Efficacy of larvicidal activity of green synthesized titanium dioxide nanoparticles using Mangifera indica extract against blood-feeding parasites

Optimizing the green synthesis of antibacterial TiO2 - anatase phase nanoparticles derived from spinach leaf extract

Titanium dioxide nanoparticles, renowned for their abundance, non-toxicity, and stability, have emerged as indispensable components in various fields such as air purification, healthcare, and industrial processes. Their applications as photocatalysts and antibacterial agents are particularly prominent. The synthesis methods significantly influence the properties and subsequent applications of these nanoparticles. While several techniques exist, the biological approach using plant extracts offers advantages such as simplicity, biocompatibility, and cost-effectiveness. This study focused on the green synthesis of titanium dioxide nanoparticles utilizing spinach leaf extract. Within the scope of this investigation, the green synthesis of titanium dioxide nanoparticles through spinach leaf extract were synthesized and optimized, followed by a comprehensive examination of their morphological, structural, and chemical attributes with UV-visible spectroscopy, FTIR spectroscopy, XRD, FESEM, and EDX. The minimum inhibitory concentration (MIC) against E. coli and S. aureus was determined to evaluate their antibacterial potential. Optimal synthesis conditions were identified at 50 °C, using a 1/30 concentration and 20 ml of spinach leaf extract. Spherical anatase nanoparticles, ranging from 10 to 40 nm, were produced under these conditions. The change in the color of the extract, absorption at 247 nm, change and increase of the peak at 800 - 400 wavelengths, and the maximum intensity of X-ray diffraction at the angle of 25.367 with the crystal plane 101 were indications of the synthesis of these nanoparticles. Notably, the synthesized nanoparticles exhibited antibacterial activity with MIC values of 0.5 mg/ml against E. coli and 2 mg/ml against S. aureus. This research presents a novel, eco-friendly approach to synthesizing titanium dioxide nanoparticles with promising antibacterial properties.

Tiny Green Army: Fighting Malaria with Plants and Nanotechnology

Malaria poses a global threat to human health, with millions of cases and thousands of deaths each year, mainly affecting developing countries in tropical and subtropical regions. Malaria's causative agent is Plasmodium species, generally transmitted in the hematophagous act of female Anopheles sp. mosquitoes. The main approaches to fighting malaria are eliminating the parasite through drug treatments and preventing transmission with vector control. However, vector and parasite resistance to current strategies set a challenge. In response to the loss of drug efficacy and the environmental impact of pesticides, the focus shifted to the search for biocompatible products that could be antimalarial. Plant derivatives have a millennial application in traditional medicine, including the treatment of malaria, and show toxic effects towards the parasite and the mosquito, aside from being accessible and affordable. Its disadvantage lies in the type of administration because green chemical compounds rapidly degrade. The nanoformulation of these compounds can improve bioavailability, solubility, and efficacy. Thus, the nanotechnology-based development of plant products represents a relevant tool in the fight against malaria. We aim to review the effects of nanoparticles synthesized with plant extracts on Anopheles and Plasmodium while outlining the nanotechnology green synthesis and current malaria prevention strategies.

Biofabrication of Titanium Dioxide Nanoparticles Catalyzed by Solanum surattense: Characterization and Evaluation of their Antiepileptic and Cytotoxic Activities

The green synthesis of nanoparticles using plant extract is a new method that can be used in various biomedical applications. Therefore, the green approach was an aspect of ongoing research for the synthesis titanium dioxide nanoparticles (TiO₂ NP) using the Solanum surattense aqueous plant extract, which acts as a stabilizing and reducing agent. The synthesis of TiO₂ NPs was confirmed by energy dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and UV-visible spectroscopy (UV-vis) analyses. The excitation energy to synthesize TiO₂ NPs was identified through the UV-vis spectrophotometric analysis at a wavelength of 244 nm. Further, the FT-IR spectroscopy visualized different biomolecules like OH, C=O, C-H, and C-O that were present in an aqueous extract of the plant and were responsible for the stabilization of TiO₂ NPs. The crystallinity and phase purity of TiO₂ NPs were illustrated by the sharp peaks of the XRD pattern. The spherical morphology with sizes ranging from 10 to 80 nm was examined using SEM images. The elemental composition of TiO₂ NPs was revealed by the intensity and narrow widths of titanium and oxygen using EDX analysis. This report also explains the antiepileptic activity of TiO₂ NPs in a maximal electroshock-induced epileptic (MESE) and pentylenetetrazol (PTZ) model. The synthesized TiO₂ NPs showed maximum antiepileptic activity in the PTZ model, significantly decreasing the convulsions (65.0 ± 5.50 s) at 180 mg/kg in contrast to standard drug phenytoin, whereas the MESE model was characterized by the appearance of extensor, clonus, and flexion. The results showed that synthesized TiO₂ NPs significantly reduced the time spent in each stage (15.3 ± 0.20, 16.8 ± 0.25, and 20.5 ± 0.14 s) at 180 mg/kg as compared to control groups. Furthermore, the cytotoxicity of synthesized produced TiO₂ NPs demonstrated that concentrations ≤80 μg/mL were biologically compatible.

