Biogenic synthesis of iron nanoparticles using Amaranthus dubius leaf extract as a reducing agent

Formulation and evaluation of azithromycin-loaded silver nanoparticles for the treatment of infected wounds

Infected wounds pose a significant challenge in healthcare, requiring innovative therapeutic strategies. Therefore, there is a critical need for innovative pharmaceutical materials to improve wound healing and combat bacterial growth. This study examined the efficacy of azithromycin-loaded silver nanoparticles (AZM-AgNPs) in treating infected wounds. AgNPs synthesized using a green method with Quinoa seed extract were loaded with AZM. Characterization techniques, including X-ray Powder Diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Uv-Vis analysis were utilized. The agar diffusion assay and determination of the MIC were used to assess the initial antibacterial impact of the formulations on both MRSA and E. coli. In addition, the antimicrobial, wound-healing effects and histological changes following treatment with the AZM-AgNPs were assessed using an infected rat model. The nanoparticles had size of 24.9 ± 15.2 nm for AgNPs and 34.7 ± 9.7 nm for AZM-AgNPs. The Langmuir model accurately characterized the adsorption of AZM onto the AgNP surface, indicating a maximum loading capacity of 162.73 mg/g. AZM-AgNPs exhibited superior antibacterial properties in vivo and in vitro compared to controls. Using the agar diffusion technique, AZM-AgNPs showed enhanced zones of inhibition against E. coli and MRSA, which was coupled with decreased MIC levels. In addition, in vivo studies showed that AZM-AgNP treated rats had the best outcome characterized by improved healing process, lower bacterial counts and superior epithelialization, compared to the control group. In conclusion, AZM-AgNPs can be synthesized using a green method with Quinoa seed with successful loading of azithromycin onto silver nanoparticles. In vitro and in vivo studies suggest the promising use of AZM-AgNPs as an effective therapeutic agent for infected wounds.

Effects of Salts and Other Contaminants on Ciprofloxacin Removal Efficiency of Green Synthesized Copper Nanoparticles

Ciprofloxacin (CIP), a broad-spectrum fluoroquinolone antibiotic, is commonly used in aquaculture to prevent and treat bacterial infections in aquatic animals. For this reason, aquatic environments contain CIP and its derivatives, which lead to the development of drug-resistant bacteria. In the present study, copper nanoparticles were prepared using Garcinia mangostana extract (GME-CuNPs) as a reducing agent and evaluated for their CIP removal efficiency (CRE). The results demonstrate that within 20 min, GME-CuNPs at 25 mM possess a CRE of 92.02 ± 0.09% from CIP-containing aqueous media with pH 6-7. The CRE is influenced by both monovalent and divalent salts. A high salt concentration significantly reduces the CRE. Contaminants in fish wastewater can reduce the CRE, but phenolics, flavonoids, tannins, and ammonia do not affect the CRE. Our results reveal that the CRE is controlled by electrostatic attraction between the negatively charged GME-CuNPs and the cationic species of CIP. The CRE is reduced by wastewater with a pH higher than 8.0, in which the CIP molecules have a negative charge, resulting in a repulsive force due to the negative charge of GME-CuNPs. In fish wastewater with a pH lower than 7.0, GME-CuNPs show the potential to achieve a CRE above 80%. Therefore, pH adjustment to a range of 6-7 in fish wastewater before treatment is deemed imperative. It is concluded that the newly developed GME-CuNPs possess excellent activity in CIP elimination from actual fish wastewater samples. Our findings suggest that GME-CuNPs can be a promising tool to effectively eliminate antibiotics from the environment.

Characteristics and Antimicrobial Activities of Iron Oxide Nanoparticles Obtained via Mixed-Mode Chemical/Biogenic Synthesis Using Spent Hop (Humulus lupulus L.) Extracts

Iron oxide nanoparticles (IONPs) have many practical applications, ranging from environmental protection to biomedicine. IONPs are being investigated due to their high potential for antimicrobial activity and lack of toxicity to humans. However, the biological activity of IONPs is not uniform and depends on the synthesis conditions, which affect the shape, size and surface modification. The aim of this work is to synthesise IONPs using a mixed method, i.e., chemical co-precipitation combined with biogenic surface modification, using extracts from spent hops (Humulus lupulus L.) obtained as waste product from supercritical carbon dioxide hop extraction. Different extracts (water, dimethyl sulfoxide (DMSO), 80% ethanol, acetone, water) were further evaluated for antioxidant activity based on the silver nanoparticle antioxidant capacity (SNPAC), total phenolic content (TPC) and total flavonoid content (TFC). The IONPs were characterised via UV-vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and Fourier-transform infrared (FT-IR) spectroscopy. Spent hop extracts showed a high number of flavonoid compounds. The efficiency of the solvents used for the extraction can be classified as follows: DMSO > 80% ethanol > acetone > water. FT-IR/ATR spectra revealed the involvement of flavonoids such as xanthohumol and/or isoxanthohumol, bitter acids (i.e., humulones, lupulones) and proteins in the surface modification of the IONPs. SEM images showed a granular, spherical structure of the IONPs with diameters ranging from 81.16 to 142.5 nm. Surface modification with extracts generally weakened the activity of the IONPs against the tested Gram-positive and Gram-negative bacteria and yeasts by half. Only the modification of IONPs with DMSO extract improved their antibacterial properties against Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, Enterococcus faecalis, Bacillus cereus) from a MIC value of 2.5-10 mg/mL to 0.313-1.25 mg/mL.

