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An important application of silver nanoparticles (Ag NPs) is their use as an antimicrobial and wound dressing material. The aim of this study is to investigate the morphological dependence on the antimicrobial activity and cellular response of Ag NPs. Ag NPs of various shapes were synthesized in an aqueous solution using a simple method. The morphology of the synthesized Ag NPs was observed via TEM imaging. The antimicrobial activity of the Ag NPs with different morphologies was evaluated against various microorganisms ( [ ] [ ] [ ]). The antimicrobial activity of the Ag NPs was also examined according to the concentration in terms of the growth rate of . The TEM images indicated that the Ag NPs with different morphologies (sphere, disk and triangular plate) had been successfully synthesized. The antimicrobial activity obtained from the inhibition zone was in the order of spherical Ag NPs > disk Ag NPs > triangular plate Ag NPs. In contrast, fibroblast cells grew well in all types of Ag NPs when the cell viability was evaluated via an MTT assay. An inductively coupled plasma mass assay showed that the difference in the antimicrobial activities of the Ag NPs was closely associated with the difference in the release rate of the Ag ions due to the difference in the surface area of the Ag NPs. The morphological dependence of the antimicrobial activity of the Ag NPs can be explained by the difference in the Ag ion release depending on the shape. Therefore, it will be possible to control the antimicrobial activity by controlling the shape and size of the Ag NPs.

Abstract The standard technologies and hazardous chemicals used in the synthesis of silver nanoparticles (Ag-NPs) can be harmful to the environment and as well as for human health. Sustainable and eco- friendly method of synthesizing nanoparticles are required. To synthesize silver nanoparticles (Ag-NPs), Grewia optiva leaf extract was used in the current research as a reducing agent. The leaves were thoroughly cleaned and dried before forming in an aqueous solution using a Jeldal apparatus for 20 minutes at 100 ºC. For the purpose, the extract and the silver nitrate (AgNO3) solution were thoroughly mixed. The method of synthesizing nanoparticles was optimized through the manipulation of multiple parameters, such as pH, temperature, and salt content. It was found that the ideal temperature for the synthesis of nanoparticles was 85 °C, the ideal pH range was 6-7, and the ideal salt concentration was 2 mL. Different techniques were used for characterization, including X-ray diffraction (XRD) to determine the crystalline structure of nanoparticles, Fourier-transform infrared spectroscopy (FT-IR) to identify chemical bonds and functional groups, using an Energy Dispersive X-ray Spectrometer (EDX) and transmission electron microscopy (TEM) to determine particle size in detail, and scanning electron microscopy (SEM) to analyze morphological aspects. The biosynthesized Ag-NPs showed potent antibacterial, phytotoxic, insecticidal, antipyretic, and analgesic properties in addition to efficient radical scavenging. The results showed that Ag-NPs made from G. optiva aqueous extract are appropriate for the production of novel medical and agricultural remedies. Since this study was carried out in a lab, more investigation is required to determine whether large-scale production is feasible and to look into possible uses of these Ag-NPs in the agricultural and biomedical sectors. Resumo As tecnologias padrão e produtos químicos perigosos usados na síntese de nanopartículas de prata (Ag-NPs) podem ser prejudiciais ao meio ambiente e também à saúde humana. Métodos sustentáveis e ecológicos de síntese de nanopartículas são necessários. Para sintetizar nanopartículas de prata (Ag-NPs), o extrato de folhas de Grewia optiva foi usado na pesquisa atual como um agente redutor. As folhas foram completamente limpas e secas antes de serem formadas em uma solução aquosa usando um aparelho Jeldal por 20 minutos a 100 ºC. Para esse propósito, o extrato e a solução de nitrato de prata (AgNO3) foram completamente misturados. O método de síntese de nanopartículas foi otimizado por meio da manipulação de múltiplos parâmetros, como pH, temperatura e teor de sal. Foi descoberto que a temperatura ideal para a síntese de nanopartículas era de 85 °C, a faixa de pH ideal era de 6-7 e a concentração ideal de sal era de 2 mL. Diferentes técnicas foram usadas para caracterização, incluindo difração de raios X (XRD) para determinar a estrutura cristalina das nanopartículas, espectroscopia de infravermelho por transformada de Fourier (FT-IR) para identificar ligações químicas e grupos funcionais, usando um espectrômetro de raios X de energia dispersiva (EDX) e microscopia eletrônica de transmissão (TEM) para determinar o tamanho das partículas em detalhes e microscopia eletrônica de varredura (SEM) para analisar aspectos morfológicos. Os Ag-NPs biossintetizados mostraram potentes propriedades antibacterianas, fitotóxicas, inseticidas, antipiréticas e analgésicas, além de eficiente eliminação de radicais. Os resultados mostraram que os Ag-NPs feitos a partir do extrato aquoso de G. optiva são apropriados para a produção de novos remédios médicos e agrícolas. Como este estudo foi realizado em laboratório, são necessárias mais investigações para determinar se a produção em larga escala é viável e para analisar possíveis usos desses Ag-NPs nos setores agrícola e biomédico.

