Green synthesis of silver nanoparticles using aqueous extract of saffron (Crocus sativus L.) wastages and its antibacterial activity against six bacteria

Could polyphenols be an effective treatment in the management of polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS), is a health problem observed in women of reproductive age. Different diets, physical activity recommendations and lifestyle changes can be effective in dealing with the symptoms of PCOS. Nutrition is indeed an essential part of the treatment of the disease as it directly affects body weight loss, insulin resistance, lipid profile, hormones, and dermatological complaints such as acne. Polyphenols, simply classified as flavonoids and non-flavonoids, are bioactive components found in plant-based foods. The most common polyphenols in the diet are flavanols, flavonols, flavanone, anthocyanins. In particular, polyphenols which are compounds naturally found in foods, have antioxidant, anticancer, anti-inflammatory, antimutagenic benefits along with many other ones. In the treatment of PCOS, polyphenols may help reduce the symptoms, improve insulin resistance and poor lipid profile, and cure hormonal disorders. It has been reported that polyphenols are influential in menstrual cycle disorders and enable a decrease in body weight, hyperandrogenism, estrogen, testosterone, luteinizing hormone (LH)/follicle stimulating hormone (FSH) ratios and LH. For adequate daily intake of polyphenols, which are found in high amounts in fruits and vegetables, at least 5 portions of fruits and vegetables should be consumed in addition to a healthy nutrition pattern. In this review, the effects of various polyphenols on polycystic ovary syndrome are discussed.

Metallic nanoparticles and photosynthesis organisms: Comprehensive review from the ecological perspective

This review presents a comprehensive analysis of the ecological implications of metallic nanoparticles (MNPs) on photosynthetic organisms, particularly plants and algae. We delve into the toxicological impacts of various MNPs, including gold, silver, copper-based, zinc oxide, and titanium dioxide nanoparticles, elucidating their effects on the growth and health of these organisms. The article also summarizes the toxicity mechanisms of these nanoparticles in plants and algae from previous research, providing insight into the cellular and molecular interactions that underpin these effects. Furthermore, it discusses the reciprocal interactions between different types of MNPs, their combined effects with other metal contaminants, and compares the toxicity between MNPs with their counterpart. This review highlights the urgent need for a deeper understanding of the environmental impact, considering their escalating use and the potential risks they pose to ecological systems, especially in the context of photosynthetic organisms that are vital to ecosystem health and stability.

Microalgae as a potential natural source for the green synthesis of nanoparticles

The increasing global population is driving the development of alternative sources of food and energy, as well as better or new alternatives for health and environmental care, which represent key challenges in the field of biotechnology. Microalgae represent a very important source material to produce several high-value-added bioproducts. Due to the rapid changes in the modern world, there is a need to build new materials for use, including those in the nanometer size, although these developments may be chronological but often do not occur at a time. In the last few years, a new frontier has opened up at the interface of biotechnology and nanotechnology. This new frontier could help microalgae-based nanomaterials to possess new functions and abilities. Processes for the green synthesis of nanomaterials are being investigated, and the availability of biological resources such as microalgae is continuously being examined. The present review provides a concise overview of the recent advances in the synthesis, characterization, and applications of nanoparticles formed using a wide range of microalgae-based biosynthesis processes. Highlighting their innovative and sustainable potential in current research, our study contributes towards the in-depth understanding and provides latest updates on the alternatives offered by microalgae in the synthesis of nanomaterials.

Tecoma stans Floral Extract-Based Biosynthesis for Enhanced Surface Plasmon-Coupled Emission and a Preliminary Study on Fluoroimmunoassay

We demonstrate the synthesis of biogenic supported silver spiked star architectures and their application to increase the electromagnetic field intensity at its tips that enhance plasmon-coupled emission. Tecoma stans floral extract has been used to synthesize silver nanocubes and spiked stars. We observe ∼445-fold and ∼680-fold enhancements in spacer and cavity configurations, respectively, in the SPCE platform. The hotspot intensity and Purcell factor are evaluated by carrying out finite-difference time-domain (FDTD) simulations. Time-based studies are presented to modulate the sharpness of the edges wherein an increase in the tip sharpness with the increase in reaction time up to 5 h is observed. The unique morphology of the silver architectures allowed us to utilize them in biosensing application. A SPCE-based fluoroimmunoassay was performed, achieving a 1.9 pg/mL limit of detection of TNF-α cytokine. This combination of anisotropic architectures, SPCE and immunoassay prove to be a powerful platform for the ultrasensitive detection of biomarkers in surface-bound assays.

Biogenic synthesis of silver nanoparticles using Rubus fruticosus extract and their antibacterial efficacy against Erwinia caratovora and Ralstonia solanacearum phytopathogens

In the current research, we produced green, cost-effective, eco-friendly silver nanoparticles using a single-step approach. Plants are considered highly desirable systems for nanoparticle synthesis because they possess a variety of secondary metabolites with significant reduction potential. In the current research, the dried leaf extract of Rubus fruticosus was utilized as a capping and reducing agent for the fabrication of silver nanoparticles, to prepare reliable biogenic silver nanoparticles and subsequently to investigate their potential against some common phytopathogens. The prepared silver nanoparticles were exploited to quantify the total flavonoid content (TFC), total phenolic content (TPC) and DPPH-based antioxidant activity. Different concentrations of aqueous extracts of plant leaves and silver nitrate (AgNO3) were reacted, and the color change of the reactant mixture confirmed the formation of Rubus fruticosus leaf-mediated silver nanoparticles (RFL-AgNPs). A series of characterization techniques such as UV-vis spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and X-ray diffraction revealed the successful synthesis of silver nanoparticles. The surface plasmon resonance peak appeared at 449 nm. XRD analysis demonstrated the crystalline nature, EDX confirmed the purity, and TEM demonstrated that the nanoparticles are mostly spherical in form. Furthermore, the biosynthesized nanoparticles were screened for in vitro antibacterial activity, antioxidant activity, and total phenolic and flavonoid content. The nanoparticles were used in different concentrations alone and in combination with plant extracts to inhibit Erwinia caratovora and Ralstonia solanacearum. In high-throughput assays used to inhibit these plant pathogens, the nanoparticles were highly toxic against bacterial pathogens. This study can be exploited for planta assays against phytopathogens utilizing the same formulations for nanoparticle synthesis and to develop potent antibacterial agents to combat plant diseases.

