Plant-extract mediated green approach for the synthesis of ZnONPs: Characterization and evaluation of cytotoxic, antimicrobial and antioxidant potentials

Eco-friendly synthesis of CuO/Bi2O3 nanocomposite for efficient photocatalytic degradation of rhodamine B dye

Plant-mediated synthesized materials are receiving more attention than conventional ones due to their wide availability, ease of access, simple preparation methods, environmental benign, and possess superior physicochemical properties. In this work, plant extract-mediated CuO, Bi2O3, and CuO/Bi2O3 nanocomposite samples were successfully synthesized using bamboo leaves extract as a capping agent. These materials were utilized for the photodegradation of Rhodamine B (RhB) dye, which served as a model organic dye pollutant. The physicochemical characterization techniques such as XRD, SEM-EDS, FTIR, and DRS-UV-vis spectrophotometry provide insight into the crystal structure, morphology, surface functional groups, and optical properties. These analyses confirm the effective formation of CuO, Bi2O3, and CuO/Bi2O3 materials. Surprisingly, upon calcination at 450 °C for 4 h, the color of the nanocomposite changed from pale green to gray greenish, providing evidence for the formation of the CuO in CuO/Bi2O3 nanocomposite. The photocatalytic optimization parameters such as pH (4), catalyst load (35 mg), irradiation time (180 min) and concentration of RhB (10 mg L-1) dye were investigated. By coupling CuO with Bi2O3 nanoparticles resulted in an improved photocatalytic property for the degradation of RhB dye under optimal conditions. As a result, CuO/Bi2O3 nanocomposite exhibited a significantly boosted photocatalytic degradation efficiency (95.6%) compared to pure CuO (40.2%) and Bi2O3 (80.5%) photocatalysts, with good reusability. For comparison purpose, the photocatalytic degradation of RhB dye using selected photocatalyst was evaluated under dark and sunlight systems. This eco-friendly approach holds great potential for synthesis new nanocomposite with modified properties, thereby enabling the practical application of high-efficiency photocatalysts. The plausible mechanism of the electrons and holes transfer was proposed.

Application of nanoparticles in breast cancer treatment: a systematic review

It is estimated that cancer is the second leading cause of death worldwide. The primary or secondary cause of cancer-related mortality for women is breast cancer. The main treatment method for different types of cancer is chemotherapy with drugs. Because of less water solubility of chemotherapy drugs or their inability to pass through membranes, their body absorbs them inadequately, which lowers the treatment's effectiveness. Drug specificity and pharmacokinetics can be changed by nanotechnology using nanoparticles. Instead, targeted drug delivery allows medications to be delivered to the targeted sites. In this review, we focused on nanoparticles as carriers in targeted drug delivery, their characteristics, structure, and the previous studies related to breast cancer. It was shown that nanoparticles could reduce the negative effects of chemotherapy drugs while increasing their effectiveness. Lipid-based nanocarriers demonstrated notable results in this instance, and some products that are undergoing various stages of clinical trials are among the examples. Nanoparticles based on metal or polymers demonstrated a comparable level of efficacy. With the number of cancer cases rising globally, many researchers are now looking into novel treatment approaches, particularly the use of nanotechnology and nanoparticles in the treatment of cancer. In order to help clinicians, this article aimed to gather more information about various areas of nanoparticle application in breast cancer therapy, such as modifying their synthesis and physicochemical characterization. It also sought to gain a deeper understanding of the mechanisms underlying the interactions between nanoparticles and biologically normal or infected tissues.

Sustainable fabrication of dimorphic plant derived ZnO nanoparticles and exploration of their biomedical and environmental potentialities

Although, different plant species were utilized for the fabrication of polymorphic, hexagonal, spherical, and nanoflower ZnO NPs with various diameters, few studies succeeded in synthesizing small diameter ZnO nanorods from plant extract at ambient temperature. This work sought to pioneer the ZnO NPs fabrication from the aqueous extract of a Mediterranean salt marsh plant species Limoniastrum monopetalum (L.) Boiss. and assess the role of temperature in the fabrication process. Various techniques have been used to evaluate the quality and physicochemical characteristics of ZnO NPs. Ultraviolet-visible spectroscopy (UV-VIS) was used as the primary test for formation confirmation. TEM analysis confirmed the formation of two different shapes of ZnO NPs, nano-rods and near hexagonal NPs at varying reaction temperatures. The nano-rods were about 25.3 and 297.9 nm in diameter and in length, respectively while hexagonal NPs were about 29.3 nm. The UV-VIS absorption spectra of the two forms of ZnO NPs produced were 370 and 365 nm for nano-rods and hexagonal NPs, respectively. FT-IR analysis showed Zn-O stretching at 642 cm-1 and XRD confirmed the crystalline structure of the produced ZnO NPs. Thermogravimetric analysis; TGA was also used to confirm the thermal stability of ZnO NPs. The anti-tumor activities of the two prepared ZnO NPs forms were investigated by the MTT assay, which revealed an effective dose-dependent cytotoxic effect on A-431 cell lines. Both forms displayed considerable antioxidant potential, particularly the rod-shaped ZnO NPs, with an IC50 of 148.43 µg mL-1. The rod-shaped ZnO NPs were superior candidates for destroying skin cancer, with IC50 of 93.88 ± 1 µg mL-1 ZnO NPs. Thus, rod-shaped ZnO NPs are promising, highly biocompatible candidate for biological and biomedical applications. Furthermore, both shapes of phyto-synthesized NPs demonstrated effective antimicrobial activity against various pathogens. The outcomes highlight the potential of phyto-synthesized ZnO NPs as an eco-friendly alternative for water and wastewater disinfection.

