Pulmonary delivery of silver nanoparticles prevents influenza infection by recruiting and activating lymphoid cells.

Silver nanoparticles (AgNPs) are a potential antiviral agent due to their ability to disrupt the viral particle or alter the virus metabolism inside the host cell. In vitro, AgNPs exhibit antiviral activity against the most common human respiratory viruses. However, their capacity to modulate immune responses during respiratory viral infections has yet to be explored. This study demonstrates that administering AgNPs directly into the lungs prior to infection can reduce viral loads and therefore virus-induced cytokines in mice infected with influenza virus or murine pneumonia virus. The prophylactic effect was diminished in mice with depleted lymphoid cells. We showed that AgNPs-treatment resulted in the recruitment and activation of lymphocytes in the lungs, particularly natural killer (NK) cells. Mechanistically, AgNPs enhanced the ability of alveolar macrophages to promote both NK cell migration and IFN-γ production. By contrast, following infection, in mice treated with AgNPs, NK cells exhibited decreased activation, indicating that these nanoparticles can regulate the potentially deleterious activation of these cells. Overall, the data suggest that AgNPs may possess prophylactic antiviral properties by recruiting and controlling the activation of lymphoid cells through interaction with alveolar macrophages.

Silver Nanoparticles as Catalysts of Foeniculum vulgare L. Callus Formation and Its Content of Vitamins and some Fatty Acids.

Background: Plants are a precious resource of a wide range of secondary metabolites, that are benefitted as flavours, pharmaceuticals, colours, colognes, food additives and also biopesticides. Objective: The current study tested the impact of silver nanoparticles (AgNPs) on Foeniculum vulgare. Materials and Methods: Foeniculum vulgare seeds were surface sterilized, Vital leaf pieces are grown on MS media including diverse mixtures of plant growth regulators, the special effects of AgNPs plus PGRs on callus propagation were evaluated, and separated compounds of fatty acid and vitamins were identified. Results: Outcomes revealed that several intensities of AgNPs expressively influenced the callus propagation and significantly raised the callus biomass with combination including the plant growth regulators. Highest fresh (7.32 g.L-1) biomass addition of callus was remarked on the media elevated in vitro at 20 ppm AgNPs combined with (2 mg.L-1 2,4-D) and results noted that the callus appeared compact and greenish in colour with 40 ppm AgNPs in combination with (2 mg.L-1 2,4-D). The results elucidated the amplification of the value of both fatty acids (stearic acid (47.85 %), oleic acid (189.28 %), Linoleic (6.34 %) and Linolenic (0.83 %)), and vitamins (Vitamin E (8.99 U.mg-1) and vitamin A (27.19 U.mg-1) by using MS + 2,4-D (2 mg.L-1) + AgNPs (20ppm). Conclusion: Application of a combination of AgNPs along with PGRs led to callus proliferation in Foeniculum vulgare L. In vitro. But, the unaccompanied use of AgNPs was originate inductive in the biosynthesis of greater quantities of special fatty acids and vitamin metabolites.

Cytotoxic and Apoptotic Effects of Green Synthesized Silver Nanoparticles via Reactive Oxygen Species-Mediated Mitochondrial Pathway in Human Breast Cancer Cells.

Due to their exceptional physicochemical features, green synthesized silver nanoparticles (AgNPs) have been of considerable interest in cancer treatment. In the present study, for the first time, we aimed to green synthesize AgNPs from Euphorbia retusa and explore their anticancer potential on human breast cancer (MCF-7) cells. First, the green synthesized AgNPs (EU-AgNPs) were well characterized by UV-visible spectroscopy, Fourier transmission infrared (FTIR) spectrum, XRD, scanning and transmission electron microscopy (SEM and TEM), and EDX techniques. The characterization data exhibited that EU-AgNPs were spherical in shape and crystalline in nature with an average size of 17.8 nm. FTIR results established the presence of active metabolites in EU-AgNPs. Second, the anticancer effect of EU-AgNPs was evaluated against MCF-7 cells by MTT and neutral red uptake (NRU) assays. Moreover, morphological changes, ROS production, MMP, and apoptotic marker genes were also studied upon exposure to cytotoxic doses of EU-AgNPs. Our results showed that EU-AgNPs induce cytotoxicity in a concentration-dependent manner, with an IC50 value of 40 µg/mL. Morphological changes in MCF-7 cells exposed to EU-AgNPs also confirm their cytotoxic effects. Increased ROS and decreased MMP levels revealed that EU-AgNPs induced oxidative stress and mitochondrial membrane dysfunction. Moreover, ROS-mediated apoptosis was confirmed by elevated levels of proapoptotic marker genes (p53, Bax, caspase-3, and caspase-9) and reduced levels of an antiapoptotic gene (Bcl-2). Altogether, these findings suggested that EU-AgNPs could induce potential anticancer effects through ROS-mediated apoptosis in MCF-7 cells.

