the proposed ratiometric electrochemical sensing platform also demonstrates high selectivity, good reproducibility, secular stability, and satisfactory applicability in vegetable samples.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Fungicidas Industriais/análise , Prata/química , Verduras/química , Técnicas Eletroquímicas/métodos , Limite de Detecção , Nanotubos de Carbono , Reprodutibilidade dos Testes
13.
Food Chem ; 361: 130091, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34029902

RESUMO

Migration of silver nanoparticles (AgNPs) from food containers (FCs) has been assessed for the first time using a screening method previously validated. Migration was evaluated using water and 3% acetic acid as food simulants (FSs), from 20 to 70 °C at contact times of 2 h and 10 days. Total and migrated Ag were determined by inductively coupled plasma-mass spectrometry (ICP-MS) in the FCs and FSs, respectively. Then, the screening method was validated, and probability of detection (POD) curves were constructed in both FSs to characterize the response to AgNPs. The results provided by the present screening method showed no release of AgNPs. The FSs in contact with FCs were spiked at levels above, inside and below the unreliability region, with a reliability rate (RLR) of 0.90. Asymmetric flow field flow fractionation coupled to inductively coupled plasma mass-spectrometry (AF4-ICP-MS) was used for confirmative analyses.


Assuntos
Embalagem de Alimentos , Espectrometria de Massas/métodos , Nanopartículas Metálicas/química , Prata/análise , Prata/química , Ácido Acético/química , Fracionamento por Campo e Fluxo , Tamanho da Partícula , Reprodutibilidade dos Testes , Fatores de Tempo , Água/química
14.
Food Chem ; 359: 129912, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33934027

RESUMO

The emerging fruit wastes valorization tactic is a strategy for minimizing the dependence on toxic solvents and chemicals commonly used in the preparation of nanoparticles (NPs). Furthermore, the NPs have exhibited promising antimicrobial applications against foodborne pathogens. Hence, a timely review of this topic is in demand to provide a clear insight into the subject. In this article, the synthesis of silver and gold NPs from fruit wastes and their antimicrobial application against foodborne pathogens are reviewed. The extraction method, mechanism of NPs formation and influences of various experimental parameters on the shape and size of the NPs are described. In the second part of the article, antimicrobial activities against foodborne pathogens regarding the nature, optimum composition, surface structure, synergism and morphology of the NPs are reviewed. Furthermore, challenges and future trends related to the synthesis and antimicrobial application of fruit wastes-mediated NPs are discussed.


Assuntos
Antibacterianos/farmacologia , Doenças Transmitidas por Alimentos/prevenção & controle , Frutas , Ouro/química , Nanopartículas Metálicas/química , Prata/química , Antibacterianos/química , Frutas/microbiologia , Humanos
15.
Food Chem ; 359: 129859, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33957323

RESUMO

This study aimed to investigate the release of silver ions from the packaging, their diffusion within a food hydrogel and the effect on the growth of Pseudomonas fluorescens. Biosorbed-silver nanoparticles (BSNPs) were synthesized using a plant extract and were incorporated into chitosan or poly (vinyl alcohol) polymer to prepare biocomposite films. The addition of BSNPs improved the physical and antimicrobial properties of the films as shown by tensile strength and inhibition of P. fluorescens in hydrogels, respectively. PVA based BSNPs film showed a stronger antimicrobial effect, compared to chitosan based BSNPs film and this correlated with a higher amount of silver ions release from the PVA film into the hydrogel. Results suggest that the strength of the interaction between BSNPs and the film polymer is the key factor leading to the difference in the release behaviour of the antimicrobials, which in turn determines the antimicrobial activity of the active packaging.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Quitosana/química , Difusão , Embalagem de Alimentos , Hidrogéis/química , Álcool de Polivinil/química , Resistência à Tração
16.
Int J Nanomedicine ; 16: 3021-3040, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33935497