Metallic nanoparticles and treatment of cutaneous leishmaniasis: A systematic review

BACKGROUND

Cutaneous leishmaniasis (LC) is an infectious vector-borne disease caused by parasites belonging to the genus Leishmania. Metallic nanoparticles (MNPs) have been investigated as alternatives for the treatment of LC owing to their small size and high surface area. Here, we aimed to evaluate the effect of MNPs in the treatment of LC through experimental, in vitro and in vivo investigations.

METHODS

The databases used were MEDLINE/ PubMed, Scopus, Web of Science, Embase, and Science Direct. Manual searches of the reference lists of the included studies and grey literature were also performed. English language and experimental in vitro and in vivo studies using different Leishmania species, both related to MNP treatment, were included. This study was registered in PROSPERO (CRD42021248245).

RESULTS

A total of 93 articles were included. Silver nanoparticles are the most studied MNPs, and L. tropica is the most studied species. Among the mechanisms of action of MNPs in vitro, we highlight the production of reactive oxygen species, direct contact of MNPs with the biomolecules of the parasite, and release of metal ions.

CONCLUSION

MNPs may be considered a promising alternative for the treatment of LC, but further studies are needed to define their efficacy and safety.

Recent advances in the synthesis, characterization and biomedical applications of zinc oxide nanoparticles

Zinc oxide nanoparticles (ZnONPs) have become the widely used metal oxide nanoparticles and drawn the interest of global researchers due to their biocompatibility, low toxicity, sustainability and cost-effective properties. Due to their unique optical and chemical properties, it emerges as a potential candidate in the fields of optical, electrical, food packaging and biomedical applications. Biological methods using green or natural routes are more environmentally friendly, simple and less use of hazardous techniques than chemical and/or physical methods in the long run. In addition, ZnONPs are less harmful and biodegradable while having the ability to greatly boost pharmacophore bioactivity. They play an important role in cell apoptosis because they enhance the generation of reactive oxygen species (ROS) and release zinc ions (Zn2+), causing cell death. Furthermore, these ZnONPs work well in conjunction with components that aid in wound healing and biosensing to track minute amounts of biomarkers connected to a variety of illnesses. Overall, the present review discusses the synthesis and most recent developments of ZnONPs from green sources including leaves, stems, bark, roots, fruits, flowers, bacteria, fungi, algae and protein, as well as put lights on their biomedical applications such as antimicrobial, antioxidant, antidiabetic, anticancer, anti-inflammatory, antiviral, wound healing, and drug delivery, and modes of action associated. Finally, the future perspectives of biosynthesized ZnONPs in research and biomedical applications are discussed.

Biogenic Zinc Oxide Nanoparticles and Their Biomedical Applications: A Review

Nanotechnology has inscribed novel perception into the material science and one of the most extensively used nanomaterials is Zinc oxide nanoparticles (ZnO NPs) with healthcare and biomedical applications. Because of its outstanding biocompatibility, low toxicity, and low cost, ZnO NPs have become one of the most prominent metal oxide NPs in biological applications. This review highlights the different aspects of ZnO NPs, like their green synthesis as a substitute of conventional route due to avoidance of threat of hazardous, costly precursors and subsequent mostly therapeutic applications. Due to their wide bandwidth and high excitation binding energy, ZnO NPs have undergone extensive research. In addition to their potential applications as antibiotics, antioxidants, anti-diabetics, and cytotoxic agents, ZnO NPs also hold a promising future as an antiviral treatment for SARS-CoV-2. Zn has antiviral properties and may be effective against a variety of respiratory virus species, particularly SARS-CoV-2. This review includes a variety of topics, including the virus's structural properties, an overview of infection mechanism, and current COVID-19 treatments. Nanotechnology-based techniques for the prevention, diagnosis, and treatment of COVID-19 are also discussed in this review.

Green Synthesis of Zinc Oxide Nanoparticles Using Nostoc sp. and Their Multiple Biomedical Properties

Zinc oxide nanoparticles (ZnONPs) are the top candidate in the field of biological applications because of their high surface area and excellent catalytic activities. In the present study, the cyanobacteria-mediated biosynthesis of zinc oxide NPs using Nostoc sp. extract as a stabilizing, chelating, and reducing agent is reported. ZnONPs were biologically synthesized using an eco-friendly and simple technique with a minimal reaction time and calcination temperature. Various methods, including X-ray diffraction (XRD), ultraviolet spectroscopy (UV), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the biosynthesized zinc oxide NPs. XRD analysis depicted the crystalline form of zinc oxide NPs, and the Scherrer equation determined a mean crystalline size of ~28.21 nm. The SEM results reveal the spherical shape of the biosynthesized nanoparticles. Various functional groups were involved in the capping and stabilization of the zinc oxide NPs, which were confirmed by FTIR analysis. The zinc oxide NPs showed strong UV-vis absorption at 340 nm. Multiple in vitro biological applications showed significant therapeutic potential for zinc oxide NPs. Potential antimicrobial assays were reported for zinc oxide NPs via the disc-diffusion method and food poisoning method, respectively. All other activities mentioned below are described with the concentration and IC50 values. Biocompatibility with human erythrocytes and macrophages (IC50: 433 µg/mL, IC50 > 323 µg/mL) and cytotoxic properties using brine shrimps (IC50: 11.15 µg/mL) and Leishmania tropics (Amastigotes IC50: 43.14 µg mL−1 and Promastigotes IC50: 14.02 µg mL−1) were determined. Enzyme inhibition assays (protein kinase and alpha amylase) were performed and showed strong potential. Free radical scavenging tests showed strong antioxidant capacities. These results indicate that zinc oxide NPs synthesized by Nostoc sp. have strong biological applications and are promising candidates for clinical development.