Natural waste-derived nano photocatalysts for azo dye degradation

Due to their widespread application in water purification, there is a significant interest in synthesising nanoscale photocatalysts. Nanophotocatalysts are primarily manufactured through chemical methods, which can lead to side effects like pollution, high-energy usage, and even health issues. To address these issues, "green synthesis" was developed, which involves using plant extracts as reductants or capping agents rather than industrial chemical agents. Green fabrication has the benefits of costs less, pollution reduction, environmental protection and human health safety, compared to the traditional methods. This article summarises recent advances in the environmentally friendly synthesis of various nanophotocatalysts employed in the degradation of azo dyes. This study compiles critical findings on natural and artificial methods to achieve the goal. Green synthesis is constrained by the time and place of production and issues with low purity and poor yield, reflecting the complexity of plants' geographical and seasonal distributions and their compositions. However, green photocatalyst synthesis provides additional growth opportunities and potential uses.

Effects of plant-based copper nanoparticles on the elimination of ciprofloxacin

Ciprofloxacin (CIP) is frequently detected in the environment and causes the emergence of drug-resistant bacteria. High levels of CIP in the environment are also harmful to humans and animals. Therefore, effective elimination of CIP is required. In this study, plant-based copper nanoparticles (CuNPs) have been fabricated for the purpose of eliminating CIP. Aqueous extracts of 6 plants were compared for their phytochemicals and reducing activity. Among all the extracts, Garcinia mangostana extract (GM) was the most potent with the highest total phenolic compounds, flavonoids, tannins, terpenoids, and reducing activity. CuNPs synthesized using GM (GM-CuNPs) were characterized using UV-VIS spectroscopy and dynamic light scattering. The results showed that the maximum absorption of GM-CuNPs was at 340 nm. The average size of GM-CuNPs is in the nanoscale range of 159.2 ± 61 nm, with a narrow size distribution and a negative zeta potential of - 4.13 ± 6.97 mV. The stability of GM-CuNPs is not solely due to their zeta potential but also phytochemicals in the extract. GM-CuNPs at 25 mM showed the highest efficiency of 95% in removing CIP from aqueous medium pH 6-7 at 25-35°C within 20 min. The results indicated that the electrostatic attraction between the negative charge of GM-CuNPs and the positive charge of CIP controlled the drug adsorption on the nanoparticles. In conclusion, the developed GM-CuNPs have excellent CIP removal efficiency. These synthesized GM-CuNPs are expected to be environmentally friendly for the removal of antibiotics and other drugs.

Green synthesized Ag nanoparticles stimulate gene expression and paclitaxel production in Corylus avellana cells

Synthesis of nanoparticles (NPs) through plant extracts has been suggested as an effective and nature-friendly method. Paclitaxel is one of the most valuable secondary metabolites with therapeutic uses, and hazelnut has been suggested as one of the sustainable resources for producing this metabolite. In the present study, we synthesized Ag NPs using the ethanolic extract of C. avellana leaves and were characterized using UV-visible, FTIR, XRD, EDX, DLS, SEM, and TEM analyses. In addition, we investigated the effect of green synthesized Ag (GS Ag) NPs (5 and 10 mg/L), para-aminobenzoic acid (PABA) (20 mg/L), and AgNO3 (10 mg/L) on cell viability, physiological characteristics, gene expression, and biosynthesis of secondary metabolites in hazelnut cell cultures. The results showed that 10 mg/L Ag NPs and AgNO3 significantly affected the cell viability, the content of ROS, peroxidation of lipids, antioxidant capacity, secondary metabolite production, and expression pattern of the genes involved in the taxanes biosynthesis pathway in the hazelnut cells. The cytotoxicity increased by increasing the GS Ag NPs concentration from 5 to 10 mg/L, which was associated with reduced membrane integrity and cell viability. Elicitation of the cells with 10 mg/L Ag NPs combined with 20 mg/L PABA (as a precursor) remarkably excited the expression of TAT and GGPPS genes and the production of secondary metabolites as well as paclitaxel. So that the highest expression of TAT and GGPPS genes (3.71 and 3.69) and the highest amount of taxol (230.21 μg g-1 FW) and baccatin (1025.8 μg g-1 FW) were observed in this treatment. KEY POINTS: • For the first time, we assessed and reported the molecular and physiological responses of C. avellana cells to GS Ag NPs, AgNO3, and PABA. • In hazel cells, GS Ag NPs stimulate several physiological and molecular responses. • In addition to increasing antioxidant activity, GS Ag NPs significantly increased the expression of genes involved in the paclitaxel biosynthesis pathway and the production of secondary metabolites.