Chitosan-based topical formulation integrated with green-synthesized silver nanoparticles utilizing Camellia sinensis leaf extracts: A promising approach for managing infected wounds

This study explores the eco-friendly biosynthesis of silver nanoparticles (AgNPs) utilizing Camellia sinensis leaf extract. We assess their antioxidant and antibacterial properties. Furthermore, we impregnated AgNPs into 2 % chitosan (CHS) gel and assessed their wound-healing potential in Escherichia coli and Staphylococcus aureus infected wounds. Optimized AgNPs demonstrated a mean particle size of 36.90 ± 1.22 nm and a PDI of 0.049 ± 0.001. Green-synthesized AgNPs exhibited enhanced free radical inhibition (IC50: 31.45 μg/mL, 34.01 μg/mL, 27.40 μg/mL) compared to leaf extract (IC50: 52.67 μg/mL, 59.64 μg/mL, 97.50 μg/mL) in DPPH, hydrogen peroxide, and nitric oxide free radical scavenging assays, respectively. The MIC/MBC values of AgNPs against E. coli and S. aureus were 5 ppm/ 7.5 ppm and 10 ppm/ 15 ppm, respectively. Furthermore, our study showed that green-synthesized AgNPs at MIC significantly reduced the biofilm production of E. coli (70.37 %) and S. aureus (67.40 %). The CHS/AgNPs gel exhibited potent wound healing activities, comparable to a commercial cream with the re-epithelialization period of 8.16 ± 0.75. Histological analysis demonstrated enhanced skin regeneration with a thicker epidermal layer, well-defined papillary dermal structure, and organized collagen fibers. In summary, these findings hold promise for addressing bacterial infections, particularly those associated with biofilms-related wound infections.

Green and environmentally friendly synthesis of silver nanoparticles with antibacterial properties from some medicinal plants

Recently there have been a variety of methods to synthesize silver nanoparticles, among which the biosynthesis method is more noticeable due to features like being eco-friendly, simple, and cost-efficient. The present study aims for the green synthesis of silver nanoparticles from the extract of the three plants A. wilhelmsi, M. chamomilla, and C. longa; moreover, it pledges to measure the antibacterial activity against some variants causing a skin rash. The morphology and size of the synthesized silver nanoparticles were evaluated by UV.vis, XRD, SEM, and FTIR analyses. Then results showed a color alteration from light yellow to dark brown and the formation of silver nanoparticles. The absorption peak with the wavelength of approximately 450 nm resulting from the Spectrophotometry analysis confirmed the synthesis of silver nanoparticles. The presence of strong and wide peaks in FTIR indicated the presence of OH groups. The SEM results showed that most synthesized nanoparticles had a spherical angular structure and their size was about 10 to 20 nm. The highest inhibition power was demonstrated by silver nanoparticles synthesized from the extract combined from all three species against Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis (23 mm) which had a performance far more powerful than the extract. Thus, it can be understood that the nanoparticles synthesized from these three species can act as potential environment-friendly alternatives to inhibit some variations causing skin disorders; an issue that calls for further clinical studies.

AgNPs-Modified Polylactic Acid Microneedles: Preparation and In Vivo/In Vitro Antimicrobial Studies

OBJECTIVE

To prepare polylactic acid microneedles (PLAMNs) with sustained antibacterial effect to avoid skin infection caused by traditional MNs-based biosensors.

METHODS

Silver nanoparticles (AgNPs) were synthesized using an in-situ reduction process with polydopamine (PDA). PLAMNs were fabricated using the hot-melt method. A series of pressure tests and puncture experiments were conducted to confirm the physicochemical properties of PLAMNs. Then AgNPs were modified on the surface of PLAMNs through in-situ reduction of PDA, resulting in the formation of PLAMNs@PDA-AgNPs. The in vitro antibacterial efficacy of PLAMNs@PDA-AgNPs was evaluated using agar diffusion assays and bacterial liquid co-culture approach. Wound healing and simulated long-term application were performed to assess the in vivo antibacterial effectiveness of PLAMNs@PDA-AgNPs.

RESULTS

The MNs array comprised 169 tiny needle tips in pyramidal rows. Strength and puncture tests confirmed a 100% puncture success rate for PLAMNs on isolated rat skin and tin foil. SEM analysis revealed the integrity of PLAMNs@PDA-AgNPs with the formation of new surface substances. EDS analysis indicated the presence of silver elements on the surface of PLAMNs@PDA-AgNPs, with a content of 14.44%. Transepidermal water loss (TEWL) testing demonstrated the rapid healing of micro-pores created by PLAMNs@PDA-AgNPs, indicating their safety. Both in vitro and in vivo tests confirmed antibacterial efficacy of PLAMNs@PDA-AgNPs.

CONCLUSIONS

In conclusion, the sustained antibacterial activity exhibited by PLAMNs@PDA-AgNPs offers a promising solution for addressing skin infections associated with MN applications, especially when compared to traditional MN-based biosensors. This advancement offers significant potential for the field of MN technology.

Bio-functionalized nickel-silica nanoparticles suppress bacterial leaf blight disease in rice (Oryza sativa L.)

Introduction

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most devastative diseases that threatens rice plants worldwide. Biosynthesized nanoparticle (NP) composite compounds have attracted attention as environmentally safe materials that possess antibacterial activity that could be used in managing plant diseases.

Methods

During this study, a nanocomposite of two important elements, nickel and silicon, was biosynthesized using extraction of saffron stigmas (Crocus sativus L.). Characterization of obtained nickel-silicon dioxide (Ni-SiO2) nanocomposite was investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission/Scanning electron microscopy (TEM/SEM), and energy-dispersive spectrum (EDS). Antibacterial activities of the biosynthesized Ni-SiO2 nanocomposite against Xoo were tested by measuring bacterial growth, biofilm formation, and dead Xoo cells.

Results and discussions

The bacterial growth (OD600) and biofilm formation (OD570) of Xoo treated with distilled water (control) was found to be 1.21 and 1.11, respectively. Treatment with Ni-SiO2 NPs composite, respectively, reduced the growth and biofilm formation by 89.07% and 80.40% at 200 μg/ml. The impact of obtained Ni-SiO2 nanocomposite at a concentration of 200 μg/ml was assayed on infected rice plants. Treatment of rice seedlings with Ni-SiO2 NPs composite only had a plant height of 64.8 cm while seedlings treated with distilled water reached a height of 45.20 cm. Notably, Xoo-infected seedlings treated with Ni-SiO2 NPs composite had a plant height of 57.10 cm. Furthermore, Ni-SiO2 NPs composite sprayed on inoculated seedlings had a decrease in disease leaf area from 43.83% in non-treated infected seedlings to 13.06% in treated seedlings. The FTIR spectra of biosynthesized Ni-SiO2 nanocomposite using saffron stigma extract showed different bands at 3,406, 1,643, 1,103, 600, and 470 cm-1. No impurities were found in the synthesized composite. Spherically shaped NPs were observed by using TEM and SEM. EDS revealed that Ni-SiO2 nanoparticles (NPs) have 13.26% Ni, 29.62% Si, and 57.11% O. Xoo treated with 200 µg/ml of Ni-SiO2 NPs composite drastically increased the apoptosis of bacterial cells to 99.61% in comparison with 2.23% recorded for the control.

