Synergistic effect of plant extract coupled silver nanoparticles in various therapeutic applications- present insights and bottlenecks

Assessing the impact of an environmentally friendly approach on irreversible dental hydrocolloid performance

BACKGROUND

Impression materials can harbour microorganisms from saliva and blood, posing cross-contamination risks. However, post-setting disinfection might compromise the dimensional accuracy and mechanical properties of alginates. Hence, it was the aim of this research to assess the detail reproduction, tear strength, elastic recovery, and surface quality of the gypsum model of newly developed dental alginates with inherent antimicrobial properties.

METHODS

Three dental alginate groups with antimicrobial alterations were formulated. One group replaced water with 0.2% chlorhexidine solution (CHX group), while the other two utilized water-based extracts of Syzygium aromaticum (SA, clove) or Zingiber officinale (ZO, ginger) to reduce silver nitrate, resulting in two silver nanoparticles (AgNPs)/extract (clove or ginger) mixture solutions. These mixture solutions were employed for the preparation of dental alginate yielding the SA + AgNP and ZO + AgNPs groups. All modified groups were compared to an unmodified control group that used water for mixing. Elastic recovery, detail reproduction, and tear strength were assessed following the ISO 21563:2021 standard. The surface roughness of plaster models was analysed using the optical profilometer. Elastic recovery was assessed by applying and then releasing load on alginate specimens to measure their ability to recover from deformation. Detail reproduction was evaluated by observing the reproducibility of a 50 μm line in a metallic mold using a light microscope, while tear strength was determined by stretching the specimens until failure at a constant speed of 500 mm/min.

RESULTS

All tested groups exhibited elastic recovery values meeting ISO standards for hydrocolloid impression materials. Regarding detail reproduction, both the control and modified alginates successfully reproduced the 50-µm line without interruption in all specimens. Tear strength values for all tested groups remained within the acceptable documented ranges, surpassing the minimum requirement of 0.38 N/mm as mandated by ISO 21563:2021. The ZO + AgNPs (0.94 ± 0.17 N/mm) demonstrated significantly higher tear strength values and surface roughness values compared to the other tested groups.

CONCLUSIONS

Chlorhexidine, Syzygium aromaticum, and Zingiber officinale green-synthesized silver nanoparticles are promising, cost-effective alternatives for disinfecting alginate impressions without compromising performance. Green nanoparticle synthesis is a safe, efficient, and non-toxic method, potentially synergizing metal ions with plant extract.

Antibacterial, mosquito larvicidal, and cytotoxicity potential of AgNPs synthesized using Pittosporum undulatum under in vitro conditions

In this study, the phytochemical profile and silver nanoparticle (AgNPs)-synthesizing ability of Pittosporum undulatum methanol extract were investigated. Furthermore, biological applications of the AgNPs, such as antibacterial effect (against Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis, and Escherichia coli), mosquito larvicidal effect (against Anopheles stephensi, Culex quinquefasciatus, and Aedes aegypti), and cytotoxicity (against fibroblast cell line L929) were evaluated using in vitro experiments. The phytochemical analysis revealed that the methanol extract contained cardiac glycosides, terpenoids, saponins, alkaloids, flavonoids, glycosides, coumarins, phenolics, and tannins. Furthermore, standard characterization techniques such as UV-Vis spectrometry, SEM, TEM, FTIR, and XRD confirmed that the methanol extract of P. undulatum effectively synthesized the AgNPs. The synthesized AgNPs had a spherical shape and size of 20-200 nm. The bactericidal analysis revealed that the AgNPs have dose-dependent antibacterial activity. The MTT assay showed that the AgNPs were bio-compatible up to a dosage of 250 μg mL-1 in the normal fibroblast cell line L929. Furthermore, the LC50 values for AgNPs against larvae of An. stephensi, Cx. quinquefasciatus, and Ae. aegypti were 0.4, 4.7, and 1.2 ppm, respectively. Field trials demonstrated that the larvicidal effect was enhanced within 24-72 h, and the rate of reduction increased over time. Thus, our findings provide an ideal sustainable AgNP bio-pesticide to combat filarial, dengue, and malaria vectors.

Phytosynthesis of Silver Nanoparticles Using Mansoa alliacea (Lam.) A.H. Gentry (Bignoniaceae) Leaf Extract: Characterization and Their Biological Activities

Background. Mansoa alliacea is a native plant renowned for its medicinal properties in traditional healing in the Amazon Region. This plant is rich in polyphenols, flavonoids, anthocyanins, phenolic acids, tannins, ketones, triterpenes, as well as other bioactive compounds. Objectives. This study aims to develop an innovative, eco-friendly method for synthesizing silver nanoparticles using an aqueous extract of M. alliacea (Ma-AgNPs), enhancing the biological activities of AgNPs by leveraging the therapeutic potential of the plant's bioactive compounds. Methods. Silver nanoparticles were synthesized using the aqueous extract of M. alliacea. The biological activities of Ma-AgNPs were assessed, including antibacterial, anti-inflammatory, antioxidant, antitumor, and anti-biofilm effects, along with evaluating their hemolytic activity. Results. Quantitative analysis revealed that Ma-AgNPs exhibit potent antibacterial activity against multidrug and non-multidrug-resistant bacteria, with MIC values ranging from 1.3 to 10.0 µg/mL. The Ma-AgNPs significantly reduced NO production by 86.9% at 4 µg/mL, indicating strong anti-inflammatory effects. They demonstrated robust antioxidant activity with an IC50 of 5.54 ± 1.48 µg/mL and minimal hemolytic activity, with no hemolysis observed up to 20 µg/mL and only 4.5% at 40 µg/mL. Their antitumor properties were notable, with IC50 values between 2.9 and 5.4 µg/mL across various cell lines, and they achieved over 50% biofilm inhibition at concentrations of 30-40 µg/mL. Conclusions. These findings underscore the potential of Ma-AgNPs for biomedical applications, particularly in developing new antimicrobial agents and bioactive coatings with reduced toxicity. This research highlights a sustainable approach that not only preserves but also amplifies the inherent biological activities of plant extracts, paving the way for innovative therapeutic solutions.

