Biosynthesis and characterization of silver nanoparticles prepared from two novel natural precursors by facile thermal decomposition methods

Green synthesis of silver nanoparticles (AgNPs) and chitosan-coated silver nanoparticles (CS-AgNPs) using Ferula gummosa Boiss. gum extract: A green nano drug for potential applications in medicine

In this study, silver nanoparticles (AgNPs) and chitosan-coated silver nanoparticles (CS-AgNPs) were synthesized in a green way using Ferula gummosa Boiss. gum extract. The as-prepared NPs were employed as efficient nanomaterials for developing antimicrobial, antioxidant, and anticancer agents. The AgNPs and the CS-AgNPs were characterized using TEM, EDX, FESEM, UV-Vis, XRD, DLS, and FTIR. The UV-Vis spectra showed the surface plasmon resonance for the AgNPs in the visible range around 420 nm. Also, the TEM images indicated particle sizes ranging from 2 to 20 nm and 5-50 nm for the AgNPs and the CS-AgNPs, respectively. Cytotoxicity of the AgNPs and the CS-AgNPs was assessed through MTT and hemolysis assays on normal and cancer cell lines. The AgNPs and the CS-AgNPs demonstrated significant antibacterial activity against Staphylococcus aureus and Bacillus subtilis. The antioxidant assays revealed substantial free radical scavenging activity, with CS-AgNPs exhibiting superior antioxidant properties. In addition, the hemolysis assay illustrated low hemolytic activity for the AgNPs and CS-AgNPs. Moreover, the MTT assay demonstrated a significant cytotoxic effect for the AgNPs and the CS-AgNPs on the MCF-7 breast cancer cell line. These results provide an effective strategy to prepare the biosynthesized AgNPs and the CS-AgNPs for future pharmaceutical applications.

Green-synthesized silver nanoparticles induced apoptotic cell death in CACO2 cancer cells by activating MLH1 gene expression

MLH1 (Mult homolog1) gene is the main element of Multlα heterodimer and plays a role in the repair of base-base mismatches and deletion and addition loops. When the MLH1 protein is not present, the number of errors that remain unrepaired increases, and this can lead to the formation of tumors in the body. Colorectal cancer is the third most common type of cancer in terms of incidence and the third type of cancer in terms of mortality worldwide. In this regard, the present study was conducted with the aim of investigating the effect of biological silver nanoparticles with anticancer properties and MLH1 gene expression on cancer cell samples of people with colorectal cancer. In this study, the green synthesis of silver nanoparticles was carried out by precipitation method with reduction of silver ions by leaf and flower extract of Moringa oleifera plant. Then, silver nanoparticles were confirmed using UV-visible spectroscopy, transmission and scanning electron microscopy. The cytotoxic effects of nanoparticles on cells were evaluated by MTT colorimetric method within 42 h. After RNA extraction of treated cells, cDNA synthesis and primers were designed by the Exon-Exon Junction method and the Real-time Polymerase test for MLH1 and Beta-actin genes was repeated three times. The final analysis of the results was done using Graphpad Prism and Rest 2009 software. The presence of a peak at the wavelength of 234 nm for the synthesized silver nanoparticles was confirmed by ultraviolet-visible spectroscopic analysis. The morphological study on the size and shape of the silver nanoparticles showed that the nanoparticles are spherical and have a size between 40 and 34 nanometers in diameter. The leaf extract typically produces smaller, more uniform particles than the flower extract. The Green-Synthesized Silver Nanoparticles of leaf extract were used to evaluation of induced Apoptotic Cell Death in CACO2 Cancer Cells by Activating MLH1 Gene Expression. MTT results showed that the anti-proliferative effect of nanoparticles depends on the concentration of synthesized silver nanoparticles. The treatment of MLH1 cancer cell line and normal with synthesized nanoparticles at a concentration of 0.44 micrograms per ml for 42 h showed the effects of cell toxicity. The percentage of cancer cell death under the influence of quercetin present in Moringa green bio-particles depends on the concentration and time, and this difference is statistically significant compared to the control group (P < 0.05). So that the lethal dose of the extract for 50% survival IC50 in a period of 48 h for intestinal cancer cells was equal to 21 μg/ml, and the expression ratio of the MLH1 gene in the tumor tissue to the adjacent healthy tissue has increased (P ≤ 0.05).

Locust bean gum-based silver nanocomposite hydrogel as a drug delivery system and an antibacterial agent

Effective drug release is of utmost importance in the medical field for treating various diseases, particularly cancer. Nanocomposite hydrogels remain the best materials for enhancing the bioavailability and therapeutic levels of drugs as they enable sustained, targeted, or controlled drug release. In this work, a nanocomposite hydrogel containing locust bean gum (LBG), poly(4-acryloylmorpholine) (PAcM), and silver nanoparticles (SN) has been made using an eco-friendly microwave (MW)-assisted method and characterized by various advanced techniques. The material is evaluated for its potential as a polymer matrix towards delivering 5-fluorouracil (5-FU), an anticancer drug in the gastrointestinal tract, and inhibiting bacterial growth. The pH-dependency of the nanocomposite material towards swelling and drug release and its antibacterial characteristics have been compared with the neat gel in order to understand the role of SN in enhancing the performance of the materials. The results indicated both polymer materials exhibit a pH-dependent release of 5-FU with a higher release at pH 1.2, simulated gastric fluid, than at pH 7.4, simulated intestinal fluid. About 72 % of the loaded drug was released from the nanocomposite, as compared to 44 % from the neat gel at pH 1.2 during the observation period of 3 h. The drug release process could be best explained by the first-order kinetic model and Fickian diffusion transport mechanism. The nanocomposite exhibited remarkable antibacterial activity against Staphylococcus aureus and Escherichia coli. The biocompatibility of the drug-loaded nanocomposite was demonstrated by a cytotoxicity study, which showed higher than 80 % viability of healthy IEC-6 cells. The results indicate the suitability of the developed nanocomposite material as a polymer matrix for sustained release of 5-FU for cancer therapy and also as an antibacterial agent to fight against bacterial infections.

Nail Lacquer Containing Origanum vulgare and Rosmarinus officinalis Essential Oils and Biogenic Silver Nanoparticles for Onychomycosis: Development, Characterization, and Evaluation of Antifungal Efficacy

Onychomycosis is a common fungal nail infection for which new antifungals are needed to overcome antimicrobial resistance and the limitations of conventional treatments. This study reports the development of antifungal nail lacquers containing oregano essential oil (OEO), rosemary essential oil (REO), and biogenic silver nanoparticles (bioAgNPs). The formulations (F) were tested against dermatophytes using agar diffusion, ex vivo nail infection, and scanning electron microscopy techniques. They were evaluated for their pharmacotechnical characteristics and by FTIR-PAS to assess permeation across the nail. F-OEO and F-OEO/bioAgNPs were promising candidates for the final nail lacquer formulation, as they permeated through the nail and showed antifungal efficacy against dermatophytes-contaminated nails after 5 days of treatment. Treated nails exhibited decreased hyphae and spores compared to the untreated control; the hyphae were atypically flattened, indicating loss of cytoplasmic content due to damage to the cytoplasmic membrane. The formulations were stable after centrifugation and thermal stress, maintaining organoleptic and physicochemical characteristics. Both F-OEO and F-OEO/bioAgNPs had pH compatible with the nail and drying times (59-90 s) within the reference for nail lacquer. For the first time, OEO and bioAgNPs were incorporated into nail lacquer, resulting in a natural and nanotechnological product for onychomycosis that could combat microbial resistance.

