Green Synthesis of Silver Nanoparticles Using Aqueous Citrus limon Zest Extract: Characterization and Evaluation of Their Antioxidant and Antimicrobial Properties

In silico mechanistic insights of ecofriendly synthesized AgNPs, SeNPs, rGO and Ag&SeNPs@rGONM's for biological applications and its toxicity evaluation using Artemia salina

The present study focused on Rosmarinus officinalis Linn. leaves extract (ROE) mediated synthesis of silver nanoparticles (AgNPs), selenium nanoparticles (SeNPs), reduced graphene oxide (rGO) and silver and selenium nanoparticles decorated on rGO nanomaterials (Ag&SeNPs@rGONM's) for its antibacterial and antifungal in silico mechanistic insight applications. In addition, the toxicity of the synthesized nanomaterials was evaluated using Artemia salina. The formation of AgNPs, SeNPs, rGO and Ag&SeNPs@rGONM's was completed within 1.0, 140, 120 and 144 h, respectively. Various optical and microscopic examinations were evident in the nanomaterial's synthesis. Further, the average size and stability of the synthesized nanomaterials were conformed through dynamic light scattering (DLS) and zeta potential analyzer, respectively. The synthesized Ag&SeNPs@rGONM's were pronounced promising results against Gram-negative bacteria of Escherichia coli and the results achieved from the route of entry and action, reactive oxygen species (ROS), and antioxidant nature of nanoparticles were evidence of its properties. Computational studies further supported these findings, indicating much of the phytochemicals present in ROE well interact with the bacterial surface proteins. Similarly, the synthesized Ag&SeNPs@rGONM's was effective against Fusarium graminearum and Alternaria alternata in a dose dependent manner than its original nanomaterials. In addition, the docking study also confirmed that rosmarinic acid and caffeic acid prominently interacted with the fungal proteins. Interestingly, Ag&SeNPs@rGONM's pronounced less toxic effect compared to AgNPs and SeNPs against Artemia salina, which shows its biocompatibility.

Formulation of silver nanoparticles using Duabanga grandiflora leaf extract and evaluation of their versatile therapeutic applications

The current research focused on the green synthesis of silver nanoparticles (AgNPs) using Duabanga grandiflora leaf extract. The green synthesis of AgNPs was confirmed by the surface plasmon resonance band at 453 nm in a UV-Visible analysis. The formulated AgNPs had a diameter of around 99.72 nm with a spherical shape. Fourier transform infrared (FTIR) spectrum revealed the bio-reducing potential of phytochemicals present in D. grandiflora, which fundamentally influenced the synthesis of AgNPs. Zeta potential, dynamic light scattering (DLS), scanning electron microscopic (SEM), energy-dispersive X-ray spectroscopic (EDX), X-ray diffraction (XRD), and transmission electron microscopic (TEM) analyses were executed to reveal the physicochemical attributes of the AgNPs. The AgNPs were further investigated for their antioxidant, antidiabetic, anticancer, and antibacterial potential. The DPPH free radical assay revealed the potential radical scavenging capacity (IC50 = 76.73 μg/ml) of green synthesized AgNPs. α-Amylase inhibitory assay displayed significant inhibitory potential (IC50 = 162.11 μg/ml) of this starch-breaking enzyme by AgNPs, revealing the antidiabetic potential of AgNPs. AgNPs exhibited potential cytotoxic activity (IC50 = 244.57 µg/ml) against malignant human kidney cells. In addition, AgNPs showed outstanding antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains. Interestingly, AgNPs showed cytotoxic and antimicrobial activities at much higher concentrations than radical scavenging and α-amylase inhibitory concentrations. Thus, our finding elaborated the scope of green synthesized AgNPs for diverse therapeutic applications (dose-dependent) for further clinical translation.

Advances in silver nanoparticles: a comprehensive review on their potential as antimicrobial agents and their mechanisms of action elucidated by proteomics

Nanoparticles play a crucial role in the field of nanotechnology, offering different properties due to their surface area attributed to their small size. Among them, silver nanoparticles (AgNPs) have attracted significant attention due to their antimicrobial properties, with applications that date back from ancient medicinal practices to contemporary commercial products containing ions or silver nanoparticles. AgNPs possess broad-spectrum biocidal potential against bacteria, fungi, viruses, and Mycobacterium, in addition to exhibiting synergistic effects when combined with certain antibiotics. The mechanisms underlying its antimicrobial action include the generation of oxygen-reactive species, damage to DNA, rupture of bacterial cell membranes and inhibition of protein synthesis. Recent studies have highlighted the effectiveness of AgNPs against various clinically relevant bacterial strains through their potential to combat antibiotic-resistant pathogens. This review investigates the proteomic mechanisms by which AgNPs exert their antimicrobial effects, with a special focus on their activity against planktonic bacteria and in biofilms. Furthermore, it discusses the biomedical applications of AgNPs and their potential non-preparation of antibiotic formulations, also addressing the issue of resistance to antibiotics.

Characterization, anti-microbial, anti-oxidant and growth promoting effects of biogenically synthesized silver nanoparticles derived from Dicliptera bupleuroides Nees

One of the most important areas of nanotechnology is the use of nanoparticles (NPs) for a variety of environmental and biological applications, with silver nanoparticles (Ag-NPs) gaining a lot attention due to their distinct properties. The current study deals with the synthesis of Ag-NPs from Dicliptera bupleuroides Nees leaf extract and to determine their antioxidant, antimicrobial potential and effects on wheat seed germination and growth. UV-Visible spectrum revealed a prominent absorption peak at 442 nm, elucidating the conformation of the Ag-NPs synthesis. Scanning electron microscopy (SEM) showed distinctive triangular, pyramidal, and irregular shape. X-ray diffraction (XRD) demonstrated their crystalline nature, with average crystallite size of the Ag-NPs measured at 20.52 nm. Fourier-transform infrared spectroscopy (FT-IR) further confirmed the presence of functional groups such as Phenols (O-H stretch), transition metal carbonyls N-H, ≡C-H, C ≡ N, C ≡ C, C-Cl, C-Br and O-H bonds on the surface Ag-NPs. The antibacterial activity of the Ag-NPs was most pronounced against Bacillus subtilis, with a zone of inhibition (ZOI) measuring 11 mm ± 0.57 at a concentration of 1000 μg/mL (45% inhibition). Likewise, Ag-NPs exhibited highest antioxidant potential (73.2%) at 100 μg/mL compared with standard (ascorbic acid) which showed (76%) at the same concentration. Furthermore, the effect of D. bupleuroides mediated Ag-NPs on wheat seeds growth and germination was recorded maximum at high concentrations (200-300 ppm). In conclusion, D. bupleuroides mediated Ag-NPs showed safe, cost effective and environmentally friendly synthesis which can be used as an antibacterial and antioxidant agent as well as for enhancing the growth and seed germination of crop seeds globally. RESEARCH HIGHLIGHTS: Nanotechnology is the study of nanoparticles for biological and environmental applications. Ag-NPs among other NPs have received broad attention because of their unique properties. D. bupleuroides Ag-NPs: 45% antibacterial, 73.2% antioxidant, enhance wheat germination. D. bupleuroides-mediated Ag-NPs are both cost-effective and environmentally beneficial.

Harnessing bio-based chelating agents for sustainable synthesis of AgNPs: Evaluating their inherent attributes and antimicrobial potency in conjunction with honey

Greenly synthesized nanoparticles have garnered attention due to their low environmental footprint, but impurities limit their applications. A novel semi-organic method for synthesizing silver nanoparticles (AgNPs) using bio-based chelating fuels (Beta vulgaris subsp., Spinacia oleracea, and Ipomoea batatas) reduces the undesirable impurities. The study also showcases the impact of bio-based chelating fuel on various characteristics of AgNPs in comparison to synthetic chelating fuel. The antimicrobial efficacy of the synthesized AgNPs in conjunction with honey was also assessed against E. coli. The XRD analysis showed cubic structure of AgNPs. The FESEM and TEM analysis showed that the well-connected spherical-shaped AgNPs (∼3-120 nm diameter) while EDS confirmed the presence of Ag in all samples. The TEM analysis also revealed layers of carbonates in AgNPs synthesized using bio-based chelating fuels. XPS investigation confirmed the absence of any prominent impurities in prepared samples and AgNPs have not experienced oxidation on their surface. However, notable surface charging effects due to the uneven conductivity of the particles were observed. The broth dilution method showed that all mixtures containing AgNPs in combination with honey exhibited a significant bacterial growth reduction over a period of 120 h. The highest growth reduction of ∼75 % is obtained for the mixture having AgNPs (Ipomoea batatas) while the least growth reduction of ∼51 % is obtained for the mixture having AgNPs (Beta vulgaris subsp.). The findings affirm that AgNPs can be successfully synthesized using bio-based chelating fuels with negligible ecological consequences and devoid of contaminants. Moreover, the synthesized AgNPs can be employed in conjunction with honey for antibacterial purposes.