Ṯābit Ibn Qurrah's contributions to toxicology

Mankind has been familiar with poisons since ancient times. On the other hand, there is a wealth of knowledge in the medical books including medieval works of Middle Eastern polymaths such as Avicenna, "al-Rāzī," and "Ṯābit Ibn Qurrah." This study presented and analyzed the knowledge of medical toxicology in one of the mainstay works of "Ṯābit Ibn Qurrah" entitled "al-Ḏaḫirah Fy Ꜥilm al-Tibb" also known as The Treasury of Medicine after the translation of the book from Arabic to English carefully and faithfully. Also, related toxicological literature was applied wherever required using English, Arabic, and Persian databases including Scopus, PubMed, Web of Science, WorldCat, Magiran, IranDoc, Scientific Information Database, Noor Mags, Noorlib, and Al Manhal. Our research revealed that chapter 25 of the mentioned book specifically focused on toxicology. This chapter was divided into sections on different aspects of toxicology from the categorization of poisons to compound mixtures causing poisonings to introducing blade poisons to signs and symptoms of poisonings, preventive approaches, and therapeutic agents. Specific antidotes and general therapies were introduced that included medicinal plants, cupping therapy, and bandages, just to name a few. Also, there were some monographs on the common poisonous agents and their treatments. The toxicological data of the book was comparable with modern toxicology. Our study highlighted the contributions of "Ṯābit Ibn Qurrah" to medical toxicology by authoring The Treasury of Medicine. Further research is recommended to elucidate the full aspects of the history of toxicology including the contributions of the past scholars.

Biogenic nanoparticles: pioneering a new era in breast cancer therapeutics-a comprehensive review

Breast cancer, a widespread malignancy affecting women globally, often arises from mutations in estrogen/progesterone receptors. Conventional treatments like surgery, radiotherapy, and chemotherapy face limitations such as low efficacy and adverse effects. However, nanotechnology offers promise with its unique attributes like targeted delivery and controlled drug release. Yet, challenges like poor size distribution and environmental concerns exist. Biogenic nanotechnology, using natural materials or living cells, is gaining traction for its safety and efficacy in cancer treatment. Biogenic nanoparticles synthesized from plant extracts offer a sustainable and eco-friendly approach, demonstrating significant toxicity against breast cancer cells while sparing healthy ones. They surpass traditional drugs, providing benefits like biocompatibility and targeted delivery. Thus, this current review summarizes the available knowledge on breast cancer (its types, stages, histopathology, symptoms, etiology and epidemiology) with the importance of using biogenic nanomaterials as a new and improved therapy. The novelty of this work lies in its comprehensive examination of the challenges and strategies for advancing the industrial utilization of biogenic metal and metal oxide NPs. Additionally; it underscores the potential of plant-mediated synthesis of biogenic NPs as effective therapies for breast cancer, detailing their mechanisms of action, advantages, and areas for further research.

Therapeutic Efficacy of Helianthemum lippii Extract and Silver Nanoparticles Synthesized from the Extract against Cadmium-Induced Renal Nephrotoxicity in Wistar Rats

This study explored the therapeutic efficacy of Helianthemum lippii and silver nanoparticles (Ag NPs) synthesized using a H. lippii extract to alleviate cadmium-induced nephrotoxicity in Wistar rats. Sub-acute toxicity assessments of H. lippii (100 mg/kg, 1000 mg/kg, and 4000 mg/kg) and Ag NPs (2 mg/kg and 10 mg/kg) did not find any significant difference, compared with untreated control rats (n = 3 animals/group). Then, the adult Wistar rats were divided into one control (untreated/unexposed) and six experimental groups (n = 5/group): Ag NPs alone, H. lippii alone, exposure to 50 mg/kg CdCl2 in drinking water for 35 days, exposure to CdCl2 for 35 days followed by treatment with 0.1 mg/kg/day Ag NPs (intraperitoneal injection) and/or 100 mg/kg/day H. lippii by gavage for 15 days. In the CdCl2-exposed group, body weight decreased; urea, creatinine, and uric acid concentrations increased (p < 0.05 vs. control), indicative of nephrotoxicity, antioxidant defenses (SOD, GSH, and CAT) were reduced, and malondialdehyde concentration increased. Moreover, the kidney's architecture in CdCl2-exposed rats was altered: fibrosis, inflammatory cell infiltration, glomerular destruction, and tubular dilatation. Treatment with H. lippii and/or Ag NPs after CdCl2 exposure improved some of the renal function and architecture alterations induced by CdCl2, and also increased body weight. This study underscores the potential therapeutic applications of H. lippii and Ag NPs to decrease oxidative stress and promote xenobiotic detoxification, in line with the growing emphasis on environmentally conscious practices in scientific research and healthcare.