Apoptotic efficiency of Dicoma anomala biosynthesized silver nanoparticles against A549 lung cancer cells

Lung cancer is one of the common forms of cancer that affects both men and women and is regarded as the leading cause of cancer related deaths. It is characterized by unregulated cell division of altered cells within the lung tissues. Green nanotechnology is a promising therapeutic option that is adopted in cancer research. Dicoma anomala (D. anomala) is one of the commonly used African medicinal plant in the treatment of different medical conditions including cancer. In the present study, silver nanoparticles (AgNPs) were synthesized using D. anomala MeOH root extract. We evaluated the anticancer efficacy of the synthesized AgNPs as an individual treatment as well as in combination with pheophorbide a (PPBa) mediated photodynamic therapy (PDT) in vitro. UV-VIS spectroscopy, high-resolution transmission electron microscopy (HR-TEM), Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) was used to confirm the formation of D.A AgNPs. Post 24 h treatment, A549 cells were evaluated for ATP proliferation, morphological changes supported by LIVE/DEAD assay, and caspase activities. All experiments were repeated four times (n=4), with findings being analysed using SPSS statistical software version 27 set at 0.95 confidence interval. The results from the present study revealed a dose-dependent decrease in cell proliferation in both individual and combination therapy of PPBa mediated PDT and D.A AgNPs on A549 lung cancer cells with significant morphological changes. Additionally, LIVE/DEAD assay displayed a significant increase in the number of dead cell population in individual treatments (i.e., IC50's treated A549 cells) as well as in combination therapy. In conclusion, the findings from this study demonstrated the anticancer efficacy of green synthesized AgNPs as a mono-therapeutic drug as well as in combination with a chlorophyll derivative PPBa in PDT. Taken together, the findings highlight the therapeutic potential of green nanotechnology in medicine.

Green synthesis of metal nanoparticles and study their anti-pathogenic properties against pathogens effect on plants and animals

According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV-Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc.

Electrospun nanofibers synthesized from polymers incorporated with bioactive compounds for wound healing

The development of innovative wound dressing materials is crucial for effective wound care. It's an active area of research driven by a better understanding of chronic wound pathogenesis. Addressing wound care properly is a clinical challenge, but there is a growing demand for advancements in this field. The synergy of medicinal plants and nanotechnology offers a promising approach to expedite the healing process for both acute and chronic wounds by facilitating the appropriate progression through various healing phases. Metal nanoparticles play an increasingly pivotal role in promoting efficient wound healing and preventing secondary bacterial infections. Their small size and high surface area facilitate enhanced biological interaction and penetration at the wound site. Specifically designed for topical drug delivery, these nanoparticles enable the sustained release of therapeutic molecules, such as growth factors and antibiotics. This targeted approach ensures optimal cell-to-cell interactions, proliferation, and vascularization, fostering effective and controlled wound healing. Nanoscale scaffolds have significant attention due to their attractive properties, including delivery capacity, high porosity and high surface area. They mimic the Extracellular matrix (ECM) and hence biocompatible. In response to the alarming rise of antibiotic-resistant, biohybrid nanofibrous wound dressings are gradually replacing conventional antibiotic delivery systems. This emerging class of wound dressings comprises biopolymeric nanofibers with inherent antibacterial properties, nature-derived compounds, and biofunctional agents. Nanotechnology, diminutive nanomaterials, nanoscaffolds, nanofibers, and biomaterials are harnessed for targeted drug delivery aimed at wound healing. This review article discusses the effects of nanofibrous scaffolds loaded with nanoparticles on wound healing, including biological (in vivo and in vitro) and mechanical outcomes.

'Green' silver nanoparticles combined with tyrosol as potential oral antimicrobial therapy

OBJECTIVES

This study aimed to evaluate silver nanoparticles (AgNPs) obtained by a 'green' route associated or not to tyrosol (TYR) against Streptococcus mutans and Candida albicans in planktonic and biofilms states.

METHODS

AgNPs were obtained by a 'green' route using pomegranate extract. The minimum inhibitory concentration (MIC) against S. mutans and C. albicans was determined for AgNPs and TYR combined and alone, and fractional inhibitory concentration index (FICI) was calculated. Single biofilms of C. albicans and S. mutans were cultivated for 24 h and then treated with drugs alone or in combination for 24 h.

RESULTS

AgNPs and TYR were effective against C. albicans and S. mutans considering planktonic cells alone and combined. The MIC values obtained for C. albicans was 312.5 µg/mL (AgNPs) and 50 mM (TYR) and for S. mutans was 78.1 µg/mL (AgNPs) and 90 mM (TYR). The combination of these antimicrobial agents was also effective against both microorganisms: 2.44 µg/mL/0.08 mM (AgNPs/TYR) for C. albicans and 39.05 µg/mL /1.25 mM (AgNPs/TYR) for S. mutans. However, synergism was observed only for C. albicans (FICI 0.008). When biofilm was evaluated, a reduction of 4.62 log10 was observed for S. mutans biofilm cells treated with AgNPs (p < 0.05, Tukey test). However, the addition of TYR to AgNPs did not improve their action against biofilm cells (p > 0.05). AgNPs combined with TYR demonstrated a synergistic effect against C. albicans biofilms.

CONCLUSIONS

These findings suggest the potential use of AgNPs with or without TYR against C. albicans and S. mutans, important oral pathogens.

CLINICAL SIGNIFICANCE

AgNPs obtained by a 'green' route combined or not with TYR can be an alternative to develop several types of oral antimicrobial therapies and biomaterials.

Silver and gold nanoparticles: Eco-friendly synthesis, antibiofilm, antiviral, and anticancer bioactivities

For the first time in this study, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were green synthesized by the cost-effective and eco-friendly procedure using Cotton seed meal and Fodder yeast extracts. The biosynthesized NPs were characterized by UV-Vis spectroscopy, dynamic light scattering analysis (DLS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and fourier-transform infrared (FTIR) spectroscopy. Furthermore, the biosynthesized NPs were tested in vitro against biofilm formation by some pathogenic negative bacteria (Escherichia coli, Proteus mirabilis, Klebsiella sp., Salmonella sp., and Pseudomonas aeruginosa) and negative bacteria (staphylococcus aureus) as well as against human denovirus serotype 5 (HAdV-5) and anticancer activity using HepG2 hepatocarcinoma cells. UV-Vis absorption spectra of reaction mixture of AgNPs and AuNPs exhibited maximum absorbance at 440 nm and 540 nm, respectively. This finding was confirmed by DLS measurements that the highest intensity of the AgNPs and AuNPs were 84 nm and 73.9 nm, respectively. FTIR measurements identified some functional groups detected in Cotton seed meal and Fodder yeast extracts that could be responsible for reduction of silver and gold ions to metallic silver and gold. The morphologies and particle size of AgNPs and AuNPs were confirmed by the TEM and SAED pattern analysis. Biosynthesized AgNPs and AuNPs showed good inhibitory effects against biofilms produced by Escherichia coli, Proteus mirabilis, Klebsiella sp., Salmonella sp., Pseudomonas aeruginosa, and Staphylococcus aureus. In addition, they showed anticancer activities against hepatocellular carcinoma (HepG-2) and antiviral activity against human adenovirus serotype 5 infection in vitro. Finally, the results of this study is expected to be extremely helpful to nano-biotechnology, pharmaceutical, and food packing applications through developing antimicrobial and/or an anticancer drugs from ecofriendly and inexpensive nanoparticles with multi-potentiality.