Composite suture material based on polylactide accelerates the healing of surgical wounds in in vivo experiment.

In laboratory conditions, composite sutures based on polylactide (PLA) containing chitin nanofibrils modified with polyethylene glycol (CN-PEG) and poviargol (silver nanoparticles stabilized with poly(N-vinylpyrrolidone)) were obtained, studied, and used as a prototype. Surgical sutures threads with the addition of CN-PEG have stable mechanical properties both in air and in a buffer simulating the environment of a living organism. The yield strength of oriented threads decreased by an average of 15%, whereas for non-oriented threads the decrease was 3-4 times. The strength values in simple units of unfilled PLA, PLA containing 5 wt % CN-PEG, and PLA with 1 wt % Poviargol were on average 50% higher than the national standard 31620-2012. The results of in vivo experiments on albino rats (cross-linking skin and muscle tissue in the linea alba area) showed that composite sutures are best for suturing muscle tissue, whereas unfilled PLA sutures are more suitable for suturing skin. When suturing muscle tissue, suturing with composite sutures increased the number of collagen fibers of different diameters.

Biogenic synthesis and characterization of silver nanoparticles (AgNPs) from aqueous extract of Lepidagathis cristata along with their antibacterial and antineoplastic activity to combat breast cancer cells (MCF-7).

Lepidagathis cristata (L. cristata) plant produces reducing and capping agents; this study utilized microwave-assisted biogenic synthesis to manufacture silver nanoparticles (AgNPs) using this plant. The structure, morphology, and crystallinity phases of prepared nanoparticles (NPs) were characterized by ultraviolet-visible spectroscopy (UV-viz), powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Biologically synthesized AgNPs were treated against pathogenic bacteria species including Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), and Staphylococcus aureus (S. aureus) and its highest zone of inhibition 10 ± 1.45 mm, 10 ± 0.74 mm, and 6 ± 0.43 mm, respectively, at the concentration of 100 µg/mL. The cytotoxic activity of AgNPs against MCF-7 breast cancer cells revealed significant growth inhibition by inhibiting cell viability, inhibitory concentration of 50% (IC50) of NPs observed at 55.76 µg/mL concentration. Finally, our findings concluded that the L. cristata-mediated biosynthesized AgNPs proved its potential antibacterial and neoplastic properties against MCF cells by endorsing the inhibition of cell proliferation especially with low concentration.

Electrochemical detection of poly(ADP-ribose) polymerase-1 with silver nanoparticles as signal labels by integrating the advantages of homogeneous reaction with surface-tethered detection.

Poly(ADP-ribose)polymerase-1 (PARP1) could be activated by binding to nucleic acids with specific sequences, thus catalyzing the poly-ADP-ribosylation (PARylation) of target proteins including PARP1 itself. Most of the previously reported electrochemical methods for the determination of PARP1 were relied on the electrostatic interactions, which required the pre-immobilization of DNA on an electrode for the capture of PARP1. Herein, we reported an "immobilization-free" electrochemical strategy for the assays of PARP1 on the basic of avidin-biotin interaction. Once PARP1 was activated by binding with the specific double-stranded DNA (dsDNA) in a homogeneous solution, the biotinylated nicotinamide adenine dinucleotide (biotin-NAD+) was transferred onto PARP1, resulting in the formation of biotinylated PAR polymers. The resulting biotinylated PAR polymers were then captured by a neutravidin (NA)-modified electrode through avidin-biotin interactions. The rich biotin moieties in the PAR polymers allowed for the capture of NA-modified silver nanoparticles (NA-AgNPs) through the avidin-biotin interactions. The surface-tethered AgNPs produced a well-defined electrochemical signal due to the characteristic solid-state Ag/AgCl process. The "immobilization-free", electrostatic interaction-independent electrochemical biosensor exhibited low background current, high sensitivity, and good stability. It has achieved the determination of PARP1 with a detection limit down to 0.7 mU. The biosensor was further applied to determine the inhibition efficiency of potential inhibitors with a satisfactory result. This method shows promising potential applications in PARP1-related clinical diagnosis and drug discovery.