Unraveling the mysteries of silver nanoparticles: synthesis, characterization, antimicrobial effects and uptake translocation in plant-a review

MAIN CONCLUSION

The study thoroughly investigates nanosilver production, properties, and interactions, shedding light on its multifaceted applications. It underscores the importance of characterizing nanosilver for predicting its behavior in complex environments. Particularly, it highlights the agricultural and environmental ramifications of nanosilver uptake by plants. Nowadays, silver nanoparticles (AgNPs) are a very adaptable nanomaterial with many uses, particularly in antibacterial treatments and agricultural operations. Clarification of key elements of nanosilver, such as its synthesis and characterization procedures, antibacterial activity, and intricate interactions with plants, particularly those pertaining to uptake and translocation mechanisms, is the aim of this in-depth investigation. Nanosilver synthesis is a multifaceted process that includes a range of methodologies, including chemical, biological, and sustainable approaches that are also environmentally benign. This section provides a critical evaluation of these methods, considering their impacts on repeatability, scalability, and environmental impact. The physicochemical properties of nanosilver were determined by means of characterization procedures. This review highlights the significance of analytical approaches such as spectroscopy, microscopy, and other state-of the-art methods for fully characterizing nanosilver particles. Although grasp of these properties is necessary in order to predict the behavior and potential impacts of nanosilver in complex biological and environmental systems. The second half of this article delves into the intricate interactions that plants have with nanosilver, emphasizing the mechanisms of absorption and translocation. There are significant ramifications for agricultural and environmental problems from the uptake of nanosilver by plants and its subsequent passage through their tissues. In summary, by summarizing the state-of-the-art information in this field, this study offers a comprehensive overview of the production, characterization, antibacterial capabilities, and interactions of nanosilver with plants. This paper contributes to the ongoing conversation in nanotechnology.

Synergistic Antibacterial Properties of Silver Nanoparticles and Its Reducing Agent from Cinnamon Bark Extract

Synthesis of silver nanoparticles with antibacterial properties using a one-pot green approach that harnesses the natural reducing and capping properties of cinnamon (Cinnamomum verum) bark extract is presented in this work. Silver nitrate was the sole chemical reagent employed in this process, acting as the precursor salt. Gas Chromatography-Mass Spectroscopy (GC-MS), High-Performance Liquid Chromatography (HPLC) analysis, and some phytochemical tests demonstrated that cinnamaldehyde is the main component in the cinnamon bark extract. The resulting bio-reduced silver nanoparticles underwent comprehensive characterization by Ultraviolet-Vis (UV-Vis) and Fourier Transform InfraRed spectrophotometry (FTIR), Dynamic Light Scattering (DLS), Transmission Electron Microscopy, and Scanning Electron Microscopy suggesting that cinnamaldehyde was chemically oxidated to produce silver nanoparticles. These cinnamon-extract-based silver nanoparticles (AgNPs-cinnamon) displayed diverse morphologies ranging from spherical to prismatic shapes, with sizes spanning between 2.94 and 65.1 nm. Subsequently, the antibacterial efficacy of these nanoparticles was investigated against Klebsiella, E. Coli, Pseudomonas, Staphylococcus aureus, and Acinetobacter strains. The results suggest the promising potential of silver nanoparticles obtained (AgNPs-cinnamon) as antimicrobial agents, offering a new avenue in the fight against bacterial infections.

Impact of silver nanoparticles on secondary metabolite composition and toxicity in anise (Pimpinella anisum L.) callus culture

BACKGROUND

There are numerous challenges associated with producing desired amounts of secondary metabolites (SMs), which are mostly unique and cannot be chemically synthesized. Many studies indicate that nanoparticles (NPs) can boost the production of SMs. Still, the precise manner in which NPs induce metabolic changes remains unidentified. This study examines the influence of eco-friendly silver NPs (AgNPs) on the chemical makeup and toxicity of Pimpinella anisum L. (anise).

RESULTS

AgNPs were introduced into anise callus cultures at different concentrations (0, 1.0, 5.0, 10, and 20 mg/L). The induced oxidative stress was tracked over intervals of 7, 14, 28, and 35 days. Chemical composition evaluations were carried out on the 35th day. Within the first 14 days, plant stress was evident, though the plant adapted to the stress later on. Notably, the plant showed high tolerance at 1 mg/L and 5 mg/L concentrations despite increased toxicity levels. However, relatively high toxicity levels were identified at 10 and 20 mg/L. The AgNP-induced stress significantly impacted anise SMs, particularly affecting fatty acid content. In the 10 and 20 mg/L AgNP groups, essential metabolites, including palmitic and linoleic acid, showed a significant increase. Polyunsaturated (omega) and monounsaturated fatty acids, vital for the food and pharmaceutical industries, saw substantial growth in the 1 and 5 mg/L AgNP groups. For the first time, vanillyl alcohol and 4-Hydroxybenzoic acid were detected along with various phenolic compounds, such as t-anethole, Salicylic acid, and Thiamazole.

