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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 â¼70% 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.
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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 , AnimaisRESUMO
The aim of this study was to systematically review the literature to investigate whether silver nanoparticles (AgNPs) have an anti-inflammatory effect in vivo. The guidelines of PRISMA were applied, and a registration was made in PROSPERO. A personalized search of the PubMed, Web of Science, Scopus, Embase, Lilacs, and Google Scholar databases was conducted in September 2023. For the data analysis, the inverse variance in the random effects model was used. The tools of SYRCLE and GRADE were used to assess the risk of bias and the certainty of evidence, respectively. From the 9185 identified studies, 5685 duplicate studies were excluded; 52 were read in full text, and 7 were included in this review. Six studies were evaluated by the meta-analysis, and an increase in anti-inflammatory molecules (SMD -5.22; PI [-6.50, -3.94]) and an increase in anti-inflammatory ones (SMD 5.75; PI [3.79, 7.72]) were observed. Qualitative analysis showed a reduction in pro-inflammatory proteins and in the COX-2 pathway. It was concluded that AgNPs present an anti-inflammatory action in vivo through mechanisms involving the reduction of pro-inflammatory molecules and proteins, the increase of anti-inflammatory molecules, and selective inhibition of the COX-2 pathway.
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Nanoparticles play a crucial role in the field of nanotechnology, offering different properties due to their surface area attributed to their small size. Among them, silver nanoparticles (AgNPs) have attracted significant attention due to their antimicrobial properties, with applications that date back from ancient medicinal practices to contemporary commercial products containing ions or silver nanoparticles. AgNPs possess broad-spectrum biocidal potential against bacteria, fungi, viruses, and Mycobacterium, in addition to exhibiting synergistic effects when combined with certain antibiotics. The mechanisms underlying its antimicrobial action include the generation of oxygen-reactive species, damage to DNA, rupture of bacterial cell membranes and inhibition of protein synthesis. Recent studies have highlighted the effectiveness of AgNPs against various clinically relevant bacterial strains through their potential to combat antibiotic-resistant pathogens. This review investigates the proteomic mechanisms by which AgNPs exert their antimicrobial effects, with a special focus on their activity against planktonic bacteria and in biofilms. Furthermore, it discusses the biomedical applications of AgNPs and their potential non-preparation of antibiotic formulations, also addressing the issue of resistance to antibiotics.
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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.
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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 , HumanosRESUMO
In this work, the hexane, chloroform, and methanol extracts from Kalanchoe fedtschenkoi were utilized to green-synthesize silver nanoparticles (Kf1-, Kf2-, and Kf3-AgNPs). The Kf1-, Kf2-, and Kf3-AgNPs were characterized by spectroscopy and microscopy techniques. The antibacterial activity of AgNPs was studied against bacteria strains, utilizing the microdilution assay. The DPPH and H2O2 assays were considered to assess the antioxidant activity of AgNPs. The results revealed that Kf1-, Kf2-, and Kf3-AgNPs exhibit an average diameter of 39.9, 111, and 42 nm, respectively. The calculated ζ-potential of Kf1-, Kf2-, and Kf3-AgNPs were -20.5, -10.6, and -7.9 mV, respectively. The UV-vis analysis of the three samples demonstrated characteristic absorption bands within the range of 350-450 nm, which confirmed the formation of AgNPs. The FTIR analysis of AgNPs exhibited a series of bands from 3500 to 750 cm-1, related to the presence of extracts on their surfaces. SEM observations unveiled that Kf1- and Kf2-AgNPs adopted structural arrangements related to nano-popcorns and nanoflowers, whereas Kf3-AgNPs were spherical in shape. It was determined that treatment with Kf1-, Kf2-, and Kf3-AgNPs was demonstrated to inhibit the growth of E. coli, S. aureus, and P. aeruginosa in a dose-dependent manner (50-300 µg/mL). Within the same range, treatment with Kf1-, Kf2-, and Kf3-AgNPs decreased the generation of DPPH (IC50 57.02-2.09 µg/mL) and H2O2 (IC50 3.15-3.45 µg/mL) radicals. This study highlights the importance of using inorganic nanomaterials to improve the biological performance of plant extracts as an efficient nanotechnological approach.