RESUMO

Purpose: Silver nanoparticles (AgNPs) are one of the most commonly investigated nanomaterials, especially due to their biomedical applications. However, their excellent cytotoxic and antimicrobial activity is often compromised in biological media due to nanoparticle aggregation. In this work, the aggregation behavior and the related biological activity of three different samples of citrate capped silver nanoparticles, with mean diameters of 10, 20, and 50 nm, respectively, were examined. Methods: Following nanoparticle synthesis and characterization with transmission electron microscopy, their aggregation behavior under various pH values, NaCl, glucose, and glutamine concentrations, furthermore in cell culture medium components such as Dulbecco's Modified Eagle's Medium and fetal bovine serum, was assessed through dynamic light scattering and ultraviolet-visible spectroscopy. Results: The results indicated that acidic pH and physiological electrolyte content universally induce micron-scale aggregation, which can be mediated by biomolecular corona formation. Remarkably, larger particles demonstrated higher resistance against external influences than smaller counterparts. In vitro cytotoxicity and antimicrobial assays were performed by treating cells with nanoparticulate aggregates in differing stages of aggregation. Conclusion: Our results revealed a profound association between colloidal stability and toxicity of AgNPs, as extreme aggregation led to the complete loss of biological activity. The higher degree of aggregation resistance observed for larger particles had a significant impact on the in vitro toxicity, since such samples retained more of their activity against microbes and mammalian cells. These findings lead to the conclusion that aiming for the smallest possible nanoparticles might not be the best course of action, despite the general standpoint of the relevant literature.


Assuntos
Nanopartículas Metálicas/química , Tamanho da Partícula , Prata/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ácido Cítrico/química , Meios de Cultura/química , Difusão Dinâmica da Luz , Fungos/efeitos dos fármacos , Glucose/farmacologia , Glutamina/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Cloreto de Sódio/química
17.
J Food Sci ; 86(6): 2481-2490, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33948960

RESUMO

The migration study of nano-Ag migration from polylactic acid (PLA) films was studied. Samples treated by high-pressure food processing (0, 100, 200, 300, and 400 MPa pressure) were soaked in acetic acid solution and incubated at 20 °C for 90 days. At the end of storage, nano-Ag particles (AgNPs) migration from the PLA/AgNPs composite film treated under 200 MPa high pressure was the lowest. However, AgNPs migration was accelerated under 400 MPa high pressure. High-pressure processing (200 MPa) could cause denser structure and higher crystallinity degree in films than other treatments. Lower amount of AgNPs induced a decline in the intensity of specific characteristic peaks. The diffraction peak intensity of α-crystal for the film sample treated with 400 MPa was the lowest on day 60. The crystallization index of the PLA matrix changed with different high-pressure processing. The result indicated that appropriate high-pressure food processing could effectively suppress AgNPs migration from PLA-based film while contacting with acidic acid food simulant. PRACTICAL APPLICATION: The release of nanoparticles from food packaging material is a very important matter when the migration is concerned with regulatory and toxicity issues. The study described the migration kinetic of AgNPs from PLA nanocomposite film into acidic food simulant after different high-pressure food processing. The results indicated that the PLA/AgNPs nanocomposite film was safe for acidic food after high-pressure treatment.


Assuntos
Ácidos/análise , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Nanocompostos/química , Poliésteres/química , Pressão , Prata/fisiologia , Ácidos/química , Cinética , Prata/química
18.
Int J Nanomedicine ; 16: 3343-3356, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34017172

RESUMO

Background: Abelmoschus esculentus (L.) Moench, an economically important malvaceous vegetable crop popularly known as okra, is used in various culinary preparations and is rich in vitamins, minerals, and nutrients. The biological properties of okra flowers in relation to nanoparticle synthesis have not yet been reported. Materials and Methods: In the current study, silver nanoparticles (AgNPs) were synthesized using extracts of the flowers of A. esculentus. The characteristics of the AgNPs were studied using a UV-vis spectrometer, Fourier transmission infrared spectrophotometer (FTIR), X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectrometer (EDX). Antibacterial activity screening was performed using the agar well diffusion method, and cytotoxicity and cell viability studies were conducted using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results: The synthesized AgNPs were spherical and ranged in size from 5.52 to 31.96 nm, with an average size of 16.19 nm, as determined by UV-vis spectroscopy, FTIR, XRD, TEM and EDX. A. esculentus flower extract-mediated silver nanoparticles (AME-AgNPs) exhibited excellent activities in vitro studies, particularly in vitro cytotoxic and antiproliferative studies against cancer cell lines, such as the TERT-4 and A-549 cell lines. The antibacterial effects on the Gram-positive pathogens Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes and the Gram-negative pathogens Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhimurium and Shigella sonnei were tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values varied with the bacterial strain. The IC50 values of the synthesized NPs for the tested cell lines were close to that of a standard drug. Conclusion: Compared to other NPs the NPs synthesized in this study were smaller in size and exhibited a higher level of antibacterial activity, cytotoxicity and apoptosis at minimal concentrations, and this is the first study on okra flower-induced anticancer and antimicrobial activities.


