Bioinspired and Green Synthesis of Silver Nanoparticles for Medical Applications: A Green Perspective

Impact of gold and silver nanoparticles injected in blood with viscous dissipation

A nano-blood model is developed to study the flow of gold- and silver-infused blood through a porous, stenotic artery under Newtonian assumptions. Wall curvature, convective heating, wall motion, and viscous dissipation are considered. Darcy's model simulates porous resistance, and the Tiwari-Das model captures nanoparticle effects. Governing equations are reduced via similarity transformations and solved using MATLAB's bvp4c solver. Validation against existing studies is provided. Results show gold-blood nanofluid achieves higher velocities than silver-blood. Increasing the Biot number enhances cooling at the arterial wall. Detailed graphs and 3D contour plots illustrate the effects on temperature, velocity, skin friction, and Nusselt number.

Functionalization of cotton fabric using the biogenic synthesized silver nanoparticles for enhanced dye reduction and antimicrobial efficiency: Response surface methodology

This study explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using Spirulina extract and their application for cotton fabrics functionalization in order to enhance the photocatalytic and antimicrobial properties. The small size of the synthesized AgNPs was confirmed using Transmission Electron Microscopy (TEM) and dynamic light scattering (DLS), revealing a spherical morphology with an average size of 8.6 nm. The functionalized cotton fabric exhibited excellent catalytic activity, achieving 100 % Congo red (CR) dye reduction at pH 9, and 45 °C for 120 min. Response surface methodology (RSM) optimization using the Box-Behnken Design (BBD) demonstrated a high correlation (R2 = 0.987) between process variables and catalytic performance. The recyclability of the AgNPs-coated cotton fabric was evaluated over 5 cycles, showing a slight decrease in efficiency to 81.6 % in the 5th cycle, indicating its durability and potential for repeated use. In antimicrobial evaluations, the AgNPs-coated fabric exhibited superior inhibition against multiple pathogenic microorganisms, including Acinetobacter baumannii (42 mm inhibition zone), Klebsiella pneumoniae (39 mm), Pseudomonas aeruginosa (41 mm), Staphylococcus aureus (37 mm), Enterococcus faecalis (35 mm), and Candida albicans (34 mm). The antibacterial efficiency exceeded that of standard ciprofloxacin, highlighting the significant potential of AgNPs-coated cotton fabric in biomedical and industrial applications. These results establish AgNPs-coated cotton fabric as a promising material for wastewater treatment and antimicrobial applications, supporting sustainable advancements in nanotechnology and textile engineering.

Concentration-dependent disturbances of digestive functions in house cricket (Insecta: Orthoptera) exposed to GO-AgNP composite

This study investigates the effects of graphene oxide (GO) and silver nanoparticle (AgNP) composite (GO-AgNP) on the digestive physiology and gut ultrastructure of Acheta domesticus (house cricket) during extended exposure. Various concentrations of GO-AgNP were tested to assess their impact on food consumption, assimilation, cell status (Dead Cells and ROS + cells), gut enzyme activity, and structural damage to gut cells. Concentration and exposure time had significant effects on oxidative stress, enzyme activity, and gut cell structure. The applied composite reduced cumulative food consumption and assimilation efficiency. Enzyme assays showed that lower concentrations enhanced carbohydrate-degrading enzyme activity, while higher concentrations inhibited protease activity. Histological analysis revealed structural damage to gut epithelial cells and signs of autophagy or necrosis at higher concentrations. These results suggest that GO and AgNPs contribute to oxidative stress, cell cycle disruption, and apoptosis, with AgNPs having a potentially stronger effect than GO. The disturbed enzyme activity may result from conformational changes caused by nanoparticle agglomeration. These findings underline potential risks associated with the environmental or agricultural use of GO-AgNP composites.

Green synthesis of silver nanoparticles using Keratinase from Pseudomonas aeruginosa-C1M, characterization and applications as novel multifunctional biocatalyst

INTRODUCTION

This study explores the biogenic synthesis of silver nanoparticles (AgNPs) using keratinase from Pseudomonas aeruginosa-C1M as a reducing and stabilizing agent. The synthesis of AgNPs was characterized by a color change from transparent to dark brown and a UV-Vis absorption peak at 450 nm, confirming nanoparticle formation. The study further investigates the structural, morphological, and functional properties of these AgNPs, particularly their antibacterial activity and their potential role in azo dye decontamination.

METHODS AND RESULTS

The FTIR confirmed that AgNPs nanoparticles formation with keratinase. X-ray diffraction analysis showed that the prepared AgNPs were crystalline in nature and had face-centered cubic lattice planes. When observed under the transmission electron microscope and scanning electron microscope the nanoparticles were monodispersed spheres of different sizes. The diameter of the AgNPs was ~ 119 nm according to dynamic light scattering. High dispersion, long-term stability and excellent colloidal properties were supported by a high negative zeta potential value. The silver nanoparticles were found to have an antibacterial activity with zone of inhibition 25 mm and 33 mm against pathogenic strains of Staphylococcus aureus and Escherichia coli respectively. The synthesized zero-valent silver nanoparticles assisted in the decontamination of azo dyes (methyl red, methyl orange, safranin O and methyl violet) through the incorporation of sodium borohydride and light-catalyzed processes.

CONCLUSION

This study demonstrates, for the first time, that keratinase from Pseudomonas aeruginosa-C1M can be used for AgNPs synthesis. The biogenic AgNPs exhibited potent antibacterial activity and played a crucial role in detoxifying hazardous azo dyes. These findings highlight the dual-functional potential of AgNPs for applications in antimicrobial treatments and environmental remediation. Future studies should explore their mechanism of action, scalability, and industrial applications.

AgNPs biosynthesized from Pseudomonas Z9.3 metabolites as antimicrobial agents against bacterial and fungal pathogens

Introduction

An eco-friendly method for the biosynthesis of functional silver nanoparticles (AgNPs) using plant growth-promoting bacteria (PGPB), specifically Pseudomonas sp. Z9.3, has been developed. The growing need for sustainable and non-toxic nanoparticle production makes this method significant for various applications.

Methods

The influence of physicochemical parameters, such as temperature, pH, and concentrations of AgNO3, on the synthesis of AgNPs was studied. The formation of AgNPs was confirmed by UVvis, SEM/TEM, FTIR, and XRD analysis. Antibacterial activity was assessed using the antibacterial disk diffusion assay. For antifungal activity, AgNPs were added to the agar medium, and the size of the inhibition zone was measured.