Mosquito-Borne Diseases and Their Control Strategies: An Overview Focused on Green Synthesized Plant-Based Metallic Nanoparticles

Mosquitoes act as vectors of pathogens that cause most life-threatening diseases, such as malaria, Dengue, Chikungunya, Yellow fever, Zika, West Nile, Lymphatic filariasis, etc. To reduce the transmission of these mosquito-borne diseases in humans, several chemical, biological, mechanical, and pharmaceutical methods of control are used. However, these different strategies are facing important and timely challenges that include the rapid spread of highly invasive mosquitoes worldwide, the development of resistance in several mosquito species, and the recent outbreaks of novel arthropod-borne viruses (e.g., Dengue, Rift Valley fever, tick-borne encephalitis, West Nile, yellow fever, etc.). Therefore, the development of novel and effective methods of control is urgently needed to manage mosquito vectors. Adapting the principles of nanobiotechnology to mosquito vector control is one of the current approaches. As a single-step, eco-friendly, and biodegradable method that does not require the use of toxic chemicals, the green synthesis of nanoparticles using active toxic agents from plant extracts available since ancient times exhibits antagonistic responses and broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on the different mosquito control strategies in general, and on repellent and mosquitocidal plant-mediated synthesis of nanoparticles in particular, has been reviewed. By doing so, this review may open new doors for research on mosquito-borne diseases.

Potential of green synthesized titanium dioxide nanoparticles for enhancing seedling emergence, vigor and tolerance indices and DPPH free radical scavenging in two varieties of soybean under salinity stress

BACKGROUND

Considering titanium dioxide nanoparticles (TiO₂ NPs) role in plant growth and especially in plant tolerance against abiotic stress, in the present work, TiO₂ NPs were green synthesized using an aqueous solution of Aloe vera leaf extract as a capping agent and titanium tetrachloride as a precursor. These green synthesized TiO₂ NPs were characterized using different techniques: UV spectrophotometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Results revealed that synthesized TiO₂ NPs possess a tetragonal morphology with a size ranging from 10 to 25 nm. Additionally, the present work evaluated the effects of three concentrations of TiO₂ NPs (0, 30 and 50 ppm) and six NaCl concentrations (0, 25, 50, 100, 150 and 200 mM) and their interactions with respect to germination parameters, vigor indices, oxidative stress and DPPH free radical scavenging of two varieties of soybean (Glycine max L. var. 22 and 35).

RESULTS

Results demonstrated that all germination traits and vigor indices were negatively affected under all salinity levels. Also, the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were significantly increased by increasing the NaCl concentrations in two soybean varieties. Most interestingly, TiO2 NPs (30 ppm) mediated positive effects on germination parameters, reducing H2O2 and MDA contents by enhancing antioxidant (decreasing IC50) whereas 50 ppm showed an intermediate response under both control and saline soil conditions.

CONCLUSION

Our findings demonstrate the growth enhancement effects of TiO₂ NPs application as well as its ameliorative potential in dealing with salinity.

Green synthesis of titanium dioxide nanoparticles using plant biomass and their applications- A review

Biosynthesized nanoparticles have sparked a lot of interest as rapidly growing classes of materials for different applications. Plants are considered to be one of the most suitable sources for Green synthesis (GS) as they follow the environment-friendly route of biosynthesis of nanoparticles (NPs). This article focuses on the excavation of Titanium dioxide (TiO₂) NP from different parts of plants belonging to a distinct classification of taxonomic groups. During the process of biological synthesis of titanium NPs from plants, the extract derived from plant sources such as from root, stem, leaves, seeds, flowers, and latex possesses phytocompounds that tend to serve as both capping as well as reducing agents. TiO₂NP is one of the most commonly used engineered nanomaterials in nanotechnology-based consumer products. This article will provide an overview of the GS and characterization of TiO₂NPs from plant extracts of different taxonomic groups. Lastly, this review summarizes the current applications of TiO₂NPs.