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Antibacterianos , Antioxidantes , Química Verde , Kalanchoe , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Extratos Vegetais , Prata , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Kalanchoe/química , Antioxidantes/farmacologia , Antioxidantes/química , Antioxidantes/síntese química , Compostos de Bifenilo/antagonistas & inibidores , Compostos de Bifenilo/química , Picratos/antagonistas & inibidores , Picratos/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Peróxido de HidrogênioRESUMO
New wound dressings based on polymeric membranes have been widely exploited for clinical applications to assist in the healing process and prevent additional complications (e.g., bacterial infections). Here we propose the development of a new production method of polymeric membranes based on chitosan, incorporating glycolic extract of Aloe vera with joint synthesis of silver nanoparticles for use as a new bioactive dressing. The membranes were obtained by casting technique, and their morphological, physicochemical characteristics, degree of swelling, degradation profile and antimicrobial activity evaluated. Morphological analyzes confirmed the synthesis and presence of silver nanoparticles in the polymeric membrane. The chemical compatibility between the materials was demonstrated through thermal analysis (TGA and DSC) combined with ATR-FTIR tests, showing the complexation of the membranes (Mb-Ch-Ex.Av-NPs). All membranes were characterized as hydrophilic material (with a contact angle (Ó©) < 90°); however, the highest degree of swelling was obtained for the chitosan. (Mb-Ch) membrane (69.91 ± 5.75%) and the lowest for Mb-Ch-Ex.Av-NPs (26.62 ± 8.93%). On the other hand, the degradation profile was higher for Mb-Ch-Ex.Av-NPs (77.85 ± 7.51%) and lower for Mb-Ch (57.60 ± 2.29%). The manufactured bioactive dressings showed activity against Escherichia coli and Staphylococcus aureus. Our work confirmed the development of translucent and flexible chitosan-based membranes, incorporating Aloe vera glycolic extract with joint synthesis of silver nanoparticles for use as a new bioactive dressing, with proven antimicrobial activity.
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Aim: To develop a ß-AgVO3 gel and evaluate its physicochemical stability and antifungal activity against Candida albicans. Materials & methods: The gel was prepared from the minimum inhibitory concentration (MIC) of ß-AgVO3. The physicochemical stability was evaluated by centrifugation, accelerated stability (AS), storage (St), pH, syringability, viscosity and spreadability tests and antifungal activity by the agar diffusion. Results: The MIC was 62.5 µg/ml. After centrifugation, AS and St gels showed physicochemical stability. Lower viscosity and higher spreadability were observed for the higher ß-AgVO3 concentration and the minimum force for extrusion was similar for all groups. Antifungal effect was observed only for the ß-AgVO3 gel with 20xMIC. Conclusion: The ß-AgVO3 gel showed physicochemical stability and antifungal activity.
We used silver and vanadium to make a gel that can kill fungi in the mouth. We looked at the color of the gel, it's smell and also checked how well it lasted. The gel turned yellow and had no smell and did not spoil for at least 2 months. When we tested the gel against a type of fungus, it worked as well as another medicine called chlorhexidine, which is sold in pharmacies. But when we compared it with another medicine called nystatin, our gel was not as effective in killing the fungus.
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In response to the steady increase in antimicrobial-resistant strains, the World Health Organisation has emphasised the need to investigate new antimicrobial agents and alternative therapies that improve the spectrum of activity and reduce the dose required, thus improving safety. This study focused on the characterisation of Acanthospermum australe essential oil and green-synthesis silver nanoparticles (AgNP), evaluating their cytotoxicity in human cells, antimicrobial activity and synergistic effect against pathogens causing skin infections. The main components of the essential oil were germacrene A (24.07%), γ-cadinene (21.47%) and trans-caryophyllene (14.97%). Spherical AgNP with a diameter of 15 ± 3 nm were synthesised. The essential oil showed antimicrobial activity against dermatophytes and Malassezia globosa, while AgNP were found to be active against bacteria, yeasts and dermatophytes. Both compounds were found to be primarily non-cytotoxic at the concentrations required to inhibit microbial growth. Furthermore, the combined use of essential oil and AgNP showed a synergistic antimicrobial effect against dermatophytes and M. globosa. In conclusion, the results suggest that the combined use of bioactive compounds from natural sources, such as essential oil and biogenic AgNP, has the potential to improve antimicrobial efficacy against specific skin pathogens, particularly Microsporum canis, Nannizzia gypsea and M. globosa.