Evaluation of biological potential of UV-spectrophotometric, SEM, FTIR, and EDS observed Punica granatum and Plectranthus rugosus extract-coated silver nanoparticles: A comparative study

Recent developments in the green synthesis of metallic nanoparticles (NPs) using phytoconstituents have attracted the attention of the global scientific community. The present study was designed to synthesize silver NPs (AgNPs) using Punica granatum and Plectranthus rugosus plant extracts. The fabricated AgNPs were characterized using UV-visible spectrophotometry (UV-Vis), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS). The shift in the color of the silver nitrate (AgNO3 ) solution after the addition of P. granatum and P. rugosus extracts indicated the synthesis of AgNPs. The effect of AgNO3 concentrations and pH on the synthesis of AgNPs was also evaluated. The findings of this study suggest that AgNO3 concentration of 1 mM, reaction time of 1 h, and pH of 7 at room temperature were the best suited conditions for the synthesis of AgNPs. According to the FTIR analysis, amidic and carbonyl compounds were primarily responsible for the encapsulation of AgNPs. SEM investigations have shown irregularly shaped geometry with sizes of 35 nm (P. granatum) and 33 nm (P. rugosus) with low agglomeration. The prepared AgNPs exhibited good potential for 2,2-diphenyl-1-picrylhydrazyl radical scavenging, with values of 70% (P. granatum) and 68% (P. rugosus). Hence, we conclude that the leaves of P. granatum and P. rugosus are excellent material for designing of different plant-extracted-conjugated AgNPs for biomedical applications. RESEARCH HIGHLIGHTS: Preparation of the AgNPs using novel plants extracts. P. granatum and P. rugosus extract as reducing, capping, stabilizing, and optimizing agents. Thorough comparative characterization using UV-Vis spectrophotometer, FTIR, SEM, and EDS which is a first of its kind. Comparative antioxidant activity.

Himalayan lichen biomass for green synthesis of silver nanocolloids: growth kinetics, effect of pH and metal sensing

Lichen is one of the most abundant non-vascular biomasses; however, a systematic study on the application of biomass in nanomaterial synthesis is very limited. In this study, an aqueous lichen extract was obtained from Hypotrachyna cirrhata, one of the most abundant Himalayan lichen biomasses, using a simple cold percolation method. The effects of extract-to-silver nitrate mixing ratio, pH and waiting time on the growth and stability of nanoparticles were systematically explored. The rate constant for bio-reduction was found to be 5.3 × 10-3 min-1. Transmission electron microscopy showed a narrow particle size distribution with a mean particle size of 11.1 ± 3.6 nm (n = 200). The X-ray diffraction and selected area electron diffraction techniques confirmed the formation of cubic crystals. The synthesized colloidal solution showed excellent response to Hg2+ and Cu2+ ions in spiked water samples. The limit of detection and calibration sensitivity for Hg2+ and Cu2+ ions were found to be 1 and 5 mg l-1 and 2.9 × 10-3 and 1.6 × 10-3 units ppm-1, respectively. These findings suggested that spherical silver nanoparticles with a narrow particle size distribution can be synthesized on a laboratory scale using an aqueous H. cirrhata lichen extract, and the colloidal solution can be used for the detection of selected heavy metals in water samples.

Scolicidal and apoptotic effects of phyto- and chemically synthesized silver/boehmite nanocomposites on Echinococcus granulosus protoscoleces

Cystic hydatid disease (CHD) is a zoonotic disease caused by the larval stage of Echinococcus granulosus (E. granulosus). This study aimed to synthesize silver nanoparticles (Ag NPs), silver boehmite nanocomposite (Ag/Bhm NC), and silver boehmite nanocomposite modified with chitosan (Ag/Bhm/Chit NC) using Rosmarinus officinalis (R. officinalis) extract and chemical method, and to evaluate their scolicidal and apoptotic effects on protoscoleces (PSCs) in vitro. The nanomaterials (NMs) were characterized by XRD, FTIR, FESEM, EDS, DLS, PDI, and zeta potential (ZP). The NMs were tested against PSCs at different concentrations (0.2-1.6 mg/mL) and exposure times (10-60 min). The size of Ag NPs, phytosynthesized Ag/Bhm NC, Ag/Bhm/Chit NC, and chemically synthesized Ag/Bhm NC were 25.55, 43, 72.3, and 60.8 nm, respectively. Ag NPs and phytosynthesized Ag/Bhm NC showed the highest scolicidal effect, with 65.34 % and 51.60 % mortality rate at 1.6 mg/mL and 60 min, respectively. Caspase-3 mRNA expression was higher in PSCs treated with Ag NPs and Ag/Bhm NC than in control groups (P < 0.05). Phytosynthesized Ag/Bhm NC had stronger scolicidal and apoptotic effect than chemically synthesized Ag/Bhm NC. Ag/Bhm/Chit NC had a weaker scolicidal effect but higher gene expression than Ag/Bhm NC. In conclusion, this study demonstrates the potential of phytosynthesized Ag NPs and Ag/Bhm NC as effective scolicidal and apoptotic agents against PSCs of hydatid cysts, which may be useful for the treatment of this disease.

Silver and Antimicrobial Polymer Nanocomplexes to Enhance Biocidal Effects

Antimicrobial resistance has become a major problem over the years and threatens to remain in the future, at least until a solution is found. Silver nanoparticles (Ag-NPs) and antimicrobial polymers (APs) are known for their antimicrobial properties and can be considered an alternative approach to fighting resistant microorganisms. Hence, the main goal of this research is to shed some light on the antimicrobial properties of Ag-NPs and APs (chitosan (CH), poly-L-lysine (PLL), ε-poly-L-lysine (ε-PLL), and dopamine (DA)) when used alone and complexed to explore the potential enhancement of the antimicrobial effect of the combination Ag-NPs + Aps. The resultant nanocomplexes were chemically and morphologically characterized by UV-visible spectra, zeta potential, transmission electron microscopy, and Fourier-transform infrared spectroscopy. Moreover, the Ag-NPs, APs, and Ag-NPs + APs nanocomplexes were tested against Gram-positive Staphylococcus aureus (S. aureus) and the Gram-negative Escherichia coli (E. coli) bacteria, as well as the fungi Candida albicans (C. albicans). Overall, the antimicrobial results showed potentiation of the activity of the nanocomplexes with a focus on C. albicans. For the biofilm eradication ability, Ag-NPs and Ag-NPs + DA were able to significantly remove S. aureus preformed biofilm, and Ag-NPs + CH were able to significantly destroy C. albicans biofilm, with both performing better than Ag-NPs alone. Overall, we have proven the successful conjugation of Ag-NPs and APs, with some of these formulations showing potential to be further investigated for the treatment of microbial infections.