Results and discussion

Two optimal conditions were identified: 37°C, pH 9, and a 5:1 ratio of bacterial supernatant to 5 mM AgNO3 (S1-9), and 37°C, pH 7, with a 2:4 ratio (S4-7). The UV-visible spectroscopy results showed an absorption range between 400 and 450 nm, confirming the formation of AgNPs. The SEM and TEM analysis showed the spherical shape of AgNPs with a good distribution of nanoparticles and the average size ranged from 8.24 ± 0.26 to 13.32 ± 0.4 nm. Antibacterial activity against different pathogenic bacteria and fungi was tested. Antibacterial activity of AgNPs against six human pathogens and three phytopathogens was evaluated. The antibacterial potential of S1-9 against Gram-negative strains was lower than against Gram-positive strains; in particular, S. epidermidis was the most sensitive (93.76%) compared to the equivalent concentration of Ag. In the case of fungi, S4-7 exhibited better inhibitory activity compared to the negative control. The highest dose (120 ppm) of S4-7 AgNP inhibited fungal growth being the most sensitive Alternaria sp. (74.97%), followed by Stemphylium sp. (66.30%), Fusarium sp. (45.62%), and Rhizopus sp. (32.68%). These findings highlight the potential of synthesized AgNPs as antimicrobial agents for both bacterial and fungal pathogens.

Novel green synthesis of silver nanoparticles using carotenoid extracted from Kocuria sp.: determination of antioxidant, antimicrobial, and anti-human breast cancer activities

In recent decades, nanotechnology has emerged as a promising field with diverse medical applications. Silver nanoparticles (Ag NPs) exhibit several biological activities. The aim of the current study was to investigate antioxidant, antimicrobial, and anti-breast cancer properties of green-synthesized Ag NPs. To achieve this, Ag NPs were synthesized using Kocuria sp., and their successful formation and physicochemical properties were evaluated using UV-vis, FTIR, XRD, DLS, zeta potential analysis, SEM, and TEM. The antioxidant capacity of Ag NPs was evaluated using a DPPH scavenging assay. The antimicrobial effects of the Ag NPs were tested on two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) using a 96-well plate. HUVEC, MCF7, and MDA-MB-231 cells were treated with varying concentrations of Ag NPs, and cell viability, migration, and apoptosis rates were assessed using MTT, scratch, and flow cytometry assays, respectively. Additionally, qPCR was performed to analyze the expression levels of some genes involved in apoptosis, such as caspases 3, 8, and 9. Characterization techniques confirmed the successful synthesis of pure crystalline structures and spherical Ag NPs. Antioxidant and antimicrobial assays demonstrated the significant antioxidant capacity of the Ag NPs and their antibacterial properties against all tested bacteria. Moreover, in vitro studies indicated that Ag NPs effectively inhibited cell proliferation, suppressed migration, and induced apoptosis, likely owing to the upregulation of caspase 3, 8, and 9 and BCL2 downregulation genes. Our findings suggest that green-synthesized Ag NPs using carotenoids extracted from Kocuria sp. might serve as promising antibacterial and anti-breast cancer agents; however, more in vitro and in vivo investigations are required to elucidate the therapeutic potential of Ag NPs.

LED light promoted synthesis of silver nanoparticle with red cabbage extract in clinical conditions and its dental applications

Silver nanoparticles (Ag NPs) are effective universal germicides toward various pathogens. Herein, we developed synthesis of fast and stable Ag NPs with red cabbage extract (RCE) used as reducing and capping agent promoted by the LED light device used in clinics for dental polymerization and investigated their antimicrobial properties for dentistry purposes. We systematically explained the formation mechanism of anthocyanins (anth) directed, existing as main and predominant components in RCE, Ag NPs (anth@Ag NP) in 10 s (sn) under photoirradiation by LED light with a standard power mode (1000 mW/cm2). We tested anth@Ag NP as an effective cavity disinfectant and caries arresting agent with its enhanced antimicrobial property against model cariogenic pathogens including standard strains of Streptococcus mutans (S. mutans) ATCC 25275, Enterococcus faecalis (E. faecalis) ATCC 29212, Staphylococcus aureus (S. aureus) ATCC 29213, and Candida albicans (C. albicans) ATCC 90028. We claim that the anth@Ag NP can be doped into several dental materials polymerized by LED light for long-term antimicrobial properties toward dental infections.

Silver Nanoparticles: A Versatile Tool Against Infectious and Non-Infectious Diseases

Silver nanoparticles possess remarkable properties that render them highly beneficial for medical applications in both infectious and non-infectious diseases. Among their most renowned attributes is their antimicrobial activity. They have demonstrated efficacy against a wide range of bacteria, fungi, protozoa, and viruses. Additionally, the antitumor and anti-diabetic properties of silver nanoparticles, along with their ability to promote wound healing and their application as biosensors, underscore their therapeutic potential for various non-infectious conditions. As silver nanoparticles are employed for medical purposes, their potential toxicity must be considered. While silver nanoparticles present a promising alternative in the therapeutic domain, further research is needed to elucidate their precise mechanisms of action, optimize their efficacy, and mitigate any potential health risks associated with their use.

Microbial Nanoparticles in Biological Plant Protection

Nanoparticles are small structures that differ in terms of their shape and composition; their high surface-to-volume ratio is responsible for their unique properties that make them perfect mediators for the delivery of substances. Nanoparticles do not only include metallic spheres but also complex polysaccharides capsule viruses or bacterial protein complexes (which can be considered bionanoparticles), which are 1-100 nm in size. Although nanoparticles are most widely studied from medical perspectives, their potential applications are almost limitless. One such promising use of functional nanoparticles is for plant protection against diseases. Although the precise use of nanoparticles decreases the need for the use of other chemical compounds, thanks to their increased product stability and delivery to a target site, the production of nanoparticles is often burdened by large quantities of toxic wastes. This problem can be limited if we apply the bioreactor green synthesis method, which includes the production of nanoparticles with the use of microorganisms. Bacteria can produce nanoparticles internally, externally, by only producing metabolites used for nanoparticle production directly, e.g., polysaccharides or surfactants, or indirectly as reducing agents for metal nanoparticle production. Regardless of the source of the nanoparticles, they can be widely used in processes from plant disease/pathogen detection to disease suppression. The endless variety of materials for nanoparticle production and the possible modifications that nanoparticles can be subjected to makes it impossible to predict how their structures will be used in the future. Nevertheless, in this study, we would like to turn attention to the fact that although nanoparticles are viewed as synthetic structures, they are ever-present in the microbial world and play an important part in intermicrobial interactions. As nanoparticle usefulness has been tested over years of co-evolution, it may be useful to look for potential future directions for this fascinating technology.