Nanomaterials have supported important technological advances due to their unique properties and their applicability in various fields, such as biomedicine, catalysis, environment, energy, and electronics. This has triggered a tremendous increase in their demand. In turn, materials scientists have sought facile methods to produce nanomaterials of desired features, i.e., morphology, composition, colloidal stability, and surface chemistry, as these determine the targeted application. The advent of photoprocesses has enabled the easy, fast, scalable, and cost- and energy-effective production of metallic nanoparticles of controlled properties without the use of harmful reagents or sophisticated equipment. Herein, we overview the synthesis of gold and silver nanoparticles via photochemical routes. We extensively discuss the effect of varying the experimental parameters, such as the pH, exposure time, and source of irradiation, the use or not of reductants and surfactants, reagents’ nature and concentration, on the outcomes of these noble nanoparticles, namely, their size, shape, and colloidal stability. The hypothetical mechanisms that govern these green processes are discussed whenever available. Finally, we mention their applications and insights for future developments.

Various methods have been used to enhance production of chemically diverse phytochemicals especially medicinal natural products. With the advancement in nanotechnology, nanoparticles have been reported to have varying impact in plant growth and inducibility of phytochemical composition. Major objective of the study was to study the secondary metabolite modulatory effect of silver nanoparticles. In the current study, treatment of fenugreek seedlings with biosynthesized silver nanoparticles (Ag-NPs) was found to have significant impact on its growth parameters such as leaf number, root length, shoot length and wet weight. On HPLC based analysis, Ag-NPs treated seedlings showed an enhancement in the production of major phytochemical diosgenin to a level of 214.06±17.07μg/mL. An untreated control gave an yield of only 164.44±7.67μg/mL of diosgenin, and the observed phytochemical enhancement effect induced by Ag-NP was very significant. Most remarkably, the Ag-NP used in the study was found to play dual role of enhancement of both plant growth and diosgenin synthesis. Hence the study is of immense application as it opens up development of new methods based on nanoelicitors to enhance the biosynthesis of medicinal natural products in plants.

Silver is easily available and is known to have microbicidal effect; moreover, it does not impose any adverse effects on the human body. The microbicidal effect is mainly due to silver ions, which have a wide antibacterial spectrum. Furthermore, the development of multidrug-resistant bacteria, as in the case of antibiotics, is less likely. Silver ions bind to halide ions, such as chloride, and precipitate; therefore, when used directly, their microbicidal activity is shortened. To overcome this issue, silver nanoparticles (Ag NPs) have been recently synthesized and frequently used as microbicidal agents that release silver ions from particle surface. Depending on the specific surface area of the nanoparticles, silver ions are released with high efficiency. In addition to their bactericidal activity, small Ag NPs (<10 nm in diameter) affect viruses although the microbicidal effect of silver mass is weak. Because of their characteristics, Ag NPs are useful countermeasures against infectious diseases, which constitute a major issue in the medical field. Thus, medical tools coated with Ag NPs are being developed. This review outlines the synthesis and utilization of Ag NPs in the medical field, focusing on environment-friendly synthesis and the suppression of infections in healthcare workers (HCWs).

A highly efficient and environmentally friendly synthetic method has been developed for the preparation of benzopyrano‐pyrimidines using multi‐walled carbon nanotubes/magnetic nanoparticles‐Biguanide‐Ag NPs as a heterogeneous nanocatalyst in choline chloride–urea (ChCl–Urea) deep eutectic solvent. This approach offers numerous advantages, including high isolated yields (86–99%) and short reaction times (10–70 min), along with broad substrate compatibility for both electron‐donating and electron‐withdrawing functional groups. The method exhibits excellent catalytic efficiency, with high turnover numbers and turnover frequencies, even at low catalyst loading. The use of ChCl–Urea as a green, biodegradable, and nonvolatile solvent aligns with sustainable chemistry principles and allows for easy solvent recovery. Additionally, the magnetic nanocatalyst is easily recoverable and reusable, maintaining activity over multiple cycles. Operational simplicity, mild conditions, and one‐pot multi‐component reaction design further enhance the method's scalability and synthetic utility. Given the biological relevance of benzopyrano‐pyrimidines, this strategy presents a valuable platform for green synthesis in medicinal chemistry and pharmaceutical development. A highly efficient and environmentally friendly synthetic method has been developed for the preparation of benzopyrano‐pyrimidines using MWCNTs/MNPs‐Biguanide‐Ag NPs as a heterogeneous nanocatalyst in choline chloride–urea (ChCl–Urea) deep eutectic solvent.