Visible light-active samarium manganite nanostructures for enhanced water-soluble pollutant degradation

In this study, a green approach was used to synthesize SmMnO3 magnetic nanoparticles via the auto combustion method, where pomegranate juice was utilized as a natural fuel. The concentration of fuel was varied to investigate its effect on the purity and morphology of SmMnO3 nanoparticles. The physiochemical properties of the synthesized nanoparticles, including crystal structures, morphology, optical, and magnetic properties, were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Diffuse Reflectance Spectroscopy (DRS), X-ray fluorescence (XRF) and Brunauer-Emmett-Teller (BET). The band gap of the as-synthesized nanoparticles was determined to be 1.8 eV, indicating their potential as a photocatalyst. The photocatalytic activity of SmMnO3 nanoparticles was evaluated against Methyl violet and Erythrosine, and the mechanism of photocatalyst was determined using EDTA, benzoic acid, and benzoquinone as scavengers. Photocatalytic activity was studied in both UV and visible light, and it was found that the maximum degradation (94%) was related to the degradation of Erythrosine (10 ppm) in the presence of visible light. The stability test of SmMnO3 performed and confirmed the stability of nanoparticles after 5 cycles. The results suggest that SmMnO3 nanoparticles synthesized via the green auto combustion method using pomegranate juice as a natural fuel can serve as a promising photocatalyst for the degradation of organic pollutants in the environment. Further studies can be conducted to investigate their potential in other applications.

Preparation and characterization of porous membranes of glucomannan and silver decorated cellulose nanocrystals for application as biomaterial

Bacterial infection usually represents a threat in medical wound care, due to the increase in treatment complexity and the risk of antibiotic resistance. For presenting interesting characteristics for the use as biomaterial, natural polymers have been explored for this application. Among them, a promising candidate is the konjac glucomannan (KGM) with outstanding biocompatibility and biodegradability but lack of antibacterial activity. In this study, KGM was combined with silver decorated cellulose nanocrystals (CNC-Ag) to prepare membranes by using a recent reported casting-freezing method. The results highlight the potential anti-adhesive activity of the new materials against Staphylococcus aureus upon contact, without the burst release of silver nanoparticles. Furthermore, the incorporation of CNC enhanced the thermal stability of these membranes while preserving the favorable mechanical properties of the KGM-based material. These findings highlight a straightforward approach to enhance the antibacterial properties of natural polymers, which can be effectively useful in medical devices like wound dressings that typically lack such properties.

In vitro and in vivo antimalarial activity of green synthesized silver nanoparticles using Sargassum tenerrimum - a marine seaweed

Green nanotechnology has recently attracted a lot of attention as a potential technique for drug development. In the present study, silver nanoparticles were synthesised by using Sargassum tenerrimum, a marine seaweed crude extract (Ag-ST), and evaluated for antimalarial activity in both in vitro and in vivo models. The results showed that Ag-ST nanoparticles exhibited good antiplasmodial activity with IC50 values 7.71±0.39 µg/ml and 23.93±2.27 µg/ml against P. falciparum and P. berghei respectively. These nanoparticles also showed less haemolysis activity suggesting their possible use in therapeutics. Further, P. berghei infected C57BL/6 mice were used for the four-day suppressive, curative and prophylactic assays where it was noticed that the Ag-ST nanoparticles significantly reduced the parasitaemia and there were no toxic effects observed in the biochemical and haematological parameters. Further to understand its possible toxic effects, both in vitro and in vivo genotoxicological studies were performed which revealed that these nanoparticles are non-genotoxic in nature. The possible antimalarial activity of Ag-ST may be due to the presence of bioactive phytochemicals and silver ions. Moreover, the phytochemicals prevent the nonspecific release of ions responsible for low genotoxicity. Together, the bio-efficacy and toxicology outcomes demonstrated that the green synthesized silver nanoparticles (Ag-ST) could be a cutting-edge alternative for therapeutic applications.

Antimicrobial and Apoptotic Efficacy of Plant-Mediated Silver Nanoparticles

Phytogenically synthesised nanoparticle (NP)-based drug delivery systems have promising potential in the field of biopharmaceuticals. From the point of view of biomedical applications, such systems offer the small size, high surface area, and possible synergistic effects of NPs with embedded biomolecules. This article describes the synthesis of silver nanoparticles (Ag-NPs) using extracts from the flowers and leaves of tansy (Tanacetum vulgare L.), which is known as a remedy for many health problems, including cancer. The reducing power of the extracts was confirmed by total phenolic and flavonoid content and antioxidant tests. The Ag-NPs were characterised by various analytical techniques including UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), Fourier transform infrared (FT-IR) spectroscopy, and a dynamic light scattering (DLS) system. The obtained Ag-NPs showed higher cytotoxic activity than the initial extracts against both human cervical cancer cell lines HeLa (ATCC CCL-2) and human melanoma cell lines A375 and SK-MEL-3 by MTT assay. However, the high toxicity to Vero cell culture (ATCC CCL-81) and human fibroblast cell line WS-1 rules out the possibility of their use as anticancer agents. The plant-mediated Ag-NPs were mostly bactericidal against tested strains with MBC/MIC index ≤4. Antifungal bioactivity (C. albicans, C. glabrata, and C. parapsilosis) was not observed for aqueous extracts (MIC > 8000 mg L^-1), but Ag-NPs synthesised using both the flowers and leaves of tansy were very potent against Candida spp., with MIC 15.6 and 7.8 µg mL^-1, respectively.

Green Synthesis of Silver Nanoparticles Using Acacia ehrenbergiana Plant Cortex Extract for Efficient Removal of Rhodamine B Cationic Dye from Wastewater and the Evaluation of Antimicrobial Activity

Silver nanoparticles (Ag-NPs) exhibit vast potential in numerous applications, such as wastewater treatment and catalysis. In this study, we report the green synthesis of Ag-NPs using Acacia ehrenbergiana plant cortex extract to reduce cationic Rhodamine B (RhB) dye and for antibacterial and antifungal applications. The green synthesis of Ag-NPs involves three main phases: activation, growth, and termination. The shape and morphologies of the prepared Ag-NPs were studied through different analytical techniques. The results confirmed the successful preparation of Ag-NPs with a particle size distribution ranging from 1 to 40 nm. The Ag-NPs were used as a heterogeneous catalyst to reduce RhB dye from aqueous solutions in the presence of sodium borohydride (NaBH₄). The results showed that 96% of catalytic reduction can be accomplished within 32 min using 20 μL of 0.05% Ag-NPs aqueous suspension in 100 μL of 1 mM RhB solution, 2 mL of deionized water, and 1 mL of 10 mM NaBH₄ solution. The results followed a zero-order chemical kinetic (R² = 0.98) with reaction rate constant k as 0.059 mol L^-1 s^-1. Furthermore, the Ag-NPs were used as antibacterial and antifungal agents against 16 Gram-positive and Gram-negative bacteria as well as 1 fungus. The green synthesis of Ag-NPs is environmentally friendly and inexpensive, as well as yields highly stabilized nanoparticles by phytochemicals. The substantial results of catalytic reductions and antimicrobial activity reflect the novelty of the prepared Ag-NPs. These nanoparticles entrench the dye and effectively remove the microorganisms from polluted water.