Conclusions

The application of Ni-SiO2 NPs significantly improved the vitality of rice plants and reduced the severity of BLB.

Topical Analgesic and Anti-Inflammatory Properties of Bioengineered Juglans regia L. Silver Nanoparticles

<b>Background and Objective:</b> Research has demonstrated the antibacterial, anti-angiogenetic, antiviral, anti-inflammatory, anticancer and antioxidant properties of colloidal silver due to its biological, optical and electrical properties. The aim of this study was the anti-inflammatory effect of the silver bioengineered nanoparticles by using the acetonitrile-unripe fruit extract of <i>Juglans regia</i> L., on experimental animal model. <b>Materials and Methods:</b> The study uses various techniques to characterize nanoparticles, including ultraviolet spectra, dynamic light scattering and Fourier transform infrared. The study used carrageenan-induced rat paw edema as an induction model for inflammation and assessed its antinociceptive effects in mice using the formalin test. As well as evaluation of proinflammatory cytokines IL-6, TNF and IL-1. <b>Results:</b> The produced AgNPs were more compact and stable, according to physical characterization methods compared to chemical prepared nanoparticles. The formulation combining unripe fruit bio-reduced nanoparticles and extract, UF, shows a greater acute anti-inflammatory effect, while leaf extract has a better late anti-inflammatory effect. These bioengineered nanoparticles show efficient <i>in vivo</i> anti-acute inflammation, reducing skin inflammation through decreased cellular infiltrates and cytokine release. <b>Conclusion:</b> <i>Juglans regia</i> L., extract and silver nanoparticles show notable effects in both the early and late stages of the antinociceptive formalin test. While, bioengineered NP/UF and NP/LV can be used as topical analgesics. The potent topical anti-inflammatory and analgesic effects of these medications provide a sufficient basis for the use of this plant material in dermatological products.

Green, facile and fast synthesis of silver nanoparticles by using solution plasma techniques and their antibacterial and anticancer activities

We herein present a simple, fast, efficient and environmentally friendly method for preparing silver nanoparticles (AgNPs) using the solution plasma method in the presence of extracts from Paramignya trimera (P. trimera). The effects of P. trimera extract concentrations and the applied voltage on the formation of AgNPs were investigated. Surface plasmon resonance spectra show a strong peak at 413 nm for the prepared samples. The Fourier-transform infrared spectroscopy measurement results indicated the presence of possible functional groups in the prepared AgNPs. Morphological analysis revealed that the AgNPs were spherical with an average size of 8 nm. The prepared AgNPs exhibited good stability in solution compared to that of AgNPs prepared by the solution plasma technique without P. trimera extract. The formation mechanism of AgNPs is also proposed. The prepared AgNPs exhibited high antibacterial ability against Gram (+) Staphylococcus aureus, Gram (-) Pseudomonas aeruginosa bacteria and strong anticancer activity for the AGS gastric cancer cell line. The obtained results demonstrated that this is a simple, rapid, environmentally friendly method for preparing AgNPs instead of conventional methods using chemical reducing agents for potential applications.

Novel extracellular synthesized silver nanoparticles using thermophilic Anoxybacillus flavithermus and Geobacillus stearothermophilus and their evaluation as nanodrugs

In this investigation, two new thermophilic bacteria were isolated. The new isolates were characterized by 16S rRNA, biochemical, morphological, and physiological analyzes and the isolates were identified as Geobacillus stearothermophilus strain Gecek20 and thermophilic Anoxybacillus flavithermus strain Gecek19. Various biological activities of extracellular Ag-NPs synthesized from thermophilic G. stearothermophilus strain Gecek20 and thermophilic A. flavithermus strain Gecek19 were evaluated. The produced NPs were analyzed by SEM, SEM-EDX, and XRD analyses. The antioxidant abilities of new synthesized Ag-NPs from thermophilic G. stearothermophilus strain Gecek20 (T1-Ag-NPs) and new synthesized Ag-NPs from thermophilic A. flavithermus strain Gecek19 (T2-Ag-NPs) were studied by DPPH inhibition and metal chelating ability. The highest DPPH and metal chelating abilities of T1-Ag-NPs and T2-Ag-NPs at 200 mg/L concentration were 93.17 and 90.85%, and 75.80 and 83.64%, respectively. The extracellular green synthesized T1-Ag-NPs and T2-AgN-Ps showed DNA nuclease activity at all tested concentrations. Moreover, both new synthesized Ag-NPs had antimicrobial activity against the strains studied, especially on Gram positive bacteria. T1-Ag-NPs and T2-AgNPs also showed powerful Escherichia coli growth inhibition. The highest biofilm inhibition percentages of T1-Ag-NPs and T2-Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus were 100.0%, respectively, at 500 mg/L.

Characterization of teff straw from selected teff varieties from Ethiopia

Utilization of biomass is important both for economic and environmental projection purposes. To use biomass for industrial applications as well as to reduce its pollution load on environment, it is important to characterize and determine the compositions of the biomass. In this work, the proximate and chemical analyses of straws of four (Dagim, Filagot, Kora and Kuncho) Teff (Eragrostis tef) varieties were investigated with three replications. The thermographic and FTIR of the teff straws and the ashes were also studied. The volatile matter contents of the teff straws were 78.80, 77.00, 80.20 and 80.60% for the Dagim, Kuncho, Kora and Filagot varieties, respectively. The ash contents of the straws were 6.34% for Dagim, Kuncho and Kora while the value is 6.00% for Filagot. The fixed carbon contents of the straws were 14.86, 16.67, 13.47 and 13.40% for Dagim, Kuncho, Kora and Filagot varieties, respectively. The silica contents of the teff straw for the Filagot, Kora, Dagim, and Kuncho varieties are 5.92, 5.66, 4.94, and 4.70%, respectively. This corresponds to 92.21, 91.59, 77.19 and 87.20% silica contents in the ashes produced from Filagot, Kora, Dagim, and Kuncho varieties, respectively. The results show that the proximate and chemical composition of ash produced from teff straws show slight differences. Moreover, the silica content of the teff straw is comparable with the values reported for rice husk and wheat straw. Thus, teff straw can be used for the production of silica.