Biogenic Synthesis of Selenium and Copper Oxide Nanoparticles and Inhibitory Effect against Multi-Drug Resistant Biofilm-Forming Bacterial Pathogens

Antimicrobial resistance (AMR), caused by microbial infections, has become a major contributor to morbid rates of mortality worldwide and a serious threat to public health. The exponential increase in resistant pathogen strains including Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) poses significant hurdles in the health sector due to their greater resistance to traditional treatments and medicines. Efforts to tackle infectious diseases caused by resistant microbes have prompted the development of novel antibacterial agents. Herein, we present selenium and copper oxide monometallic nanoparticles (Se-MMNPs and CuO-MMNPs), characterized using various techniques and evaluated for their antibacterial potential via disc diffusion, determination of minimum inhibitory concentration (MIC), antibiofilm, and killing kinetic action. Dynamic light scattering (DLS), scanning electron microscopy (SEM/EDX), and X-ray diffraction (XRD) techniques confirmed the size-distribution, spherical-shape, stability, elemental composition, and structural aspects of the synthesized nanoparticles. The MIC values of Se-MMNPs and CuO-MMNPs against S. aureus and E. coli were determined to be 125 μg/mL and 100 μg/mL, respectively. Time-kill kinetics studies revealed that CuO-MMNPs efficiently mitigate the growth of S. aureus and E. coli within 3 and 3.5 h while Se-MMNPs took 4 and 5 h, respectively. Moreover, CuO-MMNPs demonstrated better inhibition compared to Se-MMNPs. Overall, the proposed materials exhibited promising antibacterial activity against S. aureus and E. coli pathogens.

Comparative Antioxidant Efficacy of Green-Synthesised Selenium Nanoparticles From Pongamia pinnata, Citrus sinensis, and Acacia auriculiformis: An In Vitro Analysis

Aim This study aims to synthesise selenium nanoparticles (SeNPs) using extracts from Citrus sinensis peel (CSP), Millettia pinnata Leaf (MPL), and Acacia auriculiformis bark (AAB) as eco-friendly reducing agents. It seeks to compare the effectiveness of these plant extracts in the production of SeNPs and evaluate the antioxidant activities of the synthesised nanoparticles, establishing a link between the phytochemical constituents of the extracts and the antioxidant capacity of SeNPs for their potential applications in drug development and environmental sustainability. Introduction Nanotechnology offers innovative solutions in various fields, including medicine, environmental science, and materials engineering. SeNPs are of particular interest due to their unique properties and potential applications. The methods for synthesizing nanoparticles often involve hazardous chemicals, posing risks to the environment and human health. In response, green synthesis methods utilizing plant extracts have emerged as a sustainable alternative. This study focuses on utilizing CSP, MPL, and AAB extracts, rich in natural reducing agents such as flavonoids and phenolic acids, for the eco-friendly synthesis of SeNPs. These plant sources are chosen based on their known phytochemical profiles and potential antioxidant activities, and we aim to explore the correlation between the extracts' phytochemical composition and the antioxidant capabilities of the synthesised SeNPs. Methods SeNPs were synthesised using aqueous extracts of CSP, MPL, and AAB through a reduction process, in which selenium ions (Se4+) are reduced to elemental selenium. The presence of SeNPs was first visually monitored by colour change and then confirmed through UV-Vis spectroscopy and Fourier transform infrared (FTIR) spectroscopy analyses. The antioxidant activity of the synthesised SeNPs was assessed using the 1,1-diphenyl-2-picryl hydroxyl (DPPH) radical scavenging assay and the efficacy of SeNPs synthesised from different plant extracts was compared. Results The UV-Vis spectral analysis indicated a successful synthesis of SeNPs, as evidenced by the characteristic absorption peaks. The FTIR analysis confirmed the presence of organic molecules derived from the plant components on the outer layer of SeNPs, suggesting successful capping and stabilization of nanoparticles by phytochemicals in the extracts. Among the three types of SeNPs, those synthesised using Citrus sinensis peel extract (CSPE) exhibited the highest DPPH radical scavenging activity, indicating superior antioxidant properties compared to SeNPs synthesised from Millettia pinnata leaf extract (MPLE) and Acacia auriculiformis bark extract (AABE). This suggests that the antioxidant capacity of SeNPs is significantly influenced by the phytochemical composition of the plant extract used for synthesis. Conclusion The study highlights the potential of CSPE as an effective natural source for synthesising antioxidant-rich SeNPs and underscores the importance of green synthesis approaches in producing environmentally friendly and biologically active nanomaterials.

Process optimization for green synthesis of silver nanoparticles using Rubus discolor leaves extract and its biological activities against multi-drug resistant bacteria and cancer cells

Multi-drug resistant (MDR) bacteria are considered a serious public health threat. Also, increasing rate of resistance to anticancer drugs, as well as their toxicity, is another point of concern. Therefore, the new antibacterial and anticancer agents are always needed. The synthesizing silver nanoparticles (AgNPs) using medicinal plants, is an effective approach for developing novel antibacterial and anticancer agents. Rubus discolor, a native species of the Caucasus region, produces leaves that are typically discarded as a by-product of raspberry production. The present study has focused on optimizing the green synthesis of AgNPs using R. discolor leaves extract through response surface methodology. The optimal values for AgNPs synthesis were an AgNO3 concentration of 7.11 mM, a time of 17.83 h, a temperature of 56.51 °C, and an extract percentage of 29.22. The production of AgNPs was confirmed using UV-visible spectroscopy (λmax at 456.01 nm). TEM analysis revealed well-dispersed AgNPs (an average size of 37 nm). The XRD analysis confirmed the crystalline structure. The EDX detected a strong peak at 3 keV corresponded to Ag. The zeta potential value (- 44.2 mV) indicated the stability of nanoparticles. FT-IR spectra showed the presence of various functional groups from plant compounds, which play an important role in the capping and bio-reduction processes. The AgNPs revealed impressive antibacterial activities against MDR Escherichia coli and Pseudomonas aeruginosa (MIC ranging from 0.93 to 3.75 mg ml-1). The phytochemical analysis indicated the presence of phenolics, tannins, and flavonoids on the surface of AgNPs. They also showed significant cytotoxic effects on A431, MCF-7, and HepG2 cells (IC50 values ranging from 11 to 49.1 µg ml-l).

Liposome Nanocarriers Based on γ Oryzanol: Preparation, Characterization, and In Vivo Assessment of Toxicity and Antioxidant Activity

The present study aimed to develop and characterize liposome nanocarriers based on γ oryzanol and evaluate their potential in vitro and in vivo toxicity and antioxidant effects. The liposomes were physicochemically characterized using various techniques, including dynamic light scattering (DLS) for size and polydispersity index (PDI) measurements and ζ-potential analysis. The in vitro toxicity assessments were performed using hemolysis and MTT assays on the HS5 cell line. In vivo, acute oral toxicity was evaluated by using LD50 assays in mice. Additionally, antioxidant activity was assessed through biochemical analysis of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and liver tissue catalase, malondialdehyde (MDA), and glutathione (GSH) levels. The results revealed that the liposomes exhibited a uniform and spherical morphology with suitable physicochemical properties for drug delivery applications. The in vitro cytotoxicity and hemolysis assays and the in vivo LD50 experiment indicated the potential safety of γ oryzanol liposomes, especially at lower concentrations. In addition, the assessment of liver enzymes, i.e., ALT and AST, and the antioxidant markers further revealed the safety of the formulation, particularly for the liver as a highly sensitive soft organ. Overall, the liposome nanocarriers based on γ oryzanol were successfully formulated and expressed potential safety, supporting their application for the purposes of drug delivery and therapeutic interventions, particularly for hepatocellular and antioxidant therapies; however, further investigations for preclinical and clinical studies could be the future prospects for liposome nanocarriers based on γ oryzanol to explore the safety and efficacy of these nanocarriers in various disease models and clinical settings.