Electrochemical Deposition of Silver Nanoparticle Assemblies on Carbon Ultramicroelectrode Arrays

Silver nanoparticle (AgNP) assemblies combined with electrode surfaces have a myriad of applications in electrochemical energy storage and conversion devices, (bio)sensor development, and electrocatalysis. Among various nanoparticle synthesis methods, electrochemical deposition is advantageous due to its ability to control experimental parameters, enabling the formation of low-nanoscale (<50 nm) particles with narrow size distributions. Herein, we report the electrodeposition of AgNPs on a unique electrode platform based on carbon ultramicroelectrode arrays (CUAs), exploring several experimental variables including potential, time, and silver ion concentration. Extensive scanning electron microscopy analysis revealed that more reductive deposition potentials resulted in higher counts of smaller-sized AgNPs. While previous studies have employed planar, macro-sized electrodes with millimolar silver ion concentrations and minute-long times for AgNP electrodeposition, our results demonstrate that lower Ag+ concentrations (50-100 μM) and shorter deposition times (15-30 s) are sufficient for successful AgNP formation on CUAs. These findings are attributed to enhanced mass transfer from the radial diffusion of the array-based CUAs. The quantity of deposited Ag was determined to be 1100±200 nmol cm-2, consistent with AgNP-modified CUA electrocatalytic activity for hydrogen peroxide reduction. This study emphasizes the importance of carefully considering AgNP electrodeposition parameters on unconventional electrode surfaces.

Green chemistry: Modern therapies using nanocarriers for treating rare brain cancer metastasis from colon cancer

Brain metastasis (BM) from colon cancer is associated with a poor prognosis and restricted treatment alternatives, largely due to issues related to blood-brain barrier (BBB) permeability and the negative effects of standard chemotherapy. Nanotechnology improves treatment efficacy by enabling targeted and controlled drug delivery. This review article evaluates the potential of nanotechnology-based therapies for treating colon cancer BM, emphasizing their capacity to cross the BBB, diminish metastatic growth, and enhance overall survival rates. A review of multiple studies evaluated nanoparticles (NPs) as carriers for chemotherapy, focusing on parameters including particle size, surface charge, and drug-loading capacity. The study also reviewed studies that examined BBB penetration, in vitro tumor accumulation, and in vivo tumor growth inhibition. In vitro findings indicated that NPs accumulate more efficiently in BM tissue than in healthy brain tissue and show significant BBB penetration. In vivo, nanotherapy markedly inhibited tumor growth and prolonged survival relative to conventional chemotherapy or control treatments while also exhibiting reduced side effects. Recent studies demonstrated that plant extracts can effectively and safely synthesize nanomaterials, positioning them as a viable and environmentally friendly precursor for nanomaterial production. Nanotechnology-based therapies demonstrate significant potential in the treatment of colon cancer BM by minimizing systemic toxicity, enhancing therapeutic efficacy, and facilitating more targeted drug delivery. Further research is required to confirm these findings and implement them in clinical practice.

Silver immobilized magnetic iron nanoparticles fabricated via green method for detection of cobalt in water and their antibacterial activity

This study reports the eco-friendly synthesis of silver immobilized magnetic iron nanoparticles (MAgNPs) using Zingiber officinale (ginger) peel extract, which serves as a reducing and stabilizing agent. Employing a green synthesis approach, these nanoparticles are fabricated to address environmental and health-related applications. The synthesized MAgNPs demonstrated significant performance in detecting cobalt (Co2+) ion in water, with a detection limit reaching as low as 10-9M. Moreover, the antibacterial activity tests against E. coli and S. aureus exhibited substantial inhibition zones measuring up to 18.8 mm for MAgNPs at a concentration of 125 µg/mL. Structural and physicochemical characterizations were carried out using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray, UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), which confirmed the successful coating of silver on magnetic nanoparticles. The BET analysis revealed a specific surface area of 99.304 m2/g, indicating a high potential for adsorptive applications. This work not only highlights the use of natural waste in nanotechnology but also contributes to the development of nanomaterials with promising applications in the environmental and healthcare sectors, thereby supporting sustainable material development.

DIA/SWATH-Mass Spectrometry Revealing Melanoma Cell Proteome Transformations with Silver Nanoparticles: An Innovative Comparative Study

Melanoma is an aggressive cancer with rising incidence and high mortality rates, largely due to chemotherapy resistance and molecular dysregulation. Nanotechnology, particularly silver nanoparticles (AgNPs), has emerged as a promising therapeutic avenue because of the nanoparticles' ability to induce oxidative stress and apoptosis in cancer cells. However, conventional colloidal AgNPs lack selectivity, often causing significant damage to healthy cells. In this study, we introduce a green synthesis of AgNPs using plant extracts, providing an eco-friendly alternative with improved antitumor selectivity compared to traditional colloidal AgNPs. Leveraging label-free Data-Independent Acquisition/Sequential Window Acquisition of All Theoretical Mass Spectrometry (DIA/SWATH MS) quantitative proteomics, we investigated the antitumor effects of green-synthesized versus traditional AgNPs on A375 melanoma cells at 24 and 48 h. Our findings reveal that green AgNPs selectively reduced melanoma cell viability while sparing healthy keratinocytes (HaCaT), a benefit not observed with colloidal AgNPs. Proteomic analysis highlighted that green AgNPs significantly downregulated oncogenes, enhanced carbohydrate metabolism, and disrupted copper homeostasis in melanoma cells. This marks the first study to explore the differential effects of green and traditional AgNPs on melanoma using an integrated proteomic approach, underscoring the molecular potential of green AgNPs as a targeted and sustainable option for cancer therapy.