Sustainable and Green Synthesis of Iron Nanoparticles Supported on Natural Clays via Palm Waste Extract for Catalytic Oxidation of Crocein Orange G Mono Azoic Dye

In this study, the removal of Crocein Orange G dye (COG) from aqueous solution was investigated using an innovative green catalyst to overcome problems with chemical techniques. Clay bentonite El Hamma (HB)-supported nanoscale zero-valent iron (NZVI) was used as a heterogeneous Fenton-like catalyst for the oxidation of harmful COG. Palm waste extract was herein used as a reducing and capping agent to synthesize NZVI, and HB clay was employed, which was obtained from the El Hamma bentonite deposit in the Gabes province of Tunisia. HB and HB-NZVI were characterized by various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer, Emmett, and Teller (BET), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential. Under optimal conditions, total degradation of COG was attained within 180 min. Kinetic studies showed that the dye degradation rate followed well the pseudo-second-order model. The apparent activation energy was 33.11 kJ/mol, which is typical of a physically controlled reaction. The degradation pathways and mineralization study revealed that the adsorption-Fenton-like reaction was the principal mechanism that demonstrated 100% degradation efficiency of COG even after three successive runs. Obtained results suggest that HB-NZVI is an affective heterogeneous catalyst for the degradation of COG by H2O2 and may constitute a sustainable green catalyst for azoic dye removal from industrial wastewaters.

Biocatalysis as a Green Approach for Synthesis of Iron Nanoparticles—Batch and Microflow Process Comparison

There is a growing need for production of iron particles due to their possible use in numerous systems (e.g., electrical, magnetic, catalytic, biological and others). Although severe reaction conditions and heavy solvents are frequently used in production of nanoparticles, green synthesis has arisen as an eco-friendly method that uses biological catalysts. Various precursors are combined with biological material (such as enzymes, herbal extracts, biomass, bacteria or yeasts) that contain chemicals from the main or secondary metabolism that can function as catalysts for production of nanoparticles. In this work, batch (“one-pot”) biosynthesis of iron nanoparticles is reviewed, as well as the possibilities of using microfluidic systems for continuous biosynthesis of iron nanoparticles, which could overcome the limitations of batch synthesis.

Bioinorganic Nanoparticles for the Remediation of Environmental Pollution: Critical Appraisal and Potential Avenues

Nowadays, environmental pollution has become a critical issue for both developed and developing countries. Because of excessive industrialization, burning of fossil fuels, mining and exploration, extensive agricultural activities, and plastics, the environment is being contaminated rapidly through soil, air, and water. There are a variety of approaches for treating environmental toxins, but each has its own set of restrictions. As a result, various therapies are accessible, and approaches that are effective, long-lasting, less harmful, and have a superior outcome are extensively demanded. Modern research advances focus more on polymer-based nanoparticles, which are frequently used in drug design, drug delivery systems, environmental remediation, power storage, transformations, and other fields. Bioinorganic nanomaterials could be a better candidate to control contaminants in the environment. In this article, we focused on their synthesis, characterization, photocatalytic process, and contributions to environmental remediation against numerous ecological hazards. In this review article, we also tried to explore their recent advancements and futuristic contributions to control and prevent various pollutants in the environment.

Green Synthesis of Α-Fe2O3 from Ginger Extract Enhanced the Potential Antioxidant Activity Against DPPH