CONCLUSION

AgNPs can function as an elicitor to efficiently generate essential SMs such as omegas and phenolic compounds in anise callus culture. This study explores the application of AgNPs as plant elicitors in anise SM production, offering invaluable insight into potential uses.

Probing capping mechanisms and polymer matrix loading of biogenic vaterite CaCO3-Ag hybrid through X-ray photoelectron spectroscopy (XPS)

Despite extensive research in the literature, the synthesis of silver nanoparticles (AgNPs) via capping mechanisms remains incompletely understood. This study employs a mechanistic approach to unravel the underlying molecular interactions driving the capping process of biogenic vaterite CaCO3-Ag and explores their interactions with different polymer matrices. X-ray photoelectron spectroscopy (XPS) was used to reveal the capping mechanisms, surface composition alterations, and vaterite polymorph transitions. The oxidation states of AgNPs exhibited distinct changes under different capping agents. The Ag3d spin-orbit splitting profiles revealed the coexistence of Ag+ and Ag0 within CaCO3-Ag, with a significant presence of Ag0 when poly(sodium 4-styrene sulfonate) was employed as the capping agent. Conversely, the use of carboxy methyl cellulose as the capping agent resulted in Ag+ dominance. XPS analysis illuminated the transformation of CaCO3 polymorphs from calcite to vaterite structure, which remained stable following embedding within polymer matrices. Integrating CaCO3-Ag microspheres into polymer matrices and investigating their surface characteristics represents a strategic step toward tailoring material properties for potential applications in active packaging and biomedicine.

Recent Advancements and Unexplored Biomedical Applications of Green Synthesized Ag and Au Nanoparticles: A Review

Green synthesis of silver (Ag) and gold (Au) nanoparticles (NPs) has acquired huge popularity owing to their potential applications in various fields. A large number of research articles exist in the literature describing the green synthesis of Ag and Au NPs for biomedical applications. However, these findings are scattered, making it time-consuming for researchers to locate promising advancements in Ag and Au NPs synthesis and their unexplored biomedical applications. Unlike other review articles, this systematic study not only highlights recent advancements in the green synthesis of Ag and Au NPs but also explores their potential unexplored biomedical applications. The article discusses the various synthesis approaches for the green synthesis of Ag and Au NPs highlighting the emerging developments and novel strategies. Then, the article reviews the important biomedical applications of green synthesized Ag and Au NPs by critically evaluating the expected advantages. To expose future research direction in the field, the article describes the unexplored biomedical applications of the NPs. Finally, the articles discuss the challenges and limitations in the green synthesis of Ag and Au NPs and their biomedical applications. This article will serve as a valuable reference for researchers, working on green synthesis of Ag and Au NPs for biomedical applications.

Application of biomimetically synthesized silver nanoparticles as cathode catalyst, quorum-quencher, and anti-biofouling agent for the performance boosting of microbial fuel cell

A microbial fuel cell (MFC) is a cutting-edge bioelectrochemical technology, which demonstrates power and other valuables recovery while treating wastewater by cultivating electroactive microbes. However, rampant biofilm growth over the cathode surface of air cathode MFC exacerbates the oxidation-reduction reaction rate, triggering a dip in the overall performance of MFC. In this sense, biosynthesized silver nanoparticles (AgNPs) have garnered a plethora of potential applications as cathode catalysts as well as anti-biofouling agent for MFCs without harming nature. The MFC equipped with the mixture of aloe vera and algae (@5 mg/cm2) synthesized AgNPs on cathode generated a maximum power density of 66.5 mW/m2 and chemical oxygen demand removal efficiency of 85.2%, which was ca. 5.6 times and 1.2 times higher compared to control MFC operated without any catalyst on cathode. Thus, this investigation paves the way for using eco-amiable, low-cost bioderived organic compounds to assist MFC in achieving high power output and other valuables with minimal reliance on chemicals.

Antibacterial and Anti-Quorum Sensing Properties of Silver Nanoparticles Phytosynthesized Using Embelia ruminata

The rise in antibiotic resistance (AR) poses an imminent threat to human health. Nanotechnology, together with mechanisms such as quorum sensing (QS), which relies on communication between bacterial cells, may decrease the selective pressure for AR. Thus, this study aimed to investigate the effectiveness of silver nanoparticles (AgNPs) synthesized at room temperature (Rt) and 80 °C using Embelia ruminata leaf, stem-bark, and fruit extracts as antibacterial and anti-QS agents. The phytosynthesized AgNPs solutions were subjected to various characterization assays and assessed for their antibacterial activities. Quantitative QS assays were performed using Chromobacterium subtsugae CV017 and Chromobacterium violaceum ATCC 12472. Synthesized AgNPs were spherical-to-near-spherical in shape, poly-dispersed, and crystalline, with a size range of 21.06-32.15 nm. Fruit AgNPs showed stronger antibacterial activity than AgNPs from other plant organs against selected bacterial strains. In the QS assays, fruit 80 °C AgNPs demonstrated the most significant violacein inhibition in an assay performed using the short-chain acyl homoserine lactone CV017 biosensor, while the leaf and fruit Rt AgNPs demonstrated the most violacein inhibition in an assay performed using the long-chain acyl homoserine lactone ATCC 12472 biosensor. The investigations carried out in this study lay the groundwork for future innovative research into antibacterial and anti-QS strategies using E. ruminata.