Rotheca serrata Flower Bud Extract Mediated Bio-Friendly Preparation of Silver Nanoparticles: Their Characterizations, Anticancer, and Apoptosis Inducing Ability against Pancreatic Ductal Adenocarcinoma Cell Line

Over past decades, the green method of synthesizing metal nanoparticles has acquired more attentiveness by scientific consensus because of its industrial and biomedical applications. This study focuses on the anti-proliferative effectiveness of AgNPs synthesized from Rotheca serrata (L.) Steane & Mabb. flower bud extract against the PANC-1 cell line in vitro. Various analytical instruments were utilized to visualize the formation of RsFb-AgNPs, such as UV-Vis spectroscopy, FT-IR, SEM, EDS, TEM, XRD, Zeta potential, and DLS analysis. The biosynthesis of RsFb-AgNPs was observed by a change in color and UV-Vis spectroscopy (415 nm). The FT-IR spectra exhibited the existence of many functional groups. XRD confirmed the crystallinity of the AgNPs. Morphology and elemental mapping were assessed by SEM and EDS analysis. The TEM micrograph revealed spherical-shaped particles with sizes ranging from 12 to 40 nm. Zeta potential and DLS analysis were used to measure surface charge and particle size. Biological properties, including the antioxidant, antimicrobial, and anticancer properties of synthesized RsFb-AgNPs, exhibited dose-dependent activities. In DPPH assay, synthesized RsFb-AgNPs inhibited the scavenging of free radicals in a dose-dependent manner. In addition, the resultant RsFb-AgNPs displayed moderate antimicrobial activity against tested pathogens. Further, the anti-proliferative efficacy of biosynthesized RsFb-AgNPs was determined against the PANC-1 cell line using the MTT assay. The results revealed a dose-dependent decrease in viability of cancer cells with an IC50 value of 36.01 µg/mL. Flow cytometry was then used to confirm the apoptotic effects by double staining with annexin V/PI. In response to the pancreatic ductal adenocarinoma cell line, the results showed notable early and late apoptosis cell population percentages. In conclusion, the synthesized RsFb-AgNPs revealed a potential anticancer agent that can induce apoptosis in the PANC-1 cells.

Metallic and non-metallic nanoparticles from plant, animal, and fisheries wastes: potential and valorization for application in agriculture

Global agriculture is facing tremendous challenges due to climate change. The most predominant amongst these challenges are abiotic and biotic stresses caused by increased incidences of temperature extremes, drought, unseasonal flooding, and pathogens. These threats, mostly due to anthropogenic activities, resulted in severe challenges to crop and livestock production leading to substantial economic losses. It is essential to develop environmentally viable and cost-effective green processes to alleviate these stresses in the crops, livestock, and fisheries. The application of nanomaterials in farming practice to minimize nutrient losses, pest management, and enhance stress resistance capacity is of supreme importance. This paper explores innovative methods for synthesizing metallic and non-metallic nanoparticles using plants, animals, and fisheries wastes and their valorization to mitigate abiotic and biotic stresses and input use efficiency in climate-smart and stress-resilient agriculture including crop plants, livestock, and fisheries.

Leucophyllum frutescens mediated synthesis of silver and gold nanoparticles for catalytic dye degradation

The application of nanotechnology is gaining worldwide attention due to attractive physico-chemical and opto-electronic properties of nanoparticles that can be also employed for catalytic dye degradation. This study reports a phytogenic approach for fabrication of silver (AgNPs) and gold nanoparticles (AuNPs) using Leucophyllum frutescens (Berl.) I. M. Johnst (Scrophulariaceae) leaf extract (LFLE). Development of intense dark brown and purple color indicated the synthesis of AgNPs and AuNPs, respectively. Further characterization using UV-visible spectroscopy revealed sharp peak at 460 nm and 540 nm for AgNPs and AuNPs, respectively that were associated to their surface plasmon resonance. High resolution transmission electron microscope (HRTEM) revealed the spherical shape of the AgNPs, whereas anisotropic AuNPs were spherical, triangular and blunt ended hexagons. The majority of the spherical AgNPs and AuNPs were ∼50 ± 15 nm and ∼22 ± 20 nm, respectively. Various reaction parameters such as, metal salt concentration, temperature and concentration of the leaf extract were optimized. Maximum synthesis of AgNPs was obtained when 5 mM for AgNO₃ reacted with 10% LFLE for 48 h at 50°C. Likewise, AuNPs synthesis was highest when 2 mM HAuCl₄ reacted with 10% LFLE for 5 h at 30°C. Energy dispersive spectroscopy (EDS) showed phase purity of both the nanoparticles and confirmed elemental silver and gold in AgNPs and AuNPs, respectively. The average hydrodynamic particles size of AgNPs was 34.8 nm while AuNPs was 140.8 nm as revealed using dynamic light scattering (DLS) that might be due to agglomeration of smaller nanoparticles into larger clusters. ZETA potential of AgNPs and AuNPs were 0.67 mV and 5.70 mV, respectively. X-ray diffraction (XRD) analysis confirmed the crystallinity of the nanoparticles. Fourier transform infrared spectroscopy (FTIR) confirmed that various functional groups from the phytochemicals present in LFLE played a significant role in reduction and stabilization during the biogenic synthesis of the nanoparticles. The bioreduced AgNPs and AuNPs catalytically degraded Rhodamine B dye (RhB) in presence of UV-light with degradation rate constants of 0.0231 s⁻¹ and 0.00831 s⁻¹, respectively. RhB degradation followed a first order rate kinetics with 23.1 % and 31.7% degradation by AgNPs and AuNPs, respectively.

Chitosan-coated nanostructured lipid carriers for transdermal delivery of tetrahydrocurcumin for breast cancer therapy

Chitosan (Ch)-coated nanostructured lipid carriers (NLCs) have great potential for transdermal delivery with high localization of chemotherapeutics in breast cancer. This study used tetrahydrocurcumin (THC), a primary metabolite of curcumin with enhanced antioxidant and anticancer properties, as a model compound to prepare NLCs. Response surface methodology was employed to optimize THC-loaded Ch-coated NLCs (THC-Ch-NLCs) fabricated by high-shear homogenization. The optimized THC-Ch-NLCs had particle size of 244 ± 18 nm, zeta potential of -17.5 ± 0.5 mV, entrapment efficiency of 76.6 ± 0.2% and drug loading of 0.28 ± 0.01%. In vitro release study of THC-Ch-NLCs showed sustained release following the Korsmeyer-Peppas model with Fickian and non-Fickian diffusion at pH 7.4 and 5.5, respectively. THC-Ch-NLCs demonstrated significantly enhanced in vitro skin permeation, cell uptake, and remarkable cytotoxicity toward MD-MBA-231 breast cancer cells compared to the unencapsulated THC, suggesting Ch-NLCs as potential transdermal nanocarriers of THC for triple-negative breast cancer treatment.