Antibacterial, antioxidant, and anticancer potential of green fabricated silver nanoparticles made from Viburnum grandiflorum leaf extract

BACKGROUND

Recently, researchers are focusing on creating new tools to combat the antibiotic resistant bacteria and malignancy issues, which pose significant threats to humanity. Biosynthesized silver nanoparticles (AgNPs) are thought to be a potential solution to these issues. The biosynthesis method, known for its environmentally friendly and cost-effective characteristics, can produce small-sized AgNPs with antimicrobial and anticancer properties. In this study, AgNPs were bio-fabricated from the distilled water and methanolic extracts of Viburnum grandiflorum leaves. Physio-chemical characterization of the bio-fabricated AgNPs was conducted using UV-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis.

RESULTS

AgNPs produced from the methanol extract were smaller in size (12.28 nm) compared to those from the aqueous extract (17.77 nm). The bioengineered AgNPs exhibited a circular shape with a crystalline nature. These biosynthesized AgNPs demonstrated excellent bactericidal activity against both gram-negative (Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. Highest antibacterial activity was observed with the methanol extract against P. aeruginosa (14.66 ± 0.74 mm). AgNPs from the methanol extract also displayed the highest antioxidant activity, with an IC50 value of 188.00 ± 2.67 μg/mL against 2,2-diphenyl-1-picrylhydrazyl (DPPH). Furthermore, AgNPs exhibited notable cytotoxic activity against Rhabdomyosarcoma cell line (RD cell) of human muscle cancer cell. The IC50 values calculated from the MTT assay were 26.28 ± 1.58 and 21.49 ± 1.44 μg/mL for AgNPs synthesized from aqueous and methanol extracts, respectively.

CONCLUSION

The methanol extract of V. grandiflorum leaves demonstrates significant potential for synthesizing AgNPs with effective antibacterial, antioxidant, and anticancer actions, making them applicable in various biomedical applications.

In situ and bio-green synthesis of silver nanoparticles immobilized on zeolite as a recyclable catalyst for the degradation of OPDs

In this study, silver nanoparticles (Ag-NPs) were synthesized using a green and biologically inspired approach by utilizing reducing compounds from Thyme plant leaves. Zeolite was used to immobilize the synthesized Ag-NPs (Ag@Z). The modified Zeolite served as a catalyst for the reduction reaction of various organic pollutant dyes (OPDs) including 4-nitrophenol (4-NP), 4-nitroaniline (4-NA), methylene blue (MB), and methyl orange (MO) with sodium borohydride. The degradation of OPDs was monitored by measuring changes in their maximum absorption wavelength intensity. A thorough examination of multiple parameters (catalyst, silver and sodium borohydride dosage, yield degradation, and reaction time) was carried out to identify the optimized conditions for the degradation of OPDs. The results showed that the Ag@Z catalyst achieved an efficiency of over 93% in less than 10 min for the degradation of OPDs. The recoverability and reusability of the catalyst were examined, revealing a partial loss in efficiency after four recovery stages. Structural analysis using XRD, SEM, and TEM techniques confirmed the characteristics and morphology of the synthesized catalyst.

Green Synthesis of Novel Silver Nanoparticles Using Salvia blepharophylla and Salvia greggii: Antioxidant and Antidiabetic Potential and Effect on Foodborne Bacterial Pathogens

In the face of evolving healthcare challenges, the utilization of silver nanoparticles (AgNPs) has emerged as a compelling solution due to their unique properties and versatile applications. The aim of this study was the synthesis and characterization of novel AgNPs (SB-AgNPs and SG-AgNPs, respectively) using Salvia blepharophylla and Salvia greggii leaf extracts and the evaluation of their antimicrobial, antioxidant, and antidiabetic activities. Several analytical instrumental techniques were utilized for the characterization of SB-AgNPs and SG-AgNPs, including UV-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transmission infrared (FT-IR) spectroscopy, energy-dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). FTIR analysis identified various functional groups in the leaf extracts and nanoparticles, suggesting the involvement of phytochemicals as reducing and stabilizing agents. High-resolution TEM images displayed predominantly spherical nanoparticles with average sizes of 52.4 nm for SB-AgNPs and 62.5 nm for SG-AgNPs. Both SB-AgNPs and SG-AgNPs demonstrated remarkable antimicrobial activity against Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes and Gram-negative bacteria Salmonella typhimurium and Escherichia coli. SB-AgNPs and SG-AgNPs also exhibited 90.2 ± 1.34% and 89.5 ± 1.5% DPPH scavenging and 86.5 ± 1.7% and 80.5 ± 1.2% α-amylase inhibition, respectively, at a concentration of 100 μg mL-1. Overall, AgNPs synthesized using S. blepharophylla and Salvia greggii leaf extracts may serve as potential candidates for antibacterial, antioxidant, and antidiabetic agents. Consequently, this study provides viable solutions to mitigate the current crisis of antibiotic resistance and to efficiently combat antimicrobial infections and Type 2 diabetes.

Preparation of silver nanoparticles by Osbeckia stellata aqueous extract via green synthesis approach: Characterization and assessment of their antioxidant, antidiabetic, cytotoxicity, and antibacterial properties

Silver nanoparticles (Ag NPs) via green synthesis using medicinal plants have been widely used in natural product research due to the economical and eco-friendly properties of NPs. The plant-derived Ag NPs biosynthesis comprises the interaction between silver nitrate (precursor) and bioactive components of plant extract (reducing agents). In this work, Ag NPs were biosynthesized using Osbeckia stellata leaves aqueous extract. Characterization of Ag NPs was done by using ultraviolet-visible absorption (UV-Vis) spectroscopy, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray analysis (EDX). Further, antioxidant, antidiabetic, cytotoxicity, and antimicrobial activities were evaluated to establish the pharmacological properties of Ag NPs. UV-Vis spectroscopy and FTIR showed an absorption peak of Ag NPs due to the surface plasmonic resonance. In contrast, the particle size in the nanometer range was analyzed by XRD and DLS. The size of the particle was confirmed by the SEM, TEM, and EDX in the nanometer range. This study showed the spherical shape and crystalline nature of NPs. Zeta potential was used to determine the stability of Ag NPs. Biosynthesized Ag NPs showed significantly potent antioxidant, antidiabetic, and cytotoxicity activity. Ag NPs also showed effectiveness against gram-positive (Escherichia coli) and gram-negative (Staphylococcus aureus) bacteria in the antimicrobial activity study. The result concluded that these Ag NPs might be used in biomedical and pharmacological fields.

Green synthesis of Ag nanoparticle supported on graphene oxide for efficient nitrite sensing in a water sample

Water is essential for conserving biodiversity, ecology, and human health, but because of population growth and declining clean water supplies, wastewater must be treated to meet demand. Nitrite is one of the contaminants in wastewater that is well-known. It is crucial to identify nitrite since it can be fatal to humans in excessive doses. Utilizing a straightforward and effective electrochemical sensor, nitrite in actual water samples may be determined electrochemically. The sensor is created by coating the surface of a GC electrode with a thin layer of graphene oxide (GO), followed by a coating of silver nanoparticles. The modified electrode reached a linear detection range of 1-400 µM. thus, the activity of the electrode was investigated at different pH values ranging from 4 to 10 to cover acidic to highly basic environments. However, the electrode recorded limit of detection (LOD) is equal to 0.084, 0.090, and 0.055 µM for pH 4, 7, and 10, respectively. Additionally, the electrode activity was utilized in tap water and wastewater that the LOD reported as 0.16 and 0.157 µM for tape water and wastewater, respectively.

Enhanced antibacterial properties and magnetic removal of Fe3O4/fenugreek seed gum/silver nanocomposites for water treatment

This study reports the synthesis, characterization, and antibacterial activity of a novel Fe3O4 nanocomposite coated with fenugreek seed gums and silver nanoparticles (AgNPs). To enhance the antibacterial properties of AgNPs and overcome the limitations of conventional methods for the production of three-component nanocomposites, a layer of natural polymer was used. Fenugreek seed gums (FSG) were used to coat Fe3O4 NPs to prevent their decomposition and to facilitate the release of silver nanoparticles in aqueous media. The Fe3O4/FSG/Ag nanocomposites were characterized and then the antibacterial activity of the nanocomposites was evaluated against two gram-negative and two gram-positive bacteria and compared with Fe3O4, Fe3O4/FSG, FSG, and AgNO3. The results showed that the Fe3O4/FSG/Ag nanocomposites had higher antibacterial activity than the other samples and could be easily removed from treated water by a powerful magnet without causing pollution in the environment. Overall, these findings suggest that the Fe3O4/FSG/Ag nanocomposites have potential applications in water treatment for their improved antibacterial properties and ease of removal.