Sensitive and selective silver nanoparticle-based fluorescence sensor for corticosteroid determination in pharmaceutical formulations

Glucocorticoids play a crucial role in metabolic processes and have potent anti-inflammatory and immunosuppressive properties. Hence, developing a facile, sensitive, selective, and green approach to determine corticosteroids is essential. In this study, silver nanoparticles (Ag-NPs) were synthesized via the chemical reduction of silver nitrate using sodium borohydride in distilled water without using non-environmentally friendly organic stabilizers. The synthesized Ag-NPs exhibited high stability, as evidenced by a zeta potential measuring - 36.8 mV. Also, the average particle size was determined to be 8 ± 2 nm. These Ag-NPs were then employed as a nano fluorescence probe to establish a fluorometric assay for determining prednisolone sodium phosphate (PDN) and dexamethasone sodium phosphate (DXZ). Reduction in fluorescence intensity of Ag-NPs observed at 484 nm following excitation at 242 nm exhibited quantitative quenching upon the incremental addition of the investigated drugs, with limits of detection of 0.178 µg/mL and 0.145 µg/mL for PDN and DXZ, respectively. The quenching mechanisms were examined and explained using the Stern-Volmer and Inner Filter Effect methods. The method's selectivity was also assessed by testing other corticosteroids. The proposed method is suitable for drug testing in pharmaceutical products and quality control labs. It follows ICH guidelines and has been confirmed to be safe and eco-friendly.

Impeding Biofilm-Forming Mediated Methicillin-Resistant Staphylococcus aureus and Virulence Genes Using a Biosynthesized Silver Nanoparticles-Antibiotic Combination

Methicillin-resistant Staphylococcus aureus (MRSA) continues to represent a significant clinical challenge, characterized by consistently elevated rates of morbidity and mortality. Care regimen success is still difficult and necessitates assessing new antibiotics as well as supplemental services, including source control and searching for alternative approaches to combating it. Hence, we propose to synthesize silver nanoparticles (Ag-NPs) by employing a cell-free filter (CFF) of Streptomyces sp. to augment antibiotic activity and combat biofilm-forming MRSA. Seven bacterial isolates from clinical samples were identified, antibiotics were profiled with Vitek-2, and the phenotypic detecting of biofilm with Congo red medium and microplate assay was carried out. The PCR technique was used for detecting genes (icaA and icaD) coded in biofilm forming. The characterization of Ag-NPs was performed using several analytical methods, such as UV spectroscopy, dynamic light scattering (DLS), zeta potential measurement, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antibacterial properties of Ag-NPs and oxacillin-Ag-NPs were assessed against standard strains and clinical isolates by employing the agar well diffusion technique and the microdilution assay. The biogenic synthesis Ag-NPs resulted in uniformly spherical particles, with an average size of 20 nm. These Ag-NPs demonstrated significant activity against biofilm-forming MRSA, with minimum inhibitory concentrations (MICs) ranging from 12 to 15 μg/mL. Additionally, Ag-NPs completely impede biofilm formation by MRSA at sublethal doses of 0.75 MICs. The expression levels of the icaA and icaD genes were reduced by 1.9- to 2.2- and 2.4- to 2.8-fold, respectively. A significant synergistic effect was noted when Ag-NPs were used in combination with oxacillin, leading to reduced MICs of 1.87 μg/mL for oxacillin and 4.0 μg/mL for Ag-NPs against MRSA. The FICi of 0.375 further validated the synergistic relationship between oxacillin and Ag-NPs at the concentrations of 1.87 and 4 μg/mL. Findings from the time-kill test demonstrated the highest reduction in log10 (CFU)/mL of the initial MRSA inoculum after 12-hour exposure. The cytotoxicity analysis of Ag-NPs revealed no significant cytotoxic effects on the human skin cell line HFB-4 at low concentrations, with IC50 values of 61.40 µg/mL for HFB-4 and 34.2 µg/mL for HepG-2. Comparable with oxacillin-Ag-NPs, Ag-NPs showed no cytotoxic effects on HFB-4 at different concentrations and exhibited an IC50 value of 31.2 against HepG-2-cells. In conclusion, the biosynthesis of Ag-NPs has demonstrated effective antibacterial activity against MRSA and has completely hindered biofilm formation, suggesting a valuable alternative for clinical applications.

In vitro evaluation of silver-zinc oxide-eugenol nanocomposite for enhanced antimicrobial and wound healing applications in diabetic conditions

Diabetic wounds with chronic infections present a significant challenge, exacerbated by the growing issue of antimicrobial resistance, which often leads to delayed healing and increased morbidity. This study introduces a novel silver-zinc oxide-eugenol (Ag+ZnO+EU) nanocomposite, specifically designed to enhance antimicrobial activity and promote wound healing. The nanocomposite was thoroughly characterized using advanced analytical techniques, confirming its nanoscale structure, stability and chemical composition. The Ag+ZnO+EU nanocomposite demonstrated potent antimicrobial efficacy against a range of wound associated pathogens, including standard and clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Minimum inhibitory concentrations of Ag+ZnO+EU for standard and clinical isolates were significantly lower than those of the individual components, highlighting the synergistic effect of the nanocomposite. Time-kill assays revealed rapid microbial eradication, achieving complete sterility within 240-min. Importantly, the nanocomposite effectively eliminated persister-like cells, which are typically resistant to conventional treatments, suggesting a potential solution for persistent infections. In vitro scratch assays using human keratinocyte cells demonstrated that the Ag+ZnO+EU nanocomposite significantly accelerated wound closure, with near-complete healing observed within 24-h, indicating enhanced cell migration and tissue regeneration. Additionally, the nanocomposite showed potential antidiabetic effects by increasing glucose uptake up to 97.21% in an in vitro assay using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose, a fluorescent glucose analog, suggesting potential applications beyond wound healing. These findings highlight the Ag+ZnO+EU nanocomposite as a promising candidate for addressing both antimicrobial resistance and impaired wound healing in diabetic contexts.

Photocatalytic removal of textile wastewater-originated methylene blue and malachite green dyes using spent black tea extract-coated silver nanoparticles

The spent black tea extract was utilized in order to synthesize the spent black tea silver nanoparticles (SBT-AgNPs). Various parameters were tested to yield the best production of SBT-AgNPs. The characterization was conducted by X-Ray diffraction, Scanning electron microscopy, Zeta potential and energy dispersive X-ray (EDX). The XRD analysis showed hkl planes corresponding to (111), (200), (220), (311) planes at 2θ theta deg 38.3°, 40.8°, 64.5°, and 74.2°. The scanning electron microscopy reported the plate like round shaped morphology of the AgNPs. The zeta potential was examined to be -17.5 mV and a size distribution by intensity of 157.6 d. nm was observed. The EDX was employed to determine the purity of samples by reporting a strong peak of silver (Ag). The degradation activity was examined by photocatalytic removal of methylene blue and malachite green dyes from textile wastewater. The textile wastewater showed a decrease of methylene blue by 25% and 58.3%. The malachite green was also reduced by 33.3% and 60%, which was remarkably significant owing to the presence of the complex factor in the natural environment. The study sets a promising record to harbor the full potential of available food waste resource, such as spent black tea to form SBT-AgNPs and its application in the dye removal from textile waste. The multifaceted outcomes of this study resulted in an eco-friendly procedure, thereby reusing the waste material for environmental cleanup.