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Pomegranate waste poses an environmental challenge in Arequipa. Simultaneously, interest in sustainable materials like natural rubber latex (NRL) is growing, with Peruvian communities offering a promising source. This study explores the green synthesis of silver nanoparticles (AgNPs) using pomegranate peel extract and their incorporation into NRL nanofibers for enhanced functionalities. An eco-friendly process utilized silver nitrate and pomegranate peel extract as a reducing and capping agent to synthesize AgNPs. The resulting AgNPs and NRL/AgNPs nanofibers were characterized using imaging and spectroscopic techniques such as UV-vis, TGA, FTIR, XRD, Raman, SEM, and DLS. Green-synthesized AgNPs were spherical and crystalline, with an average diameter of 59 nm. They showed activity against K. pneumoniae, E. coli, B. cereus, and S. aureus (IC50: 51.32, 4.87, 27.72, and 69.72 µg/mL, respectively). NRL and NRL/AgNPs nanofibers (300-373 nm diameter) were successfully fabricated. The composite nanofibers exhibited antibacterial activity against K. pneumoniae and B. cereus. This study presents a sustainable approach by utilizing pomegranate waste for AgNP synthesis and NRL sourced from Peruvian communities. Integrating AgNPs into NRL nanofibers produced composites with antimicrobial properties. This work has potential applications in smart textiles, biomedical textiles, and filtration materials where sustainability and antimicrobial functionality are crucial.
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The study presents the successful development of a new electrochemical sensor with low cost and disposability for application in nitrofurazone detection in environmental and pharmaceutical samples. The sensors were fabricated using materials obtained from local storage and conductive carbon ink. The modification of the screen-printed electrodes with the hybrid nanomaterial based on silver nanoparticles, carbon quantum dots, and carbon nanotubes showed synergistic contributions in the nitrofurazone electrooxidation, as observed in the wide linear range (0.008 at 15.051 µM), with a sensitivity of 0.650 µA/µM. The limit of detection obtained was 4.6 nM. Differential pulse voltammetry, cyclic voltammetry, X-ray photoelectron spectroscopy, X-ray diffraction analysis, and high-resolution transmission electron microscopy were used to evaluate the electrochemical and structural characteristics. Studies of possible interferences were considered with nitrofurazone in the presence of the ions and organic molecules. The results were satisfactory, with a variation of 93.3% ± 4.39% at 100% ± 2.40%. The low volume used in the analyses (50 µL), disposability, high sensibility, selectivity, and low limit of detection are advantages that make the proposed sensor an electrochemical tool of high viability for the NFZ detection in environmental matrices and pharmaceutical formulations.
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Antibacterianos , Técnicas Eletroquímicas , Nanopartículas Metálicas , Nanotubos de Carbono , Nitrofurazona , Nitrofurazona/análise , Nitrofurazona/química , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono/química , Nanopartículas Metálicas/química , Antibacterianos/análise , Limite de Detecção , Prata/química , Eletrodos , Pontos Quânticos/químicaRESUMO
In the present study, pyroligneous acid, also known as wood vinegar, has been employed as reducing and stabilizing agent in the synthesis of silver nanoparticles (AgNPs) anchored on nanocellulose (NC). The idea is to confer the latter bactericidal properties for its typical uses such as in cosmetics and food-packing. It has been demonstrated that AgNPs can be directly produced onto NC in one-pot fashion while dramatically enhancing the kinetics of AgNPs synthesis (2 h for reaction completion) in comparison to the NC-less counterpart (10 days for reaction completion). Furthermore, NC allowed for a narrower size distribution of AgNPs. NC-supported and non-supported AgNPs had sizes of 5.1 ± 1.6 nm and 16.7 ± 4.62 nm, respectively. Immortalized human keratinocytes (HaCat) cells were then employed as model to evaluate the cytotoxicity of the AgNPs-NC compound. The latter was found not to impact cell proliferation at any formulation, while decreasing the viability by only 6.8% after 72 h. This study contributes to the development of more environmentally benign routes to produce nanomaterials and to the understanding of their impact on cells.