Characterization of Silver Carbonate Nanoparticles Biosynthesized Using Marine Actinobacteria and Exploring of Their Antimicrobial and Antibiofilm Activity

Bacterial resistance to different antimicrobial agents is growing with alarming speed, especially when bacterial cells are living in biofilm. Hybrid nanoparticles, synthesized through the green method, hold promise as a potential solution to this challenge. In this study, 66 actinomycete strains were isolated from three distinct marine sources: marine sediment, the algae Codium bursa, and the marine sponge Chondrosia reniformis. From the entirety of the isolated strains, one strain, S26, identified as Saccharopolyspora erythrea, was selected based on its taxonomic position and significant antimicrobial activity. Using the biomass of the selected marine Actinobacteria, the green synthesis of eco-friendly silver carbonate nanoparticles (BioAg2CO3NPs) is reported for the first time in this pioneering study. The BioAg2CO3NPs were characterized using different spectroscopic and microscopic analyses; the synthesized BioAg2CO3NPs primarily exhibit a triangular shape, with an approximate size of 100 nm. Biological activity evaluation indicated that the BioAg2CO3NPs exhibited good antimicrobial activity against all tested microorganisms and were able to remove 58% of the biofilm formed by the Klebsiella pneumoniae kp6 strain.

Evaluation of the biological responses of silver nanoparticles synthesized using Pelargonium x hortorum extract

Silver nanoparticles (AgNPs) are one of the widely studied nanomaterials for diverse biomedical applications, in particular, as antimicrobial agents to kill bacteria, fungi, and viruses. In this report, AgNPs were synthesized using a geranium (Pelargonium x hortorum) leaves extract and tested for their antimicrobial and cytotoxic activity and reactive oxygen species (ROS) production. Using green biosynthesis, the leaves extract was employed as a reducing and stabilizing agent. Synthesis parameters like reaction time and precursor (silver nitrate AgNO3) volume final were modified, and the products were tested against Streptococcus mutans. For the first time, the metabolomic analysis of extract, we have identified more than 50 metabolites. The UV-Vis analysis showed a peak ranging from 410-430 nm, and TEM confirmed their nearly spherical morphology for all NPs. The antimicrobial activity of the NPs revealed a minimum inhibitory concentration (MIC) of 10 μg mL-1. Concerning cytotoxicity, a dose-time-dependent effect was observed with a 50% cellular cytotoxicity concentration (CC50) of 4.51 μg mL-1 at 24 h. Interestingly, the cell nuclei were visualized using fluorescence microscopy, and no significant changes were observed. These results suggest that synthesized spherical AgNPs are promising potential candidates for medical applications.

Investigating the Effects of Biogenic Zinc Oxide Nanoparticles Produced Using Papaver somniferum Extract on Oxidative Stress, Cytotoxicity, and the Induction of Apoptosis in the THP-1 Cell Line

This study investigated the effect of novel zinc oxide nanoparticles (ZnO NPs) biosynthesized employing Papaver somniferum leaf on oxidative stress, necrosis, and apoptosis in the leukemia cancer THP-1 cell. The obtained ZnO was examined using SEM, AFM, and TEM microscopy, which revealed an irregular spherical morphology with a size ranging from 20 to 30 nm, and the UV-vis absorbance revealed a strong absorption peak in the range of 360-370, nm confirming the production of ZnO NPs. THP-1 cells were subjected to an MTT, an EdU proliferation, a lactate dehydrogenase release tests, a reactive oxygen species (ROS) induction experiment, a DAPI staining detection assay, and a flow cytometric analysis for Annexin V to measure the effects of ZnO NPs on cancer cell growth inhibition, apoptosis, and necrosis. Our results show that ZnO NPs inhibit THP-1 line in a concentration-dependent pattern. It was observed that ZnO NPs triggered necrosis (cell death) and apoptosis in the cell line. ZnO NPs massively improved the formation of intracellular ROS, which is crucial in deactivating the development of leukemic cells. In conclusion, ZnO nanoparticles synthesized using Papaver somniferum extract have the ability to inhibit proliferation leukemic cancer cells, making them potential anticancer agents.

Silver-cored Ziziphus spina-christi extract-loaded antimicrobial nanosuspension: overcoming multidrug resistance

Aims: To synthesize a silver-cored nanosuspension utilizing Ziziphus spina-christi fresh-leaf extract and evaluate their antimicrobial activity against multidrug-resistant pathogenic microbes. Materials and Methods: The prepared nanosuspension was analyzed by spectro-analytical techniques and tested for antimicrobial activity and resistance to biofilm formation. The leaf extract and nanosuspension were tested separately and together as a mixture. Results: Constituent nanoparticles were average-sized (∼34 nm) and were active against both Gram-positive and Gram-negative microbes and yeast. Candida albicans showed a 24.50 ± 1.50 mm inhibition zone, followed by Escherichia coli and Staphylococcus aureus. Increased bioactivity with the highest multifold increments, 150%, for erythromycin against all tested microbes was observed. Carbenicillin and trimethoprim showed 166%- and 300%-fold increments for antimicrobial activity against Pseudomonas aeruginosa, respectively. Conclusion: The nanosuspension exhibited strong potential as an antimicrobial agent and overcame multidrug resistance.

Revisiting the Green Synthesis of Nanoparticles: Uncovering Influences of Plant Extracts as Reducing Agents for Enhanced Synthesis Efficiency and Its Biomedical Applications

Background

Conventional nanoparticle synthesis methods involve harsh conditions, high costs, and environmental pollution. In this context, researchers are actively searching for sustainable, eco-friendly alternatives to conventional chemical synthesis methods. This has led to the development of green synthesis procedures among which the exploration of the plant-mediated synthesis of nanoparticles experienced a great development. Especially, because plant extracts can work as reducing and stabilizing agents. This opens up new possibilities for cost-effective, environmentally-friendly nanoparticle synthesis with enhanced size uniformity and stability. Moreover, bio-inspired nanoparticles derived from plants exhibit intriguing pharmacological properties, making them highly promising for use in medical applications due to their biocompatibility and nano-dimension.

Objective

This study investigates the role of specific phytochemicals, such as phenolic compounds, terpenoids, and proteins, in plant-mediated nanoparticle synthesis together with their influence on particle size, stability, and properties. Additionally, we highlight the potential applications of these bio-derived nanoparticles, particularly with regard to drug delivery, disease management, agriculture, bioremediation, and application in other industries.

Methodology

Extensive research on scientific databases identified green synthesis methods, specifically plant-mediated synthesis, with a focus on understanding the contributions of phytochemicals like phenolic compounds, terpenoids, and proteins. The database search covered the field's development over the past 15 years.

Results

Insights gained from this exploration highlight plant-mediated green synthesis for cost-effective nanoparticle production with significant pharmacological properties. Utilizing renewable biological resources and controlling nanoparticle characteristics through biomolecule interactions offer promising avenues for future research and applications.

Conclusion

This review delves into the scientific intricacies of plant-mediated synthesis of nanoparticles, highlighting the advantages of this approach over the traditional chemical synthesis methods. The study showcases the immense potential of green synthesis for medical and other applications, aiming to inspire further research in this exciting area and promote a more sustainable future.

Citrus By-Products as a Valuable Source of Biologically Active Compounds with Promising Pharmaceutical, Biological and Biomedical Potential

Citrus fruits processing results in the generation of huge amounts of citrus by-products, mainly peels, pulp, membranes, and seeds. Although they represent a major concern from both economical and environmental aspects, it is very important to emphasize that these by-products contain a rich source of value-added bioactive compounds with a wide spectrum of applications in the food, cosmetic, and pharmaceutical industries. The primary aim of this review is to highlight the great potential of isolated phytochemicals and extracts of individual citrus by-products with bioactive properties (e.g., antitumor, antimicrobial, antiviral, antidiabetic, antioxidant, and other beneficial activities with health-promoting abilities) and their potential in pharmaceutical, biomedical, and biological applications. This review on citrus by-products contains the following parts: structural and chemical characteristics; the utilization of citrus by-products; bioactivities of the present waxes and carotenoids, essential oils, pectins, and phenolic compounds; and citrus by-product formulations with enhanced biocactivities. A summary of the recent developments in applying citrus by-products for the treatment of different diseases and the protection of human health is also provided, emphasizing innovative methods for bioaccessibility enhancements (e.g., extract/component encapsulation, synthesis of biomass-derived nanoparticles, nanocarriers, or biofilm preparation). Based on the representative phytochemical groups, an evaluation of the recent studies of the past six years (from 2018 to 2023) reporting specific biological and health-promoting activities of citrus-based by-products is also provided. Finally, this review discusses advanced and modern approaches in pharmaceutical/biological formulations and drug delivery (e.g., carbon precursors for the preparation of nanoparticles with promising antimicrobial activity, the production of fluorescent nanoparticles with potential application as antitumor agents, and in cellular imaging). The recent studies implementing nanotechnology in food science and biotechnology could bring about new insights into providing innovative solutions for new pharmaceutical and medical discoveries.