Bio-efficacy of Mangifera leaf extracts on mortality of Aedes aegypti and inhibition of egg hatching

Background and Aim: To develop an environmentally friendly alternative to mosquito larvicides for vegetables, leaf extracts of Mangifera laurina, Mangifera casturi, Mangifera indica, Mangifera odorata, Mangifera caesia, and Mangifera foetida were prepared. This study aimed to determine the biological efficacy of several Mangifera leaf extracts on the mortality of Aedes aegypti mosquito and the inhibition of egg hatching. Materials and Methods: Extraction was performed in an organic solvent (methanol) using a Soxhlet extractor. The larvicidal potential of six leaves of Mangifera essential oil was evaluated against the third instar larvae of A. aegypti at concentrations of 1500, 2000, 3000, and 5000 ppm using the World Health Organization protocol. After Probit analysis, the 48 h LC50 and LC90 values of the essential oils were determined. The inhibitory effect on egg hatching was also tested at 160, 320, 480, and 640 ppm. Results: The extraction of essential oils from several Mangifera species had excellent larvicidal activity and inhibitory activity against A. aegypti egg hatching. The LC50/LC90 values were: M. casturi, 241/1964 ppm; M. laurina, 2739/4035 ppm; and M. caesia, 1831/2618 ppm. The inhibitory effect on hatching was 78% for M. foetida, 70% for M. caesia, and 59% for M. casturi. Conclusion: The test results indicate the potential of some Mangifera species for use as larvicides and inhibitors of egg hatching; thus, they have the potential to control A. aegypti in the early stages of development.

Acaricidal Potential and Ecotoxicity of Metallic Nano-Pesticides Used against the Major Life Stages of Hyalomma Ticks

Ticks (Acari: Ixodidae) are blood-feeding parasites capable of transmitting diseases to animals (Piroplasmosis) and humans (Congo fever, Lyme disease). The non-judicious use of chemical acaricides has led to the development of acaricide-resistant ticks, making the control of ticks and tick-borne diseases difficult. This study reports the efficacy of magnesium oxide (MgO), iron oxide (Fe₂O₃), and zinc oxide (ZnO) nanoparticles (NPs) as alternatives to traditional acaricides/pesticides using in vitro tests against major representative stages of Hyalomma ticks. Nanopesticides were chemically synthesized as rods (Fe₂O₃), stars (ZnO), and spheres (MgO) and were characterized by XRD and SEM analysis. The in vitro bioassays included adult immersion, larval immersion, and larval packet tests. Non-target effects of the nanopesticides were evaluated using snails. The LC₉₀ values of Fe₂O₃ NPs (4.21, 2.83, 0.89 mg/L) were lowest followed by MgO (4.27, 2.91, 0.93 mg/L) and ZnO (4.49, 3.05, 0.69 mg/L), for the tick adult, larval and egg stages, respectively. Fe₂O₃ NPs were capable of arresting oviposition and larval hatching in the study ticks in vitro. The snail toxicity experiments revealed minimum to mild off-target effects for all nanopesticides tested. This study is the first to report the comparative efficacy of magnesium, iron, and zinc nanomaterials for toxicity in egg, adult and larval stages of Hyalomma ticks. Further studies of NPs on establishing the efficacy against ticks and safety at host-human-environment interface could lead to promising nanopesticde applications.