Silver Nanoparticles Synthesized from Abies alba and Pinus sylvestris Bark Extracts: Characterization, Antioxidant, Cytotoxic, and Antibacterial Effects

In recent years, phytofunctionalized AgNPs have attracted great interest due to their remarkable biological activities. In the present study, AgNPs were synthesized using Abies alba and Pinus sylvestris bark extracts. The chemical profile of these bark extracts was analyzed by LC-HRMS/MS. As a first step, the synthesis parameters (pH, AgNO₃ concentration, ratio of bark extract and AgNO₃, temperature, and reaction time) were optimized. The synthesized AgNPs were characterized by ATR-FTIR spectroscopy, DLS, SEM, EDX, and TEM. Their antioxidant, cytotoxic, and antibacterial properties were evaluated by the DPPH, ABTS, MTT, and broth microdilution assays, respectively. Abies alba and Pinus sylvestris bark extract-derived AgNPs were well-dispersed, spherical, small (average particle size of 9.92 and 24.49 nm, respectively), stable (zeta potential values of -10.9 and -10.8 mV, respectively), and cytotoxic to A-375 human malignant melanoma cells (IC₅₀ = 2.40 ± 0.21 and 6.02 ± 0.61 μg/mL, respectively). The phytosynthesized AgNPs also showed antioxidant and antibacterial effects.

Current Knowledge of the Antidepressant Activity of Chemical Compounds from Crocus sativus L

Psychotropic effect of Crocus sativus L. (family Iridaceae) biologically active chemical compounds are quite well documented and they can therefore be used in addition to the conventional pharmacological treatment of depression. This systematic review on antidepressant compounds in saffron crocus and their mechanisms of action and side effects is based on publications released between 1995−2022 and data indexed in 15 databases under the following search terms: antidepressant effect, central nervous system, Crocus sativus, cognitive impairement, crocin, crocetin, depression, dopamine, dopaminergic and serotonergic systems, picrocrocin, phytotherapy, neurotransmitters, safranal, saffron, serotonin, and biologically active compounds. The comparative analysis of the publications was based on 414 original research papers. The investigated literature indicates the effectiveness and safety of aqueous and alcoholic extracts and biologically active chemical compounds (alkaloids, anthocyanins, carotenoids, flavonoid, phenolic, saponins, and terpenoids) isolated from various organs (corms, leaves, flower petal, and stigmas) in adjuvant treatment of depression and anxiety. Monoamine reuptake inhibition, N-methyl-d-aspartate (NMDA) receptor antagonism, and gamma-aminobutyric acid (GABA)-α agonism are the main proposed mechanism of the antidepressant action. The antidepressant and neuroprotective effect of extract components is associated with their anti-inflammatory and antioxidant activity. The mechanism of their action, interactions with conventional drugs and other herbal preparations and the safety of use are not fully understood; therefore, further detailed research in this field is necessary. The presented results regarding the application of C. sativus in phytotherapy are promising in terms of the use of herbal preparations to support the treatment of depression. This is particularly important given the steady increase in the incidence of this disease worldwide and social effects.

Diversity of Biogenic Nanoparticles Obtained by the Fungi-Mediated Synthesis: A Review

Fungi are very promising biological objects for the green synthesis of nanoparticles. Biogenic synthesis of nanoparticles using different mycological cultures and substances obtained from them is a promising, easy and environmentally friendly method. By varying the synthesis conditions, the same culture can be used to produce nanoparticles with different sizes, shapes, stability in colloids and, therefore, different biological activity. Fungi are capable of producing a wide range of biologically active compounds and have a powerful enzymatic system that allows them to form nanoparticles of various chemical elements. This review attempts to summarize and provide a comparative analysis of the currently accumulated data, including, among others, our research group's works, on the variety of the characteristics of the nanoparticles produced by various fungal species, their mycelium, fruiting bodies, extracts and purified fungal metabolites.

Antibacterial activity of green gold and silver nanoparticles using ginger root extract

Recent studies demonstrated that the speed of synthesis, biocompatibility, and antimicrobial activity of gold (Au) and silver (Ag) metals is enhanced when biosynthesized in nano-sized particles. In the present study, Au- and Ag-based nanoparticles (NPs) were synthesized via a biological process using aqueous Ginger root extract and characterized by various spectroscopic methods. The NPs have hexagonal and spherical shapes. The average particle size for Au and Ag NPs was 20 and 15 nm, respectively. The dynamic light scattering (DLS) technique has shown that the zeta potential values of synthesized NPs were 4.8 and - 7.11 mv, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis of Ginger root extract revealed 25 compounds. The synthesized NPs showed significant activity against Staphylococcus aureus and Escherichia (E). coli in vitro, with IC50 and IC90 values for Au and Ag NPs, respectively, noted to be 7.5 and 7.3 µg/ml and 15 and 15.2 µg/ml for both bacterial strains. The protein leakage level was tremendous and morphological changes occurred in bacteria treated with biosynthesized NPs. These results suggest that the biosynthesized metallic NPs have the suitable potential for application as antibacterial agents with enhanced activities.

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.

Green synthesis, characterization, and antibacterial activity of silver nanoparticles using stem extract of Zanthoxylum armatum

In this study, we report the green synthesis of silver nanoparticles (AgNPs) using Zanthoxylum armatum stem extract. The characteristic absorption at 385 nm suggested synthesis of AgNPs which was further confirmed by SEM, with a size in the range of 46.66 nm to 60.12 nm and a spherical shape, having an FCC structure, analyzed by XRD. FTIR analysis revealed the presence of phenol and secondary alcohol groups over the AgNPS. The elemental composition was further investigated by FESEM-EDX analysis which revealed the presence of silver in the synthesis nanoparticles. The synthesized silver nanoparticles exhibited antimicrobial activity against tested microorganisms with a zone of inhibition of 21 mm for Staphylococcus aureus, 17 mm for Pseudomonas aeruginosa, 18 mm for Salmonella enteric, and 18 mm for Escherichia coli. Overall, the results showed that the green silver nanoparticles could be safe, as they are capable of potential antimicrobial activity against S. aureus.