The Biogenic Synthesis of Bimetallic Ag/ZnO Nanoparticles: A Multifunctional Approach for Methyl Violet Photocatalytic Degradation and the Assessment of Antibacterial, Antioxidant, and Cytotoxicity Properties

In this study, bimetallic nanoparticles (NPs) of silver (Ag) and zinc oxide (ZnO) were synthesized using Leptadenia pyrotechnica leaf extract for the first time. Monometallic NPs were also obtained for comparison. The characterization of the prepared NPs was carried out using various techniques, including UV-Visible spectroscopy (UV-Vis), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The latter confirmed the crystalline nature and diameter of the monometallic and bimetallic NPs of Ag and ZnO. The SEM images of the prepared NPs revealed their different shapes. The biological activities of the NPs were evaluated concerning their antibacterial, antioxidant, and cytotoxic properties. The antibacterial activities were measured using the time-killing method. The results demonstrated that both the monometallic and bimetallic NPs inhibited the growth of Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. The antioxidant activities of the NPs were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and their cytotoxicity was checked using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The results indicated that the controlled quantity of the monometallic and bimetallic NPs did not affect the viability of the cells. However, the decreased cell (L-929) viability suggested that the NPs could have anticancer properties. Furthermore, the photocatalytic degradation of methyl violet and 4-nitrophenol was investigated using the prepared Ag/ZnO NPs, examining the factors affecting the degradation process and conducting a kinetic and thermodynamic study. The prepared Ag/ZnO NPs demonstrated good photocatalytic degradation (88.9%) of the methyl violet (rate constant of 0.0183 min^-1) in comparison to 4-nitrophenol (NPh), with a degradation rate of 81.37% and 0.0172 min^-1, respectively. Overall, the bimetallic NPs showed superior antibacterial, antioxidant, cytotoxic, and photocatalytic properties compared to the monometallic NPs of Ag and ZnO.

Exploring the biological application of Penicillium fimorum-derived silver nanoparticles: In vitro physicochemical, antifungal, biofilm inhibitory, antioxidant, anticoagulant, and thrombolytic performance

This study showed the anti-candida, biofilm inhibitory, antioxidant, anticoagulant, and thrombolytic properties of biogenic silver nanoparticles (AgNPs) fabricated by using the supernatant of Penicillium fimorum (GenBank accession number OQ568180) isolated from soil. The biogenic AgNPs were characterized by using different analytical techniques. A sharp surface plasmon resonance (SPR) peak of the colloidal AgNPs at 429.5 nm in the UV-vis spectrum confirmed the fabrication of nanosized silver particles. The broth microdilution assay confirmed the anti-candida properties of AgNPs with a minimum inhibitory concentration (MIC) of 4 μg mL^-1. In the next step, the protein and DNA leakage assays as well as reactive oxygen species (ROS) assay were performed to evaluate the possible anti-candida mechanisms of AgNPs representing an increase in the total protein and DNA of supernatant along with a climb-up in ROS levels in AgNPs-treated samples. Flow cytometry also confirmed a dose-dependent cell death in the AgNPs-treated samples. Further studies also confirmed the biofilm inhibitory performance of AgNPs against Candia albicans. The AgNPs at the concentrations of MIC and 4*MIC inhibited 79.68 ± 14.38% and 83.57 ± 3.41% of biofilm formation in C. albicans, respectively. Moreover, this study showed that the intrinsic pathway may play a significant role in the anticoagulant properties of AgNPs. In addition, the AgNPs at the concentration of 500 μg mL^-1, represented 49.27%, and 73.96 ± 2.59% thrombolytic and DPPH radical scavenging potential, respectively. Promising biological performance of AgNPs suggests these nanomaterials as a good candidate for biomedical and pharmaceutical applications.

Cadmium Sulfide Nanoparticles: Preparation, Characterization, and Biomedical Applications

Cadmium sulfide nanoparticles (CdS NPs) have been employed in various fields of nanobiotechnology due to their proven biomedical properties. They are unique in their properties due to their size and shape, and they are popular in the area of biosensors, bioimaging, and antibacterial and anticancer applications. Most CdS NPs are generally synthesized through chemical, physical, or biological methods. Among these methods, biogenic synthesis has attracted more attention due to its high efficiency, environmental friendliness, and biocompatibility features. The green approach was found to be superior to other methods in terms of maintaining the structural characteristics needed for optimal biomedical applications. The size and coating components of CdS NPs play a crucial role in their biomedical activities, such as anticancer, antibacterial, bioimaging, and biosensing applications. CdS NPs have gained significant interest in bioimaging due to their desirable properties, including good dispersion, cell integrity preservation, and efficient light scattering. Despite these, further studies are necessary, particularly in vivo studies to reduce NPs' toxicity. This review discusses the different methods of synthesis, how CdS NPs are characterized, and their applications in the biomedical field.

Green Biofabrication of Silver Nanoparticles of Potential Synergistic Activity with Antibacterial and Antifungal Agents against Some Nosocomial Pathogens

Nosocomial bacterial and fungal infections are one of the main causes of high morbidity and mortality worldwide, owing to the high prevalence of multidrug-resistant microbial strains. Hence, the study aims to synthesize, characterize, and investigate the antifungal and antibacterial activity of silver nanoparticles (AgNPs) fabricated using Camellia sinensis leaves against nosocomial pathogens. The biogenic AgNPs revealed a small particle diameter of 35.761 ± 3.18 nm based on transmission electron microscope (TEM) graphs and a negative surface charge of −14.1 mV, revealing the repulsive forces between nanoparticles, which in turn indicated their colloidal stability. The disk diffusion assay confirmed that Escherichia coli was the most susceptible bacterial strain to the biogenic AgNPs (200 g/disk), while the lowest sensitive strain was found to be the Acinetobacter baumannii strain with relative inhibition zones of 36.14 ± 0.67 and 21.04 ± 0.19 mm, respectively. On the other hand, the biogenic AgNPs (200 µg/disk) exposed antifungal efficacy against Candida albicans strain with a relative inhibition zone of 18.16 ± 0.14 mm in diameter. The biogenic AgNPs exposed synergistic activity with both tigecycline and clotrimazole against A. baumannii and C. albicans, respectively. In conclusion, the biogenic AgNPs demonstrated distinct physicochemical properties and potential synergistic bioactivity with tigecycline, linezolid, and clotrimazole against gram-negative, gram-positive, and fungal strains, respectively. This is paving the way for the development of effective antimicrobial combinations for the effective management of nosocomial pathogens in intensive care units (ICUs) and health care settings.

Synthesis and Characterization of Sulfur Nanoparticles of Citrus limon Extract Embedded in Nanohydrogel Formulation: In Vitro and In Vivo Studies

The study aimed to synthesize non-noxious, clean, reliable, and green sulfur nanoparticles (SNPs) from Citrus limon leaves. The synthesized SNPs were used to analyze particle size, zeta potential, UV–visible spectroscopy, SEM, and ATR-FTIR. The prepared SNPs exhibited a globule size of 55.32 ± 2.15 nm, PDI value of 0.365 ± 0.06, and zeta potential of −12.32 ± 0.23 mV. The presence of SNPs was confirmed by UV–visible spectroscopy in the range of 290 nm. The SEM image showed that the particles were spherical with a size of 40 nm. The ATR-FTIR study showed no interaction, and all the major peaks were preserved in the formulations. An antimicrobial and antifungal study of SNPs was carried out against Gram-positive bacteria (Staph. aureus, Bacillus), Gram-negative bacteria (E. coli and Bordetella), and fungal strains (Candida albicans). The study showed that Citrus limon extract SNPs exhibited better antimicrobial and antifungal activities against Staph. aureus, Bacillus, E. coli, Bordetella, and Candida albicans at a minimal inhibitory concentration of 50 μg/mL. Different antibiotics were used alone and in combination with SNPs of Citrus limon extract to evaluate their activity against various strains of bacteria and fungal strains. The study showed that using SNPs of Citrus limon extract with antibiotics has a synergistic effect against Staph.aureus, Bacillus, E. coli, Bordetella, and Candida albicans. SNPs were embedded in nanohydrogel formulations for in vivo (wound healing) studies. In preclinical studies, SNPs of Citrus limon extract embedded within a nanohydrogel formulation (NHGF4) have shown promising results. To be widely used in clinical settings, further studies are needed to evaluate their safety and efficacy in human volunteers.