Green Synthesis of Metal Oxides Semiconductors for Gas Sensing Applications

During recent decades, metal oxide semiconductors (MOS) have sparked more attention in various applications and industries due to their excellent sensing characteristics, thermal stability, abundance, and ease of synthesis. They are reliable and accurate for measuring and monitoring environmentally important toxic gases, such as NO₂, NO, N₂O, H₂S, CO, NH₃, CH₄, SO₂, and CO₂. Compared to other sensing technologies, MOS sensors are lightweight, relatively inexpensive, robust, and have high material sensitivity with fast response times. Green nanotechnology is a developing branch of nanotechnology and aims to decrease the negative effects of the production and application of nanomaterials. For this purpose, organic solvents and chemical reagents are not used to prepare metal nanoparticles. On the contrary, the synthesis of metal or metal oxide nanoparticles is done by microorganisms, either from plant extracts or fungi, yeast, algae, and bacteria. Thus, this review aims at illustrating the possible green synthesis of different metal oxides such as ZnO, TiO₂, CeO₂, SnO₂, In₂O₃, CuO, NiO, WO_3, and Fe₃O₄, as well as metallic nanoparticles doping.

Screening, characterisation and bioactivities of green fabricated TiO2 NP via cyanobacterial extract

The present study was aimed at exploring 37 strains of cyanobacteria for the biofabrication of TiO₂ NP and evaluation of their antioxidant, antifungal, antibacterial and hemolytic activity. Screening of cyanobacterial strains was done via SEM, followed by optimisation and characterisation of the best strain. Synechocystis NCCU-370 appeared as the best strain for the synthesis of TiO₂ NP in terms of size (73.39 nm) and time (24 h) after screening. Following optimisation, nanoparticles were synthesised in 12 h having an average grain size of 16 nm. The aqueous extract preparation required heating of 5 mg/ml of powdered biomass to 60 °C for 10 min. Optimum conditions for the synthesis of TiO₂ NP were found to be pH 7, 30 °C and 12-h cell extract exposure to 0.1 mM of salt. Antioxidant activity was evaluated via DPPH, ABTS and FRAP assay. Antifungal potential was explored against Candida albicans (MIC = 125 µg/ml), Candida glabrata (MIC = 500 µg/ml) and Candida tropicalis (MIC = 250 µg/ml), whereas antibacterial potential was gauged for Bacillus cereus (MIC = 31.25 µg/ml), Escherichia coli (MIC = 31.25 µg/ml) and Klebsiella pneumoniae (MIC = 500 µg/ml) strains. Biogenic TiO₂ NP demonstrated partial synergistic effect and excellent biocompatibility.

Methods for Green Synthesis of Metallic Nanoparticles Using Plant Extracts and their Biological Applications - A Review

Nanotechnology, a fast-developing branch of science, is gaining extensive popularity among researchers simply because of the multitude of applications it can offer. In recent years, biological synthesis has been widely used instead of physical and chemical synthesis methods, which often produce toxic products. These synthesis methods are now being commonly adapted to discover new applications of nanoparticles synthesized using plant extracts. In this review, we elucidate the various ways by which nanoparticles can be biologically synthesized. We further discuss the applications of these nanoparticles.

Acaricidal and Repellent Effects of Essential Oils against Ticks: A Review

Tick control is a priority in order to prevent the transmission of vector-borne diseases. Industrial chemical acaricides and repellents have been the most efficient tools against hard ticks for a long time. However, the appearance of resistances has meant the declining effectiveness of the chemicals available on the market. The trend today is to develop alternative control methods using natural products to replace nonefficient pesticides and to preserve the efficient ones, hoping to delay resistance development. Traditional in vitro evaluation of acaricidal activity or resistance to synthetic pesticides have been reviewed and they mainly focus on just one species, the one host tick (Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)). Recent reports have called for the standardization of natural product components, extraction techniques, and experimental design to fully discover their acaricidal potential. This study reviews the main variables used in the bibliography about the efficiency of natural products against ticks, and it proposes a unification of variables relating to ticks, practical development of bioassays, and estimation of ixodicidal activity.

Green synthesis and characterization of titanium dioxide nanoparticles using leaf extract of Pouteria campechiana and larvicidal and pupicidal activity on Aedes aegypti