Emerging Nanoparticle-Based Diagnostics and Therapeutics for Cancer: Innovations and Challenges

Malignant growth is expected to surpass other significant causes of death as one of the top reasons for dismalness and mortality worldwide. According to a World Health Organization (WHO) study, this illness causes approximately between 9 and 10 million instances of deaths annually. Chemotherapy, radiation, and surgery are the three main methods of treating cancer. These methods seek to completely eradicate all cancer cells while having the fewest possible unintended impacts on healthy cell types. Owing to the lack of target selectivity, the majority of medications have substantial side effects. On the other hand, nanomaterials have transformed the identification, diagnosis, and management of cancer. Nanostructures with biomimetic properties have been grown as of late, fully intent on observing and treating the sickness. These nanostructures are expected to be consumed by growth in areas with profound disease. Furthermore, because of their extraordinary physicochemical properties, which incorporate nanoscale aspects, a more prominent surface region, explicit geometrical features, and the ability to embody different substances within or on their outside surfaces, nanostructures are remarkable nano-vehicles for conveying restorative specialists to their designated regions. This review discusses recent developments in nanostructured materials such as graphene, dendrimers, cell-penetrating peptide nanoparticles, nanoliposomes, lipid nanoparticles, magnetic nanoparticles, and nano-omics in the diagnosis and management of cancer.

Utilizing Plant Phytoconstituents in Metal Oxide Nanoparticle Synthesis for Cancer Therapies

BACKGROUND

The metal oxide nanoparticles possess unique properties such as biological compatibility, superior reactivity, and capacity to develop reactive oxygen species, due to this they have drawn significant interest in cancer treatment. The various MONPs such as Cerium oxide, Copper oxide, Iron oxide, Titanium dioxide, and Zinc oxide have been investigated for several types of cancers including brain, breast, cervical, colon, leukemia, liver, lung, melanoma, ovarian, and prostate cancers. However, traditional physiochemical synthetic methods for MONPs commonly include toxic materials, a major concern that raises questions regarding their biocompatibility and safety.

OBJECTIVE

This study aims to investigate the role of plant phytoconstituents in the development of MONPs via green synthesis and explore the therapeutic effectiveness of MONPs in treating several types of cancer. Primarily, it examines the potential of plant phytoconstituents (phenolic compounds, flavonoids, glycosides, alkaloids, etc.) in the development of MONPs as well as their improved ability to target numerous types of cancer.

METHODS

A systemic search was conducted on recent literature, focusing on developing green MONPs by utilizing plants' phytoconstituents (plant extracts). The study of plant phytochemicals (present in different parts of a plant such as leaves, flowers, stems, peels, and roots) and their role in the synthesis of green metal oxide nanoparticles as well as their anticancer activity against several types of cancers was analyzed. Also focusing on their anticancer mechanism that involves ROS production, generates oxidative stress, and apoptosis leads to cancer inhibition.

RESULTS

Phytochemicals-mediated metal oxide nanoparticle synthesis revealed many advantages such as improved biological compatibility and enhanced sensitivity towards cancer cells. Phytochemicals present in plant extracts act as natural capping, reducing, and stabilizing agents, enhancing nanoparticle synthesis which leads to synergistic anticancer activity. Additionally, the natural antioxidant and anticancer activity of various phytochemicals enhances the therapeutic potential of metal oxide nanoparticles, producing them more effective against ROS-generated apoptosis and showing negligible toxicity towards normal cells.

CONCLUSION

The utilization of plant phytochemicals in metal oxide nanoparticle production presents a safe, eco-friendly, sustainable, and effective approach to developing effective and safer cancer nanomedicines. Green synthesis not only increases anticancer activity but also decreases the biocompatibility problems associated with the physiochemical synthetic approach. Further research needs to concentrate on improving this synergy to create a targeted phytochemical-based metal oxide nanoparticle for cancer therapeutics.

Green metal nanotechnology in monogastric animal health: current trends and future prospects - A review

Green nanotechnology is an emerging field of research in recent decades with rapidly growing interest. This integrates green chemistry with green engineering to avoid using toxic chemicals in the synthesis of organic nanomaterials. Green nanotechnology would create a huge potential for the use of nanoparticles for more sustainable utilization in improving animal health. Nanoparticles can be synthesised by physical, chemical and biological processes. Traditional methods for physical and chemical synthesis of nanoparticles are toxic to humans, animals and environmental health, which limits their usefulness. Green synthesis of nanoparticles via biological processes and their application in animal health could maximize the benefits of nanotechnology in terms of enhancing food animal health and production as well as minimize the undesirable impacts on Planetary Health. Recent advances in nanotechnology have meant different nanomaterials, especially those from metal sources, are now available for use in nanomedicine. Metal nanoparticles are one of the most widely researched in green nanotechnology, and the number of articles on this subject in food animal production is growing. Therefore, research on metal nanoparticles using green technologies have utmost importance. In this review, we report the recent advancement of green synthesized metal nanoparticles in terms of their utilization in monogastric animal health, elucidate the research gap in this field and provide recommendations for future prospects.