Synthesis of nano-oxides in an easy and environmentally friendly way using simple and green materials is one of the hot interests of sustainable chemistry for lots of pharmaceutical and medical applications. Herein, we synthesized α-Fe2O3 nanoparticles (α-Fe2O3 NPs) using ginger extract after that calcination at 400 C° for 4 h. The prepared α-Fe2O3 nanoparticles were examined using ultraviolet-visible reflection spectroscopy (UV-VIS), Fourier Transform Infrared Spectroscopy (FTIR), photoluminescence spectroscopy (PL), X-ray diffraction (XRD), field emission scanning microscopy (FE-SEM), energy-dispersive X-ray (EDX) spectroscopy, and zeta potential. After well characterizations, the potency of the prepared α-Fe2O3 nanoparticles to monitor some scavenging activity was explored against DPPH. Results revealed that PL intensity has one peak in the UV region between (480-490) nm of the spectrum depending on the geometric shape and size of the α-Fe2O3 NPS. The UV-visible spectra showed a peak at 296.0 nm, which represented the α-Fe2O3 NPs. The EDX micrograph confirmed pure oxide and the XRD pattern showed that the α-Fe2O3 NPs had an average crystal size (19.3) nm. SEM images of α-Fe2O3 NPs revealed spherical, rod, and irregular shapes and sizes ranging from (15 to 60) nm. Moreover, the antioxidant activity of α-Fe2O3 NPs against DPPH showed 51.8% free radical scavenging ability at 360 μg/mL, which approved good evidence of the antioxidant activity of α-Fe2O3 NPs.

Cefotaxime removal enhancement via bio-nanophotocatalyst α-Fe2O3 using photocatalytic degradation technique and its echo-biomedical applications

The present paper evaluates the photocatalytic degradation (PCD) performance of the biofabricated hematite nanoparticles (α-HNPs) for the degradation approach of the Cefotaxime (Cfm). The optimum pH of the solution to achieve the best PCD was found to be 10.5. The kinetics study for the PCD of the Cfm via α-HNPs has been investigated and the reaction was found to be fellow pseudo-first-order at R² = 0.992. The mass loading impact of α-HNPs was investigated and estimated for the maximum degradation of Cfm 0.4 mg/mL. UV–Vis confirmed that α-HNPs had a direct transition bandgap at 3.78 eV at a maximum absorption wavelength of 362 nm with suspension stability for 7 days. The probable mechanism of the Cfm PCD via α-HNPs and the degradation pathway was conducted. The validation of the suspension stability of the α-HNPs (−68.6 ± 11.8 mV) was determined using the zeta potential investigation test. XRD investigation was conducted after Cfm PCD showing an average crystallite size of 27.0 nm. XRD, TEM, SEM, EDX, and FT-IR analyses have been conducted for the α-HNPs before and after Cfm PCD confirming the high efficiency for the reusability of the current biocatalyst α-HNPs for further use. TEM results of the particle sizes of α-HNPs were found at 19.2 ± 4.4 and 20.6 ± 7.4 nm respectively before and after Cfm PCD. The efficiency of the Cfm PCD was found to be 99.1% after 6 h. High potent as an antibacterial agent of α-HNPs was investigated either α-HNPs alone or after its PCD activity against Cfm. The antibacterial activity revealed high sensitivity, especially toward Gram-positive species indicating its promising ability against pathogenic issues. Interestingly, Cfm@α-HNPs showed superior anti-proliferative activity as tested by MTT assay and were able to induce apoptosis in MCF7 and HepG2 cell lines using the flow cytometry technique at 20.7% and 17% respectively. Also, The IC₅₀ of hydrogen peroxide scavenging was estimated and it was manifested that 635.8 and 665.6 μg/mL of α-HNPs before and after the PCD process of Cfm respectively.

Antiviral potential of nanoparticles for the treatment of Coronavirus infections

BACKGROUND

On 31st December 2019 in Wuhan, China, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was acknowledged. This virus spread quickly throughout the world causing a global pandemic. The World Health Organization declared COVID-19 a pandemic disease on 11th March 2020. Since then, the whole world has come together and have developed several vaccines against this deadly virus. Similarly, several alternative searches for pandemic disease therapeutics are still ongoing. One of them has been identified as nanotechnology. It has demonstrated significant promise for detecting and inhibiting a variety of viruses, including coronaviruses. Several nanoparticles, including gold nanoparticles, silver nanoparticles, quantum dots, carbon dots, graphene oxide nanoparticles, and zinc oxide nanoparticles, have previously demonstrated remarkable antiviral activity against a diverse array of viruses.

OBJECTIVE

This review aims to provide a basic and comprehensive overview of COVID-19's initial global outbreak and its mechanism of infiltration into human host cells, as well as the detailed mechanism and inhibitory effects of various nanoparticles against this virus. In addition to nanoparticles, this review focuses on the role of several antiviral drugs used against COVID-19 to date.

CONCLUSION

COVID-19 has severely disrupted the social and economic lives of people all over the world. Due to a lack of adequate medical facilities, countries have struggled to maintain control of the situation. Neither a drug nor a vaccine has a 100% efficacy rate. As a result, nanotechnology may be a better therapeutic alternative for this pandemic disease.