Nano-architectural design of TiO2 for high performance photocatalytic degradation of organic pollutant: A review

In the past several decades, significant efforts have been paid toward photocatalytic degradation of organic pollutants in environmental research. During the past years, titanium dioxide nano-architectures (TiO₂ NAs) have been widely used in water purification applications with photocatalytic degradation processes under Uv/Vis light illumination. Photocatalysis process with nano-architectural design of TiO₂ is viewed as an efficient procedure for directly channeling solar energy into water treatment reactions. The considerable band-gap values and the subsequent short life time of photo-generated charge carriers are showed among the limitations of this approach. One of these effective efforts is the using of oxidation processes with advance semiconductor photocatalyst NAs for degradation the organic pollutants under UV/Vis irradiation. Among them, nano-architectural design of TiO₂ photocatalyst (such as Janus, yolk-shell (Y@S), hollow microspheres (HMSs) and nano-belt) is an effective way to improve oxidation processes for increasing photocatalytic activity in water treatment applications. In the light of the above issues, this study tends to provide a critical overview of the used strategies for preparing TiO₂ photocatalysts with desirable physicochemical properties like enhanced absorption of light, low density, high surface area, photo-stability, and charge-carrier behavior. Among the various nanoarchitectural design of TiO₂, the Y@S and HMSs have created a great appeal given their considerable large surface area, low density, homogeneous catalytic environment, favorable light harvesting properties, and enhanced molecular diffusion kinetics of the particles. In this review was summarized the developments that have been made for nano-architectural design of TiO2 photocatalyst. Additional focus is placed on the realization of interfacial charge and the possibility of achieving charge carriers separation for these NAs as electron migration is the extremely important factor for increasing the photocatalytic activity.

Synthesis and antibacterial potential of Loranthus pulverulentus conjugated silver nanoparticles

The green method is not only harmonious to our environment but saves time and is comparatively cheaper than other methods. The current study is aimed to synthesize the silver nanoparticles (AgNPs) using the green method by using the leaves of Loranthus pulverulentus Wall (LPW) which functioned as a reducing as well as capping agent. The synthesis of biogenic AgNPs was confirmed by UV-Vis spectroscopy (UV-Vis.), Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), and Fourier transform infrared (FTIR). The absorbance maxima of the synthesized AgNPs were observed in the range of 405-435 nm. The SEM was used to find out the size and shape of the synthesized AgNPs, which revealed that the NPs were rectangular having sizes from 05 to 16 nm. XRD revealed that the synthesized NPs were crystalline and face-centered cubic (FCC). EDX analysis reflected the elemental composition of the synthesized product and showed that the percentage of silver = 92. FTIR was used to confirm the functional groups responsible for the reduction and stabilization of silver ions. It revealed that biomolecules present in plant extract were responsible for the reduction and stabilization of silver ions. The effect of temperature, pH, reaction time, silver nitrate concentration, and plant extract concentration on the synthesis of AgNPs were also investigated. The synthesized silver nanoparticles were tested against four bacterial strains which showed strong antibacterial activity. We conclude that biogenic silver nanoparticles could be used as antibacterial agents to treat various diseases.

Biosynthesis of Silver Nanoparticles Using Bersama engleriana Fruits Extracts and Their Potential Inhibitory Effect on Resistant Bacteria

The absence of novel, safe, and effective bactericide is an urgent concern worldwide and remains a challenge in scientific communities. The unique proprieties of silver nanoparticles (SNPs) synthesized from plant extracts make them a suitable candidate to overcome these limitations. Herein, we synthesized SNPs from Bersama engleriana fruit (BEfr) extracts and determined their potential antibacterial activity and mode of action. SNPs were synthesized from BEfr methanolic fruit extracts at 25 and 70 °C, and the antibacterial effectiveness of SNPs against bacterial strains was investigated. The surface plasmon resonance peaked at 430.18 and 434.08 nm, respectively, for SNPs synthesized at 25 and 70 °C, confirming SNPs synthesis. BEfr-SNPs had minimum inhibitory concentrations (MIC) range of 0.234 to >50 µg/mL, which was 30-fold greater than extract alone (MIC of 500 µg/mL). BEfr-SNPs-25 °C was potent against six bacterial strains (S. aureus, S. enterica, MRS. aureus, K. pneumonia, and S. pyogenes), with MIC range of 0.339 to 6.25 µg/mL. The mode of action of BEfr-SNPs-25 °C was achieved by an MRSA bacteria strain outer membrane and DNA nucleotide linkage. These results suggest that our synthesized SNPs, especially BEfr-SNPs-25 °C, demonstrated an enhanced antibacterial effect and could be potential candidates for bacterial infection treatment.

Antioxidant, Cytotoxic, and Antimicrobial Potential of Silver Nanoparticles Synthesized using Tradescantia pallida Extract

Silver nanoparticles have received much attention, due to their wide range of biological applications as an alternative therapy for disease conditions utilizing the nanobiotechnology domain for synthesis. The current study was performed to examine the antioxidant, anticancer, antibacterial, and antifungal potential of biosynthesized silver nanoparticles (TpAgNPs) using plant extract. The TpAgNPs were produced by reacting the Tradescantia pallida extract and AgNO₃ solution in nine various concentration ratios subjected to bioactivities profiling. According to the current findings, plant extract comprising phenolics, flavonoids, and especially anthocyanins played a critical role in the production of TpAgNPs. UV–visible spectroscopy also validated the TpAgNP formation in the peak range of 401–441 nm. Further, the silver ion stabilization by phytochemicals, face-centered cubic structure, crystal size, and spherical morphology of TpAgNPs were analyzed by FTIR, XRD, and SEM. Among all TpAgNPs, the biosynthesized TpAgNP6 with a medium concentration ratio (5:10) and the plant extract had effective antioxidant potentials of 77.2 ± 1.0% and 45.1 ± 0.5% free radical scavenging activity, respectively. The cytotoxic activity of TpAgNP6 in comparison to plant extract for the rhabdomyosarcoma cell line was significantly the lowest with IC₅₀ values of 81.5 ± 1.9 and 90.59 ± 1.6 μg/ml and cell viability % of 24.3 ± 1.62 and 27.4 ± 1.05, respectively. The antibacterial and antifungal results of TpAgNPs revealed significant improvement in comparison to plant extract, i.e., minimum inhibition concentration (MIC) 64 μg/ml against Gram-negative Pseudomonas aeruginosa while, in the case of antifungal assay, TpAgNP6 was active against Candida parapsilosis. These TpAgNPs play a crucial role in determining the therapeutic potential of T. pallida due to their biological efficacy.