Mycosynthesis of AgNPs: mechanisms of nanoparticle formation and antimicrobial activities

INTRODUCTION

The inactivation and eradication of multidrug-resistant bacteria, fungi, and viruses by conventional antibiotics and drugs have not been effective. The hindering of these pathogens in hospital-acquired infections caused by Gram-positive bacteria, particularly strains of S. aureus including community-acquired methicillin-resistant (CA-MRSA) and hospital-acquired MRSA (HA-MRSA), is more complicated, specifically in patients having immunodeficiency syndrome.

RESEARCH AREA

Bare and functionalized metal and metal oxide nanoparticles (NPs) specifically silver (Ag) NPs have shown significant antibacterial, antifungal, and antiviral activities. Biosynthesis of AgNPs by fungal species in media of cell-free filtrate and culture supernatant can provide new therapeutic properties compared to physical and chemical methods.

EXPERT OPINION

Various primary and secondary metabolites of fungi such as phytochelatin, trichodin, primin, altersolanol A, periconicin A, brefeldin A, graphislactone A, phomol, polysaccharides (chitin, glucans, and galactomannans), and enzymes can contribute to reducing Ag⁺ ions and stabilizing NPs in one-pot method. These natural compounds can augment antimicrobial activity by bypassing multidrug-resistance barriers in viruses, bacteria, and fungi. Controlling physicochemical properties and effective therapeutic concentration of fungal AgNPs can be the determinative parameters for the antimicrobial strength of AgNPs. Therefore, in this review, we have tried to address the antimicrobial mechanisms and physicochemical properties of fungal synthesized AgNPs.

Green synthesis of AgNPs using Delonix regia bark for potential catalytic and antioxidant applications

Nanoparticle synthesis from plant resources has recently gained significant impact due to its low cost, simple equipment requirements, and ease of availability. In this work, DR-AgNPs were synthesized using bark extract of Delonix regia (D. regia) plant under microwave irradiation. The formation of DR-AgNPs has been confirmed with UV-Vis, XRD, FTIR, FESEM, HRTEM, EDS, DLS, and zeta potential analysis. Catalytic and antioxidant activities were tested on synthesized spherical nanoparticles with a size range of 10-48 nm. The effects of pH and catalyst dosage on the methylene blue (MB) dye degradation were carried out. It was observed from the treatment results that 95% MB dye degradation efficiency was achieved within 4 min with a degradation rate constant of 0.772 min^-1 . The synthesized nanoparticles showed a strong antioxidant property when analyzed by a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The calculated IC₅₀ value for DR-AgNPs was 37.1 ± 0.12 μg mL^-1 . Therefore, DR-AgNPs are excellent in both catalytic and antioxidant activities when compared to previously reported works. HIGHLIGHTS: Green synthesis of silver nanoparticles (DR-AgNPs) using Delonix regia bark extract. The catalytic activity of DR-AgNPs is remarkable against Methylene Blue. DR-AgNPs also have a strong DPPH radical antioxidant effect. Short degradation time, high degradation rate constant, and a good scavenging activity are key features of this study compared to previously reported works.

Transfer of AgNPs' Anti-Biofilm Activity into the Nontoxic Polymer Matrix

A biological method was successfully applied to synthesize spherical silver nanoparticles (AgNPs) while using the extract of lavender (Ex-L) (lat. Lavandula angustifolia) as the reducing and stabilizing agent. The produced nanoparticles were spherical with an average size of 20 nm. The AgNPs' synthesis rate confirmed the extract's excellent ability to reduce silver nanoparticles from the AgNO₃ solution. The presence of good stabilizing agents was confirmed by the excellent stability of the extract. Nanoparticles' shapes and sizes did not change. UV-Vis absorption spectrometry, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the silver nanoparticles. The silver nanoparticles were incorporated into the PVA polymer matrix by the "ex situ" method. The polymer matrix composite with AgNPs was prepared in two ways: as a composite film and nanofibers (nonwoven textile). The anti-biofilm activity of AgNPs and the ability of AgNPs to transfer toxic properties into the polymer matrix were proved.

In vitro and in vivo synergistic wound healing and anti-methicillin-resistant Staphylococcus aureus (MRSA) evaluation of liquorice-decorated silver nanoparticles

The multi-drug resistant Staph. aureus strain, Methicillin-resistant Staphylococcus aureus (MRSA), is an emerging pathogen that could penetrate skin cuts and wounds, causing a life-threatening condition. The green biosynthesis of silver nanoparticles with liquorice extract has been demonstrated over several years for anticancer and antioxidant effects, as well as antibacterial effect against both Gram-positive and Gram-negative bacteria. The study was designed to evaluate the synergistic in vivo and in vitro wound healing and anti-MRSA activity of decorated liquorice silver nanoparticles (LD-AgNPs). The LD-AgNPs were prepared by thoroughly mixing diluted liquorice extract with AgNO₃ at room temperature. The prepared nanoparticles were characterized by size measurement, IR spectroscopy, TEM imaging, and X-ray diffraction. The in vitro and in vivo antibacterial and wound healing testing were also performed. The obtained LD-AgNPs were spherical in shape and had a hydrodynamic size of about 50.16 ± 5.37 nm. Moreover, they showed potent antibacterial activity against Gram-positive and Gram-negative resistant bacteria, produced a significantly higher level of procollagen type I compared to either liquorice extract or standard silver sulfadiazine, and promoted the wound healing process in rabbits. The formulation of silver nanoparticles with liquorice extract showed synergetic effects in enhancing the treatment of wounds, with significant antibacterial activity against E. coli and MRSA.

Biogenic copper oxide nanoparticles from Bacillus coagulans induced reactive oxygen species generation and apoptotic and anti-metastatic activities in breast cancer cells

The present study examined the anticancer capabilities of Bacillus coagulans supernatant-produced copper oxide nanoparticles (BC-CuONPs) on MCF-7 and SKBR3 cancer cells. The X-ray diffraction, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission scanning electron microscopy, energy-dispersive X-ray, dynamic light scattering, and zeta potential techniques were used to characterize BC-CuONPs. This study also investigated the cellular and molecular processes of NPs' anti-proliferative and apoptotic properties on human breast cancer cells and compared them to the commercial pharmaceutical tamoxifen. The size of the spherical NP was from 5 to 47 nm with negative zeta potential. The MTT results showed the great cytotoxic effect of BC-CuONPs against breast cancer cells. The BC-CuONPs inhibited the growth of breast cancer cells in a time- and dose-dependent manner. The up-regulation of BCL2-associated X (BAX), cyclin dependent kinase inhibitor 1A (P21), Caspase 3 (CASP3), and Caspase 9 (CASP9), the down-regulation of BCL2 apoptosis regulator (BCL2), Annexin V-FITC/propidium iodide, and reactive oxygen species (ROS) generation results suggested that BC-CuONPs had a significant apoptotic impact when compared to the control. Scratch tests and vascular endothelial growth factor receptor gene (VEGF) down-regulation demonstrated that BC-CuONPs had anti-metastatic activity. The cell cycle analysis and down-regulation of Cyclin D1 (CCND1) and cyclin dependent kinase 4 (CDK4) revealed that cancer cells were arrested in the sub-G1 phase. Finally, the results showed that the secondary metabolites in the supernatant of Bacillus coagulans could form CuONPs, and biogenic BC-CuONPs showed anti-metastasis and anticancer properties on breast cancer cells while having less adverse effects on normal cells. Therefore, the synthesized CuONPs using B. coagulans supernatant can be shown as a potential candidate for a new therapeutic strategy in cancer management.

Green synthesis of nanoparticles using botanicals and their application in management of fungal phytopathogens: a review

Green synthesis of nanoparticles is an emerging aspect in plant disease management that blends nanotechnology and plant-derived ingredients to produce a biocontrol formulation. Different physical and chemical processes employed in the synthesis of nanoparticles are polluting, expensive, and also release hazardous by- products. The range of secondary metabolites present in plants makes them efficient reducing and stabilizing agent during the synthesis process. These metabolites serve a vital role in plant defense against the invasion of phytopathogens including fungi, bacteria, viruses, insect pests, etc. The plant metabolites, such as sugars, terpenoids, polyphenols, alkaloids, phenolic acids, and proteins, have been shown to be crucial in the reduction of metal ions into nanoparticles. In green synthesis of nanoparticles, the plant extracts are used as potential reducing and capping. This also restricts the formation of clusters or aggregates and improves the colloidal stability. The nanoparticles exhibit excellent antimycotic against a variety of phytopathogens and are very efficient in managing plant diseases. The aim of this review is to highlight plants, phytochemicals exhibiting antifungal properties, green synthesis of nanoparticles using plant material and their antimycotic activity.