Sustainable Green Nanotechnologies for Innovative Purifications of Water: Synthesis of the Nanoparticles from Renewable Sources

Polluting the natural water resources is a serious global issue, which is confirmed by the fact that today at least 2 billion people consume water from contaminated sources. The conventional wastewater treatment methods cannot effectively remove the persistent pollutants (e.g., drugs, organic dyes, pesticides) from the aqueous environment. Heterogeneous photocatalysis is a promising and sustainable alternative for water remediation. It is based on the interaction between light irradiation and the semiconductors (e.g., TiO₂, ZnO) as photocatalysts, but these compounds, unfortunately, have some disadvantages. Hence, great attention has been paid to the nanotechnology as a possible way of improvement. Nanomaterials have extraordinary properties; however, their conventional synthesis is often difficult and requires a significant amount of dangerous chemicals. This concise topical review gives recent updates and trends in development of sustainable and green pathways in the synthesis of nanomaterials, as well as in their application for water remediation. In our review we put emphasis on the eco-friendly, mostly plant extract-based materials. The importance of this topic, including this study as well, is proved by the growing number of publications since 2018. Due to the current serious environmental issues (e.g., global warming, shortage of pure and quality water), it is necessary for the traditional TiO₂ and ZnO semiconductors to be replaced with the harmless, non-toxic, and more powerful nanocomposites as photocatalysts. Not only because of their higher efficiency as compared to the bulk semiconductors, but also because of the presence of biomolecules that can add up to the pollutant removal efficiency, which has been already confirmed in many researches. However, despite the fact that the application of heterogeneous photocatalysis together with green nanotechnology is absolutely the future in water purification, there are some challenges which have to be overcome. The exact effects of the biomolecules obtained from plants in the synthesis of nanoparticles, as well as in the photocatalytic processes, are not exactly known and require further investigation. Furthermore, heterogeneous photocatalysis is a well-known and commonly examined process; however, its practical use outside the laboratory is expensive and difficult. Thus, it has to be simplified and improved in order to be available for everyone. The aim of our review is to suggest and prove that using these bio-inspired compounds it is possible to reduce human footprint in the nature.

A Review on Silver Nanoparticles: Classification, Various Methods of Synthesis, and Their Potential Roles in Biomedical Applications and Water Treatment

Recent developments in nanoscience have appreciably modified how diseases are prevented, diagnosed, and treated. Metal nanoparticles, specifically silver nanoparticles (AgNPs), are widely used in bioscience. From time to time, various synthetic methods for the synthesis of AgNPs are reported, i.e., physical, chemical, and photochemical ones. However, among these, most are expensive and not eco-friendly. The physicochemical parameters such as temperature, use of a dispersing agent, surfactant, and others greatly influence the quality and quantity of the synthesized NPs and ultimately affect the material’s properties. Scientists worldwide are trying to synthesize NPs and are devising methods that are easy to apply, eco-friendly, and economical. Among such strategies is the biogenic method, where plants are used as the source of reducing and capping agents. In this review, we intend to debate different strategies of AgNP synthesis. Although, different preparation strategies are in use to synthesize AgNPs such as electron irradiation, optical device ablation, chemical reduction, organic procedures, and photochemical methods. However, biogenic processes are preferably used, as they are environment-friendly and economical. The review covers a comprehensive discussion on the biological activities of AgNPs, such as antimicrobial, anticancer anti-inflammatory, and anti-angiogenic potentials of AgNPs. The use of AgNPs in water treatment and disinfection has also been discussed in detail.

Antioxidants: Classification, Natural Sources, Activity/Capacity Measurements, and Usefulness for the Synthesis of Nanoparticles

Natural extracts are the source of many antioxidant substances. They have proven useful not only as supplements preventing diseases caused by oxidative stress and food additives preventing oxidation but also as system components for the production of metallic nanoparticles by the so-called green synthesis. This is important given the drastically increased demand for nanomaterials in biomedical fields. The source of ecological technology for producing nanoparticles can be plants or microorganisms (yeast, algae, cyanobacteria, fungi, and bacteria). This review presents recently published research on the green synthesis of nanoparticles. The conditions of biosynthesis and possible mechanisms of nanoparticle formation with the participation of bacteria are presented. The potential of natural extracts for biogenic synthesis depends on the content of reducing substances. The assessment of the antioxidant activity of extracts as multicomponent mixtures is still a challenge for analytical chemistry. There is still no universal test for measuring total antioxidant capacity (TAC). There are many in vitro chemical tests that quantify the antioxidant scavenging activity of free radicals and their ability to chelate metals and that reduce free radical damage. This paper presents the classification of antioxidants and non-enzymatic methods of testing antioxidant capacity in vitro, with particular emphasis on methods based on nanoparticles. Examples of recent studies on the antioxidant activity of natural extracts obtained from different species such as plants, fungi, bacteria, algae, lichens, actinomycetes were collected, giving evaluation methods, reference antioxidants, and details on the preparation of extracts.