The frequent application of synthetic insecticides creates resistance among insects, including mosquitoes, and causes environmental pollution and health issues. The current work aim at assessing the possibilities to produce and characterize the titanium dioxide (TiO₂) nanoparticles (TiO₂ NPs) mediated through the aqueous leaf extract of Pouteria campechiana, and their larvicidal and pupicidal activities against Aedes aegypti. The attained results showed that the aqueous leaf extract of P. campechiana had the efficiency to fabricate TiO₂ NPs from TiO₂. Under the UV-vis spectrum analysis, a sharp peak was recorded at 320 nm, which indicated the production of TiO₂ NPs by the plant extract. The SEM analysis revealed that the synthesized TiO₂ NPs were spherical, and 5 dissimilar diffractions were detected in the XRD spectrum analysis related to the TiO₂ NPs. In FTIR analysis, a prominent peak was found at 1052.41 cm^-1, corresponding to alcohol, and confirmed metal reduction. In the EDX analysis, there was a signal of around 58.44%, confirming the decrease in Ti from TiO₂ NPs, and the remaining percentages were Ca, Al, and Mg. About 900 μg mL^-1 of TiO₂ NPs had excellent lethal activity against various larvae and pupa stages of Ae. aegypti. The attained results showed that the P. campechiana aqueous leaf extract could reduce TiO₂ into TiO₂ NPs and could be considered a mosquito control agent. Furthermore, this is the initial report about the aqueous leaf extract of P. campechiana effectively synthesizing the TiO₂ NPs with anti-mosquito activity.

Synthesis and characterization of TiO2 NPs by aqueous leaf extract of Coleus aromaticus and assess their antibacterial, larvicidal, and anticancer potential

The frequent applications of synthetic chemical insecticides and drugs create resistance among insects and microbes, creating a new threat to human and environmental welfare. This investigation focused on evaluating the possibilities of fabricating and characterizing the titanium dioxide nanoparticles (TiO₂ NPs) from titanium dioxide (TiO₂) through the aqueous leaf extract of Coleus aromaticus. Their biological applications were studied against the larvae of Aedes aegypti human pathogenic bacteria, and cancer cell line. The results revealed that the aqueous leaf extract had the metal reducing proficiency to produce nanoparticles from TiO₂. The synthesized TiO₂ NPs were initially confirmed by visible color changes and Ultraviolet-Visible Spectrophotometer analysis that showed a predominant peak at 332 nm. Furthermore, the nanocrystals, structural alignment, functional groups and elemental compositions were studied by following standard operating protocol in XRD (X-ray Powder Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), TEM (Transmission Electron Microscopy), and EDX (Energy-Dispersive X-ray Spectroscopy) techniques, respectively. The results attained from these techniques confirmed that the plant mediated and fabricated particles were in the nanoscale range (12-33 nm) with a hexagonal shape. The synthesized TiO₂ NPs had an outstanding (1000 μg mL^-1) larvicidal activity against the four stages of instars larvae of Ae. aegypti at 1000 μg mL^-1. It also had an excellent antibacterial potential against E. faecalis (33 mm), followed by S. boydii (30 mm) at 30 mg L^-1 concentration. The green fabricated TiO₂ NPs had a fabulous (92.37%) cytotoxic activity on the HeLa cell line at 100 μg mL^-1 dosage within one day of exposure. The entire results concluded that the C. aromaticus mediated TiO₂ NPs have excellent biological applications and thus, could be considered for the welfare of human beings.

Nanotechnology-based formulations toward the improved topical delivery of anti-acne active ingredients

Introduction: Acne vulgaris is a chronic inflammatory skin disorder that affects an extremely concerning percentage of teenagers (ca. 85%), gathering serious negative impacts on the social life and psychological well-being of individuals. Conventional topical formulations for acne show low tolerability and side effects, such as skin irritation, leading to a decrease in the user's adherence to therapy. Nanotechnology-based formulations were developed as new strategies for topical acne management, particularly to overcome the difficulties associated with conventional treatments.Areas covered: This paper presents a critical analysis of reviewed nanosized anti-acne technological strategies, strongly supporting controlled active ingredient release, improved skin permeation, and lower skin irritation. An updated regulatory framework, considering the promising applications in nanomedicine, and the toxicity of these nanosystems are also addressed.Expert opinion: Nanosystems evidence several advantages, attending to the possibility of controlled active ingredient release, better skin permeation, and lower skin irritation. However, novel nanotechnological strategies for acne treatment and care can lead to new side effects, but also environmental nano pollution. Little is known about the toxicology of these nanotechnology-based formulations, therefore, as future trends, more studies should be conducted to assure the consumers' health and environmental safety.