Fabrication of a Polycaprolactone/Chitosan Nanofibrous Scaffold Loaded with Nigella sativa Extract for Biomedical Applications

In this study, biocompatible electrospun nanofiber scaffolds were produced using poly(-caprolactone (PCL)/chitosan (CS) and Nigella sativa (NS) seed extract, and their potential for biomedical applications was investigated. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), total porosity measurements, and water contact angle measurements were used to evaluate the electrospun nanofibrous mats. Additionally, the antibacterial activities of Escherichia coli and Staphylococcus aureus were investigated, as well as cell cytotoxicity and antioxidant activity, using MTT and DPPH assays, respectively. The obtained PCL/CS/NS nanofiber mat was observed by SEM to have a homogeneous and bead-free morphology, with average diameters of 81.19 ± 4.38 nm. Contact angle measurements showed that the wettability of the electrospun PCL/Cs fiber mats decreased with the incorporation of NS when compared to the PCL/CS nanofiber mats. Efficient antibacterial activity against S. aureus and E. coli was displayed, and an in vitro cytotoxic assay demonstrated that the normal murine fibroblast cell line (L929 cells) remained viable after 24, 48, and 72 h following direct contact with the produced electrospun fiber mats. The results suggest that the PCL/CS/NS hydrophilic structure and the densely interconnected porous design are biocompatible materials, with the potential to treat and prevent microbial wound infections.

Synergistic Antibacterial Potential of Greenly Synthesized Silver Nanoparticles with Fosfomycin Against Some Nosocomial Bacterial Pathogens

Introduction

A considerable number of morbidities and fatalities occur worldwide as a result of the multidrug resistant microorganisms that cause a high prevalence of nosocomial bacterial infections. Hence, the current investigation was conducted to evaluate the antibacterial potency of green fabricated silver nanoparticles (AgNPs) against four different nosocomial pathogens.

Methods

The flower extract of Hibiscus sabdariffa mediated green fabrication of AgNPs and their physicochemical features were scrutinized using different techniques. Antimicrobial activity of the biogenic AgNPs and their synergistic patterns with fosfomycin antibiotic were evaluated using disk diffusion assay.

Results and Discussion

UV spectral analysis affirmed the successful formation of AgNPs through the detection of broad absorption band at 395 and 524 nm, indicating the surface plasmon resonance of the biofabricated AgNPs. In this setting, the biofabricated AgNPs demonstrated average particle size of 58.682 nm according to transmission electron microscope (TEM) micrographs. The detected hydrodynamic diameter was higher than that noticed by TEM analysis, recording 72.30 nm in diameter and this could be attributed to the action of capping agents, which was confirmed by Fourier Transform Infrared (FT-IR) analysis. Disk diffusion assay indicated the antibacterial potency of biogenic AgNPs (50 μg/disk) against Enterobacter cloacae, Methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli strains with relative inhibition zone diameters of 12.82 ± 0.36 mm, 14.54 ± 0.15 mm, 18.35 ± 0.24 mm and 21.69 ± 0.12 mm, respectively. In addition, E. coli was found to be the most susceptible strain to the biogenic AgNPs. However, the highest synergistic pattern of AgNPs-fosfomycin combination was detected against K. pneumonia strain recording relative synergistic percentage of 64.22%. In conclusion, the detected synergistic efficiency of AgNPs and the antibiotic fosfomycin highlight the potential for utilizing this combination in the biofabrication of effective antibacterial agents against nosocomial pathogens.

Green-Based Approach to Synthesize Silver Nanoparticles Using the Fungal Endophyte Penicillium oxalicum and Their Antimicrobial, Antioxidant, and In Vitro Anticancer Potential

A green-based approach for the synthesis of silver nanoparticles has gained tremendous attention in biomedical applications. Fungal endophytes have been recognized as a remarkable biological source for the synthesis of potential nanodrugs. The present study focuses on the fabrication of silver nanoparticles using the fungal endophyte Penicillium oxalicum (POAgNPs) associated with the leaf of the Amoora rohituka plant. Sharp UV-visible spectra at 420 nm appeared due to the surface plasmon resonance of POAgNPs and the reduction of silver salt. FT-IR analysis revealed the presence of functional groups of bioactive compounds of P. oxalicum responsible for the reduction of silver salt and validated the synthesis of POAgNPs. A high degree of crystallinity was revealed through XRD analysis, and microscopy-based characterizations such as AFM, TEM, and FESEM showed uniformly distributed, and spherically shaped nanoparticles. Furthermore, POAgNPs showed a potential inhibitory effect against bacterial and fungal strains of pathogenic nature. POAgNPs also exhibited potential antioxidant activity against the synthetically generated free radicals such as DPPH, superoxide, hydroxyl, and nitric oxide with EC50 values of 9.034 ± 0.449, 56.378 ± 1.137, 34.094 ± 1.944, and 61.219 ± 0.69 μg/mL, respectively. Moreover, POAgNPs exhibited cytotoxic potential against the breast cancer cell lines, MDA-MB-231 and MCF-7 with IC50 values of 20.080 ± 0.761 and 40.038 ± 1.022 μg/mL, respectively. POAgNPs showed anticancer potential through inhibition of wound closure and by altering the nuclear morphology of MDA-MB-231 and MCF-7 cells. Further anticancer activity revealed that POAgNPs induced apoptosis in MDA-MB-231 and MCF-7 cells by differential expression of genes related to apoptosis, tumor suppression, and cell cycle arrest and increased the level of Caspase-3. The novel study showed that P. oxalicum-mediated silver nanoparticles exhibit potential biological activity, which can be exploited as nanodrugs in clinical applications.

Green Synthesis of Silver Nanoparticles Using Spilanthes acmella Leaf Extract and its Antioxidant-Mediated Ameliorative Activity against Doxorubicin-Induced Toxicity in Dalton's Lymphoma Ascites (DLA)-Bearing Mice

Green synthesis of metal nanoparticles is a rapidly growing research area in the field of nanotechnology because of their biomedical applications. This study describes the synthesis of silver nanoparticles (AgNPs) using Spilanthes acmella leaf extract and its ameliorative effects against doxorubicin-induced toxicity. The formation of AgNPs was confirmed by a ultraviolet-visible (UV-vis) spectrum that revealed an absorption band at 430 nm. A shift in the absorption bands in Fourier-transform infrared spectroscopy (FT-IR) confirmed the bioactive molecules of S. acmella leaf extract that acted as a reducing and capping agent. The spherical shape of AgNPs was confirmed by scanning electron microscope (SEM) analysis, and the presence of elemental silver was indicated by energy dispersive X-ray spectroscopy (EDS) analysis. X-ray diffraction (XRD) analysis revealed that the crystalline size of the synthesized AgNPs was 6.702 nm. Treatment of Dalton's lymphoma ascites (DLA) mice with 20 mg/kg of doxorubicin (DOX) significantly increased the activities of serum toxicity markers including aspartate amino-transferase (AST), alanine amino-transferase (ALT), and lactate dehydrogenase (LDH). However, compared to DOX alone treatment, the coadministration of DOX and AgNPs reduced AST, ALT, and LDH activities. DOX alone treatment reduced glutathione (GSH) contents and decreased the activities of glutathione-s-transferase (GST) and superoxide dismutase (SOD) in DLA mice. However, the administration of AgNPs to DOX-treated DLA mice increased GSH content and the activities of GST and SOD. Consistently, biosynthesized AgNPs were found to possess significantly higher free-radical scavenging activities when compared to the S. acmella leaf extract, as measured by ABTS, DPPH, and O2 •- assays. The biosynthesized AgNPs also showed significant inhibitory activities against erythrocyte hemolysis and lipid peroxidation in the liver homogenate.