Radical Scavenging and Catalytic Activity of Fe-Cu Bimetallic Nanoparticles Synthesized from Ixora finlaysoniana Extract

Iron–copper bimetallic nanoparticles (Fe-Cu BNPs) were prepared via a green synthesis route. Ixora finlaysoniana has been used in this study as a capping and stabilizing agent in the modification of Fe-Cu BNPs. As-synthesized BNPs were characterized using different techniques including UV/Vis spectrophotometry, FTIR, XRD and SEM. A particle size analyzer and SEM studies indicated the particle size to be in the range of 50–200 nm. In addition, degradation of MB dye in an aqueous system and radical-scavenging potential in a DPPH assay were also examined using BNPs. Methylene blue dye degradation in 17 min was monitored with UV/Vis spectrophotometry, which exhibited the efficiency of Fe-Cu BNPs. Bimetallic nanoparticles were also found to be efficient in neutralizing DPPH free radicals. Furthermore, kinetic studies of both dye degradation and radical scavenging potential are reported in this article. Subsequently, Fe-Cu BNPs synthesized via a green and sustainable method can be employed for dye degradation and free radical-scavenging activities.

Potential of Gum Arabic Functionalized Iron Hydroxide Nanoparticles Embedded Cellulose Paper for Packaging of Paneer

Recently, the interest of scientists has turned towards eco-friendly metal nanoparticles due to their distinctive physicochemical properties that have been used in several biochemical and food applications, including drug and bioactive component delivery, sensing of food pathogenic bacteria, imaging techniques, and theranostics. Therefore, this study aimed to fabricate gum arabic stabilized iron hydroxide nanoparticles (IHNPs) using the co-precipitation process and to develop nanoparticles decorated antimicrobial cellulose paper. The agglomeration of IHNPs is a major concern, therefore, the varied concentration (0.25-2.0%) of gum arabic was used to functionalize and stabilize the nanoparticles, and based on UV-visible spectroscopy and particle size analysis, 1% gum arabic concentration was screened out. Scanning electron microscopy displayed polygonal disc shapes of IHNPs that had sides of approximately equal lengths. Energy dispersive spectroscopy was used to determine the purity of the IHNPs and results illustrated the elemental iron peak at 0.8 keV and 6.34 keV. For thermal stability, differential scanning calorimetry (DSC) was employed, and the glass transition temperature was observed at 138.50 °C with 138.31 °C onset and 147.14 °C endset temperature, respectively. Functionalized IHNPs showed a significantly (p < 0.05) higher zone of inhibition against S. aureus (29.63 mm) than that of E. coli and were found to be non-toxic to Caco-2 cells during cell viability assay. Time-kill kinetics showed that cellulose paper embedded with nanoparticles possessed excellent antibacterial activity against S. aureus. To explore the food application of developed cellulose paper, citric acid coagulated dairy product (Paneer), similar to cottage cheese was formulated, and it was evaluated for its microbial shelf life. The unwrapped sample showed higher microbial load during the fourth day of the storage. However, both wrapped samples were acceptable till the 10th of storage.

A review of green methods for phyto-fabrication of hematite (α-Fe2O3) nanoparticles and their characterization, properties, and applications

The aim of the current work is the introduction of a quick and simple literature survey about the bio-fabrication of the Alpha Hematite nanoparticles (α-Fe₂O₃) using the plant extracts green method. The survey manifested the utilities of the environmentally friendly biosynthesis methods via extracting different plant species, some of its important physicochemical properties, various instrumental analysis characterization tools, and potential applications.

Green-synthesized nanocatalysts and nanomaterials for water treatment: Current challenges and future perspectives

Numerous hazardous environmental pollutants in water bodies, both organic and inorganic, have become a critical global issue. As greener and bio-synthesized versions of nanoparticles exhibit significant promise for wastewater treatment, this review discusses trends and future prospects exploiting the sustainable applications of green-synthesized nanocatalysts and nanomaterials for the removal of contaminants and metal ions from aqueous solutions. Recent trends and challenges about these nanocatalysts and nanomaterials and their potential applications in wastewater treatment and water purification are highlighted including toxicity and biosafety issues. This review delineates the pros and cons and critical issues pertaining to the deployment of these nanomaterials endowed with their superior surface area, mechanical properties, significant chemical reactivity, and cost-effectiveness with low energy consumption, for removal of hazardous materials and contaminants from water; comprehensive coverage of these materials for industrial wastewater remediation, and their recovery is underscored by recent advancements in nanofabrication, encompassing intelligent and smart nanomaterials.