Facile synthesis of silver nanoparticles using Calotropis procera leaves: unraveling biological and electrochemical potentials.

HIGHLIGHTS: CPL-AgNPs exhibited improved biomimetic attributes. Antibiotic resistance against pathogens were challenged through use of CPL-AgNPs. Supercapacitor application of facile synthesized AgNPs for the first time demonstrated improved physical application.

In vitro antimicrobial activity of silver nanoparticles against selected Gram-negative and Gram-positive pathogens.

Background and aim: Infections caused by pathogenic bacteria increase patient morbidity and mortality and significantly raise treatment costs. The use of silver nanoparticles as an alternative treatment for S aureus, E coli, MRSA, E faecalis, K pneumoniae and P aeruginosa indicates their antibacterial effect and prompts medical research to consider the next generation of antibacterial drugs that could change antibiotic therapy. By combining silver nanoparticles with different classes of antibiotics, the antibacterial effect is evidenced by increased values of the inhibition zone compared to the values obtained for some antibiotics commonly used in the treatment of bacterial infections. This study focuses on comparing the antibacterial activity of antibiotics versus antibiotics combined with silver nanoparticles against various bacteria, by comparing inhibition zones obtained for both. We aim to prove that the size of the inhibition zone for antibiotics combined with silver nanoparticles is greater, thus confirming the improved antibacterial effect. Metods: In this study we tested the antibacterial activity of solutions of silver nanoparticles alone or in combination with different antibiotics. We used standard bacterial strains, ATCC, both Gram positive bacteria Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, as well as Gram negative bacteria Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, but also on clinical isolates: a strain MRSA (Methicillin Resistant Staphylococcus aureus) and a PDR strain (pan drug resistant) of Klebsiella pneumoniae. Bacterial identification was performed using Vitek MS analyzer (bioMerieux). Antibiotic susceptibility determination was performed with VITEK2 COMPACT SYSTEM (bio Merieux, Inc Durham NC) with ready to use VITEK AST cards. The interpretation of the results was done in compliance with EUCAST 2023-2024 standards. Testing was performed for several classes of antibiotics, silver nanoparticle solutions in 2 concentrations (10 µg/mL and 100 µg/mL) and for combinations of antibiotics with silver nanoparticle solutions. The diameter of the inhibition zone (ZOI) for silver nanoparticles, antibiotics and silver nanoparticles combined with antibiotic against each bacterium was expressed in millimeters. The Kirby-Bauer disk-diffusion method, in accordance with current EUCAST standards, was used to analyze the antibacterial effect of antibiotics, silver nanoparticles, and antibiotics combined with silver nanoparticles at biocompatible doses of 10 and 100 µg/mL. The experiments were conducted in triplicate, and the results were almost identical. Results: The results of this study show that the silver nanoparticles displayed antibacterial activity, proven by the appearance of the inhibition zone, in various sizes, for all bacteria studied. The antibiotic classes tested were beta-lactamins, first, second, third and fourth generation cephalosporins, macrolides, fluoroquinolones, lincosamides, aminoglycosides, glycopeptides, tetracyclines, oxazolidinones, sulfonamides, rifamycins, amphenicols. Testing S aureus ATCC 29213, the highest zone of inhibition was demonstrated for cephalosporins (32.6667 ± 0.701 mm), macrolides (31.6667 ± 0.701 mm, and lincosamides (29.6667 ± 0.701 mm). Testing MRSA (internal code GR0333), the highest zone of inhibition for combination of silver nanoparticles and antibiotics was demonstrated for fluoroquinolones (36.3333 ± 0.701 mm), lincosamides (32.3333 ± 0.701 mm), Fusid acid (32.3333 ± 0.701 mm) and aminoglicosides (31.3333 ± 0.701 mm). Testing E coli ATCC 25922 the highest zone of inhibition was for Fosfomycine, 39 mm and for E faecalis ATCC 29212 for aminoglicosides was 19 mm. For K pneumoniae (internal code GQ8575) the inhibition zone for silver nanoparticles 100 µg/mL was 12.3333 ± 0.701 mm and for P aeruginosa ATCC 27253 was 16 ± 1.214 mm. Conclusions: The use of metallic nanoparticles, especially silver ones, as antimicrobial agents with definite bactericidal activity has led medical specialists to consider this new treatment which may change antibacterial therapy. Studies of in vitro combinations between silver nanoparticles and different classes of antibiotics represent a highly efficient and effective new antibacterial treatment against multidrug-resistant bacteria. To avoid the problem of antimicrobial resistance associated with conventional antibiotics, it is necessary to understand the adaptive mechanisms of bacteria under the action of metal nanoparticles, which could be exploited in future studies. Further in vitro and in vivo studies that would assess specify the biocompatibility and toxicity of silver nanoparticles will make these super nanomaterials the medicines of the future.