A Review on the Efficacy of Plant-derived Bio-active Compounds Curcumin and Aged Garlic Extract in Modulating Cancer and Age-related Diseases

Aging is a process characterized by accumulating degenerative changes resulting in the death of an organism. Aging is mediated by various pathways that are directly linked to the individual's lifespan and are shunted for many age-related diseases. Many strategies for alleviating age-related diseases have been studied, which can target cells and molecules. Modern drugs such as Metformin, Rapamycin, and other drugs are used to reduce the effects of age-related diseases. Despite their beneficial activity, they possess some side effects which can limit their applications, mainly in older adults. Natural phytochemicals which have anti-aging activities have been studied by many researchers from a broader aspect and suggested that plant-based compounds can be a possible, direct, and practical way to treat age-related diseases which has enormous anti-aging activity. Also, studies indicated that the synergistic action of phytochemicals might enhance the biological effect rather than the individual or summative effects of natural compounds. Curcumin has an antioxidant property and is an effective scavenger of reactive oxygen species. Curcumin also has a beneficial role in many age-related diseases like diabetes, cardiovascular disease, neurological disorder, and cancer. Aged garlic extracts are also another bioactive component that has high antioxidant properties. Many studies demonstrated aged garlic extract, which has high antioxidant properties, could play a significant role in anti-aging and age-related diseases. The synergistic effect of these compounds can decrease the requirement of doses of a single drug, thus reducing its side effects caused by increased concentration of the single drug.

Construction of cellulose acetate-based composite nanofiber films with effective antibacterial and filtration properties

In recent years, the safety of public health has attracted more and more attention. In order to avoid the spread of bacteria and reduce the diseases caused by their invasion of the human body, novel filtration and antibacterial materials have attracted more and more attention. In this work, the antibacterial agents silver nanoparticles (AgNPs) and cetylpyridine bromide (CPB) were introduced into a cellulose acetate (CA) nanofiber film by electrospinning technology to prepare CA-based composite films with good antibacterial and filtration properties. The results of the antibacterial test of the composite nanofiber films showed that AgNPs and CPB had synergistic antibacterial effects and exhibited good antibacterial properties against a variety of bacteria. In addition, in vitro cytotoxicity, skin irritation and skin sensitization experiments proved that the CA/AgNPs, CA/CPB and CA/CPB/AgNPs films produced no skin irritation or sensitization in the short term. These are expected to become potential materials for the preparation of new antibacterial masks. This work provides a new idea for developing materials with good antibacterial properties for enhancing protection via filtration masks.

Biosynthesis of Artemisia abyssinica Leaf Extract-Mediated Bimetallic ZnO-CuO Nanoparticles: Antioxidant, Anticancer, and Molecular Docking Studies

Currently, plant extract-mediated synthesized metal oxide nanoparticles (MO NPs) have played a substantial role in biological applications. Hence, this study focused on the eco-benign one-pot synthesis of bimetallic ZnO-CuO nanoparticles (ZC NPs) using the leaf extract of Artemisia abyssinica (LEAA) and evaluations of their anticancer, antioxidant, and molecular binding efficacy. The optical absorption peak at 380 nm from UV-visible (UV-vis) analysis revealed the formation of ZC NPs. X-ray diffraction (XRD) results revealed the fabrication of mixed-phase crystals with hexagonal and monoclinic structures of ZC NPs with an average crystallite size of 14 nm. Moreover, the biosynthesis of ZC NPs with a spherical morphology and an average particle size of 13.09 nm was confirmed by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM) results. Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA/DTA) spectroscopy confirmed the involvement of functional groups from LEAA during the synthesis of ZC NPs. ZC NPs have exhibited the ferric ion reducing power (FRAP) with an absorbance of 1.826 ± 0.00 at 200 μg/mL and DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) radical scavenging activity of 95.71 ± 0.02% at 200 μg/mL with an IC50 value of 3.28 μg/mL. Moreover, ZC NPs had shown a promising in vitro anticancer activity of 89.20 ± 0.038 at 500 μg/mL with an IC50 value of 33.12 μg/mL against breast cancer (MCF-7) cell lines. Likewise, ZC NPs have shown strong binding affinity (-8.50 kcal/mol) against estrogen receptor α (ERα) in molecular docking simulations. These findings suggested that the biosynthesized ZC NPs could be used as promising antioxidant and anticancer drug candidates, particularly for breast cancer ailments. However, the in vivo cytotoxicity test will be recommended to ensure further use of ZC NPs.

Phytofabrication of silver nanoparticles using Averrhoa bilimbi leaf extract for anticancer activity

Averrhoa bilimbi leaf extract was successfully utilized as a reducing agent to synthesize silver nanoparticles (AgNPs) in the laboratory. The phytochemicals in the extract helped keep the silver nanoparticles stable and slowed them down. Different methods, such as UV-visible, FT-IR spectroscopies, XRD, and SEM analyses, were used to characterize the size, shape, and morphology of the nanoparticles, and the results showed that the synthesized nanoparticles were spherical and monodispersed. FTIR spectrum streaching vibrations shown stabillization of silver nanoparticles by green extract. On the other hand, these nanoparticles were labelled as Averrhoa bilimbi (AB) extract silver nanoparticles (AB-AgNPs). The biological synthesis process was proven to enhance the efficacy of the synthesized silver nanoparticles. The effectiveness of AB-AgNPs in fighting cancer could be enhanced specifically for lung cancer (A549 cell line) and breast cancer (MCF7 cell line) by optimizing the necessary conditions. The IC50 value for A549 cells was 49.52 g mL-1, while that for MCF7 cells was 78.40 g mL-1. The effect of AgNPs on both cell lines was assessed using an MTT assay, which showed a dose-dependent cytotoxicity effect. The biosynthesized AB-AgNPs hold great potential as anticancer agents. Their synthesis using Averrhoa bilimbi leaf extract as a reducing agent was proven to be successful, resulting in spherical and monodispersed nanoparticles that exhibit effective cytotoxicity against cancer cells.