Cd(II) and Pb(II) Adsorption Using a Composite Obtained from Moringa oleifera Lam. Cellulose Nanofibrils Impregnated with Iron Nanoparticles

This work informs on the green synthesis of a novel adsorbent and its adsorption capacity. The adsorbent was synthesized by the combination of iron nanoparticles and cellulose nanofibers (FeNPs/NFCs). Cellulose nanofibers (NFCs) were obtained from Moringa (Moringa oleifera Lam.) by a pulping Kraft process, acid hydrolysis, and ultrasonic methods. The adsorption method has advantages such as high heavy metal removal in water treatment. Therefore, cadmium (Cd) and lead (Pb) adsorption with FeNP/NFC from aqueous solutions in batch systems was investigated. The kinetic, isotherm, and thermodynamic parameters, as well as the adsorption capacities of FeNP/NFC in each system at different temperatures, were evaluated. The adsorption kinetic data were fitted to mathematical models, so the pseudo-second-order kinetic model described both Cd and Pb. The kinetic rate constant (K2), was higher for Cd than for Pb, indicating that the metal adsorption was very fast. The adsorption isotherm data were best described by the Langmuir–Freundlich model for Pb multilayer adsorption. The Langmuir model described Cd monolayer sorption. However, experimental maximum adsorption capacities (qe exp) for Cd (>12 mg/g) were lower than those for Pb (>80 mg/g). In conclusion, iron nanoparticles on the FeNP/NFC composite improved Cd and Pb selectivity during adsorption processes, indicating the process’ spontaneous and exothermic nature.

Critical analysis of biophysicochemical parameters for qualitative improvement of phytogenic nanoparticles

Conventional chemical approaches for synthesizing nanoparticles (NPs) may restrict their applicability as they are not eco-friendly, energetically efficient and often involve toxic reducing/capping agents; but phytonanotechnology enabled the synthesis of safe, inexpensive, highly biocompatible NPs. In this regard, thorough understanding of green components and the modulatory effects of different reaction conditions on the physicochemical parameters of green synthesized NPs would be a prerequisite, which is not depicted elsewhere. This review critically analyzes the relevant reaction conditions from their mechanistic viewpoints in plant-based synthesis of NPs arising fundamental issues which need to be determined carefully. The size, stability and surface chemistry of phytogenic NPs may be fabricated as a function of multiple interconnected reaction parameters and the plant species used. The therapeutic potential of phytogenic NPs may depend on the plant species used; and so the meticulous understanding of physicochemical parameters and the family wise shorting of elite plant species may potentially benefit the theranostic future of plant-based NPs.

Green synthesis and environmental application of iron-based nanomaterials and nanocomposite: A review

Green chemistry has been proven to be an efficient route for nanoparticle synthesis. Plant extract based green synthesis of various nanoparticles is extensively studied since the last decade. This paper "Green synthesis and environmental application of Iron-based nanomaterials and nanocomposite: A review" unveils all the possible greener techniques for the synthesis of iron-based nanoparticles and nanocomposites. The use of different plant sources, microorganisms, and various biocompatible green reagents such as biopolymers, cellulose, haemoglobin, and glucose for the synthesis of iron nanoparticles reported in the last decade are summarized. The microwave method, along with hydrothermal synthesis due to their lower energy consumption are also been referred to as a green route. Apart from different plant parts, waste leaves and roots used for the synthesis of iron nanoparticles are extensively briefed here. This review is thus compact in nature which covers all the broad areas of green synthesis of iron nanoparticles (NPs) and iron-based nanocomposites. Detailed discussion on environmental applications of the various green synthesized iron NPs and their composites with performance efficiency is provided in this review article. The advantages of bimetallic iron-based nanocomposites over iron NPs in various environmental applications are discussed in detail. The hazards and toxic properties of green synthesized iron-based NPs are compared with those obtained from chemical methods. The prospects and challenges section of this article provides a vivid outlook of adapting such useful technique into a more versatile process with certain inclusions which may encourage and provide a new direction to future research.