Synergistic Antibacterial Proficiency of Green Bioformulated Zinc Oxide Nanoparticles with Potential Fosfomycin Synergism against Nosocomial Bacterial Pathogens

The drug resistance of bacterial pathogens causes considerable morbidity and death globally, hence there is a crucial necessity for the development of effective antibacterial medicines to address the antibacterial resistance issue. The bioprepared zinc oxide nanoparticles (ZnO-NPs) were prepared utilizing the flower extract of Hibiscus sabdariffa and then characterized using different physicochemical techniques. The antibacterial effectiveness of the bioprepared ZnO-NPs and their synergism with fosfomycin were evaluated using disk diffusion assay against the concerned pathogens. Transmission electron microscopy (TEM) investigation of the bioprepared ZnO-NPs showed that their average particle size was 18.93 ± 2.65 nm. Escherichia coli expressed the highest sensitivity to the bioinspired ZnO-NPs with a suppressive zone of 22.54 ± 1.26 nm at a concentration of 50 µg/disk, whereas the maximum synergistic effect of the bioinspired ZnO-NPs with fosfomycin was noticed against Klebsiella pneumoniae strain with synergism ratio of 100.29%. In conclusion, the bioinspired ZnO-NPs demonstrated significant antibacterial and synergistic efficacy with fosfomycin against the concerned nosocomial bacterial pathogens, highlighting the potential of using the ZnO NPs-fosfomycin combination for effective control of nosocomial infections in intensive care units (ICUs) and health care settings. Furthermore, the biogenic ZnO-NPs’ potential antibacterial action against food pathogens such as Salmonella typhimurium and E. coli indicates their potential usage in food packaging applications.

Exploring Physical Characterization and Different Bio-Applications of Elaeagnus angustifolia Orchestrated Nickel Oxide Nanoparticles

Elaeagnus angustifolia (EA) mediated green chemistry route was used for the biofabrication of NiONPs without the provision of additional surfactants and capping agents. The formation of NiONPs was confirmed using advanced different characterization techniques such as Scanning electron microscopy, UV, Fourier transmission-infrared, RAMAN, and energy dispersal spectroscopic and dynamic light scattering techniques. Further, different biological activities of EA-NiONPs were studied. Antibacterial activities were performed using five different bacterial strains using disc-diffusion assays and have shown significant results as compared to standard Oxytetracycline discs. Further, NiONPs exhibited excellent antifungal performance against different pathogenic fungal strains. The biocompatibility test was performed using human RBCs, which further confirmed that NiONPs are more biocompatible at the concentration of 7.51-31.25 µg/mL. The antioxidant activities of NiONPs were investigated using DPPH free radical scavenging assay. The NiONPs were demonstrated to have much better antioxidant potentials in terms of % DPPH scavenging (93.5%) and total antioxidant capacity (81%). Anticancer activity was also performed using HUH7 and HEP-G2 cancer cell lines and has shown significant potential with IC₅₀ values of 18.45 μg/mL and 14.84 μg/mL, respectively. Further, the NiONPs were evaluated against Lesihmania tropica parasites and have shown strong antileishmanial potentials. The EA-NiONPs also showed excellent enzyme inhibition activities; protein kinase (19.4 mm) and alpha-amylase (51%). In conclusion, NiONPs have shown significant results against different biological assays. In the future, we suggest various in vivo activities for EA-NiONPs using different animal models to further unveil the biological and biomedical potentials.

Metal nanoparticles produced by plants with antibacterial properties against Staphylococcus aureus

Staphylococcus aureus (S. aureus) is a pathogenic bacteria that causes a variety of potentially fatal infections. The emergence of antibiotic-resistant strains of S. aureus has made treatment even more difficult. In recent years, nanoparticles have been used as an alternative therapeutic agent for S. aureus infections. Among various methods for the synthesis of nanoparticles, the method utilizing plant extracts from different parts of a plant, such as root, stem, leaf, flower, seeds, etc. is gaining widespread usage. Phytochemicals present in plant extract are an inexpensive, eco-friendly, natural material that act as reducing and stabilization agent for the nanoparticle synthesis. The utilization of plant-fabricated nanoparticles against S. aureus is currently in trend. The current review discusses recent findings in the therapeutic application of phytofabricated metal-based nanoparticles against Staphylococcus aureus.

Screening of four accelerated synthesized techniques in green fabrication of ZnO nanoparticles using Willow leaf extract

Using hydro-alcoholic extract of Willow leaf, zinc oxide nanoparticles (ZnO NPs) were synthesized via four accelerated different heating methods namely, Bain-Marie heating (40 °C for 2 h), Conventional heating with stirrer (80 °C for 2 h), hydrothermal autoclave (1.5 atm and 121 °C for 15 min) and microwave irradiation (800 W and 160 °C for 3 min). Calcination process was finally completed on the obtained colloidal solutions in a furnace (350 °C for 2 h). The characteristics of the resulted ZnO NPs including particle size, grain size, crystallinity, specific surface area, morphology, photocatalytic, antioxidant bactericidal activities were estimated using X-ray diffractometry, scanning electron microscopy and Ultraviolet-visible spectroscopy techniques. Attained results indicated that among four different utilized synthetic methods, the fabricated ZnO NPs via Bain-Marie heating, had desired physico-chemical characteristics and bactericidal effect including small particle size (70 nm), high specific area (284 m2/gr), antioxidant activity (28.5%), photocatalytic activity (degradation of 50% of Methylene Blue), and bactericidal effects against Escherichia coli (clear zone diameter of 1.4 ± 0.1 cm) and Staphylococcus aureus (1.3 ± 0.1 cm).