Fabrication of Silver Nanoparticles Using Cordyline fruticosa L. Leave Extract Endowing Silk Fibroin Modified Viscose Fabric with Durable Antibacterial Property

The current work presented a green synthetic route for the fabrication of silver nanoparticles obtained from aqueous solutions of silver nitrate using Cordyline fruticosa L. leaf extract (Col) as a reducing and capping agent for the first time. The bio-synthesized silver nanoparticles (AgCol) were investigated using UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA). The obtained data demonstrated that AgCol in spherical shape with an average size of 28.5 nm were highly crystalline and well capped by phytocompounds from the Col extract. Moreover, the bio-synthesized AgCol also exhibited the effective antibacterial activities against six pathogenic bacteria, including Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Salmonella enterica (S. enterica), Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and Enterococcus faecalis (E. faecalis). The AgCol were applied as an antibacterial finishing agent for viscose fabric using a pad-dry curing technique. The AgCol-treated viscose fabrics exhibited a good synergistic antimicrobial activity against E. coli and S. aureus bacteria. Furthermore, the silk fibroin regenerated from Bombyx mori cocoon waste was utilized as an ecofriendly binder for the immobilization of AgCol on the viscose fabric. Thus, the antimicrobial efficacy of the AgCol and fibroin modified viscose fabric still reached 99.99% against the tested bacteria, even after 30 washing cycles. The colorimetric property, morphology, elemental composition, and distribution of AgCol on the treated fabrics were investigated using several analysis tools, including colorimetry, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic absorption spectroscopy (AAS), Kjeldahl, and FTIR. Because of the excellent antimicrobial efficiency and laundering durability, as well as the green synthesis method, the AgCol and fibroin modified viscose fabric could be utilized as an antibacterial material in sportswear and medical textile applications.

Silver Nanoparticles Synthesized Using Eichhornia crassipes Extract from Yuriria Lagoon, and the Perspective for Application as Antimicrobial Agent

The antimicrobial effects of silver (Ag) ions and salts are well known. However, the antimicrobial effects, mechanism, and the cytotoxic activity in vitro of Ag nanoparticles (AgNP) has recently been validated. In this work, we report the green synthesis of AgNPs using the extract of Eichhornia crassipes as a reducing agent and evaluate its antimicrobial activity against Escherichia coli (ATCC-25922). The morphology, size, chemical composition, and inhibition properties of the nanoparticles as a function of the reduction time and temperature were analyzed. According to TEM imaging, nanoparticles with average diameters between 20–40 nm were synthesized. Antibacterial results suggest that AgNPs can be used as an effective growth inhibitor with higher antimicrobial activity against Escherichia coli after 120 min of reaction with a synthesis temperature of 95°. More extensive analysis is required for the appropriate selection of the synthesis parameters and adequate concentration for use in biomedical applications and antibacterial control systems.

A Review on Current Designation of Metallic Nanocomposite Hydrogel in Biomedical Applications

In the past few decades, nanotechnology has been receiving significant attention globally and is being continuously developed in various innovations for diverse applications, such as tissue engineering, biotechnology, biomedicine, textile, and food technology. Nanotechnological materials reportedly lack cell-interactive properties and are easily degraded into unfavourable products due to the presence of synthetic polymers in their structures. This is a major drawback of nanomaterials and is a cause of concern in the biomedicine field. Meanwhile, particulate systems, such as metallic nanoparticles (NPs), have captured the interest of the medical field due to their potential to inhibit the growth of microorganisms (bacteria, fungi, and viruses). Lately, researchers have shown a great interest in hydrogels in the biomedicine field due to their ability to retain and release drugs as well as to offer a moist environment. Hence, the development and innovation of hydrogel-incorporated metallic NPs from natural sources has become one of the alternative pathways for elevating the efficiency of therapeutic systems to make them highly effective and with fewer undesirable side effects. The objective of this review article is to provide insights into the latest fabricated metallic nanocomposite hydrogels and their current applications in the biomedicine field using nanotechnology and to discuss the limitations of this technology for future exploration. This article gives an overview of recent metallic nanocomposite hydrogels fabricated from bioresources, and it reviews their antimicrobial activities in facilitating the demands for their application in biomedicine. The work underlines the fabrication of various metallic nanocomposite hydrogels through the utilization of natural sources in the production of biomedical innovations, including wound healing treatment, drug delivery, scaffolds, etc. The potential of these nanocomposites in relation to their mechanical strength, antimicrobial activities, cytotoxicity, and optical properties has brought this technology into a new dimension in the biomedicine field. Finally, the limitations of metallic nanocomposite hydrogels in terms of their methods of synthesis, properties, and outlook for biomedical applications are further discussed.

A Green Approach for the Synthesis of Silver Nanoparticle-Embedded Chitosan Bionanocomposite as a Potential Device for the Sustained Release of the Itraconazole Drug and Its Antibacterial Characteristics

The present research work intended to demonstrate the green synthesis of silver nanoparticles (AgNPs) using the plant extract Saccharum officinarum, and then the development of chitosan–silver (CH-Ag) bionanocomposite. The synthesized AgNPs were characterized using UV spectroscopy, Fourier transform infrared (FTIR), and transmission electron microscopy (TEM). The maximum absorption spectrum peak was observed at 420 nm, revealing the formation of AgNPs by the stem extract of S. officinarum. The AgNPs sizes were in the range of 10–50 nm. Itraconazole is an antifungal that is used as a novel drug to study its release through synthesized bionanocomposite. Different kinetic models, such as zero order, first order, Korsmeyer–Peppas, Hixson–Crowell and Higuchi, were used to study the drug release profile from the synthesized CH-Ag bionanocomposite. The first-order kinetic model showed the best fit for the drug release with the maximum regression coefficient value. The antibacterial activity of the synthesized CH-Ag bionanocomposite was examined against Bacillus cereus, Staphylococcus, and Escherichia coli, and it was shown to be efficient against these strains.

Medicinal plants mediated the green synthesis of silver nanoparticles and their biomedical applications

The alarming effect of antibiotic resistance prompted the search for alternative medicine to resolve the microbial resistance conflict. Over the last two decades, scientists have become increasingly interested in metallic nanoparticles to discover their new dimensions. Green nano synthesis is a rapidly expanding field of interest in nanotechnology due to its feasibility, low toxicity, eco‐friendly nature, and long‐term viability. Some plants have long been used in medicine because they contain a variety of bioactive compounds. Silver has long been known for its antibacterial properties. Silver nanoparticles have taken a special place among other metal nanoparticles. Silver nanotechnology has a big impact on medical applications like bio‐coating, novel antimicrobial agents, and drug delivery systems. This review aims to provide a comprehensive understanding of the pharmaceutical qualities of medicinal plants, as well as a convenient guideline for plant‐based silver nanoparticles and their antimicrobial activity.