Spectroscopic approach to optimize the biogenic silver nanoparticles for photocatalytic removal of ternary dye mixture and ecotoxicological impact of treated wastewater

The fabricating of extremely effective, economical, ecologically safe, and reusable nanoparticle (NP) catalysts for the removal of water pollution is urgently needed. This study, spectroscopically optimizes the process parameters for the biogenic synthesis of AgNP catalysts using Cledrdendrum infortunatum leaf extract. The optimization of several synthesis parameters was systematically studied using UV-Vis spectroscopy to identify the ideal conditions for AgNPs formation. The AgNPs are spherical with a size of ~ 20 nm, pure and stable. Mechanistic insights into the biogenic synthesis process were explored. The photocatalytic performance of biogenic AgNPs was evaluated for the degradation of three common (crystal violet, thioflavin T, and methylene blue) dyes as models in ternary mixtures under the influence of sunlight. AgNPs show excellent photocatalytic efficiency in terms of degradation percentage (82.89-96.96% within 110 min), kinetics (0.0247-0.0331 min-1), half-life (20.96-28.11 min), and T80 (48.67-65.28 min) and also easily recovered and reused. Ecological safety assessment of the treated wastewater was assessed on the growths of rice, mustard, and lentil plants, and preliminary findings demonstrated that seedling growths for treated wastewater were nearly similar to the control sample but retarded in dye-contaminated wastewater suggesting potential use of treated wastewater for sustainable agriculture without compromising ecological balance. So, this study explores biogenic AgNPs as cost-effective, safe, and sustainable photocatalytic agents for the remediation of hazardous mix dyes and real-life applications of treated water for agricultural purposes.

Nanoparticle Strategies for Treating CNS Disorders: A Comprehensive Review of Drug Delivery and Theranostic Applications

This review aims to address the significant challenges of treating central nervous system (CNS) disorders such as neurodegenerative diseases, strokes, spinal cord injuries, and brain tumors. These disorders are difficult to manage due to the complexity of disease mechanisms and the protective blood-brain barrier (BBB), which restricts drug delivery. Recent advancements in nanoparticle (NP) technologies offer promising solutions, with potential applications in drug delivery, neuroprotection, and neuroregeneration. By examining current research, we explore how NPs can cross the BBB, deliver medications directly to targeted CNS regions, and enhance both diagnostics and treatment. Key NP strategies, such as passive targeting, receptor-mediated transport, and stimuli-responsive systems, demonstrate encouraging results. Studies show that NPs may improve drug delivery, minimize side effects, and increase therapeutic effectiveness in models of Alzheimer's, Parkinson's, stroke, and glioblastoma. NP technologies thus represent a promising approach for CNS disorder management, combining drug delivery and diagnostic capabilities to enable more precise and effective treatments that could significantly benefit patient outcomes.

Assessment of the Biocontrol Efficacy of Silver Nanoparticles Synthesized by Trichoderma asperellum Against Infected Hordeum vulgare L. Germination

This study investigated the biosynthesis, statistical optimization, characterization, and biocontrol activity of silver nanoparticles (AgNPs) produced by newly isolated Trichoderma sp. The Trichoderma asperellum strain TA-3N was identified based on the ITS gene sequence, together with its phenotypic characteristics (GenBank accession number: OM321439). The color change from light yellow to brown after the incubation period indicates AgNPs biosynthesis. The UV spectrum revealed a single peak with the maximum absorption at 453 nm, indicating that T. asperellum produces AgNPs effectively. A Rotatable Central Composite Design (RCCD) was used to optimize the biosynthesis of AgNPs using the aqueous mycelial-free filtrate of T. asperellum. The optimal conditions for maximum AgNPs biosynthesis (156.02 µg/mL) were predicted theoretically using the desirability function tool and verified experimentally. The highest biosynthetic produced AgNPs by T. asperellum reached 160.3 µg/mL using AgNO3 concentration of 2 mM/mL, initial pH level of 6, incubation time of 60 h, and biomass weight of 6 g/100 mL water. SEM and TEM imaging revealed uniform spherical shape particles that varied in size between 8.17 and 17.74 nm. The synthesized AgNPs have a Zeta potential value of -9.51 mV. FTIR analysis provided insights into the surface composition of AgNPs, identifying various functional groups such as N-H, -OH, C-H, C=O, and the amide I bond in proteins. Cytotoxicity and genotoxicity assays demonstrated that AgNPs in combination with T. asperellum can mitigate the toxic effects of Fusarium oxysporum on barley. This intervention markedly enhanced cell division rates and decreased chromosomal irregularities. The results indicate that AgNPs synthesized by T. asperellum show the potential as an eco-friendly and efficient method for controlling plant diseases. Further studies are necessary to investigate their possible use in the agricultural sector.

Green Synthesis of Silver Oxide Nanoparticles from Mauritia flexuosa Fruit Extract: Characterization and Bioactivity Assessment

The increasing prevalence of multidrug-resistant (MDR) pathogens, persistent biofilms, oxidative stress, and cancerous cell proliferation poses significant challenges in healthcare and environmental settings, highlighting the urgent need for innovative and sustainable therapeutic solutions. The exploration of nanotechnology, particularly the use of green-synthesized nanoparticles, offers a promising avenue to address these complex biological challenges due to their multifunctional properties and biocompatibility. Utilizing a green synthesis approach, Mauritia flexuosa Mf-Ag2ONPs were synthesized and characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy coupled with scanning electron microscopy (EDS-SEM), UV-Vis spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The Mf-Ag2ONPs exhibited potent antibacterial effects against both non-resistant and MDR bacterial strains, with minimum inhibitory concentrations (MICs) ranging from 11.25 to 45 µg/mL. Mf-Ag2ONPs also demonstrated significant antifungal efficacy, particularly against Candida glabrata, with an MIC of 5.63 µg/mL. Moreover, the nanoparticles showed strong biofilm inhibition capabilities and substantial antioxidant properties, underscoring their potential to combat oxidative stress. Additionally, Mf-Ag2ONPs exhibited pronounced anticancer properties against various cancer cell lines, displaying low IC50 values across various cancer cell lines while maintaining minimal hemolytic activity at therapeutic concentrations. These findings suggest that Mf-Ag2ONPs synthesized via an eco-friendly approach offer a promising alternative for biomedical applications, including antimicrobial, antifungal, antioxidant, and anticancer therapies, warranting further in vivo studies to fully exploit their therapeutic potential.

Insight into Antiviral Activity of Ag/TiO2 Nanocomposites Against Influenza H1N1 Virus and Its Antiviral Mechanism

Purpose

Synthesis and characterization of silver (Ag)/titanium dioxide (TiO2) nanocomposite (ATA) to investigate its antiviral activity against the H1N1 influenza virus and antiviral mechanisms.

Materials and Methods

A water-dispersible ATA was prepared by a photocatalytic reduction process from AgNO3 and TiO2. The characterization of ATA was performed by ultraviolet-visible spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. The antiviral activities and the antiviral mechanism of ATA were investigated in detail by light microscopy, transmission electron microscopy and biological techniques such as cell cytotoxicity, 50% tissue culture infectious dose detection, western blot and reverse transcription-polymerase chain reaction.