Facile Biogenic Synthesis and Characterization of Seven Metal-Based Nanoparticles Conjugated with Phytochemical Bioactives Using Fragaria ananassa Leaf Extract

In this investigation, for the first time, we used Fragaria ananassa (strawberry) leaf extract as a source of natural reducing, capping or stabilizing agents to develop an eco-friendly, cost-effective and safe process for the biosynthesis of metal-based nanoparticles including silver, copper, iron, zinc and magnesium oxide. Calcinated and non-calcinated zinc oxide nanoparticles also synthesized during a method different from our previous study. To confirm the successful formation of nanoparticles, different characterization techniques applied. UV-Vis spectroscopy, X-ray Diffraction (XRD) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS), Photon Cross-Correlation Spectroscopy (PCCS) and Fourier Transformed Infrared Spectroscopy (FT-IR) were used to study the unique structure and properties of biosynthesized nanoparticles. The results show the successful formation of metal-based particles in the range of nanometer, confirmed by different characterization techniques. Finally, the presented approach has been demonstrated to be effective in the biosynthesis of metal and metal oxide nanoparticles.

In vitro acaricidal activity of green synthesized nickel oxide nanoparticles against the camel tick, Hyalomma dromedarii (Ixodidae), and its toxicity on Swiss albino mice

The green synthesized nanoparticles have been determined as a novel pesticide against arthropod pests. This study was designed to evaluate the in vitro acaricidal activity of green synthesized nickel oxide nanoparticles (NiO NPs) using aqueous extract of Melia azedarach ripened fruits against different developmental stages of the camel tick Hyalomma dromedarii in addition to their toxic effect on laboratory animals. The synthesized NiO NPs were characterized by UV-visible (UV-Vis) spectroscopy, Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The UV-Vis spectra of the NiO NPs showed an absorption peak at 307 nm. FTIR analysis showed the possible functional groups used for capping and stabilization of NiO NPs with strong bands at 3416.2 and 1626.6 cm^-1. The SEM images of the NiO NPs exhibited a size ranging from 21 to 35 nm. The immersion test was used for the in vitro application of the synthesized NiO NPs on the various tick stages (egg, nymph, larva, and adult). Mortality percentages and LC₅₀ values of each tick stage were calculated. The oviposition and hatchability of the engorged females were monitored for the survived tick after treatment. The LC₅₀ values for NiO NPs on embryonated eggs, larvae, and engorged nymphs were 5.00, 7.15, and 1.90 mg/mL, respectively. The egg productive index (EPI), egg number, and hatchability (%) were lower in females treated with the NiO NPs than in control ticks. The toxicity of the NiO NPs on laboratory animals was also investigated using Swiss albino mice by oral dose of 500 mg/kg/day administration for five consecutive days. The hematological, biochemical, and histopathological changes were evaluated. The hematological analysis showed significant increase in the level of white blood cells (WBC) and hemoglobin (Hb). Biochemical analysis showed non-significant decrease in alkaline phosphatase (ALP) and alanine amino transferase (ALT). We concluded that NiO NPs have a significant acaricidal activity as demonstrated on eggs, larvae, engorged nymphs, and fully fed females of H. dromedarii. From a toxicological point of view further in vivo investigations are needed to determine the mechanism of toxic effect of NiO NPs.

Synthesis of TiO2 nanoparticles by chemical and green synthesis methods and their multifaceted properties

In this present work, Titanium dioxide nanoparticles (TiO2 NPs) successfully synthesized using the chemical as well as the green synthesis routine. The ethanol provoked the chemical reduction of ions. In the green synthesis, jasmine flower extract was used as a reducing and stabilizing agent because it contains alkaloids, coumarins, flavonoids. The Rutile phase of TiO2 NPs with an average crystalline size of 31–42 nm was revealed from the XRD pattern. From the UV–Visible spectroscopy, the optically active region of TiO2 NPs at 385 nm represents the visible region spectrum. The Ti–O–Ti and Ti–O vibration bond formation confirms the formation of TiO2 NPs. The SEM image of TiO2 NPs reveals that the spherical shaped NPs with randomly arranged manner. The obtained results have revealed that the property of TiO2 nanoparticles was similar in both processes. The Photodegradation of methylene blue dye was investigated and resulted in the maximum degradation efficiency of 92% is achieved at 120 min of irradiation. The Photodegradation study shows the biosynthesized TiO2 NPs exhibits a higher degradation efficiency compared to chemically synthesized TiO2 NPs. The antibacterial activity of prepared TiO2 NP’s was studied using grams-positive and gram-negative strains. The biological activities of green synthesized TiO2 NPs are enhanced compared to the chemically synthesized TiO2 NPs. Hence the degradation efficiency and zone inhibition layer indicate that the prepared TiO2 NPs are the potential candidate for environmental and biomedical applications.