Antioxidant Functionalized Nanoparticles: A Combat against Oxidative Stress

Numerous abiotic stresses trigger the overproduction of reactive oxygen species (ROS) that are highly toxic and reactive. These ROS are known to cause damage to carbohydrates, DNA, lipids and proteins, and build the oxidative stress and results in the induction of various diseases. To resolve this issue, antioxidants molecules have gained significant attention to scavenge these free radicals and ROS. However, poor absorption ability, difficulty in crossing the cell membranes and degradation of these antioxidants during delivery are the few challenges associated with both natural and synthetic antioxidants that limit their bioavailability. Moreover, the use of nanoparticles as an antioxidant is overlooked, and is limited to a few nanomaterials. To address these issues, antioxidant functionalized nanoparticles derived from various biological origin have emerged as an important alternative, because of properties like biocompatibility, high stability and targeted delivery. Algae, bacteria, fungi, lichens and plants are known as the producers of diverse secondary metabolites and phenolic compounds with extraordinary antioxidant properties. Hence, these compounds could be used in amalgamation with biogenic derived nanoparticles (NPs) for better antioxidant potential. This review intends to increase our knowledge about the antioxidant functionalized nanoparticles and the mechanism by which antioxidants empower nanoparticles to combat oxidative stress.

Plant extract mediated synthesis enhanced the functional properties of silver ferrite nanoparticles over chemical mediated synthesis

In this study, the antibacterial, antioxidant and cytotoxicity behaviour of silver ferrite nanoparticles (AgFeO2 NPs) synthesized through chemical and green routes were compared. Green synthesis (Bio) of AgFeO2 NPs were prepared by precipitation method using Amaranthus blitum leaves extract as a reducing agent. Chemical synthesis (Che) of AgFeO2 NPs was mediated by sodium borohydride as a reducing agent. [AgFeO2 (Bio)] NPs showed reduced size, better monodispersity and surface area compared to [AgFeO2 (Che)] NPs. The results showed that synthesized NPs have better antibacterial activity against E. coli than S. aureus. In addition, 250 μg of AgFeO2 (Bio) and (Che) NPs showed antioxidant efficiency of 98 and 86%. The results showed that [AgFeO2 (Bio)] NPs showed lower cytotoxicity [AgFeO2 (Che)] NPs against human human embryonic kidney (HEK 293) cells. These results suggest that [AgFeO2 (Bio)] NPs have improved physicochemical properties thereby they can be used as an effective biocatalytic material in biotechnology.

Bacteria-assisted biogreen synthesis of radical scavenging exopolysaccharide-iron complexes: an oral nano-sized nutritional supplement with high in vivo compatibility

Microbial exopolysaccharides (EPSs) have recently served as an efficient substrate for the production of biocompatible metal nanoparticles (NPs) given their favorable stabilizing and reducing properties due to the presence of polyanionic functional groups in their structure. In the present work, Pantoea sp. BCCS 001 GH was used to produce EPS-stabilized biogenic Fe NPs as a complex through a novel biosynthesis reaction. Physicochemical characterization of the EPS-Fe complex was performed, indicating high thermal stability, desirable magnetic properties due to the uniform distribution of the Fe NPs with the average size of ∼10 nm and spherical shape within the EPS matrix. In addition, the in vivo toxicity of the EPS-stabilized Fe NPs was evaluated to investigate their potential for the treatment of iron deficiency anemia. Biological blood parameters and organ histology studies confirmed very high safety of the biosynthesized composite, making EPS-Fe a suitable candidate with an economical and environment friendly synthesis method for a wide spectrum of potential fields in medicine.

Novelty of Bioengineered Iron Nanoparticles in Nanocoated Surgical Cotton: A Green Chemistry

The current focus of nanotechnology is to develop environmentally safe methodologies for the formulation of nanoparticles. The phytochemistry of Zingiber officinale inspired us to utilize it for the synthesis of iron nanoparticles. GC-MS analysis revealed the phytochemical profile of ginger. Out of 20 different chemicals, gingerol was found to be the most potent phytochemical with a retention time of 40.48 min. The present study reports a rapid synthesis method for the formation of iron nanoparticles and its potential efficacy as an antibacterial agent and an antioxidant. Because of its antibacterial property, ginger extract was used to coat surgical cotton. Synthesized ginger root iron nanoparticles (GR-FeNPs) were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis, and particle size analysis. XRD confirmed the crystalline structure of iron oxide nanoparticles as it showed the crystal plane (2 2 0), (3 1 1), (2 2 2), and (4 0 0). The particle size analyzer (PSA) showed the average size of the particles, 56.2 nm. The antimicrobial activity of the FeNPs was tested against different Gram-positive and Gram-negative bacteria. E. coli showed maximum inhibition as compared with the other organisms. Antioxidant activity proved the maximum rate of free radicals at 160 µg/mL produced by nanoparticles. In addition, the antimicrobial activity of nanocoated surgical cotton was evaluated on the first day and 30^th day after coating, which clearly showed excellent growth inhibition of organisms, setting a new path in the field of medical microbiology. Hence, iron-nanocoated surgical cotton synthesized using green chemistry, which is antimicrobial and cost effective, might be economically helpful and provide insights to the medical field, replacing conventional wound healing treatments, for better prognosis.