Synthesis of Iron, Zinc, and Manganese Nanofertilizers, Using Andean Blueberry Extract, and Their Effect in the Growth of Cabbage and Lupin Plants

The predominant aim of the current study was to synthesize the nanofertilizer nanoparticles ZnO_MnO-NPs and FeO_ZnO-NPs using Andean blueberry extract and determine the effect of NPs in the growth promotion of cabbage (Brassica oleracea var. capitata) and Andean lupin (Lupinus mutabilis sweet) crops. The nanoparticles were analyzed by visible spectrophotometry, size distribution (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Solutions of nanoparticle concentrations were applied to cabbage, with solutions of 270 and 540 ppm of ZnO_MnO-NPs and 270 and 540 ppm of FeO_ZnO-NPs applied to Andean lupin. Zinc was used in both plants to take advantage of its beneficial properties for plant growth. Foliar NPs sprays were applied at the phenological stage of vegetative growth of the cabbage or Andean lupin plants grown under greenhouse conditions. The diameter of the NPs was 9.5 nm for ZnO, 7.8 nm for FeO, and 10.5 nm for MnO, which facilitate the adsorption of NPs by the stomata of plants. In Andean lupin, treatment with 270 ppm of iron and zinc indicated increases of 6% in height, 19% in root size, 3.5% in chlorophyll content index, and 300% in leaf area, while treatment with 540 ppm of iron and zinc yielded no apparent increases in any variable. In cabbage, the ZnO_MnO-NPs indicate, at a concentration of 270 ppm, increases of 10.3% in root size, 55.1% in dry biomass, 7.1% in chlorophyll content, and 25.6% in leaf area. Cabbage plants treated at a concentration of 540 ppm produced increases of 1.3% in root size and 1.8% in chlorophyll content, compared to the control, which was sprayed with distilled water. Therefore, the spray application of nanofertilizers at 270 ppm indicated an important improvement in both plants’ growth.

Diospyros malabarica Fruit Extract Derived Silver Nanoparticles: A Biocompatible Antibacterial Agent

Biogenic silver nanoparticles demonstrate excellent antibacterial activity against a broad range of bacteria. Herein, aqueous biogenic silver nanoparticles (Aq@bAgNPs) and ethanolic biogenic silver nanoparticles (Et@bAgNPs) were synthesized using aqueous as well as ethanolic extracts of Diospyros malabarica fruit, respectively. The as-prepared biogenic silver nanoparticles (bAgNPs) were characterized using UV-Vis, FTIR as well as energy dispersive X-ray (EDS) spectroscopy, electron microscopy, dynamic light scattering spectroscopy (DLS), and zetasizer. The zeta potentials of Aq@bAgNPs and Et@bAgNPs were −9.8 ± 2.6, and −12.2 ± 1.9 mV, respectively. The antibacterial activity of bAgNPs was investigated against seven bacterial strains (i.e., pathogenic and nonpathogenic) and Et@bAgNPs exhibited the highest antibacterial propensity (i.e., 20 nm in diameter) against Bacillus subtillis through disk diffusion assay. The trypan blue dye exclusion assay also confirmed the antibacterial propensity of as-prepared bAgNPs. Furthermore, both Aq@bAgNPs and Et@bAgNPs oxidize bacterial membrane fatty acids and generate lipid peroxides which eventually form complexes with thiobarbituric acid (i.e., malondialdehyde-thiobarbituric acid adduct) to bring about bacterial death. Both the nanoparticles demonstrated good hemocompatibility against human as well as rat red blood cells (RBCs). In addition, they exhibited excellent biocompatibility in vivo in terms of rat liver (i.e., serum ALT, AST, and γ-GT) and kidneys (i.e., serum creatinine) function biomarkers.

Intelligent control of nanoparticle synthesis through machine learning

The synthesis of nanoparticles is affected by many reaction conditions, and their properties are usually determined by factors such as their size, shape and surface chemistry. In order for the synthesized nanoparticles to have functions suitable for different fields (for example, optics, electronics, sensor applications and so on), precise control of their properties is essential. However, with the current technology of preparing nanoparticles on a microreactor, it is time-consuming and laborious to achieve precise synthesis. In order to improve the efficiency of synthesizing nanoparticles with the expected functionality, the application of machine learning-assisted synthesis is an intelligent choice. In this article, we mainly introduce the typical methods of preparing nanoparticles on microreactors, and explain the principles and procedures of machine learning, as well as the main ways of obtaining data sets. We have studied three types of representative nanoparticle preparation methods assisted by machine learning. Finally, the current problems in machine learning-assisted nanoparticle synthesis and future development prospects are discussed.

Phytochemical Composition and Bioactivities of Aqueous Extract of Rambutan (Nephelium lappaceum L. cv. Rong Rian) Peel

Thailand is one of the leading exporting countries of rambutan and rambutan peels are considered as a biological waste. In this study, rambutan (Nephelium lappaceum L. cv. Rong Rian) peel extracts (RPE) obtained by water extraction were analyzed for their phytochemical composition, antibacterial and antioxidant activities, and cytotoxicity. The bioactive compounds in RPE identified by GC-MS were mome inositol (35.99 mg/g), catechol (29.37 mg/g), 5-hydroxymethylfurfural (5.69 mg/g), 2-pentenal, (E)-(5.22 mg/g), acetic acid (3.69 mg/g), 1,2,3-propanetriol (3.67 mg/g), 2-furan-carboxaldehyde (2.66 mg/g), and other compounds. FT-IR analysis confirmed the presence of alcohol and phenol in the extract. Antibacterial activities of RPE against food pathogenic and spoilage bacteria showed that RPE could inhibited Bacillus subtilis, B. cereus, Staphylococcus aureus, Vibrio cholerae, V. parahaemolyticus, Pseudomonas aeruginosa, and P. fluorescens, with MIC values ranging between 1024 and 8192 µg/mL. The extract also showed antioxidant properties, as determined by DPPH and ABTS assays. The cytotoxicity analysis after 72 h of treatment showed the IC50 values at 194.97 ± 4.87, 205.92 ± 2.55, and 94.11 ± 1.33 µg/mL for L929, Vero, and MCF-7 cell lines, respectively. Therefore, this study provided a basis of knowledge of rambutan peels as an excellent source of natural bioactive compounds for various applications.

Green in situ immobilization of gold and silver nanoparticles on bacterial nanocellulose film using Punica granatum peels extract and their application as reusable catalysts

In this study, Punica granatum peels extract induced in situ deposition was applied to prepare Au and Ag nanoparticles on bacterial nanocellulose film. Bacterial nanocellulose provided as an eco-friendly and excellent support for the interaction of P. granatum peel biomolecules and further reduction of Au and Ag ions. Meanwhile, a possible in situ growth mechanism of Au and Ag on bacterial cellulose by P. granatum peel extract biomolecules was presented. Further, the metal nanoparticles incorporated bacterial cellulose films were used to catalyze the reduction of 4-nitrophenol. The results of the present study indicated excellent catalytic reduction properties of Au and Ag nanocellulose films for 4 consecutive cycles. In addition, Au and Ag incorporated cellulose nanofiber films exhibited superior antioxidant activity and improved mechanical properties compared to pristine cellulose nanofiber film. The findings of this study may provide new insights and broad application of bacterial cellulose and green synthesis method for the development of various metal-cellulose composites.