Characterization of Silver Nanoparticles Synthesized by the Aqueous Extract of Zanthoxylum nitidum and Its Herbicidal Activity against Bidens pilosa L

Phytosynthesis of silver nanoparticles (Ag NPs) has been progressively acquiring attractiveness. In this study, the root of Zanthoxylum nitidum was used to synthesize Ag NPs, and its pre-emergence herbicidal activity was tested. The synthesized Ag NPs by the aqueous extract from Z. nitidum were characterized by visual inspection, ultraviolet-visible spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The plant-mediated synthesis was completed within 180 min and the Ag NPs exhibited a characteristic peak at around 445 nm. The results of the DLS measurement showed that the average hydrodynamic diameter was 96 nm with a polydispersity index (PDI) of 0.232. XRD results indicated the crystalline nature of the phytogenic Ag NPs. A TEM analysis revealed that the nanoparticles were spherical with an average particle size of 17 nm. An EDX spectrum confirmed the presence of an elemental silver signal. Furthermore, the Ag NPs exhibited a herbicidal potential against the seed germination and seedling growth of Bidens Pilosa L. The present work indicates that Ag NPs synthesized by plant extract could have potential for the development of a new nanoherbicide for weed prevention and control.

Biosynthesis and Characterization of Calcium Oxide Nanoparticles from Citrullus colocynthis Fruit Extracts; Their Biocompatibility and Bioactivities

Modern nanotechnology encompasses every field of life. Nowadays, phytochemically fabricated nanoparticles are being widely studied for their bioactivities and biosafety. The present research studied the synthesis, characterization, stability, biocompatibility, and in vitro bioactivities of calcium oxide nanoparticles (CaONPs). The CaONPs were synthesized using Citrullus colocynthis ethanolic fruit extracts. Greenly synthesized nanoparticles had an average size of 35.93 ± 2.54 nm and showed an absorbance peak at 325 nm. An absorbance peak in this range depicts the coating of phenolic acids, flavones, flavonols, and flavonoids on the surface of CaONPs. The XRD pattern showed sharp peaks that illustrated the preferred cubic crystalline nature of triturate. A great hindrance to the use of nanoparticles in the field of medicine is their extremely reactive nature. The FTIR analysis of the CaONPs showed a coating of phytochemicals on their surface, due to which they showed great stability. The vibrations present at 3639 cm^-1 for alcohols or phenols, 2860 cm^-1 for alkanes, 2487 cm^-1 for alkynes, 1625 cm^-1 for amines, and 1434 cm^-1 for carboxylic acids and aldehydes show adsorption of phytochemicals on the surface of CaONPs. The CaONPs were highly stable over time; however, their stability was slightly disturbed by varying salinity and pH. The dialysis membrane in vitro release analysis revealed consistent nanoparticle release over a 10-h period. The bioactivities of CaONPs, C. colocynthis fruit extracts, and their synergistic solution were assessed. Synergistic solutions of both CaONPs and C. colocynthis fruit extracts showed great bioactivity and biosafety. The synergistic solution reduced cell viability by only 14.68% and caused only 16% hemolysis. The synergistic solution inhibited Micrococcus luteus slightly more effectively than streptomycin, with an activity index of 1.02. It also caused an 83.87% reduction in free radicals.

Combining the Potent Reducing Properties of Pecan Nutshell with a Solvent-Free Mechanochemical Approach for Synthesizing High Ag0 Content-Silver Nanoparticles: An Eco-Friendly Route to an Efficient Multifunctional Photocatalytic, Antibacterial, and Antioxidant Material

A straightforward, low-cost, and scalable solid-state mechanochemical protocol for the synthesis of silver nanoparticles (AgNP) based on the use of the highly reducing agri-food by-product pecan nutshell (PNS) is reported herein. Under optimized conditions (180 min, 800 rpm, PNS/AgNO₃ ratio = 55/45 w/w), a complete reduction in silver ions was achieved, leading to a material containing ca. 36% w/w Ag⁰ (X-ray diffraction analysis). Dynamic light scattering and microscopic analysis showed a uniform size distribution (15-35 nm average diameter) of the spherical AgNP. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay revealed lower-although still absolutely high (EC₅₀ = 5.8 ± 0.5 mg/mL)-antioxidant properties for PNS for the further incorporation of AgNP, supporting the efficient reduction of Ag⁺ ions by PNS phenolic compounds. Photocatalytic experiments indicated that AgNP-PNS (0.4 mg/mL) was able to induce the >90% degradation of methylene blue after 120 min visible light irradiation, with good recycling stability. Finally, AgNP-PNS demonstrated high biocompatibility and significantly light-enhanced growth inhibition properties against Pseudomonas aeruginosa and Streptococcus mutans at concentrations as low as 250 μg/mL, also eliciting an antibiofilm effect at 1000 μg/mL. Overall, the adopted approach allowed to reuse a cheap and abundant agri-food by-product and required no toxic or noxious chemicals, making AgNP-PNS a sustainable and easy-to-access multifunctional material.