Polyaniline-coated nanoparticles of zinc oxide and copper oxide as antifungal agents against Aspergillus parasiticus

Aspergillus parasiticus (A. parasiticus) is known for producing aflatoxins and is a major threat to the food industry. Green synthesis of nanoparticles (NPs) is a cost-effective and environment-friendly approach. A variety of NPs have been explored as antifungal agents; however, their antifungal characteristics need to be further enhanced to compete with traditional fungicides. The present work describes the green synthesis of ZnO and CuO NPs by precipitation method using aqueous leaf extract of Manilkara zapota and their surface modification through polyaniline (PANI). Still, there is no published study on the application of PANI-coated particles as antifungal agents against A. parasiticus and hence was the focus of this work. The polymer-coated NPs were synthesized, characterized, and investigated for their antifungal properties against A. parasiticus. Textural and structural characterization of PANI-coated and non-coated ZnO and CuO NPs were confirmed through FT-IR, SEM, and XRD techniques. The PANI-coated NPs presented higher fungal growth inhibition (%) as compared to the non-coated ones. The maximum inhibition of 77 ± 2% (n = 3) was shown by PANI/ZnO NPs at a concentration of 12 mmol L^-1 and 72 h of incubation. The non-coated NPs presented a lower inhibition rate with respect to their coated NPs, thus justifying the role of polymeric coating in improving antifungal efficiency.

Phytochemistry, biological activities and in silico molecular docking studies of Oxalis pes-caprae L. compounds against SARS-CoV-2

Phytochemicals are directly involved in therapeutic treatment or precursors to synthesize useful drugs. The current study was aimed to evaluate the phytocompounds and their biopotentials using methanolic and n-hexane extracts of various parts of Oxalis pes-caprae. For the phytochemical analysis, standard procedures were used, whereas Aluminum Chloride reagent and Follin-ciocalteau reagent methods were used to determine total flavonoid and phenolic contents. Radical scavenging DPPH, phosphomolybdenum reduction, and reducing power assays were used to assess antioxidative potentials. Antibacterial potential was determined by applying disc diffusion method while cytotoxicity was determined employing brine shrimp assay. FT-IR (Fourier-transform infrared) analysis was utilized to gather spectral information, while molecular docking tools were employed to look at how O. pes-caprae plant-based ligands interact with the target protein COVID-19 3CLPro (PDB:6LU7). Phenols, flavonoids, alkaloids and saponins were tested positive in preliminary phytochemical studies. TPC and TFC in different extracts ranging from (38.55 ± 1.72) to (65.68 ± 0.88) mg/g GAE/g and (24.75 ± 1.80) to (14.83 ± 0.92) mg/g QUE/g were used respectively. IC₅₀ value (24.75 ± 0.76 g/mL) by OXFH, total antioxidant capacity (55.89 ± 1.75) mg/g by OXLM, reducing potential (34.98 ± 1.089) mg/g by OXSM, maximum zone of inhibition against B. subtilis (24 ± 0.65 mm) by OXLM and maximum cytotoxicity 96% with LD₅₀ 19.66 (μg/mL) by OXSM were the best calculated values among all extracts. Using molecular docking, it was found that Caeruleanone A, 2',4'-Dihydroxy-2″-(1-hydroxy-1-methylethyl) dihydrofuro [2,3-h] flavanone and Vadimezan demonstrated best affinity with the investigated SARS CoV-2 Mpro protein. This work provide justification about this plant as a source of effective phytochemicals and their potential against microbes could lead to development of biosafe drugs for the welfare of human being. In future, different in vitro and in vivo biological studies can be performed to further investigate its biomedical potentials.

ZnO Nanoparticle-Mediated Seed Priming Induces Biochemical and Antioxidant Changes in Chickpea to Alleviate Fusarium Wilt

Chickpea (Cicer arietinum L.) is one of the main pulse crops of Pakistan. The yield of chickpea is affected by a variety of biotic and abiotic factors. Due to their environmentally friendly nature, different nanoparticles are being synthesized and applied to economically important crops. In the present study, Trichoderma harzianum has been used as a stabilizing and reducing agent for the mycosynthesis of zinc oxide nanoparticles (ZnO NPs). Before their application to control Fusarium wilt of chickpea, synthesized ZnO NPs were characterized. X-ray diffraction (XRD) analysis revealed the average size (13 nm) of ZnO NPs. Scanning electron microscopy (SEM) indicated their spherical structure, and energy dispersive X-ray analysis (EDX) confirmed the oxide formation of ZnO NPs. Transmission electron microscopy (TEM) described the size and shape of nanoparticles, and Fourier transform infrared (FTIR) spectroscopy displayed the presence of reducing and stabilizing chemical compounds (alcohol, carboxylic acid, amines, and alkyl halide). Successfully characterized ZnO NPs exhibited significant mycelial growth inhibition of Fusarium oxysporum, in vitro. In a greenhouse pot experiment, the priming of chickpea seeds with ZnO NPs significantly increased the antioxidant activity of germinated plants and they displayed 90% less disease incidence than the control. Seed priming with ZnO NPs helped plants to accumulate higher quantities of sugars, phenol, total proteins, and superoxide dismutase (SOD) to create resistance against wilt pathogen. These nanofungicides were produced in powder form and they can easily be transferred and used in the field to control Fusarium wilt of chickpea.

Plant-Actuated Micro-Nanorobotics Platforms: Structural Designs, Functional Prospects, and Biomedical Applications

Plants are anatomically and physiologically different from humans and animals; however, there are several possibilities to utilize the unique structures and physiological systems of plants and adapt them to new emerging technologies through a strategic biomimetic approach. Moreover, plants provide safe and sustainable results that can potentially solve the problem of mass-producing practical materials with hazardous and toxic side effects, particularly in the biomedical field, which requires high biocompatibility. In this review, it is investigated how micro-nanostructures available in plants (e.g., nanoparticles, nanofibers and their composites, nanoporous materials, and natural micromotors) are adapted and utilized in the design of suitable materials for a micro-nanorobot platform. How plants' work on micro- and nanoscale systems (e.g., surface roughness, osmotically induced movements such as nastic and tropic, and energy conversion and harvesting) that are unique to plants, can provide functionality on the platform and become further prospective resources are examined. Furthermore, implementation across organisms and fields, which is promising for future practical applications of the plant-actuated micro-nanorobot platform, especially on biomedical applications, is discussed. Finally, the challenges following its implementation in the micro-nanorobot platform are also presented to provide advanced adaptation in the future.