The Role of Ferroptosis in Adverse Left Ventricular Remodeling Following Acute Myocardial Infarction

Ferroptosis is an iron-dependent form of regulated cell death and is distinct from other conventional forms of regulated cell death. It is often characterized by the dysfunction of the antioxidant selenoprotein glutathione peroxidase 4 (GPX4) antioxidant system. This loss of antioxidant capacity leads to the peroxidation of lipids and subsequent compromised plasma membrane structure. Disruption of the GPX4 antioxidant system has been associated with various conditions such as cardiomyopathy and ischemia-reperfusion (I/R) injury. GPX4 regulates lipid peroxidation, and chemical or genetic inhibition of GPX4 leads to reduced cardiac function. Iron chelators or antioxidants can be used for inhibiting ferroptosis, which restores functionality in in vivo and ex vivo experiments and confers overall cardioprotective effects against I/R injury. Moreover, suppression of ferroptosis also suppresses inflammation and limits the extent of left ventricle remodeling after I/R injury. Future research is necessary to understand the role of ferroptosis following an ischemic incident and can lead to the discovery of more potential therapeutics that prevent ferroptosis in the heart.

Hierarchically Structured Conductive Polymer Binders with Silver Nanowires for High-Performance Silicon Anodes in Lithium-Ion Batteries

Silicon (Si) anodes in lithium-ion batteries (LIBs) suffer from huge volume changes that lead to a rapid capacity decrease and short cycle life. A conductive binder can be a key factor to overcome this issue, maintaining continuous electron paths under pulverization of Si. Herein, composites of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and poly(vinyl alcohol) (PVA) are augmented with poly(ethylene glycol) (PEG) and poly(ethylene oxide) (PEO) as a binder for Si anodes, which forms hierarchical structures due to different chain lengths of PEG and PEO. The integration of PEG and PEO imparts higher electrical conductivity (∼40%) and stretchability (∼60%) through densely spread hydrogen bonding and cross-linking, compared to conductive polymer binders with PEO or PEG. Further, a silver nanowire (AgNW) network combined with the polymer binder supplies an effective three-dimensional (3D) electrical path, sufficient void space to buffer the volume changes, and highly adhesive interaction with the current collector. The fabricated Si anode demonstrates a higher specific capacity of 1066 mAh g^-1 at 0.8 A g^-1 after 100 cycles and improved rate capability.

Recent progression of cyanobacteria and their pharmaceutical utility: an update

Cyanobacteria (blue-green algae) are Gram-negative photosynthetic eubacteria that are found everywhere. This largest group of photosynthetic prokaryotes is rich in structurally novel and biologically active compounds; several of which have been utilized as prospective drugs against cancer and other ailments, as well. Consequently, the integument of nanoparticles-synthetic approaches in cyanobacterial extracts should increase pharmacological activity. Moreover, silver nanoparticles (AgNPs) are small materials with diameters below 100 nm that are classified into different classes based on their forms, sizes, and characteristics. Indeed, the biosynthesized AgNPs are generated with a variety of organisms, algae, plants, bacteria, and a few others, for the medicinal purposes, as the bioactive compounds of curio and some proteins from cyanobacteria have the potentiality in the treatment of a wide range of infectious diseases. The critical focus of this review is on the antimicrobial, antioxidant, and anticancer properties of cyanobacteria. This would be useful in the pharmaceutical industries in the future drug development cascades.Communicated by Ramaswamy H. Sarma.

Surface plasmon resonance allied applications of silver nanoflowers synthesized from Breynia vitis-idaea leaf extract

An environmentally friendly, green synthesis process has been adopted to synthesize silver nanoparticles (AgNPs) in an aqueous solution from a new remedial plant. Breynia vitis-idaea leaves act like natural capping and reducing agents. The resulting AgNPs were characterized and analyzed using different characterization techniques, such as UV-Vis spectroscopy, X-ray diffraction, zeta potential, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The UV-Vis absorption spectrum showed high stability and a surface plasmon resonance (SPR) peak around 430 nm. The effects of several processing variables, such as reaction time, temperature, concentration and pH, were analyzed. High temperature and alkaline pH intensify the ability to form flower-shaped AgNPs with enhanced properties. AgNPs were investigated for antibacterial activity against Gram-negative E. coli bacterial strains with a 10 mm zone of inhibition. These AgNPs showed dye degradation up to 88% when an aqueous crystal violet dye solution was mixed with AgNPs as the catalyst. Further, AgNPs alone were effectively used in the detection of hydrogen peroxide (H2O2) in an aqueous medium with a LOD (limit of detection) of 21 μM, limit of quantification (LOQ) of 64 μM and a decrease in absorption intensity up to 89%. Based on these results, these AgNPs were effectively used in numerous fields, such as biomedical, water purification, antibacterial and sensing of H2O2.

Antibacterial, Antifungal, and Antioxidant Activities of Silver Nanoparticles Biosynthesized from Bauhinia tomentosa Linn

The biogenic synthesis of silver nanoparticles (AgNPs) has a wide range of applications in the pharmaceutical industry. Here, we synthesized AgNPs using the aqueous flower extract of Bauhinia tomentosa Linn. Formation of AgNPs was observed using ultraviolet-visible light spectrophotometry at different time intervals. Maximum absorption was observed after 4 h at 420 nm due to the reduction of Ag⁺ to Ag⁰. The stabilizing activity of functional groups was identified by Fourier-transform infrared spectroscopy. Size and surface morphology were also analyzed using scanning electron microscopy. The present study revealed the AgNPs were spherical in form with a diameter of 32 nm. The face-centered cubic structure of AgNPs was indexed using X-ray powder diffraction with peaks at 2θ = 37°, 49°, 63°, and 76° (corresponding to the planes of silver 111, 200, 220, 311), respectively. Energy-dispersive X-ray spectroscopy revealed that pure reduced silver (Ag⁰) was the major constituent (59.08%). Antimicrobial analyses showed that the biosynthesized AgNPs possess increased antibacterial activity (against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), with larger zone formation against S. aureus (9.25 mm) compared with that of E. coli (6.75 mm)) and antifungal activity (against Aspergillus flavus and Candida albican (with superior inhibition against A. flavus (zone of inhibition: 7 mm) compared with C. albicans (zone of inhibition: 5.75 mm)). Inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was found to be dose-dependent with half-maximal inhibitory concentration (IC₅₀) values of 56.77 μg/mL and 43.03 μg/mL for AgNPs and ascorbic acid (control), respectively, thus confirming that silver nanoparticles have greater antioxidant activity than ascorbic acid. Molecular docking was used to determine the mode of antimicrobial interaction of our biosynthesized B. tomentosa Linn flower-powder extract-derived AgNPs. The biogenic AgNPs preferred hydrophobic contacts to inhibit bacterial and fungal sustainability with reducing antioxidant properties, suggesting that biogenic AgNPs can serve as effective medicinal agents.

Wu-Zi-Yan-Zong-Wan protects mouse blood-testis barrier from Tripterygium wilfordii Hook. f. multiglycoside-induced disruption by regulating proinflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Wu-Zi-Yan-Zong-Wan (WZYZW) is a classical traditonal Chinese herbal formula and a Chinese patent medicine used to treat male infertility. However, the chemical components of WZYZW and its mechanism are not yet fully clarified.