Silver Nanostructures prepared via novel green approach as an effective platform for biological and environmental applications

Silver nanoparticles play a significant role in biomedical sciences due to their unique properties allowing for their use as an effective sensing and remediation platform Herein, the green synthesis of silver nanostructures (Ag NSs), prepared via aqueous extract of waste Brassica oleracea leaves in the presence of silver nitrate solution (10^-4 M), is reported. The Ag NSs are fully characterized and their efficacy with respect to 4-nitrophenol reduction, glucose sensing, and microbes is determined. Visually, the color of silver nitrate containing solution altered from colorless to yellowish, then reddish grey, confirming the formation of Ag NSs. HRTEM and SEAD studies revealed the Ag NSs to have different morphologies (triangular, rod-shaped, hexagonal, etc., within a size range of 20–40 nm) with face-centered cubic (fcc) crystal structure. The Ag NSs possess high efficacy for nitrophenol reduction (<11 min and degradation efficiency of 98.2%), glucose sensing (LOD: 5.83 µM), and antimicrobial activity (E. coli and B. subtilis with clearance zones of 18.3 and 14 mm, respectively). Thus, the current study alludes towards the development of a cost-effective, sustainable, and efficient three-in-one platform for biomedical and environmental applications.

Multidrug resistance from a one health perspective in Ethiopia: A systematic review and meta-analysis of literature (2015–2020)

Purpose

The emergence of antimicrobial resistance is a major global health challenge and becoming an urgent priority for policymakers. There is a paucity of scientific studies presenting the multidrug resistance pattern from one health perspective in Ethiopia. Therefore, a systematic review and meta-analysis aimed to determine the pooled prevalence of multidrug resistance in bacteria from human, animal, food, and environmental sources.

Methods

In this systematic review and meta-analysis, an electronic search was made in PubMed & Google scholar using different keywords. The studies conducted in all areas of Ethiopia, published from 2015 to 2020 in peer-reviewed journals, English full-length papers were included. The meta-analysis was done on STATA version 14. The pooled prevalence of multidrug resistance for each bacterium was analysed using the random-effects model; Cochran Q statistics and the I² statistic was used to analyse heterogeneity and considered significant at p < 0.01.

Results

81 studies were included in the systematic review and meta-analysis; 53 human studies, eight animal studies, and 16 environments/food studies. The meta-analysis included six species from gram-positive bacteria and 13 from gram-negative bacteria. S. aureus 53% (95%CI: 42–64%), Coagulase negative Staphylococci 68%(95%CI:53–82), Pseudomonas spp. 73%(95%CI:48–93%), E. coli 70% (95%CI:61–78%), Citrobacter spp. 71%(95%CI:54–87%), Klebsiella spp. 68% (54–80%), Enterobacter spp. 67% (48–83%) and Salmonella spp. 65% (95%CI:48–81%) were the common multidrug-resistant species of bacteria from two or more sources.

Conclusion

In Ethiopia, the pooled prevalence of MDR is high in most bacterial species from humans, animals, food, and environmental sources. Staphylococcus, most members of the Enterobacteriaceae and Pseudomonas, are the standard MDR bacterial population involving all sources. Therefore, integrated policy and intervention measures should be implemented to reduce the emergence and spread of MDR bacteria for better animal and human health outcomes.

Multifarious global flora fabricated phytosynthesis of silver nanoparticles: a green nanoweapon for antiviral approach including SARS-CoV-2

The progressive research into the nanoscale level upgrades the higher end modernized evolution with every field of science, engineering, and technology. Silver nanoparticles and their broader range of application from nanoelectronics to nano-drug delivery systems drive the futuristic direction of nanoengineering and technology in contemporary days. In this review, the green synthesis of silver nanoparticles is the cornerstone of interest over physical and chemical methods owing to its remarkable biocompatibility and idiosyncratic property engineering. The abundant primary and secondary plant metabolites collectively as multifarious phytochemicals which are more peculiar in the composition from root hair to aerial apex through various interspecies and intraspecies, capable of reduction, and capping with the synthesis of silver nanoparticles. Furthermore, the process by which intracellular, extracellular biological macromolecules of the microbiota reduce with the synthesis of silver nanoparticles from the precursor molecule is also discussed. Viruses are one of the predominant infectious agents that gets faster resistance to the antiviral therapies of traditional generations of medicine. We discuss the various stages of virus targeting of cells and viral target through drugs. Antiviral potential of silver nanoparticles against different classes and families of the past and their considerable candidate for up-to-the-minute need of complete addressing of the fulminant and opportunistic global pandemic of this millennium SARS-CoV2, illustrated through recent silver-based formulations under development and approval for countering the pandemic situation.

Graphical abstract

Biogenic Synthesis of Ag Nanoparticles of 18.27 nm by Zanthozylum armatum and Determination of Biological Potentials

Nanotechnology has become a dire need of the current era and the green synthesis of nanoparticles offers several advantages over other methods. Nanobiotechnology is an emerging field that contributes to many domains of human life, such as the formulation of nanoscale drug systems or nanomedicine for the diagnosis and treatment of diseases. Medicinal plants are the main sources of lead compounds, drug candidates and drugs. This work reports the green synthesis of Ag nanoparticles (AgNPs) using the aqueous bark extract of Zanthozylum armatum, which was confirmed by a UV absorption at 457 nm. XRD analysis revealed an average size of 18.27 nm and SEM showed the particles’ spherical shape, with few irregularly shaped particles due to the aggregation of the AgNPs. FT-IR revealed the critical functional groups of phytochemicals which acted as reducing and stabilizing agents. The bark extract showed rich flavonoids (333 mg RE/g) and phenolic contents (82 mg GAE/g), which were plausibly responsible for its high antioxidant potency (IC₅₀ = 14.61 µg/mL). Extract-loaded AgNPs exhibited the highest but equal inhibition against E. coli and P. aeruginosa (Z.I. 11.0 mm), whereas methanolic bark extract inhibited to a lesser extent, but equally to both pathogens (Z.I. 6.0 mm). The aqueous bark extract inhibited P. aeruginosa (Z.I. 9.0 mm) and (Z.I. 6.0 mm) E. coli. These findings—especially the biosynthesis of spherical AgNPs of 18.27 nm—provide promise for further investigation and for the development of commercializable biomedical products.

PEGylation of silver nanoparticles by physisorption of cyclic poly(ethylene glycol) for enhanced dispersion stability, antimicrobial activity, and cytotoxicity

Silver nanoparticles (AgNPs) are practically valuable in biological applications. However, no steady PEGylation has been established, which is essential for internal use in humans or animals. In this study, cyclic PEG (c-PEG) without any chemical inhomogeneity is physisorbed onto AgNPs to successfully PEGylate and drastically enhance the dispersion stability against physiological conditions, white light, and high temperature. In contrast, linear HO-PEG-OH and MeO-PEG-OMe do not confer stability to AgNPs, and HS-PEG-OMe, which is often used for gold nanoparticles, sulfidates the surface to considerably degrade the properties. TEM shows an essentially intact nanostructure of c-PEG-physisorbed AgNPs even after heating at 95 °C, while complete disturbance is observed for other AgNPs. Molecular weight- and concentration-dependent stabilization by c-PEG is investigated, and DLS and ζ-potential measurements prove the formation of a c-PEG layer on the surface of AgNPs. Furthermore, c-PEG-physisorbed AgNPs exhibit persistent antimicrobial activity and cytotoxicity.