Immunomodulatory Antibacterial Hydrogel for Wound Infection Management.

Background: Wound healing has always been a focal point in clinical work. Bacterial infections and immune microenvironment disorders can both hinder normal wound healing. Current wound dressings only serve a covering function. Developing wound dressings with antibacterial and immunomodulatory functions is crucial for aiding wound healing. To address this issue, we have developed a hydrogel with antibacterial and immunomodulatory functions for managing infected wounds. Methods: The present study describes a photo-crosslinked antibacterial hydrogel composed of curcumin, silver nanoparticles-loaded reduced graphene oxide, and silk fibroin methacryloyl for the treatment of infected wounds. The study assessed its antibacterial properties and its capacity to induce macrophage M2 polarization through in vitro and in vivo experiments. Results: The hydrogel demonstrates robust antibacterial properties and enhances macrophage M2 polarization in both in vitro and in vivo settings. Moreover, it accelerates the healing of infected wounds in vivo by stimulating collagen deposition and angiogenesis. Conclusion: Overall, this hydrogel shows great potential in managing wound infections.

Evaluating the pharmacological activities of Aloe perryi-Silver nanoparticles induced apoptosis against colon cancer cells (HCT-116).

Aloe perryi has been studied and possesses several activities, including antibacterial, antiparasitic, and anticancer properties. In this study, A. perryi was used as a reducing agent of silver ions into silver nanoparticles. Aloe perryi-silver nanoparticles (APS-NPs) were characterized and evaluated using characterization techniques. However, the antioxidative, antibacterial, and anticancer assays were studied to evaluate the pharmacological activities of APS-NPs. APS-NPs were developed and changed to dark brown and the maximum absorption was 442 nm. SEM (5-583 nm), TEM (4-110 nm), XRD (21.84 nm), and zeta potential analysis (63.39 nm) revealed that the APS-NPs were nano-sized, and the APS-NPs had a cubic crystalline structure, according to the XRD results. FTIR analysis suggested that functional groups of A. perryi metabolites were involved in forming APS-NPs. The zeta potential indicated that the APS-NPs were negatively charged (-32 mV), suggesting good stability. APS-NPs showed significant antioxidative stress activity by reducing DPPH-free radicles in a dose-dependent manner. APS-NPs-induced antibacterial effect against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Acinetobacter baumannii (A. baumannii). APS-NPs reduced the cell viability and cell migration of the human colon tumor cell line (HCT 116) compared with controls, indicating that APS-NPs could play a role in reducing metastasis and inducing cell apoptosis against colon cancer. In conclusion, the nanoparticle synthesis from A. perryi extract demonstrated excellent antioxidant, antibacterial, and anticancer activities, thus suggesting that our APS-NPs have the potential to be used as antioxidative and antibacterial in food and pharmaceutical industries.

Antibiofilm effect of different concentrations of silver nanoparticles combined with calcium hydroxide against Enterococcus faecalis biofilm: An ex vivo study.