Antimicrobial Efficacy of Green Synthesized Nanosilver with Entrapped Cinnamaldehyde against Multi-Drug-Resistant Enteroaggregative Escherichia coli in Galleria mellonella

The global emergence of antimicrobial resistance (AMR) needs no emphasis. In this study, the in vitro stability, safety, and antimicrobial efficacy of nanosilver-entrapped cinnamaldehyde (AgC) against multi-drug-resistant (MDR) strains of enteroaggregative Escherichia coli (EAEC) were investigated. Further, the in vivo antibacterial efficacy of AgC against MDR-EAEC was also assessed in Galleria mellonella larval model. In brief, UV-Vis and Fourier transform infrared (FTIR) spectroscopy confirmed effective entrapment of cinnamaldehyde with nanosilver, and the loading efficiency was estimated to be 29.50 ± 0.56%. The AgC was of crystalline form as determined by the X-ray diffractogram with a mono-dispersed spherical morphology of 9.243 ± 1.83 nm in electron microscopy. AgC exhibited a minimum inhibitory concentration (MIC) of 0.008−0.016 mg/mL and a minimum bactericidal concentration (MBC) of 0.008−0.032 mg/mL against MDR- EAEC strains. Furthermore, AgC was stable (high-end temperatures, proteases, cationic salts, pH, and host sera) and tested safe for sheep erythrocytes as well as secondary cell lines (RAW 264.7 and HEp-2) with no negative effects on the commensal gut lactobacilli. in vitro, time-kill assays revealed that MBC levels of AgC could eliminate MDR-EAEC infection in 120 min. In G. mellonella larvae, AgC (MBC values) increased survival, decreased MDR-EAEC counts (p < 0.001), had an enhanced immunomodulatory effect, and was tested safe to the host. These findings infer that entrapment enhanced the efficacy of cinnamaldehyde and AgNPs, overcoming their limitations when used individually, indicating AgC as a promising alternative antimicrobial candidate. However, further investigation in appropriate animal models is required to declare its application against MDR pathogens.

Toxicity and modulation of silver nanoparticles synthesized using abalone viscera hydrolysates on bacterial community in aquatic environment

Polysaccharide decorated silver nanoparticles (AgNPs) are a new type of antibacterial agent in aquaculture, but their effects on the bacterial community structure in aquaculture water are still unknown. In this study, the primary hydrolysate from abalone (Haliotis discus hannai) viscera (AVH) was used to biosynthesize AVH-AgNPs by in situ reduction, and the crystallinity nature, size, morphology, and chemical composition were analyzed by high-resolution characterization techniques such as Ultraviolet–visible spectroscopy (UV–vis), X-rays diffraction (XRD), Transmission Electron Microscope (TEM), Dynamic light scattering (DLS), Zeta potential, inductively coupled plasma-optical emission spectrometry (ICP-OES) and Turbiscan stability index (TSI) values. Furthermore, the acute toxicity of AVH-AgNPs to zebrafish (Danio rerio) and their effects on bacterial community structure in fish culture water at low concentrations were studied. The results showed that the spherical AVH-AgNPs with an average diameter of 54.57 ± 12.96 nm had good stability, low toxicity, and good in vitro antibacterial activity. Within the experimental concentration range, all AVH-AgNPs treatments had decreased the bacterial diversity in zebrafish culture water to varying degrees. The bacteria with significantly decreased abundances were pathogenic or potential pathogenic, such as Aeromonas veronii, Flavobacterium columnare, and genera Flectobacillus and Bosea. The abundance of Haliscomenobacter sp. JS224, which might cause sludge swelling, also decreased significantly. On the other hand, the relative abundance of some bacterial taxa could remove xenobiotics (e.g., Runella defluvii and Phenylobacterium), control water eutrophication (Sediminibacterium), and reduce toxic algae proliferation (Candidatus Intestinusbacter nucleariae and Candidatus Finniella), increased significantly. Thus, the application of AVH-AgNPs in aquaculture water at low concentrations is relatively safe and has positive significance for improving the aquaculture environment. Also, AVH-AgNPs have good prospects in aquaculture.

Electrospun Ag-decorated reduced GO-graft-chitosan composite nanofibers with visible light photocatalytic activity for antibacterial performance