Green Fabrication of Bioactive Silver Nanoparticles Using Mentha pulegium Extract under Alkaline: An Enhanced Anticancer Activity

Fabrication of silver nanoparticles (AgNPs) using Chinese herbal medicine is popular as the bioactive components included in them would generate potential synergistic effect with the metal nanoparticles. The leaf of Mentha pulegium, whose extract contains a range of phytochemicals and exhibits a wide spectrum of bioactivities, is used as Chinese herbal medicine after drying naturally. Thus, the green synthesis of AgNPs using Mentha pulegium has aroused interests from analysts. However, the biosynthesis of AgNPs under alkaline conditions and the biological activities remain elusive, where alkaline conditions may influence the physicochemical properties and the biological activities of biosynthesized AgNPs. In this study, we were stimulated to fabricate bioactive AgNPs using Mentha pulegium extract under alkaline conditions, accompanied by a systematic evaluation on the effect of biosynthesis parameters on the formation, average size, and polydispersity of AgNPs. Our results showed that alkaline conditions could accelerate the formation of AgNPs with a small average size but at a disadvantage to the polydispersity. Additionally, the as-prepared AgNPs had a hexagonal structure and spherical shape with an average size of 15.7 ± 0.1 nm, existing in the monodispersed form and revealing a high degree of stability. The AgNPs exhibited potent antioxidant and significant inhibitory activity for both bacterial and cancer cell lines. The MIC values of AgNPs for Staphylococcus aureus and Escherichia coli were both 50.0 μg·mL-1, and the IC50 values for HCT116, HepG2, and HeLa cells were 9.0, 14.5, and 31.5 μg·mL-1, respectively. The AgNPs biosynthesized using M. pulegium under alkaline conditions, which had a smaller size and more surface loads, are entirely different with those synthesized under acidic conditions, and the anticancer activity increased significantly. The internalization of AgNPs inside these five cells displayed a variant trend with variable AgNPs concentrations, suggesting the different mechanism of cell death. For two pathogens, HCT116 and HepG2 cancer cell lines, both cell wall and intracellular damage may be responsible for the cell death. However, for Hela cell line the cell death may be rooted in oxidative stress or intracellular penetration. These results confirmed that the AgNPs biosynthesized from M. pulegium extract under alkaline conditions would act as better anticancer agents in biomedicine.

Novel Perspectives towards RNA-Based Nano-Theranostic Approaches for Cancer Management

In the fight against cancer, early diagnosis is critical for effective treatment. Traditional cancer diagnostic technologies, on the other hand, have limitations that make early detection difficult. Therefore, multi-functionalized nanoparticles (NPs) and nano-biosensors have revolutionized the era of cancer diagnosis and treatment for targeted action via attaching specified and biocompatible ligands to target the tissues, which are highly over-expressed in certain types of cancers. Advancements in multi-functionalized NPs can be achieved via modifying molecular genetics to develop personalized and targeted treatments based on RNA interference. Modification in RNA therapies utilized small RNA subunits in the form of small interfering RNAs (siRNA) for overexpressing the specific genes of, most commonly, breast, colon, gastric, cervical, and hepatocellular cancer. RNA-conjugated nanomaterials appear to be the gold standard for preventing various malignant tumors through focused diagnosis and delivering to a specific tissue, resulting in cancer cells going into programmed death. The latest advances in RNA nanotechnology applications for cancer diagnosis and treatment are summarized in this review.

A review of the phytochemical mediated synthesis of AgNP (silver nanoparticle): the wonder particle of the past decade

Silver nanoparticle (AgNP) has been one of the most commonly used nanoparticles since the past decade for a wide range of applications, including environmental, agricultural, and medical fields, due to their unique physicochemical properties and ease of synthesis. Though chemical and physical methods of fabricating AgNPs have been quite popular, they posed various environmental problems. As a result, the bioinspired route of AgNP synthesis emerged as the preferred pathway for synthesis. This review focuses extensively on the biosynthesis of AgNP-mediated through different plant species worldwide in the past 10 years. The most popularly utilized application areas have been highlighted with their in-depth mechanistic approach in this review, along with the discussion on the different phytochemicals playing an important role in the bio-reduction of silver ions. In addition to this, the environmental factors which govern their synthesis and stability have been reviewed. The paper systematically analyses the trend of research on AgNP biosynthesis throughout the world through bibliometric analysis. Apart from this, the feasibility analysis of the plant-mediated synthesis of nanoparticles and their applications have been intrigued considering the perspectives of engineering, economic, and environmental limitations. Thus, the review is not only a comprehensive summary of the achievements and current status of plant-mediated biosynthesis but also provides insight into emerging future research frontier.

Ultrasound-assisted biosynthesis of Ag nanoparticles using Juglans negia L. leaves extract; Evaluation of total phenols, flavonoids, antioxidant potential and antibacterial activity

The present study aimed to synthesize silver nanoparticles (AgNPs) by using black walnut (Juglans negia L.) leaf extract from Iran through a rapidly and ecofriendly ultrasound-assisted method and stirring-assisted method. The synthesized AgNPs by two methods were characterized by different techniques such as Transmission Electron Microscopy (TEM), Scanning Electron Microscope (SEM), and UV–VIS Spectroscopy, FTIR, X-Ray Diffraction (XRD). The antimicrobial activities of both synthesized silver nanoparticles by two methods and also Juglans negia L. leaf extract were determined against four gram negative and two gram positive bacteria by well diffusion method and the Minimum Inhibitory Concentration test (MIC) and the results were comparable. The minimum inhibitory concentrations were achieved for biosynthesized AgNPs with assisted ultrasound method against two gram-negative bacteria E. coli and S. typhimurium (both 8 mg/mL). However, total phenols and flavonoids content of Juglans negia L. leaves extract were also determined. Additionally, the antioxidant activity was evaluated based on 2,2-diphenyl-1-picryl-hydrazyl (DPPH). Total phenols were 78.82±6.83 mg/g gallic acid equivalent, and total flavonoids were 446.23±2.32 mg/g rutin equivalent, and antioxidant capacity was 127.26±0.04 mg/g IC50.