This study aimed to evaluate the antibiofilm activity of different concentrations of silver nanoparticles (AgNPs) in combination with calcium hydroxide [Ca(OH)2] against Enterococcus faecalis biofilm. On an E. faecalis biofilm on dentin discs, the following medicaments were applied for 7 days (n = 13/group): 0.005% AgNPs+Ca(OH)2, 0.01% AgNPs+Ca(OH)2, 0.02% AgNPs + Ca(OH)2, Ca(OH)2 and saline/control. Specimens were stained with LIVE/DEAD® BacLight™ dye and analysed with confocal laser scanning microscopy. Proportion of dead bacteria was calculated and analysed. There was a significant reduction in E. faecalis biofilm in all medicament groups (43.5%, 49.1%, 69.1%, 48.7%) respectively, compared with control group (2.54%) (p < 0.001). The 0.02% AgNPs + Ca(OH)2 group demonstrated the most significantly superior antibiofilm effect, with no significant difference between remaining groups. In conclusion, combining 0.02% AgNPs enhanced the antibiofilm effect of Ca(OH)2 on E. faecalis biofilm compared with lower AgNPs concentrations.

Exploring bee venom and silver nanoparticles for controlling foulbrood pathogen and enhancing lifespan of honeybees.

The beekeeping industry plays a crucial role in local economies, contributing significantly to their growth. However, bee colonies often face the threat of American foulbrood (AFB), a dangerous disease caused by the Gram-positive bacterium Paenibacillus larvae (P. l.). While the antibiotic Tylosin has been suggested as a treatment, its bacterial resistance necessitates the search for more effective alternatives. This investigation focused on evaluating the potential of bee venom (BV) and silver nanoparticles (Ag NPs) as antibacterial agents against AFB. In vitro treatments were conducted using isolated AFB bacterial samples, with various concentrations of BV and Ag NPs (average size: 25nm) applied individually and in combination. The treatments were administered under both light and dark conditions. The viability of the treatments was assessed by monitoring the lifespans of treated bees and evaluating the treatment's efficiency within bee populations. Promising results were obtained with the use of Ag NPs, which effectively inhibited the progression of AFB. Moreover, the combination of BV and Ag NPs, known as bee venom/silver nanocomposites (BV/Ag NCs), significantly extended the natural lifespan of bees from 27 to 40 days. Notably, oral administration of BV in varying concentrations (1.53, 3.12, and 6.25 mg/mL) through sugary syrup doubled the bees' lifespan compared to the control group. The study established a significant correlation between the concentration of each treatment and the extent of bacterial inhibition. BV/Ag NCs demonstrated 1.4 times greater bactericidal efficiency under photo-stimulation with visible light compared to darkness, suggesting that light exposure enhances the effectiveness of BV/Ag NCs. The combination of BV and Ag NPs demonstrated enhanced antibacterial efficacy and prolonged honeybee lifespan. These results offer insights that can contribute to the development of safer and more efficient antibacterial agents for maintaining honeybee health.

Development of a Synergistic Nanomaterial Scaffold Combining Silver Nanoparticles, Collagen, and Doxycycline for Enhanced Scar-Free Skin Regeneration.

Introduction The efficacy of wound-healing treatments can be significantly enhanced through innovative combination therapies. This research investigates the wound-healing properties of a combination therapy involving silver nanoparticles (AgNPs) synthesized using Delphinium denudatum (Dd), bovine tendon collagen (BTC), and the antibiotic doxycycline (DOX) in Wistar albino rats. Each component has known therapeutic benefits: AgNPs possess antimicrobial properties, BTC aids in tissue regeneration, and DOX is an effective antibiotic. The synergy between these components is hypothesized to enhance wound closure, reduce inflammation, and promote scar-free healing. Methods The synthesis of DdAgNPs was carried out using Dd. The presence of AgNPs was confirmed by ultraviolet-visible (UV-Vis) spectroscopy and high-resolution transmission electron microscopy (HRTEM). The study was conducted on Wistar albino rats following ethical guidelines for animal research. The rats were divided into different groups to receive various treatments: DdAgNPs alone, BTC alone, DOX alone, combinations of two components, and the triple combination of DdAgNPs: BTC: DOX. Wound closure rates, epithelialization, and collagen deposition were monitored and recorded over time. Tissue samples from the wound sites were collected for histological analysis. Hematoxylin and eosin (H&E) staining was used to evaluate epithelialization and overall tissue architecture. Collagen deposition was assessed using Masson's trichrome staining. Additionally, the expression of cyclooxygenase-2 (COX-2) was measured as an indicator of inflammation. Results UV-Vis spectroscopy provided the characteristic surface plasmon resonance peak indicative of AgNPs, while HRTEM revealed the morphology and size of the nanoparticles, showing spherical particles with an average size of 35±10.42 nm. The combination therapy of DdAgNPs: BTC: DOX significantly enhanced wound closure compared to individual and dual-component treatments. This was evidenced by faster epithelialization and increased collagen deposition. The histological analysis showed that the triple combination treatment resulted in more organized tissue architecture and denser collagen fibers. Furthermore, the treatment led to a marked decrease in COX-2 expression, indicating reduced inflammation and potential for lower scar formation. Conclusion The synergistic application of DdAgNPs, BTC, and DOX presents a promising strategy for advanced wound healing and tissue regeneration. The combination therapy not only accelerates wound closure but also enhances the quality of healing by promoting epithelialization and collagen deposition while reducing inflammation. These findings offer a potential pathway for developing effective, scar-free healing solutions, highlighting the benefits of integrating multiple therapeutic agents in wound care.