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Sobrevivência Celular , Celulose , Células HaCaT , Nanopartículas Metálicas , Prata , Humanos , Prata/química , Nanopartículas Metálicas/química , Celulose/química , Celulose/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Queratinócitos/citologia , Tamanho da Partícula , Proliferação de Células/efeitos dos fármacos , Ácido Acético/química , Ácido Acético/farmacologiaRESUMO
Silver nanoparticles (AgNPs) hold promise for cancer therapy. This study aimed to evaluate their impact on tumor and non-tumor cell number, viability, and morphology. Antitumor activity was tested on U-87MG (glioblastoma) and DU-145 (prostate cancer) cell lines. Treatment with AgNPs notably reached a reduction of U-87MG and DU-145 cell growth by 89.30% and 79.74%, respectively, resulting in slower growth rates. AgNPs induced DNA damage, evidenced by reduced nuclear area and DNA content via fluorescent image-based analyses. Conversely, HFF-1 non-tumor cells displayed no significant changes post-AgNPs exposure. Viability assays revealed substantial reductions in U-87MG and DU-145 cells (79% and 63% in MTT assays, 30% and 52.2% in high-content analyses), while HFF-1 cells exhibited lower sensitivity. Tumor cells had notably lower IC50 values than non-tumor cells, indicating selective susceptibility. Transmission electron microscopy (TEM) showed morphological changes post-AgNPs administration, including increased vacuoles, myelin figures, membrane ghosts, cellular extravasation, and membrane projections. The findings suggest the potential of AgNPs against glioblastoma and prostate cancer, necessitating further exploration across other cancer cell lines.
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Antineoplásicos , Sobrevivência Celular , Glioblastoma , Nanopartículas Metálicas , Neoplasias da Próstata , Prata , Humanos , Nanopartículas Metálicas/toxicidade , Masculino , Prata/toxicidade , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Linhagem Celular Tumoral , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Sobrevivência Celular/efeitos dos fármacos , Antineoplásicos/farmacologia , Contagem de Células , Dano ao DNA/efeitos dos fármacosRESUMO
Wearable technologies are becoming pervasive in our society, and their development continues to accelerate the untapped potential of continuous and ubiquitous sensing, coupled with big data analysis and interpretation, has only just begun to unfold. However, existing wearable devices are still bulky (mainly due to batteries and electronics) and have suboptimal skin contact. In this work, we propose a novel approach based on a sensor network produced through inkjet printing of nanofunctional inks onto a semipermeable substrate. This network enables real-time monitoring of critical physiological parameters, including temperature, humidity, and muscle contraction. Remarkably, our system operates under battery-free and wireless near-field communication (NFC) technology for data readout via smartphones. Moreover, two of the three sensors were integrated onto a naturally adhesive bioinspired membrane. This membrane, developed using an eco-friendly, high-throughput process, draws inspiration from the remarkable adhesive properties of mussel-inspired molecules. The resulting ultra-conformable membrane adheres effortlessly to the skin, ensuring reliable and continuous data collection. The urgency of effective monitoring systems cannot be overstated, especially in the context of rising heat stroke incidents attributed to climate change and high-risk occupations. Heat stroke manifests as elevated skin temperature, lack of sweating, and seizures. Swift intervention is crucial to prevent progression to coma or fatality. Therefore, our proposed system holds immense promise for the monitoring of these parameters on the field, benefiting both the general population and high-risk workers, such as firefighters.