Assuntos
Abelmoschus/química , Flores/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/química , Prata/farmacologia , Células A549 , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Humanos , Testes de Sensibilidade Microbiana
19.
Int J Mol Sci ; 22(7)2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33917615

RESUMO

Patients receiving orthopedic implants are at risk of implant-associated infections (IAI). A growing number of antibiotic-resistant bacteria threaten to hamper the treatment of IAI. The focus has, therefore, shifted towards the development of implants with intrinsic antibacterial activity to prevent the occurrence of infection. The use of Ag, Cu, and Zn has gained momentum as these elements display strong antibacterial behavior and target a wide spectrum of bacteria. In order to incorporate these elements into the surface of titanium-based bone implants, plasma electrolytic oxidation (PEO) has been widely investigated as a single-step process that can biofunctionalize these (highly porous) implant surfaces. Here, we present a systematic review of the studies published between 2009 until 2020 on the biomaterial properties, antibacterial behavior, and biocompatibility of titanium implants biofunctionalized by PEO using Ag, Cu, and Zn. We observed that 100% of surfaces bearing Ag (Ag-surfaces), 93% of surfaces bearing Cu (Cu-surfaces), 73% of surfaces bearing Zn (Zn-surfaces), and 100% of surfaces combining Ag, Cu, and Zn resulted in a significant (i.e., >50%) reduction of bacterial load, while 13% of Ag-surfaces, 10% of Cu-surfaces, and none of Zn or combined Ag, Cu, and Zn surfaces reported cytotoxicity against osteoblasts, stem cells, and immune cells. A majority of the studies investigated the antibacterial activity against S. aureus. Important areas for future research include the biofunctionalization of additively manufactured porous implants and surfaces combining Ag, Cu, and Zn. Furthermore, the antibacterial activity of such implants should be determined in assays focused on prevention, rather than the treatment of IAIs. These implants should be tested using appropriate in vivo bone infection models capable of assessing whether titanium implants biofunctionalized by PEO with Ag, Cu, and Zn can contribute to protect patients against IAI.


Assuntos
Cobre/química , Próteses e Implantes , Prata/química , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/metabolismo , Titânio/química , Zinco/química , Humanos , Osteoblastos/metabolismo , Osteoblastos/patologia , Oxirredução , Porosidade , Infecções Estafilocócicas/patologia , Células-Tronco/metabolismo , Células-Tronco/patologia
20.
Food Chem ; 355: 129666, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33799256

RESUMO

The gold electrode was functionalized with anti-bisphenol A (BPA) aptamer and captured the BPA as analyte. By dropping the aptamer-modified magnetic Fe3O4/Au nanoparticles solution onto the electrode, a BPA molecule attaches to many aptamers that are in contact with a large number of Fe3O4/Au nanoparticles. The modified electrode were transferred to a solution containing Ag+ ions. Fe3O4/Au nanoparticles reduce the Ag+ ions to Ag0. A potential scan was applied for the oxidation of the Ag0-loaded magnetic nanoparticles to the AgCl. The magnitude of the stripping anodic signal of the Ag0 was related to the concentration of the BPA. The assay shows a detection limit of 0.6 fmol L-1 and linear range of 1 fmol L-1-150 pmol L-1 and. The applicability of the aptasensor is measured by its successful use in the sensing BPA in water, milk and juice samples and measuring BPA migration from different commercial plastic products.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos Benzidrílicos/análise , Técnicas Biossensoriais/métodos , Compostos Férricos/química , Ouro/química , Nanopartículas Metálicas/química , Fenóis/análise , Prata/química , Compostos Benzidrílicos/química , Catálise , Eletrodos , Limite de Detecção , Oxirredução , Fenóis/química
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