Composite Nanoarchitectonics of Electrospun Piezoelectric PVDF/AgNPs for Biomedical Applications, Including Breast Cancer Treatment.

This study focused on preparing composite nanomats by incorporating silver nanoparticles (AgNPs) in polyvinylidene fluoride (PVDF) nanofibers through the electrospinning process. A short review of piezoelectric PVDF-related research is presented. PVDF is known for its biocompatibility and piezoelectric properties. Since electrical signals in biological tissues have been shown to be relevant for therapeutic applications, the influence of the addition of AgNPs to PVDF on its piezoelectricity is studied, due to the ability of AgNPs to increase the piezoelectric signal, along with providing antibacterial properties. The prepared samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. In addition, the biological activity of composites was examined using a cytotoxicity assay and an assessment of the antibacterial activity. The obtained results show that the incorporation of AgNPs into PVDF nanofibers further enhances the piezoelectricity (crystalline ß-phase fraction), already improved by the electrospinning process, compared to solution-casted samples, but only with a AgNPs/PVDF concentration of up to 0.3%; a further increase in the nanoparticles led to a ß-phase reduction. The cytotoxicity assay showed a promising effect of PVDF/AgNPs nanofibers on the MDA-MB-231 breast cancer cell line, following the non-toxicity displayed in regard to the healthy MRC-5 cell line. The antibacterial effect of PVDF/AgNPs nanofibers showed promising antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, as a result of the Ag content. The anticancer activity, combined with the electrical properties of nanofibers, presents new possibilities for smart, multifunctional materials for cancer treatment development.

Silver and Carbon Nanomaterials/Nanocomplexes as Safe and Effective ACE2-S Binding Blockers on Human Skin Cell Lines.

(1) Background: Angiotensin-converting enzyme 2 (ACE2) is a crucial functional receptor of the SARS-CoV-2 virus. Although the scale of infections is no longer at pandemic levels, there are still fatal cases. The potential of the virus to infect the skin raises questions about new preventive measures. In the context of anti-SARS-CoV-2 applications, the interactions of antimicrobial nanomaterials (silver, Ag; diamond, D; graphene oxide, GO and their complexes) were examined to assess their ability to affect whether ACE2 binds with the virus. (2) Methods: ACE2 inhibition competitive tests and in vitro treatments of primary human adult epidermal keratinocytes (HEKa) and primary human adult dermal fibroblasts (HDFa) were performed to assess the blocking capacity of nanomaterials/nanocomplexes and their toxicity to cells. (3) Results: The nanocomplexes exerted a synergistic effect compared to individual nanomaterials. HEKa cells were more sensitive than HDFa cells to Ag treatments and high concentrations of GO. Cytotoxic effects were not observed with D. In the complexes, both carbonic nanomaterials had a soothing effect against Ag. (4) Conclusions: The Ag5D10 and Ag5GO10 nanocomplexes seem to be most effective and safe for skin applications to combat SARS-CoV-2 infection by blocking ACE2-S binding. These nanocomplexes should be evaluated through prolonged in vivo exposure. The expected low specificity enables wider applications.

Surface Charge-Modulated Toxicity of Cysteine-Stabilized Silver Nanoparticles.