Green Synthesis of Silver Nanoparticles Using Randia aculeata L. Cell Culture Extracts, Characterization, and Evaluation of Antibacterial and Antiproliferative Activity

The demand for metallic nanoparticles synthesized using green methods has increased due to their various therapeutic and clinical applications, and plant biotechnology may be a potential resource facilitating sustainable methods of AgNPs synthesis. In this study, we evaluate the capacity of extracts from Randia aculeata cell suspension culture (CSC) in the synthesis of AgNPs at different pH values, and their activity against pathogenic bacteria and cancer cells was evaluated. Using aqueous CSC extracts, AgNPs were synthesized with 10% (w/v) of fresh biomass and AgNO3 (1 mM) at a ratio of 1:1 for 24 h of incubation and constant agitation. UV-vis analysis showed a high concentration of AgNPs as the pH increased, and TEM analysis showed polydisperse nanoparticles with sizes from 10 to 90 nm. Moreover, CSC extracts produce reducing agents such as phenolic compounds (162.2 ± 27.9 mg gallic acid equivalent/100 g biomass) and flavonoids (122.07 ± 8.2 mg quercetin equivalent/100 g biomass). Notably, AgNPs had strong activity against E. coli, S. pyogenes, P. aeruginosa, S. aureus, and S. typhimurium, mainly with AgNPs at pH 6 (MIC: 1.6 to 3.9 µg/mL). AgNPs at pH 6 and 10 had a high antiproliferative effect on cancer cells (IC50 < 5.7 µg/mL). Therefore, the use of cell suspension cultures may be a sustainable option for the green synthesis of AgNPs.

Synthesis of ZnO/Au Nanocomposite for Antibacterial Applications

Annually, antimicrobial-resistant infections-related mortality worldwide accelerates due to the increased use of antibiotics during the coronavirus pandemic and the antimicrobial resistance, which grows exponentially, and disproportionately to the current rate of development of new antibiotics. Nanoparticles can be an alternative to the current therapeutic approach against multi-drug resistance microorganisms caused infections. The motivation behind this work was to find a superior antibacterial nanomaterial, which can be efficient, biocompatible, and stable in time. This study evaluated the antibacterial activity of ZnO-based nanomaterials with different morphologies, synthesized through the solvothermal method and further modified with Au nanoparticles through wet chemical reduction. The structure, crystallinity, and morphology of ZnO and ZnO/Au nanomaterials have been investigated with XRD, SEM, TEM, DLS, and FTIR spectroscopy. The antibacterial effect of unmodified ZnO and ZnO/Au nanomaterials against Escherichia coli and Staphylococcus aureus was investigated through disc diffusion and tetrazolium/formazan (TTC) assays. The results showed that the proposed nanomaterials exhibited significant antibacterial effects on the Gram-positive and Gram-negative bacteria. Furthermore, ZnO nanorods with diameters smaller than 50 nm showed better antibacterial activity than ZnO nanorods with larger dimensions. The antibacterial efficiency against Escherichia coli and Staphylococcus aureus improved considerably by adding 0.2% (w/w) Au to ZnO nanorods. The results indicated the new materials' potential for antibacterial applications.

Optimization of the synthesis of silver nanoparticles using the leaf extract of Ocimum sanctum and evaluation of their antioxidant potential

This work investigates the green synthesis of silver nanoparticles (AgNPs) utilizing the aqueous leaf extract of Ocimum sanctum L. A change in colour to dark brown from yellow and an absorption maximum at 460 nm provided evidence for the synthesis of AgNPs. Several reaction conditions namely leaf extract volume, AgNO3 concentration and duration of incubation were optimized. Maximum synthesis of AgNPs could be achieved with 1 ml of 5% aqueous leaf extract, 1 mM AgNO3 and 2.5 h incubation period. DPPH (2, 2—diphenyl − 1 - picrylhydrazyl) assay revealed that AgNPs are better than the leaf extract in terms of antioxidant potential. These results strongly recommend the application of green-synthesized AgNPs as effective antioxidants against oxidative stresses associated with degenerative diseases. Characterization of AgNPs were then carried out using certain methods namely as x-ray diffraction (XRD) measurement, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD study confirmed the synthesis of face-centered cubic-shaped AgNPs that are of crystalline nature. The mean particle size of the synthesized AgNPs computed employing the Debye–Scherrer formula, was 22 nm. FTIR study demonstrated that the AgNPs consisted of certain functional groups of O. sanctum which might have helped in reducing AgNO3 and capping AgNPs. SEM images showed the synthesis of AgNPs of various shapes viz. globular, cubical and flaky. The scattered AgNPs were found to have a size close to 20 nm, which roughly matches with the XRD analysis of the current study.

Box-Behnken Design: Optimization of Proanthocyanidin-Loaded Transferosomes as an Effective Therapeutic Approach for Osteoarthritis

Transferosomes are one of the vesicular carriers that have received extensive research and attention recently because of their capacity to get beyond the barriers posed by the stratum corneum to penetration. The intent of the current study is to optimize and evaluate proanthocyanidin (PAC) containing transferosomal transdermal gels. PAC-containing transferosomes were prepared using the film hydration method and then loaded into a 4% methylcellulose gel. A 2³ Box-Behnken design was used to optimize the PAC-loaded transferosomal gel, where the effects of phospholipid 90 G (X1), Tween 80 (X2), and sonication time (X3) were evaluated. The formulation factors, such as the drug entrapment efficiency percentage (PEE) and in vitro drug release, were characterized. A PEE of 78.29 ± 1.43% and a drug release in vitro at 6 h of 24.2 ± 1.25% were obtained. The optimized transferosomal-loaded proanthocyanidin (OTP) formulation penetrated the porcine skin at an excellent rate (0.123 ± 0.0067 mg/cm²/h). Stability tests were conducted for OTP to predict the effects of various temperature conditions on the physical appearance, drug content, and PEE for periods of 15, 30, and 45 days. Finally, this transferosomal system for transdermal PAC delivery may be a suitable alternative to the conventional treatment for osteoarthritis.

Green Synthesis of Silver Nanoparticles for Preparation of Gelatin Films with Antimicrobial Activity

Silver nanoparticles were successfully synthesized using Thuja orientalis aqueous extract and AgNO₃ as a precursor. UV–Vis showed a distinct absorption peak at 424 nm attributed to silver nanoparticles due to their surface plasmon resonance. Atomic absorption analysis reflected an increase in the concentration of nanoparticles in relation to the progress of the synthesis, obtaining a peak concentration value of 15.7 mg/L at 50 min. The FTIR spectra revealed the characteristic functional groups of phytomolecules involved in the silver–ion binding process, such as R–O–H (3335 cm⁻¹⁾ O=C–OH (2314 cm⁻¹) and C—C=C (1450 cm⁻¹). At 50 min, zeta potential showed the stability of the nanoparticles with the value of −21.73 mV. TEM micrographs revealed the formation of spherical nanoparticles with an average size of about 85.77 nm. Furthermore, films incorporated with nanoparticles exhibited a Tg from 66.42 °C to 73.71 °C and Tm at 103.31 °C. Films from the G22 formulation presented excellent antibacterial properties inhibiting the growth of Staphylococcus aureus. Thuja orientalis aqueous extract could be a low-cost, eco-friendly, and efficient reducing and capping agent for the synthesis of nanometric-sized Ag particles. Gelatin films with nanoparticles are expected to have high potential as an active food packaging system.

Ciprofloxacin-Loaded Silver Nanoparticles as Potent Nano-Antibiotics against Resistant Pathogenic Bacteria

Silver nanoparticles (AgNPs) have demonstrated numerous physicochemical, biological, and functional properties suitable for biomedical applications, including antibacterial and drug carrier properties. In the present study, the antibiotic, ciprofloxacin (CIP), was loaded onto AgNPs, which were synthesized via the chemical reduction method, thereby enhancing CIP's antibacterial activity against Gram-negative (Acinetobacter baumannii and Serratia marcescens) and Gram-positive (Staphylococcus aureus) bacterial strains. Polyethylene glycol-400 (PEG) was used to prepare an AgNPs-PEG conjugate with enhanced stability and to act as the linker between CIP and AgNPs, to produce the novel nanocomposite, AgNPs-PEG-CIP. The prepared AgNPs and their conjugates were characterized by ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, zeta potential analysis, and dynamic light scattering techniques. The inhibitory activity of AgNPs and their conjugates on the growths of pathogenic bacteria was assessed using the well-diffusion method. The results showed the enhanced antibacterial effects of AgNPs-CIP compared to CIP alone. The AgNPs-PEG-CIP nanocomposite showed excellent inhibitory effects against bacterial isolates, with its inhibition zones diameters reaching 39, 36, and 40 mm in S. aureus, A. baumannii, and S. marcescens, respectively. The minimum inhibitory concentration and minimum bactericidal concentration of fogNPs and their conjugates and their antibiofilm effects were also determined. The antioxidant potentials of AgNPs and their conjugates, tested via their 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging ability, showed that the activity increased with increasing AgNPs concentration and the addition of the PEG and/or CIP. Overall, according to the results obtained in the present study, the new nanocomposite, AgNPs-PEG-CIP, showed the highest antibacterial, antibiofilm, and antioxidant activity against the pathogenic bacteria tested, compared to CIP alone. The preparation has high clinical potential for prospective use as an antibacterial agent.