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

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

Green synthesis and characterization of nanosilver derived from extracellular metabolites of potent Bacillus subtilis for antifungal and eco-friendly action against phytopathogen

The potent antagonist Bacillus isolated from the soil rhizosphere elucidated the highest antagonism against the phytopathogen Fusarium oxysporum f. sp. cumini and was identified as Bacillus subtilis strain JSD-RSCu-8D based on molecular recognition by 16S rRNA sequencing (NCBI Accession No. KT894724). Live Bacillus may not work as effectively against phytopathogen under unfavorable environmental conditions like temperature, humidity, or other abiotic stresses. The extracellular metabolites, obtained from culturing potent B. subtilis, were exploited for the creation of green nanosilver for proficient actions in a changing climate. The synthesized green nanosilver was illustrated for shape (spherical with 65.21 ± 3.71 nm under SEM), size (70.9 nm in PSA), purity (2.69 keV peak corresponded to the binding energy of silver under EDAX), and stability (44.2 mV as ZETA). The formation of green Ag-NPs from extracellular metabolites was confirmed by a comparative appraisal of the electromagnetic peak of the metabolite's functional groups, silver nitrate, and green nanoparticles in Fourier transform infrared spectroscopy. The novel mode of action of pathogen mycelium degradation was elucidated by the minimum inhibitory concentration (MIC) of green nanosilver as 40 µg Ag ml^-1 to diminish F. oxysporum (SEM morphology). The green nanosilver at 2 DAI renowned the leakage of sugars from mycelia of the cell membrane and defeated the activity of respiratory chain dehydrogenases, followed by lipid peroxidation and the highest leakage of proteins at 3 DAI on MIC. The in-vivo study might allow for novel insight to utilize green nanosilver at MIC (40 µg Ag ml^-1) as an eco-friendly and fungicide alternate way for antifungal action to demolish Fusarium wilt infection under harsh conditions.

Rhamnella gilgitica functionalized green synthesis of ZnONPs and their multiple therapeutic properties

In the recent years, green synthesis of zinc oxide nanoparticles (ZnONPs) using plant extracts and phytochemicals has gained significant attention. In present research study, facile, green, and tunable ZnONPs were biosynthesized from Rhamnella gilgitica leaf aqueous extract as a strong reducing and stabilizing agents. The prepared ZnONPs@Rhamnella were characterized and validated using common nanotechnology techniques (UV-Vis, XRD, EDX, FT-IR, SEM, TEM, DLS, and Raman) and revealed spherical morphology with particle size ~21 nm. The asynthesized ZnONPs were further evaluated for different biological applications. Strong antimicrobial efficacies were reported for ZnONPs using disc-diffusion method and were capable of rendering significant antimicrobial potential. ZnONPs were evaluated against HepG2 (IC₅₀ : 18.40 μg/ml) and HUH7 (IC₅₀ : 20.59 μg/ml) cancer cell lines and revealed strong anticancer properties. Dose-dependent MTT cytotoxicity assay was confirmed using Leishmania tropica "KWH23 strain" (promastigote: IC₅₀ : 26.78 μg/ml and amastigote: IC₅₀ : 29.57 μg/ml). Antioxidant activities (DPPH: 93.36%, TAC: 72.43%) were performed to evaluate their antioxidant potentials. Further, protein kinase and α-amylase inhibition assays were determined. Biocompatibility assays were done using human RBCs and macrophages thus revealed biosafe and non-toxic nature of ZnONPs@Rhamnella. In current experiment, we concluded that greenly orchestrated ZnONPs is an attractive, non-toxic and ecofriendly candidate and showed potential biological activities. In future, different clinical trials and in vivo studies are necessary for the confirmation of these remedial properties of ZnONPs using different animal models.

Gums-based engineered bio-nanostructures for greening the 21st-century biotechnological settings

Naturally occurring plant-based gums and their engineered bio-nanostructures have gained an immense essence of excellence in several industrial, biotechnological, and biomedical sectors of the modern world. Gums derived from bio-renewable resources that follow green chemistry principles are considered green macromolecules with unique structural and functional attributes. For instance, gum mostly obtained as exudates are bio-renewable, bio-degradable, bio-compatible, sustainable, overall cost-effective, and nontoxic. Gum exudates also offer tunable attributes that play a crucial role in engineering bio-nanostructures of interest for several bio- and non-bio applications, e.g., food-related items, therapeutic molecules, sustained and controlled delivery cues, bio-sensing constructs, and so on. With particular reference to plant gum exudates, this review focuses on applied perspectives of various gums, i.e., gum Arabic, gum albizzia, gum karaya, gum tragacanth, and gum kondagogu. After a brief introduction with problem statement and opportunities, structural and physicochemical attributes of plant-based natural gums are presented. Following that, considerable stress is given to green synthesis and stabilization of gum-based bio-nanostructures. The final part of the review focuses on the bio- and non-bio related applications of various types of gums polysaccharides-oriented bio-nanostructures.