Results

These results showed the successful synthesis of ATA nanocomposite with uniform particle size and distribution. It demonstrated the highly efficient antiviral activity of ATA in a dose- and time-dependent manner, as indicated by the reduction of viral titer and the reduction of cytopathic effects caused by viral infection. In the presence of ATA, the structure of the H1N1 influenza virus is directly destroyed and even disintegrated, with the damaged surface membrane proteins and fuzzy contour. It reduces the infection efficiency of influenza by suppressing the activity and expression of hemagglutinin and neuraminidase. The results of mechanistic studies suggested that ATA nanocomposite primarily interferes with virus attachment to viral receptors on the cell surface.

Conclusion

Our study suggests that ATA may be a good antiviral candidate against the influenza virus. Compared with AgNPs alone, our synthesized ATA nanocomposites can achieve similar viral inactivation rates using only a much smaller concentration of AgNPs, greatly reducing the amount of AgNPs and their potential side effects. It has great practical value for attaching ATA to the high-efficiency particulate air network in the air purifier, which can kill the virus attached to it and limit its spread.

Review of Gold Nanoparticles: Synthesis, Properties, Shapes, Cellular Uptake, Targeting, Release Mechanisms and Applications in Drug Delivery and Therapy

The remarkable versatility of gold nanoparticles (AuNPs) makes them innovative agents across various fields, including drug delivery, biosensing, catalysis, bioimaging, and vaccine development. This paper provides a detailed review of the important role of AuNPs in drug delivery and therapeutics. We begin by exploring traditional drug delivery systems (DDS), highlighting the role of nanoparticles in revolutionizing drug delivery techniques. We then describe the unique and intriguing properties of AuNPs that make them exceptional for drug delivery. Their shapes, functionalization, drug-loading bonds, targeting mechanisms, release mechanisms, therapeutic effects, and cellular uptake methods are discussed, along with relevant examples from the literature. Lastly, we present the drug delivery applications of AuNPs across various medical domains, including cancer, cardiovascular diseases, ocular diseases, and diabetes, with a focus on in vitro and in vivo cancer research.

Impeding microbial biofilm formation and Pseudomonas aeruginosa virulence genes using biologically synthesized silver Carthamus nanoparticles

Long-term antibiotic treatment results in the increasing resistance of bacteria to antimicrobials drugs, so it is necessary to search for effective alternatives to prevent and treat pathogens that cause diseases. This study is aimed for biological synthesis of silver Carthamus nanoparticles (Ag-Carth-NPs) to combat microbial biofilm formation and Pseudomonas aeruginosa virulence genes. Ag-Carth-NPs are synthesized using Carthamus tenuis aqueous extract as environmentally friendly method has no harmful effect on environment. General factorial design is used to optimize Ag-Carth-NPs synthesis using three variables in three levels are Carthamus extract concentration, silver nitrate concentration and gamma radiation doses. Analysis of response data indicates gamma radiation has a significant effect on Ag-Carth-NPs production. Ag-Carth-NPs have sharp peak at λ max 425 nm, small and spherical particles with size 20.0 ± 1.22 nm, high stability up to 240 day with zeta potential around - 43 ± 0.12 mV, face centered cubic crystalline structure and FT-IR spectroscopy shows peak around 620 cm-1 that corresponding to AgNPs that stabilized by C. tenuis extract functional moiety. The antibacterial activity of Ag-Carth-NPs against pathogenic bacteria and fungi was determined using well diffusion method. The MIC values of Ag-Carth-NPs were (6.25, 6.25, 3.126, 25, 12.5, 12.5, 25 and 12.5 µg/ml), MBC values were (12.5, 12.5, 6.25, 50, 25, 25, 50 and 25 µg/ml) and biofilm inhibition% were (62.12, 68.25, 90.12, 69.51, 70.61, 71.12, 75.51 and 77.71%) against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Candida tropicalis and Candida albicans respectively. Ag-Carth-NPs has bactericidal efficacy and significantly reduced the swarming, swimming motility, pyocyanin and protease production of P. aeruginosa. Furthermore, P. aeruginosa ToxA gene expression was significantly down regulated by 81.5%, while exoU reduced by 78.1%, where lasR gene expression reduction was 68%, while the reduction in exoU was 66% and 60.1% decrease in lasB gene expression after treatment with Ag-Carth-NPs. This activity is attributed to effect of Ag-Carth-NPs on cell membrane integrity, down regulation of virulence gene expression, and induction of general and oxidative stress in P. aeruginosa. Ag-Carth-NPs have no significant cytotoxic effects on normal human cell (Hfb4) but have IC50 at 5.6µg/mL against of HepG-2 cells. Limitations of the study include studies with low risks of silver nanoparticles for in vitro antimicrobial effects and its toxicity.

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

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

Anti-inflammatory action of silver nanoparticles in vivo: systematic review and meta-analysis

The aim of this study was to systematically review the literature to investigate whether silver nanoparticles (AgNPs) have an anti-inflammatory effect in vivo. The guidelines of PRISMA were applied, and a registration was made in PROSPERO. A personalized search of the PubMed, Web of Science, Scopus, Embase, Lilacs, and Google Scholar databases was conducted in September 2023. For the data analysis, the inverse variance in the random effects model was used. The tools of SYRCLE and GRADE were used to assess the risk of bias and the certainty of evidence, respectively. From the 9185 identified studies, 5685 duplicate studies were excluded; 52 were read in full text, and 7 were included in this review. Six studies were evaluated by the meta-analysis, and an increase in anti-inflammatory molecules (SMD -5.22; PI [-6.50, -3.94]) and an increase in anti-inflammatory ones (SMD 5.75; PI [3.79, 7.72]) were observed. Qualitative analysis showed a reduction in pro-inflammatory proteins and in the COX-2 pathway. It was concluded that AgNPs present an anti-inflammatory action in vivo through mechanisms involving the reduction of pro-inflammatory molecules and proteins, the increase of anti-inflammatory molecules, and selective inhibition of the COX-2 pathway.