The toxicity of silver nanoparticles (AgNPs) depends on their physicochemical properties. The ongoing research aims to develop effective methods for modifying AgNPs using molecules that enable control over the processes induced by nanoparticles in both normal and cancerous cells. Application of amino acid-stabilized nanoparticles appears promising, exhibiting tunable electrokinetic properties. Therefore, this study focused on determining the influence of the surface charge of cysteine (CYS)-stabilized AgNPs on their toxicity towards human normal B (COLO-720L) and T (HUT-78) lymphocyte cell lines. CYS-AgNPs were synthesized via the chemical reduction. Transmission electron microcopy (TEM) imaging revealed that they exhibited a quasi-spherical shape with an average size of 18 ± 3 nm. CYS-AgNPs remained stable under mild acidic (pH 4.0) and alkaline (7.4 and 9.0) conditions, with an isoelectric point observed at pH 5.1. Following a 24 h treatment of lymphocytes with CYS-AgNPs, concentration-dependent alterations in cell morphology were observed. Positively charged CYS-AgNPs notably decreased lymphocyte viability. Furthermore, they exhibited grater genotoxicity and more pronounced disruption of biological membranes compared to negatively charged CYZ-AgNPs. Despite both types of AgNPs interacting similarly with fetal bovine serum (FBS) and showing comparable profiles of silver ion release, the biological assays consistently revealed that the positively charged CYS-AgNPs exerted stronger effects at all investigated cellular levels. Although both types of CYS-AgNPs have the same chemical structure in their stabilizing layers, the pH-induced alterations in their surface charge significantly affect their biological activity.

Impact of Silver Nanoparticle Treatment and Chitosan on Packaging Paper's Barrier Effectiveness.

In this study, a comparative analysis of silver nanoparticles treatment and chitosan coating on packaging paper barrier properties was carried out. In order to examine the water, grease, and antibacterial barrier properties of silver nanoparticle-treated and chitosan-coated laboratory-obtained paper samples, a mixture of bleached softwood and hardwood celluloses was used. In order to conduct the comparative analysis SEM, water contact angle, Cobb60, and Kit tests were carried out on a cellulose sample, and four paper samples (three of them treated with silver nanoparticles-1, 2, and 3 mL/20 cm2 or chitosan coated-0.5, 1, and 2 g/m2) together with the inhibition activity against nine Gram-positive and Gram-negative bacteria, yeast, and fungal strains. The study found out that increasing the silver nanoparticle treatment and chitosan coating led to improved water resistance, while grease resistance was improved only for chitosan coated paper samples. Additionally, paper treated with 3 mL/20 cm2 of silver nanoparticles had the highest antibacterial protection (81.6%) against the Gram-positive bacterium Staphylococcus aureus, followed by Gram-negative Escherichia coli (75.8%). For the rest of the studied microorganisms, the average efficiency of the treated paper was 40.79%. The treatment of the paper with 1 and 2 mL/20 cm2 of silver nanoparticles was less effective-27.13 and 39.83%, respectively. The antibacterial protection of 2 g/m2 chitosan-coated paper samples was the most effective (average 79%) against the tested bacterial, yeast, and fungal strains. At 1 and 0.5 g/m2 chitosan coatings, the efficiency was 72.38% and 54.67%, respectively. Gram-positive bacteria, yeasts, and fungal strains were more sensitive to chitosan supplementation.

Evaluation of in vitro anthelmintic activity of crude extract and synthesized green silver nanoparticles of the leaves of Mammea americana L.

One of the most severe parasite infections to ever plague animals, paramphistomosis is particularly devastating in tropical and subtropical areas and causes significant economic losses to the world's food industry and poor animal health. In the present study potency of the crude extract and green synthesized silver nanoparticles from fresh and mature Mammea americana L. leaves was evaluated on trematode Paramphistomum cervi, collected from the infected rumen of the cow (Bos indicus) in 0.9% phosphate-buffered saline (PBS). The crude extract at five dose levels (1 mL, 2 mL, 3 mL 4 mL, and 5 ml), and silver nanoparticles (AgNps) at the five dose levels (10 mg/mL, 30 mg/mL, 50 mg/mL, 70 and 90 mg/mL) were applied. The synthesized AgNPs were characterized using UV-VIS spectrophotometry, X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Characterization studies of AgNPs revealed the synthesis of stable, crystalline AgNPs measuring an average size of 20-50 nm. The efficacy was evaluated based on the spontaneous movement reduction and death of P. cervi. Maximum anthelmintic activity was found at the dose of 5 mL of crude extract and 90 mg/mL of AgNPs of M. americana leaves. The scanning electron micrograph study of treated helminths of crude and AgNps revealed conspicuous distortion on the surface architecture. It also showed shrinkage of the whole body and severe damage on both suckers (anterior and posterior). AgNPs caused more shredded and torn tegumental surfaces with loss of tegumental papillae compared to untreated. Thus, this study confirmed that the M. americana leaves extract and synthesized AgNPs can be a potential alternative herbal drug in traditional folklore medicine against serious helminth infections in our livestock industry.