BackgroundTriple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. Radiation therapy (RT) is a modality for TNBC management. Radiosensitizers can mitigate the adverse effects of RT. Applying green-synthesized silver nanoparticles (Ag-NPs) from biological sources such as plants is a potential strategy to sensitize cancer cells to radiotherapy due to the low toxicity. Therefore, identifying novel natural sources for synthesizing stable and broadly applicable green-Ag-NPs has gained more attention in cancer therapy. In the present study, we synthesized green- Ag-NPs from pumpkin peel extract and elucidated the impact of green-synthesized Ag-NPs as a radiosensitizer in MDA-MB 231 cells (a model of TNBC).ResultsThe prepared Ag-NPs had a spherical shape with an average size of 81 nm and a zeta potential of − 9.96 mV. Combination of green-synthesized Ag-NPs with RT exhibited synergistic anticancer effects with an optimum combination index (CI) of 0.49 in MDA-MB-231 cells. Green-synthesized Ag-NPs synergistically potentiated RT-induced apoptosis in MDA-MB-231 cells compared to the corresponding monotherapies. Morphological features of apoptosis were further confirmed by the DAPI–TUNEL staining assay. HIF-1α expression was decreased in cells subjected to combination therapy. Bax and p53 expression increased, whereas Bcl-2 genes decreased. Combination therapy significantly increased the protein level of PERK and CHOP while decreasing cyclin D1 and p-ERK/total ERK levels compared to monotherapies.ConclusionThese findings indicate the potential effect of green-synthesized Ag-NPs as a radiosensitizer for TNBC treatment.

Research on the use of different parts of the Moringa oleifera plant as a nutritional and pharmaceutical resource for human and animals has increased in recent years. This study aimed to investigate the chemical composition and the TPCs and TFCs of Moringa leaves, the antimicrobial activities of Moringa successive ethanolic, aqueous, crude aqueous extracts, and green-chemically synthesized characterized Ag-NPs. The results indicated that the ethanolic extract recorded the highest activity against E. coli. On the other side, the aqueous extract showed higher activity, and its effects ranged from 0.03 to 0.33 mg/mL against different strains. The MIC values of Moringa Ag-NPs against different pathogenic bacteria ranged from 0.05 mg/mL to 0.13 mg/mL, and the activity of the crude aqueous extract ranged from 0.15 to 0.83 mg/mL. For the antifungal activity, the ethanolic extract recorded the highest activity at 0.04 mg/mL, and the lowest activity was recorded at 0.42 mg/mL. However, the aqueous extract showed effects ranging from 0.42 to 1.17 mg/mL. Moringa Ag-NPs showed higher activity against the different fungal strains than the crude aqueous extract, and they ranged from 0.25 to 0.83 mg/mL. The MIC values of the Moringa crude aqueous extract ranged from 0.74 to 3.33 mg/mL. Moringa Ag-NPs and their crude aqueous extract may be utilized to boost antimicrobial attributes.

Silver nanotechnology has received tremendous attention in recent years, owing to its wide range of applications in various fields and its intrinsic therapeutic properties. In this review, an attempt is made to critically evaluate the chemical, physical, and biological synthesis of silver nanoparticles (AgNPs) as well as their efficacy in the field of theranostics including microbiology and parasitology. Moreover, an outlook is also provided regarding the performance of AgNPs against different biological systems such as bacteria, fungi, viruses, and parasites (leishmanial and malarial parasites) in curing certain fatal human diseases, with a special focus on cancer. The mechanism of action of AgNPs in different biological systems still remains enigmatic. Here, due to limited available literature, we only focused on AgNPs mechanism in biological systems including human (wound healing and apoptosis), bacteria, and viruses which may open new windows for future research to ensure the versatile application of AgNPs in cosmetics, electronics, and medical fields.

In this study, we report a novel and facile colorimetric assay based on silver citrate-coated Au@Ag nanoparticles (Au@AgNPs) as a chemosensor for the naked-eye detection of morphine (MOR). The developed optical sensing approach relied on the aggregation of Au@Ag NPs upon exposure to morphine, which led to an evident color variation from light-yellow to brown. Au@Ag NPs have been prepared by two different protocols, using high- and low-power ultrasonic irradiation. The sonochemical method was essential for the sensing properties of the resulting nanoparticles. This facile sensing method has several advantages including excellent stability, selectivity, prompt detection, and cost-effectiveness.