Investigating UV-Irradiation Parameters in the Green Synthesis of Silver Nanoparticles from Water Hyacinth Leaf Extract: Optimization for Future Sensor Applications

Silver nanoparticles (AgNPs) can be produced safely and greenly using water hyacinth, an invasive aquatic plant, as a reducing agent. This study aimed to optimize the UV-irradiation parameters for the synthesis of AgNPs from water hyacinth leaf extract. The study varied the reaction time and pH levels and added a stabilizing agent to the mixture. The synthesized AgNPs were characterized using UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The findings revealed that the optimal conditions for synthesizing AgNPs were achieved by adjusting the pH level to 8.5, adding starch as a stabilizing agent, and exposing the mixture to UV-A radiation for one hour. These conditions resulted in the smallest size and highest quantity of AgNPs. Furthermore, the synthesized AgNP colloids remained stable for up to six months. This study highlights the potential of utilizing water hyacinth as a sustainable and cost-effective reducing agent for AgNP synthesis, with potential applications in pharmaceuticals, drug development, catalysis, and sensing detection.

Recent advances in nanoformulation-based delivery for cancer immunotherapy

Cancer is one of the leading causes of mortality worldwide, and its treatment faces several challenges. Phytoconstituents derived from recently discovered medicinal plants through nanotechnology potentially target cancer cells via PI3K/Akt/mTOR pathways and exert their effects selectively through the generation of reactive oxygen species through β-catenin inhibition, DNA damage, and increasing caspase 3/9 and p53 expression. These nanocarriers act specifically against different cancer cell lines such as HT-29, MOLT-4 human leukemia cancer and MCF-7 cell lines SKOV-3, Caov-3, SW-626, HepG2, A-549, HeLa, and MCF-7. This review comprehensively elaborates on the cellular and molecular mechanisms, and therapeutic prospects of various plant-mediated nanoformulations to attain a revolutionary shift in cancer immunotherapy.

Clean synthesis of silver nanoparticles (AgNPs) on polyamide fabrics by Verbascum thapsus L. (mullein) extract: characterization, colorimetric, antibacterial, and colorfastness studies

The production of antibacterial colored textiles using nanomaterials (NMs) has become an ideal goal from both a research and industrial perspective. In this study, the clean synthesis and characterization of silver nanoparticles (AgNPs) on polyamide fabrics were performed using mullein extract for the first time. Natural dyes were extracted from mullein leaves using an ultrasonic method, with an optimal amount of 15 g/L. The synthesized AgNPs in different ratios of mullein extract and Ag ions were analyzed (using UV-visible spectroscopy) and dynamic light scattering (DLS). It was found that AgNPs synthesized with a ratio of 1:4 of mullein extract: to Ag ions had a diameter of 85 nm. The active site groups of the synthesized AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR). Nylon fabrics dyed with different ratios of mullein extract and Ag ions exhibited acceptable color strength values (K/S) of 3.36. Furthermore, the reduction in bacterial growth for dyed fabrics improved with an increase in the ratio of Ag ions, with a 100% reduction observed for a sample dyed with mullein extract: Ag ions at a ratio of 1:4. Overall, this method offers a simple, low-cost, and compatible process with environment without the consumption of any chemicals to producing nylon with acceptable antibacterial and dyeing properties.

Green synthesis of CuO nanoparticles using Ligustrum lucidum extract, and the antioxidant and antifungal evaluation

Biosynthesis of metal oxide nanoparticles using plant extract is an inexpensive, simple, rapid, and environmentally friendly approach to obtaining nanoparticles for biological applications. Herein, copper oxide nanoparticles (CuO-NPs) were successfully synthesized using an aqueous extract from Ligustrum lucidum leaves. The structural, optical, and morphological characteristics of the nanoparticles were assessed using x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectrophotometer, transmission and scanning electron microscopy (TEM and SEM), and energy-dispersive x-ray (EDX). Nanocrystalline CuO with an average crystalline size of 22.0 nm and a band gap energy of 1.4 eV were confirmed from the XRD and UV-vis spectrophotometer, respectively. Morphological studies showed spherical nanoparticles, whose particle size estimation (30 ± 5 nm) agrees with the crystalline size deduced from the XRD pattern. A free radical scavenging activity of the CuO nanoparticles, evaluated using the 1, 1-diphenhyl-2-picrylhydrazyl (DPPH) assay, showed that it exhibited high antioxidant activity (IC50: 63.35 μg ml−1) that is concentration dependent. Antifungal evaluation using four different fungal strains (Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, and Trichoderma harzianum) indicated a direct relationship between the potency of the particles and their concentration, with 1 ppm solution exhibiting the highest potency. The green synthesized CuO-NPs using Ligustrum lucidum may be potentially used as an antioxidant and antifungal agent for therapeutic applications.

Antimicrobial and Cytotoxic Effect of Positively Charged Nanosilver-Coated Silk Sutures

Sutures are a crucial component of surgical procedures, serving to close and stabilize wound margins to promote healing. However, microbial contamination of sutures can increase the risk of surgical site infections (SSI) due to colonization by pathogens. This study aimed to tackle SSI by synthesizing positively charged silver nanoparticles (P-AgNPs) and using them to produce antimicrobial sutures. The P-AgNPs were reduced and stabilized using polyethylenimine (PEI), a cationic branched polymer. The physiochemical characteristics of P-AgNPs were confirmed from the surface plasmon resonance (SPR) peak at 419 nm, spherical morphology with a particle size range of 8-10 nm, PEI functional groups on NPs, a hydrodynamic diameter of 12.3 ± 2.4 nm, and a zeta potential of 31.3 ± 6 mV. Subsequently, the surfaces of silk sutures were impregnated with P-AgNPs at different time intervals (24, 48, and 96 h) using an ex situ method. Scanning electron microscopy (SEM) and tensile strength studies were conducted to determine the coating and durability of the NP-coated sutures. The NPs were quantified on sutures using inductively coupled plasma optical emission spectrophotometry (ICP-OES), which was in the range of 1-5 μg. Primarily, antimicrobial activity was studied using three microorganisms (Candida albicans, Streptococcus mutans, and Staphylococcus aureus) for both P-AgNPs and suture-coated P-AgNPs using the agar diffusion method. The results showed that only the NPs and NP-coated sutures exhibited enhanced antimicrobial effects against bacteria and fungi. Finally, the cytotoxicity of the sutures was investigated using stem cells from the apical papilla (SCAPs) for 24 h, which exhibited more than 75% cell viability. Overall, the results indicate that NP-coated sutures can potentially be used as antimicrobial sutures to diminish or inhibit SSI in postoperative or general surgery patients.