Green synthesis of zinc oxide nanoparticles using Elaeagnus angustifolia L. leaf extracts and their multiple in vitro biological applications

Due to their versatile applications, ZnONPs have been formulated by several approaches, including green chemistry methods. In the current study, convenient and economically viable ZnONPs were produced using Elaeagnus angustifolia (EA) leaf extracts. The phytochemicals from E. angustifolia L. are believed to serve as a non-toxic source of reducing and stabilizing agents. The physical and chemical properties of ZnONPs were investigated employing varying analytical techniques (UV, XRD, FT-IR, EDX, SEM, TEM, DLS and Raman). Strong UV–Vis absorption at 399 nm was observed for green ZnONPs. TEM, SEM and XRD analyses determined the nanoscale size, morphology and crystalline structure of ZnONPs, respectively. The ZnONPs were substantiated by evaluation using HepG2 (IC₅₀: 21.7 µg mL⁻¹) and HUH7 (IC₅₀: 29.8 µg mL⁻¹) cancer cell lines and displayed potential anticancer activities. The MTT cytotoxicity assay was conducted using Leishmania tropica “KWH23” (promastigotes: IC₅₀, 24.9 µg mL⁻¹; and amastigotes: IC₅₀, 32.83 µg mL⁻¹). ZnONPs exhibited excellent antimicrobial potencies against five different bacterial and fungal species via the disc-diffusion method, and their MIC values were calculated. ZnONPs were found to be biocompatible using human erythrocytes and macrophages. Free radical scavenging tests revealed excellent antioxidant activities. Enzyme inhibition assays were performed and revealed excellent potential. These findings suggested that EA@ZnONPs have potential applications and could be used as a promising candidate for clinical development.

Characterization and bioefficacy of green nanosilver particles derived from fungicide-tolerant Tricho-fusant for efficient biocontrol of stem rot (Sclerotium rolfsii Sacc.) in groundnut (Arachis hypogaea L.)

An efficient and eco-friendly bioefficacy of potent Tricho-fusant (Fu21) and its green nanosilver formulation against stem rot (Sclerotium rolfsii) in groundnut was established. Fu21 demonstrated higher in-vitro growth inhibition of pathogen with better fungicide tolerance than the parental strains. The green nanosilver particles were synthesized from the extracellular metabolites of Fu21 and characterized for shape (spherical, 59.34 nm in scanning electron microscope), purity (3.00 KeV, energy dispersive X-ray analysis), size (54.3 nm in particle size analyzer), and stability (53.7 mv, zeta). The field efficacy study exhibited that the seedling emergence was high in seeds treated with green nanosilver (minimum inhibitory concentration-[MIC] 20 µg Ag/ml), and a low disease severity index of stem rot during the crop growth was followed by the live antagonist (Fu21) in addition to seed treatment with a fungicide mix under pathogen infestation. The seed quality analysis of harvested pods revealed a high oil content with balanced fatty acid composition (3.10 oleic/linoleic acid ratio) in green nanosilver treatment under pathogen infestation. The residual analysis suggested that green nanosilver applied at the MIC level as seed treatment yielded similar effects as the control for silver residue in the harvested groundnut seeds. The green nanosilver at MIC has a high pod-yield under S. rolfsii infestation, demonstrating green chemistry and sustainability of the nanoproduct.

Photodegradation of Biohazardous Dye Brilliant Blue R Using Organometallic Silver Nanoparticles Synthesized through a Green Chemistry Method

Simple Summary

In the paper, we utilize silver nanoparticles as a catalyst in the degradation of a hazardous dye. The nanoparticles are formed from the simple silver salt by using only a plant extract from a commonly occurring herb. The plant extract contains compounds that can both reduce the silver salt and subsequently cap the surface of the as-prepared particles. There are many environmental advantages to using such an approach—nanoparticles are prepared by using simple green chemistry and the catalytic degradation of dye is carried out by sunlight energy. Such a method can be used as a very cheap, green method to neutralize hazardous substances in-house.

Abstract

Nowadays, nanostructures having tremendous chemical and physical properties are gaining attention in the biomedical industry. However, when they are prepared through classical methods (physical and chemical), they are often non-biocompatible and toxic. Considering the mentioned factors, in this research, organometallic silver nanostructures (OMAgNs) have been prepared by the green chemistry method using the acetone, methanol, and methanol-hexane-based extracts of the medicinally important plant Cichorium intybus. Secondary metabolites from C. intybus can be used as an alternative to synthetic reagents at an industrial scale to manufacture biosafe and economical nanostructures with enhanced physicochemical parameters. Prepared nanostructures were characterized using SEM, XRD, FTIR, TGA, UV, and zeta potential measurement. SEM analysis revealed different shapes of OMAgNs, prepared with various extracts. XRD analysis showed the crystallinity of the nanostructures. FTIR spectroscopy helped to identify groups of compounds present in the extracts and used for the OMAgNs synthesis. Out of the three tested OMAgNs, those prepared with methanol extract were selected due to the highest obtained yield and stability (highest negative zeta potential) and were tested as a cost-efficient and active agent to photodegrade organic pollutant, Brilliant Blue R, using energy from sunlight. A decrease in UV-VIS absorbance confirmed the rapid degradation of the dye.

Precursor effects on the physical, biological, and catalytic properties of Fagonia indica Burm.f. mediated zinc oxide nanoparticles

We report a facile, green and precursor-based comparative study on the biosynthesis of zinc oxide (ZnO) nanoparticles (NPs) using anticancerous Fagonia indica as effective chelating agent. Biosynthesis was carried out using zinc sulfate and zinc acetate as precursor salts to make ZnO_S and ZnO_A NPs under similar experimental conditions which were characterized extensively for physical and biological properties. Scherrer equation deduced a mean crystallite size of ~23.4 nm for ZnO_A NPs and ~41 nm for ZnO_S NPs. The nature of the NPs was compared using UV, diffuse reflectance spectra, Fourier transform infrared spectroscopy, thermogravimetric analysis-DTA, selected area electron diffraction, EDS, zeta potential, high resolution (HR)-SEM, and HR-TEM. Detailed in vitro pharmacognostic activities revealed a significant therapeutic potential for ZnO_A and ZnO_S . Potential antimicrobial activities for the NPs and their nanocosmeceutical formulations are reported. ZnO_A NPs were more cytotoxic to Leishmania tropica as compared to ZnO_S . Significant antioxidant and protein kinase inhibition was obtained. The hemolytic assay indicated a hemocompatible nature of both ZnO_A and ZnO_S NPs. Catalytic degradation of crystal violet dye (CVD) by NPs was examined under different parameters (light, dark, UV). Furthermore, sonophotocatalytic degradation of CVD was also studied. Our results suggested that precursor can have a significant effect on the physical, biological, and catalytic properties of the NPs. In future, we recommend different other in vitro, in vivo biological activities, and mechanistic studies of these as-synthesized NPs.