The treatment of water contaminated by bacteria is becoming a necessity. The nanomaterials possessing both intrinsic antibacterial properties and photocatalytic activity are excellent candidates for water disinfection. The powdered form of nanomaterials can be aggregated while embedding the nanomaterials into the NFs can overcome the limitation and enhance the photocatalytic activity and transition from UV-light to visiblelight. Here, graphene oxide (GO) was synthesized, grafted to chitosan, and decorated with silver nanoparticles (Ag NPs) to produce Ag-decorated reduced GO-graft-Chitosan (AGC) NPs. The blends of polyacrylonitrile (PAN) and AGC NPs were prepared in various concentrations of 0.5 wt%, 1.0 wt%, 5.0 wt%, and 10.0 wt% and used to fabricate the electrospun composite NFs. FTIR/ATR, UV-Vis, Raman, XRD, and SEM/EDAX analyses confirmed the successful preparation of the NPs and NFs. The cytotoxicity and antibacterial activity of the composite NFs were received in the order of composite NFs 10.0 wt%˃ 5.0 wt%˃ 1.0 wt%˃ 0.5 wt% in both conditions with/without light irradiation. Their cytotoxicity and antibacterial activity were more under light irradiation compared to the dark. The composite NFs (5.0 wt%) were distinguished as the optimum NFs with cell viability of 80% within 24 h and 60% within 48 h on L929 cells and inhibition zone diameter (IZD) of 12 mm for E. coli and 13 mm for S. aureus after 24 h under the light irradiation. The optimum composite NFs showed thermal stability up to 180 °C and tensile strength of 1.11 MPa with 21.71% elongation at break.

A Critical Review of the Antimicrobial and Antibiofilm Activities of Green-Synthesized Plant-Based Metallic Nanoparticles

Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.

Synthesis and Antioxidant Activity of Silver Nanoparticles Using the Odontonema strictum Leaf Extract

The aqueous extract of the leaves of Odontonema strictum (OSM) is used in folk medicine for its antihypertensive properties, and it contains a wide range of secondary metabolites, mostly polyphenols such as verbascoside and isoverbascoside, which could play a major role in the preparation of silver nanoparticles. In this study, we aimed to prepare AgNPs for the first time using the OSM leaf extract (OSM-AgNPs) to investigate their free radical-scavenging potency against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H₂O₂). Dynamic light scattering (DLS), UV/Vis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) were used to characterize the OSM-AgNPs. With a size around 100 nm and a ζ-potential of −41.1 mV, OSM-AgNPs showed a good stability and a better colloidal property due to electrostatic repulsion and the dispersity. The strong absorption peak at 3 keV in the EDX spectra indicated that silver was the major constituent. Additionally, the existence of silver atoms was confirmed by the Ag 3d_5/2 peak around 367 eV in the XPS spectra. IC₅₀ values of 116 μg/mL and 4.4 μg/mL were obtained for the scavenging activities of DPPH and H₂O₂, respectively. The synthetic OSM-AgNPs can be further exploited as potential antioxidant agents.

Green Metallic Nanoparticles: Biosynthesis to Applications

Current advancements in nanotechnology and nanoscience have resulted in new nanomaterials, which may pose health and environmental risks. Furthermore, several researchers are working to optimize ecologically friendly procedures for creating metal and metal oxide nanoparticles. The primary goal is to decrease the adverse effects of synthetic processes, their accompanying chemicals, and the resulting complexes. Utilizing various biomaterials for nanoparticle preparation is a beneficial approach in green nanotechnology. Furthermore, using the biological qualities of nature through a variety of activities is an excellent way to achieve this goal. Algae, plants, bacteria, and fungus have been employed to make energy-efficient, low-cost, and nontoxic metallic nanoparticles in the last few decades. Despite the environmental advantages of using green chemistry-based biological synthesis over traditional methods as discussed in this article, there are some unresolved issues such as particle size and shape consistency, reproducibility of the synthesis process, and understanding of the mechanisms involved in producing metallic nanoparticles via biological entities. Consequently, there is a need for further research to analyze and comprehend the real biological synthesis-dependent processes. This is currently an untapped hot research topic that required more investment to properly leverage the green manufacturing of metallic nanoparticles through living entities. The review covers such green methods of synthesizing nanoparticles and their utilization in the scientific world.

Green Silver Nanoparticles Promote Inflammation Shutdown in Human Leukemic Monocytes

The use of silver nanoparticles (Ag NPs) in the biomedical field deserves a mindful analysis of the possible inflammatory response which could limit their use in the clinic. Despite the anti-cancer properties of Ag NPs having been widely demonstrated, there are still few studies concerning their involvement in the activation of specific inflammatory pathways. The inflammatory outcome depends on the synthetic route used in the NPs production, in which toxic reagents are employed. In this work, we compared two types of Ag NPs, obtained by two different chemical routes: conventional synthesis using sodium citrate and a green protocol based on leaf extracts as a source of reduction and capping agents. A careful physicochemical characterization was carried out showing spherical and stable Ag NPs with an average size between 20 nm and 35 nm for conventional and green Ag NPs respectively. Then, we evaluated their ability to induce the activation of inflammation in Human Leukemic Monocytes (THP-1) differentiated into M0 macrophages using 1 µM and 2 µM NPs concentrations (corresponded to 0.1 µg/mL and 0.2 µg/mL respectively) and two-time points (24 h and 48 h). Our results showed a clear difference in Nuclear Factor κB (NF-κb) activation, Interleukins 6–8 (IL-6, IL-8) secretion, Tumor Necrosis Factor-α (TNF-α) and Cyclooxygenase-2 (COX-2) expression exerted by the two kinds of Ag NPs. Green Ag NPs were definitely tolerated by macrophages compared to conventional Ag NPs which induced the activation of all the factors mentioned above. Subsequently, the exposure of breast cancer cell line (MCF-7) to the green Ag NPs showed that they exhibited antitumor activity like the conventional ones, but surprisingly, using the MCF-10A line (not tumoral breast cells) the green Ag NPs did not cause a significant decrease in cell viability.