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Técnicas Biossensoriais , Bivalves , Golpe de Calor , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio , Humanos , Tecnologia sem Fio/instrumentação , Técnicas Biossensoriais/instrumentação , Animais , Golpe de Calor/prevenção & controle , Bivalves/química , Adesivos/química , Membranas Artificiais , Desenho de Equipamento , SmartphoneRESUMO
Water pollution is a worldwide environmental and health problem that requires the development of sustainable, efficient, and accessible technologies. Nanotechnology is a very attractive alternative in environmental remediation processes due to the multiple properties that are conferred on a material when it is at the nanometric scale. This present review focuses on the understanding of the structure-physicochemical properties-performance relationships of silver nanoparticles, with the objective of guiding the selection of physicochemical properties that promote greater performance and are key factors in their use as antibacterial agents, surface modifiers, colorimetric sensors, signal amplifiers, and plasmonic photocatalysts. Silver nanoparticles with a size of less than 10 nm, morphology with a high percentage of reactive facets {111}, and positive surface charge improve the interaction of the nanoparticles with bacterial cells and induce a greater antibacterial effect. Adsorbent materials functionalized with an optimal concentration of silver nanoparticles increase their contact area and enhance adsorbent capacity. The use of stabilizing agents in silver nanoparticles promotes selective adsorption of contaminants by modifying the surface charge and type of active sites in an adsorbent material, in addition to inducing selective complexation and providing stability in their use as colorimetric sensors. Silver nanoparticles with complex morphologies allow the formation of hot spots or chemical or electromagnetic bonds between substrate and analyte, promoting a greater amplification factor. Controlled doping with nanoparticles in photocatalytic materials produces improvements in their electronic structural properties, promotes changes in charge transfer and bandgap, and improves and expands their photocatalytic properties. Silver nanoparticles have potential use as a tool in water remediation, where by selecting appropriate physicochemical properties for each application, their performance and efficiency are improved.
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Synthesis of silver nanoparticles with antibacterial properties using a one-pot green approach that harnesses the natural reducing and capping properties of cinnamon (Cinnamomum verum) bark extract is presented in this work. Silver nitrate was the sole chemical reagent employed in this process, acting as the precursor salt. Gas Chromatography-Mass Spectroscopy (GC-MS), High-Performance Liquid Chromatography (HPLC) analysis, and some phytochemical tests demonstrated that cinnamaldehyde is the main component in the cinnamon bark extract. The resulting bio-reduced silver nanoparticles underwent comprehensive characterization by Ultraviolet-Vis (UV-Vis) and Fourier Transform InfraRed spectrophotometry (FTIR), Dynamic Light Scattering (DLS), Transmission Electron Microscopy, and Scanning Electron Microscopy suggesting that cinnamaldehyde was chemically oxidated to produce silver nanoparticles. These cinnamon-extract-based silver nanoparticles (AgNPs-cinnamon) displayed diverse morphologies ranging from spherical to prismatic shapes, with sizes spanning between 2.94 and 65.1 nm. Subsequently, the antibacterial efficacy of these nanoparticles was investigated against Klebsiella, E. Coli, Pseudomonas, Staphylococcus aureus, and Acinetobacter strains. The results suggest the promising potential of silver nanoparticles obtained (AgNPs-cinnamon) as antimicrobial agents, offering a new avenue in the fight against bacterial infections.