Green Approach: ''A Forwarding Step for Curing Leishmaniasis-A Neglected Tropical Disease''

The present review focuses on a dreaded vector-mediated leishmaniasis, with the existing therapeutic approaches including a variety of drugs along with their limitations, the treatment with natural compounds, and different types of metal/metal oxide nanoparticles (NPs). As evidenced, various metallic NPs, comprising silver, silver oxide, gold, zinc oxide, titanium, lead oxide, etc., played a curative role to treat leishmaniasis, are also presented. Keeping in view the advance success of vaccines against the prevalent dreaded diseases in the past and the present scenario, efforts are also being made to develop vaccines based on these NP formulations.

Facile In-Situ Fabrication of a Ternary ZnO/TiO2/Ag Nanocomposite for Enhanced Bactericidal and Biocompatibility Properties

This paper presents for the first time a successful fabrication of ternary ZnO/TiO2/Ag nanocomposites consisting of zinc oxide (ZnO), titania (TiO2) and silver (Ag) nanoparticles (NPs) synthesised using Morinda citrifolia fruit (MCF) extract. ZnONPs were synthesised using the co-precipitation method, and TiO2 and Ag were introduced into the precursor solutions under microwave irradiation to obtain ZnO/TiO2/Ag nanocomposites (NCs). This material demonstrated enhanced bactericidal effect towards bacterial pathogens compared to that of the binary TiO2/Ag, Ag and TiO2 alone. In vitro cytotoxicity results of the as-synthesised ZnO/TiO2/AgNCs on RAW 264.7 macrophages and A549 cell lines revealed a negative role in cytotoxicity, but contributed astoundingly towards antimicrobials as compared of Ag alone and binary Ag/TiO2. This study shows that the resultant ternary metal/bi-semiconductor nanocomposites may provide a therapeutic strategy for the eradication of bacterial pathogens without affecting the healthy mammalian cells.

Green Synthesis of Metallic Nanoparticles and Their Prospective Biotechnological Applications: an Overview

The green synthesis of nanoparticles (NPs) using living cells is a promising and novelty tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs; however, biological methods are preferred due to its eco-friendly, clean, safe, cost-effective, easy, and effective sources for high productivity and purity. High pressure or temperature is not required for the green synthesis of NPs, and the use of toxic and hazardous substances and the addition of external reducing, stabilizing, or capping agents are avoided. Intra- or extracellular biosynthesis of NPs can be achieved by numerous biological entities including bacteria, fungi, yeast, algae, actinomycetes, and plant extracts. Recently, numerous methods are used to increase the productivity of nanoparticles with variable size, shape, and stability. The different mechanical, optical, magnetic, and chemical properties of NPs have been related to their shape, size, surface charge, and surface area. Detection and characterization of biosynthesized NPs are conducted using different techniques such as UV-vis spectroscopy, FT-IR, TEM, SEM, AFM, DLS, XRD, zeta potential analyses, etc. NPs synthesized by the green approach can be incorporated into different biotechnological fields as antimicrobial, antitumor, and antioxidant agents; as a control for phytopathogens; and as bioremediative factors, and they are also used in the food and textile industries, in smart agriculture, and in wastewater treatment. This review will address biological entities that can be used for the green synthesis of NPs and their prospects for biotechnological applications.

Phytofabrication of cobalt oxide nanoparticles from Rhamnus virgata leaves extract and investigation of different bioactivities

The tunable cobalt oxide nanoparticles (CoONPs) are produced due to the phytochemicals present in Rhamnus virgata (RhV) leaf extract which functions as reducing and stabilization agents. The synthesis of CoONPs was confirmed using different analytical techniques: UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamics light scatterings (DLS), Fourier-transform infrared spectroscopy (FTIR), energy dispersive X-ray, and Raman spectroscopy analyses. Furthermore, multiple biological activities were performed. Significant antifungal and antibacterial potentials have been reported. The in vitro cytotoxic assays of CoONPs revealed strong anticancer activity against human hepatoma HUH-7 (IC₅₀ : 33.25 μg/ml) and hepatocellular carcinoma HepG2 (IC₅₀ : 11.62 μg/ml) cancer cells. Dose-dependent cytotoxicity potency was confirmed against Leishmania tropica (KMH₂₃ ); amastigotes (IC₅₀ : 58.63 μg/ml) and promastigotes (IC₅₀ : 32.64 μg/ml). The biocompatibility assay using red blood cells (RBCs; IC₅₀ : 4,636 μg/ml) has confirmed the bio-safe nature of CoONPs. On the whole, results revealed nontoxic nature of RhV-CoONPs with promising biological potentials.

Flower shaped ZnO—NPs; phytofabrication, photocatalytic, fluorescence quenching, and photoluminescence activities