Effectiveness of white tea-mediated silver nanoparticles as an intracanal irrigant against Enterococcus faecalis: An in vitro study.

BACKGROUND: The probability of a positive outcome of root canal therapy is substantially higher if the infection is eradicated successfully before the obturation of the root canal system. Irrigation is an essential aspect of root canal debridement, as it enables more thorough cleaning than is possible with root canal instrumentation alone. To overcome the side effects of chemical irrigants, there has been a search for herbal medicines as substitutes. OBJECTIVES: The aim of the present study was to explore the antimicrobial efficacy of white tea-mediated silver nanoparticles (AgNPs) formulated as an intracanal irrigant against Enterococcus faecalis, and to compare it with the efficacy of chlorhexidine and sodium hypochlorite irrigants. MATERIAL AND METHODS: The experimental groups were as follows: group I - white tea-mediated AgNPs; group II - 2% chlorhexidine; and group III - 2.5% sodium hypochlorite. The characterization of AgNPs was performed using ultraviolet-visible (UV-Vis) spectroscopy and transmission electron microscopy (TEM) analysis. Enterococcus faecalis was inoculated onto Mueller-Hinton agar plates. The disks impregnated with irrigants were placed on the inoculated plates and incubated aerobically at 37°C for 24 h. Then, the growth inhibition zones were measured. Statistical analysis was performed using the one-way analysis of variance (ANOVA) and the post hoc tests. RESULTS: A concentration of 50 µL of white tea-mediated AgNPs exhibited the greatest zone of inhibition (32 ±2 mm), followed by 2% chlorhexidine (25 ±1 mm) and 2.5% sodium hypochlorite (23 ±3 mm). CONCLUSIONS: White tea-mediated AgNPs showed promising results in the elimination of E. faecalis, being superior to chlorhexidine and sodium hypochlorite irrigants.

Eco-friendly Strategy for Producing Bio-based Silver Nanoparticles (AgNPs) Employing Sepioteuthis lessoniana ink, in Addition to Biological and Degradation of Dye Applications.

The squid, Sepioteuthis lessoniana, is a remarkable fishery product which is exported by many nations for use in industrial production or human consumption. This study focused on the synthesis of silver nanoparticles (AgNPs) from squid ink (SI) and its wide range of applications. The formation of the nanoparticles was confirmed through UV-Visible spectroscopy, FTIR, XRD, SEM with EDX, DLS, and zeta potential analysis. The results showed a strong absorbance peak at 407 nm, the presence of various functional groups, a nanocrystalline structure with a crystalline size of 17.56 nm, spherical-shaped particles with an average size of 76 nm, and the presence of the highest % mass of Ag and uniformly dispersed particles, respectively. The bioactivity of the synthesized squid ink silver nanoparticles was analyzed through antibacterial, antioxidant, anticancer, and toxicity studies. The dye degradation assay was also analyzed as a means of wastewater treatment for different industrial dyes. The antibacterial activity showed the highest zone of inhibition of 24 mm at a concentration of 100 µg/ml against Escherichia coli, followed by other tested strains. The nitric oxide radical scavenging assay showed the highest antioxidant activity (92%) at a concentration of 100 µg/ml. The cytotoxic ability of SI-AgNPs against the MDA-MB-231 breast cancer cell line revealed an IC50 value of 4.52 µg/ml. The toxicity study revealed a dose and time-dependent activity with the LC50 value of 5.090 and 3.303 mg/ml for 24 and 48 h, respectively. The successful degradation of dyes by SI-AgNPs is attributed to the cooperative action of the electron relay system with Ag as a catalyst and SI as a catalytic support. These findings indicate that SI-AgNPs are a novel potential product that should be further studied to improve its pharmacological, biomedical, and environmental applications.