AIM OF THE STUDY

The purpose of this study is to observe the effect and underlying mechanism of WZYZW on ameliorating blood-testis barrier (BTB) dysfunction in mice with spermatogenic dysfunction induced by administration of Tripterygium wilfordii Hook. f. multiglycosides (GTW).

MATERIALS AND METHODS

WZYZW was administered by gavage to mice with GTW-induced spermatogenic dysfunction (kidney essence deficiency pattern) for 40 days. Testis tissues were obtained for subsequent histopathological analysis. Biotin tracing was used to evaluate the permeability of Sertoli cell tight junctions. The levels of proinflammatory cytokines including interleukin (IL)-6, IL-17A, IL-1α and tumor necrosis factor (TNF)-α were analyzed by ELISA. The expression levels of proteins related to tight junction including ZO-1, JAM-A and occludin were analyzed by western blotting. The ultrastructures of tight junctions were observed by transmission electron microscopy.

RESULTS

WZYZW ameliorated GTW-induced testicular spermatogenic dysfunction. Levels of IL-6, IL-17A, IL-1α, and TNF-α in the groups receiving low, medium, and high doses of WZYZW decreased in a dose-dependent manner. WZYZW impeded a biotin tracer from permeating the BTB, protecting its integrity in GTW-treated mice. In addition, our results showed no significant changes in the protein expressions of ZO-1, JAM-A, and occludin after WZYZW administration compared with the GTW group. Meanwhile, WZYZW exhibited a linear arrangement and restored the typical "sandwich" structure of BTB. No acute poisoning incidences were observed in all groups during the experiment.

CONCLUSIONS

Our findings demonstrate that WZYZW may ameliorate some GTW-induced BTB dysfunction, possibly by regulating proinflammatory cytokine levels. In vitro studies on the regulation of BTB permeability by WZYZW and its active components are further required.

Silver nanomaterials: synthesis and (electro/photo) catalytic applications

In view of their unique characteristics and properties, silver nanomaterials (Ag NMs) have been used not only in the field of nanomedicine but also for diverse advanced catalytic technologies. In this comprehensive review, light is shed on general synthetic approaches encompassing chemical reduction, sonochemical, microwave, and thermal treatment among the preparative methods for the syntheses of Ag-based NMs and their catalytic applications. Additionally, some of the latest innovative approaches such as continuous flow integrated with MW and other benign approaches have been emphasized that ultimately pave the way for sustainability. Moreover, the potential applications of emerging Ag NMs, including sub nanomaterials and single atoms, in the field of liquid-phase catalysis, photocatalysis, and electrocatalysis as well as a positive role of Ag NMs in catalytic reactions are meticulously summarized. The scientific interest in the synthesis and applications of Ag NMs lies in the integrated benefits of their catalytic activity, selectivity, stability, and recovery. Therefore, the rise and journey of Ag NM-based catalysts will inspire a new generation of chemists to tailor and design robust catalysts that can effectively tackle major environmental challenges and help to replace noble metals in advanced catalytic applications. This overview concludes by providing future perspectives on the research into Ag NMs in the arena of electrocatalysis and photocatalysis.

Low Sintering Temperature Nano-Silver Pastes with High Bonding Strength by Adding Silver 2-Ethylhexanoate

A silver precursor (silver 2-ethylhexanoate) and silver nanoparticles were synthesized and used to prepare a low sintering temperature nano-silver paste (PM03). We optimized the amount of silver 2-ethylhexanoate added and the sintering temperature to obtain the best performance of the nano-silver paste. The relationship between the microstructures and properties of the paste was studied. The addition of silver 2-ethylhexanoate resulted in less porosity, leading to lower resistivity and higher shear strength. Thermal compression of the paste PM03 at 250 °C with 10 MPa pressure for 30 min was found to be the proper condition for copper-to-copper bonding. The resistivity was (3.50 ± 0.02) × 10^-7 Ω∙m, and the shear strength was 57.48 MPa.

Phytoassisted synthesis and characterization of palladium nanoparticles (PdNPs); with enhanced antibacterial, antioxidant and hemolytic activities

With increasing demand for the treatment of microbial resistance around the globe, it is necessary to develop metallic nanoparticles , ideally by the use of nontoxic medium i.e. plant constituents, that could arrest the microbial growth. For this reason, small and highly crystalline PdNPs were effectively synthesized by using Eryngium caeruleum leaf extract as both the reducing and capping agent. During the synthesis of PdNPs, the size and shape were made controlled by using different solvents i.e., ethanol, methanol and aqueous extract of Eryngium caeruleum. A series of physicochemical characterizations were applied to inquire the synthesis, crystal structure, particles size, and surface morphology of PdNPs. Furthermore, the PdNPs demonstrated excellent potential for the inactivation of gram-positive and gram-negative bacteria, where the methanol-PdNPs exhibited maximum growth inhibition zones against tested bacteria as compared to ethanol-PdNPs and aqueous-PdNPs. Besides, PdNPs showed better antioxidant activity to effectively scavenge 2, 2 diphenyl-1-picrylhydrazyl (DPPH). More importantly, the synthesized PdNPs are not only active for ROS generation but also show no hemolytic activity. We believe that this greener approach uncovered the useful and efficient applications of highly active PdNPs and their biocompatibility.

The Recent Progress on Silver Nanoparticles: Synthesis and Electronic Applications

Nanoscience enables researchers to develop new and cost-effective nanomaterials for energy, healthcare, and medical applications. Silver nanoparticles (Ag NPs) are currently increasingly synthesized for their superior physicochemical and electronic properties. Good knowledge of these characteristics allows the development of applications in all sensitive and essential fields in the service of humans and the environment. This review aims to summarize the Ag NPs synthesis methods, properties, applications, and future challenges. Generally, Ag NPs can be synthesized using physical, chemical, and biological routes. Due to the great and increasing demand for metal and metal oxide nanoparticles, researchers have invented a new, environmentally friendly, inexpensive synthetic method that replaces other methods with many defects. Studies of Ag NPs have increased after clear and substantial support from governments to develop nanotechnology. Ag NPs are the most widely due to their various potent properties. Thus, this comprehensive review discusses the different synthesis procedures and electronic applications of Ag NPs.

Biogenic Synthesis and Catalytic Efficacy of Silver Nanoparticles Based on Peel Extracts of Citrus macroptera Fruit

Biogenically synthesized silver nanoparticles (AgNP) increase the fascination over chemical ones due to their facile and green synthetic process. This study reports the development of an eco-friendly and cost-effective synthesis of AgNPs using an aqueous extract of Citrus macroptera fruit peel, an agricultural waste, as a sole agent with both reducing and capping abilities. The formation of AgNPs was verified by the surface plasmon resonance peak at 426 nm in the UV-vis spectrum, X-ray diffraction pattern, and transmission electron micrography images. The AgNPs obtained under the optimized conditions consist of face-centered cubic crystals and spherical morphology with an average size of 11 nm. The AgNPs are coated with phytochemicals in the C. macroptera fruit peel extract and are stably dispersible due to their negatively charged nature. The AgNPs effectively catalyzed the reduction of 4-nitrophenol to 4-aminophenol and the degradation of methyl orange and methylene blue in the presence of sodium borohydride. This method employing a fruit peel extract is facile, efficient, eco-friendly, and cost-effective and has potential for industrial green fabrication of AgNPs.