Phytofabrication of Zinc Oxide nanoparticles (ZnO–NPs) through Nephelium lappaceum L. and Garcinia mangostana L. plants’ wastes were achieved as an environmentally friendly method of synthesizing nanoparticles. Biogenic ZnO–NPs were characterized by Ultra Violet Visible (UV–vis) spectrophotometry, Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Energy Dispersive Energy (EDX ), and Fourier Transform Infrared spectroscopy (FTIR). UV- Visible absorption of ZnO–NPs indicated a characteristic absorption band at 362–368 nm region. The synthesized nanoparticles were flower in shape, as shown by the SEM images, and they were further elucidated by the TEM images. ZnO-NP synthesized via Rambutan Peel Extract (RPE), Rambutan Seed Extract (RSE), Mangosteen Peel Extract (MPE) and Mangosteen Seed Extract (MSE) showed the average particle size of 29 nm–184 nm, 86 nm–260 nm, 92 nm–247 nm, and 233 nm–334 nm respectively. FTIR spectra demonstrated peaks at 3269–3500 cm−1, 2308–2361 cm−1, 2103–2110 cm−1 and 1630–1640 cm−1, 586–632 cm−1 for the plant extracts, whereas an additional peak appeared within the range of 458–499 cm−1 in ZnO–NPs spectra. The photocatalytic activity of the synthesized ZnO–NPs was measured by the degradation of Methylene Blue under sunlight. The highest degradation of Methylene Blue dye was detected in ZnO—NPs synthesized using the seed extract of Nephelium lappaceum L., where a Half-life of 78 min and 97% degradation efficiency at 150 min time frame was observed. The ZnO–NPs were identified to possess fluorescence quenching ability of Rhodamine B. The highest quenching ability was recorded in ZnO–NPs synthesized via Garcinia mangostana L. seed. The Photoluminescence study showed that the intensity of spectral lines of biogenic ZnO–NPs were higher compared with the chemically synthesized ZnO–NPs.

Green fabricated zinc oxide nanoformulated media enhanced callus induction and regeneration dynamics of Panicum virgatum L

The current study focuses on the usage of bio synthesized zinc oxide nanoparticles to increase the tissue culture efficiency of important forage grass Panicum virgatum. Zinc being a micronutrient enhanced the callogenesis and regeneration efficiency of Panicum virgatum at different concentrations. Here, we synthesized zinc oxide nanoparticles through Cymbopogon citratus leaves extract to evaluate the effect of zinc oxide nanoparticles on plant regeneration ability in switchgrass. X-ray diffraction (XRD) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) validate phase purity of green synthesize Zinc oxide nanoparticles whereas, electron microscopy (SEM) has illustrated the average size of particle 50±4 nm with hexagonal rod like shape. Energy dispersive spectroscopy X-ray (EDS) depicted major peaks of Zn (92.68%) while minor peaks refer to Oxygen (7.32%). ZnO-NPs demonstrated the incredibly promising results against callogenesis. Biosynthesized ZnO-NPs at optimum concentration showed very promising effect on plant regeneration ability. Both the explants, seeds and nodes showed dose dependent response and upon high doses exceeding 40 mg/L the results were recorded negative, whereas at 30 mg/L both explants demonstrated 70% and 76% regeneration frequency. The results conclude that ZnO-NPs enhance the plant growth and development and tailored the nutritive properties at nano-scale. Furthermore, eco-friendly approach of ZnO-NPs synthesis is strongly believed to improve in vitro regeneration frequencies in several other monocot plants.

Phytogenic Synthesis of Nickel Oxide Nanoparticles (NiO) Using Fresh Leaves Extract of Rhamnus triquetra (Wall.) and Investigation of Its Multiple In Vitro Biological Potentials

Chemically nickel oxide nanoparticles (NiONPs) involve the synthesis of toxic products, which restrict their biological applications. Hence, we developed a simple, eco-friendly, and cost-efficient green chemistry method for the fabrication of NiONPs using fresh leaf broth of Rhamnus triquetra (RT). The RT leaves broth was used as a strong reducing, capping, and stabilizing agent in the formation of RT-NiONPs. The color change in solution from brown to greenish black suggests the fabrication of RT-NiONPs which was further confirmed by absorption band at 333 nm. The synthesis and different physicochemical properties of RT-NiONPs were investigated using different analytical techniques such as UV-Vis (ultraviolet-visible spectroscopy), XRD (X-ray powder diffraction), FT-IR (Fourier-transform infrared spectroscopy), SEM (scanning electron microscopy), TEM (transmission electron microscopy), EDS (energy-dispersive X-ray spectroscopy), DLS (dynamic light scattering) and Raman. Further, RT-NiONPs were subjected to different in vitro biological activities and revealed distinctive biosafe and biocompatibility potentials using erythrocytes and macrophages. RT-NiONPs exhibited potential anticancer activity against liver cancer cell lines HUH7 (IC₅₀: 11.3 µg/mL) and HepG2 (IC₅₀: 20.73 µg/mL). Cytotoxicity potential was confirmed using Leishmanial parasites promastigotes (IC₅₀: 27.32 µg/mL) and amastigotes (IC₅₀: 37.4 µg/mL). RT-NiONPs are capable of rendering significant antimicrobial efficacy using various bacterial and fungal strains. NiONPs determined potent radical scavenging and moderate enzyme inhibition potencies. Overall, this study suggested that RT-NiONPs can be an attractive and eco-friendly candidate. In conclusion, current study showed potential in vitro biological activities and further necessitate different in vivo studies in various animal models to develop leads for new drugs to treat several chronic diseases.

Reactive oxygen species generating photosynthesized ferromagnetic iron oxide nanorods as promising antileishmanial agent

Aim: To investigate the photodynamic therapeutic potential of ferromagnetic iron oxide nanorods (FIONs), using Trigonella foenum-graecum as a reducing agent, against Leishmania tropica. Materials & methods: FIONs were characterized using ultraviolet visible spectroscopy, x-ray diffraction and scanning electron microscopy. Results: FIONs showed excellent activity against L. tropica promastigotes and amastigotes (IC₅₀ 0.036 ± 0.003 and 0.072 ± 0.001 μg/ml, respectively) upon 15 min pre-incubation light-emitting diode light (84 lm/W) exposure, resulting in reactive oxygen species generation and induction of cell death via apoptosis. FIONs were found to be highly biocompatible with human erythrocytes (LD₅₀ 779 ± 21 μg/ml) and significantly selective (selectivity index >1000) against murine peritoneal macrophages (CC₅₀ 102.7 ± 2.9 μg/ml). Conclusion: Due to their noteworthy in vitro antileishmanial properties, FIONs should be further investigated in an in vivo model of the disease.