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Due to its antimicrobial resistance characteristics, the World Health Organization (WHO) classifies A. baumannii as one of the critical priority pathogens for the development of new therapeutic strategies. Vaccination has been approached as an interesting strategy to overcome the lack of effective antimicrobials and the long time required to develop and approve new drugs. In this study, we aimed to evaluate as a vaccine the hypothetical adhesin protein CAM87009.1 in its recombinant format (rCAM87009.1) associated with aluminum hydroxide (Alhydrogel®) or biogenic silver nanoparticles (bio-AgNP) as adjuvant components against lethal infection by A. baumannii MDR strain. Both vaccine formulations were administered in three doses intramuscularly in BALB/c murine models and the vaccinated animals were tested in a challenge assay with A. baumannii MDR strain (DL100). rCAM87009.1 protein associated with both adjuvants was able to protect 100 % of animals challenged with the lethal strain during the challenge period. After the euthanasia of the animals, no A. baumannii colonies were detected in the lungs of animals vaccinated with the rCAM87009.1 protein in both formulations. Since the first immunization, high IgG antibody titers were observed (1:819,200), with results being statistically similar in both vaccine formulations evaluated. rCAM87009.1 associated with both adjuvants was capable of inducing at least one class of isotypes associated with the processes of neutralization (IgG2b and IgA for bio-AgNP and Alhydrogel®, respectively), opsonization (IgG1 in both vaccines) and complement activation (IgM and IgG3 for bio-AgNP and Alhydrogel®, respectively). Furthermore, reduced tissue damage was observed in animals vaccinated with rCAM87009.1 + bio-AgNP when compared to animals vaccinated with Alhydrogel®. Our results indicate that the rCAM87009.1 protein associated with both bio-AgNP and Alhydrogel® are combinations capable of promoting immunity against infections caused by A. baumannii MDR. Additionally, we demonstrate the potential of silver nanoparticles as alternative adjuvant molecules to the use of aluminum salts.
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Infecções por Acinetobacter , Acinetobacter baumannii , Adesinas Bacterianas , Adjuvantes Imunológicos , Anticorpos Antibacterianos , Nanopartículas Metálicas , Camundongos Endogâmicos BALB C , Prata , Animais , Prata/administração & dosagem , Prata/farmacologia , Acinetobacter baumannii/imunologia , Acinetobacter baumannii/efeitos dos fármacos , Camundongos , Infecções por Acinetobacter/prevenção & controle , Infecções por Acinetobacter/imunologia , Adesinas Bacterianas/imunologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Farmacorresistência Bacteriana Múltipla , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/administração & dosagem , Compostos de Alúmen/administração & dosagem , Feminino , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Modelos Animais de DoençasRESUMO
Dental implant success is threatened by peri-implantitis, an inflammation leading to implant failure. Conventional treatments struggle with the intricate microbial and host factors involved. Antibacterial membranes, acting as barriers and delivering antimicrobials, may offer a promising solution. Thus, this study highlights the potential of developing antibacterial membranes of poly-3-hydroxybutyrate and silver nanoparticles (Ag Nps) to address peri-implantitis challenges, discussing design and efficacy against potential pathogens. Electrospun membranes composed of PHB microfibers and Ag Nps were synthesized in a blend of DMF/chloroform at three different concentrations. Various studies were conducted on the characterization and antimicrobial activity of the membranes. The synthesized Ag Nps ranged from 4 to 8 nm in size. Furthermore, Young's modulus decreased, reducing from 13.308 MPa in PHB membranes without Ag Nps to 0.983 MPa in PHB membranes containing higher concentrations of Ag Nps. This demonstrates that adding Ag Nps results in a less stiff membrane. An increase in elongation at break was noted with the rise in Ag Nps concentration, from 23.597 % in PHB membranes to 60.136 % in PHB membranes loaded with Ag Nps. The antibiotic and antibiofilm activity of the membranes were evaluated against Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus mutans, and Candida albicans. The results indicated that all PHB membranes containing Ag Nps exhibited potent antibacterial activity by inhibiting the growth of biofilms and planktonic bacteria. However, inhibition of C. albicans occurred only with the PHB-Ag Nps C membrane. These findings emphasize the versatility and potential of Ag Nps-incorporated membranes as a multifunctional approach for preventing and addressing microbial infections associated with peri-implantitis. The combination of antibacterial and antibiofilm properties in these membranes holds promise for improving the management and treatment of peri-implantitis-related complications.
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Antibacterianos , Biofilmes , Hidroxibutiratos , Membranas Artificiais , Nanopartículas Metálicas , Peri-Implantite , Prata , Prata/química , Prata/farmacologia , Biofilmes/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas Metálicas/química , Peri-Implantite/tratamento farmacológico , Peri-Implantite/microbiologia , Hidroxibutiratos/química , Hidroxibutiratos/farmacologia , Poliésteres/química , Testes de Sensibilidade Microbiana , Humanos , Staphylococcus aureus/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Poli-HidroxibutiratosRESUMO
This study investigated the effect of AgNPs and AgNO3, at concentrations equivalent, on the production of primary and secondary metabolites on transgenic soybean plants through an NMR-based metabolomics. The plants were cultivated in a germination chamber following three different treatments: T0 (addition of water), T1 (addition of AgNPs), and T2 (addition of AgNO3). Physiological characteristics, anatomical analyses through microscopic structures, and metabolic profile studies were carried out to establish the effect of abiotic stress on these parameters in soybean plants. Analysis of the 1H NMR spectra revealed the presence of amino acids, organic acids, sugars, and polyphenols. The metabolic profiles of plants with AgNP and AgNO3 were qualitatively similar to the metabolic profile of the control group, suggesting that the application of silver does not affect secondary metabolites. From the PCA, it was possible to differentiate the three treatments applied, mainly based on the content of fatty acids, pinitol, choline, and betaine.
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Glycine max , Espectroscopia de Ressonância Magnética , Metabolômica , Nanopartículas Metálicas , Plantas Geneticamente Modificadas , Prata , Glycine max/metabolismo , Glycine max/genética , Glycine max/química , Glycine max/efeitos dos fármacos , Glycine max/crescimento & desenvolvimento , Prata/metabolismo , Prata/química , Nanopartículas Metálicas/química , Espectroscopia de Ressonância Magnética/métodos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/química , Aminoácidos/metabolismo , Ácidos Graxos/metabolismo , Ácidos Graxos/químicaRESUMO
Aim: To investigate whether medical devices coated with a synthesized nanocomposite of poly(methylmethacrylate-co-dimethyl acrylamide) (PMMDMA) and silver nanoparticles (AgNPs) could improve their antibiofilm and antimicrobial activities. We also investigated the nanocomposite's safety. Materials & methods: The nanocomposite was synthesized and characterized using analytical techniques. Medical devices coated with the nanocomposite were evaluated for bacterial adhesion and hemolytic activity in vitro. Results: The nanocomposite formation was demonstrated with the incorporation of AgNPs into the polymer matrix. The nanocomposite proved to be nonhemolytic and significantly inhibited bacterial biofilm formation. Conclusion: The PMMDMA-AgNPs nanocomposite was more effective in preventing biofilm formation than PMMDMA alone and is a promising strategy for coating medical devices and reducing mortality due to hospital-acquired infections.
[Box: see text].
Assuntos
Biofilmes , Nanopartículas Metálicas , Nanocompostos , Prata , Biofilmes/efeitos dos fármacos , Prata/química , Prata/farmacologia , Nanocompostos/química , Nanopartículas Metálicas/química , Humanos , Antibacterianos/farmacologia , Antibacterianos/química , Aderência Bacteriana/efeitos dos fármacos , Equipamentos e Provisões/microbiologia , Hemólise/efeitos dos fármacos , Acrilamidas/química , Acrilamidas/farmacologiaRESUMO
The Escherichia coli Keio mutant collection has been a tool for assessing the role of specific genes and determining their role in E. coli physiology and uncovering novel functions. In this work, specific mutants in the DNA repair pathways and oxidative stress response were evaluated to identify the primary targets of silver nanoparticles (NPs) and their mechanism of action. The results presented in this work suggest that NPs mainly target DNA via double-strand breaks and base modifications since the recA, uvrC, mutL, and nfo mutants rendered the most susceptible phenotype, rather than involving the oxidative stress response. Concomitantly, during the establishment of the control conditions for each mutant, the katG and sodA mutants showed a hypersensitive phenotype to mitomycin C, an alkylating agent. Thus, we propose that KatG catalase plays a key role as a cellular chaperone, as reported previously for the filamentous fungus Neurospora crassa, a large subunit catalase. The Keio collection mutants may also be a key tool for assessing the resistance mechanism to metallic NPs by using their potential to identify novel pathways involved in the resistance to NPs.