Graphic abstract

Biological activity of Pomegranate peels Punica granatum Silver nanoparticles AgNPs extract against Fourth larvae of Culex quinquefasciatus mosquito (Diptera: Culicidae)

Present study was included the assessment of biological activity of Pomegranate Peels Punica granaatum plant extract toward fourth Culex quinquefasciatus larvae mosquito (Order: Diptera, Family: Culicidae) by testing ethanolic and Silver nanoparticles extracts. Results of present study revealed that Silver nanoparticles extract was more toxic than ethanolic extract and the mortality rates were reached to 90 % after 72 h exposure time when it treated with 5 µg/ml compared to 0% at control treatments. Ethanolic extract also was toxic at concentration 5 µg/ml and mortality rates were reached to 80% after 72 h exposure time. Study of larvae after death showed that penetration of Silver nanoparticles extract was entered inside mid gut of larvae after damage of body wall. SEM analysis indicated to that more deformation found in body wall thus AgNPs were easily penetration through skin of fourth larvae. SEM analysis also was showed that Silver nanoparticles were clustered and irregular or oval shapes.

Larvicidal and antibacterial activity of aqueous leaf extract of Peepal (Ficus religiosa) synthesized nanoparticles

In this study, the zinc oxide nanoparticles (ZnO NPs) and titanium dioxide nanoparticles (TiO2 NPs) were synthesized using the aqueous leaf extract of Ficus religiosa (Peepal tree). The synthesized nanoparticles were tested as larvicides against the larvae of Anopheles stephensi. Further, the synthesized nanoparticles were tested as antibacterial agents against the Escherichia coli (gram negative) and Staphylococcus aureus (gram positive) bacteria. The synthesized nanoparticles were characterized with UV-visible spectroscopy, X-rays powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The larvicidal mortality was observed after 24 h and 48 h by probit analysis. The antibacterial activity was evaluated using the well diffusion method. The synthesized nanoparticles were irregular shape and varied size. The larvae of An. stephensi were found highly susceptible against the ZnO NPs than the TiO2 NPs and aqueous leaves extract. The highest mortality was observed in synthesized ZnO NPs against first to third instars of (LC50 50, 75, and 5 ppm) and 100% mortality in fourth instars of An. stephensi. The higher zone of inhibition was occurred against the E. coli. This report of present investigation revealed that the rapid biological synthesis of ZnO NPs and TiO2 NPs using aqueous leaf extract of F. religiosa would be effective potential larvicides for mosquito control as well as antimicrobial agents with eco-friendly approach.

Biogenic nanoparticles: a comprehensive perspective in synthesis, characterization, application and its challenges

BACKGROUND

Translating the conventional scientific concepts into a new robust invention is a much needed one at a present scenario to develop some novel materials with intriguing properties. Particles in nanoscale exhibit superior activity than their bulk counterpart. This unique feature is intensively utilized in physical, chemical, and biological sectors. Each metal is holding unique optical properties that can be utilized to synthesize metallic nanoparticles. At present, versatile nanoparticles were synthesized through chemical and biological methods. Metallic nanoparticles pose numerous scientific merits and have promising industrial applications. But concerning the pros and cons of metallic nanoparticle synthesis methods, researchers elevate to drive the synthesis process of nanoparticles through the utilization of plant resources as a substitute for use of chemicals and reagents under the theme of green chemistry. These synthesized nanoparticles exhibit superior antimicrobial, anticancer, larvicidal, leishmaniasis, wound healing, antioxidant, and as a sensor. Therefore, the utilization of such conceptualized nanoparticles in treating infectious and environmental applications is a warranted one.

CONCLUSION

Green chemistry is a keen prudence method, in which bioresources is used as a template for the synthesis of nanoparticles. Therefore, in this review, we exclusively update the context of plant-based metallic nanoparticle synthesis, characterization, and applications in detailed coverage. Hopefully, our review will be modernizing the recent trends going on in metallic nanoparticles synthesis for the blooming research fraternities.

Phyto-Mediated Synthesis of Porous Titanium Dioxide Nanoparticles From Withania somnifera Root Extract: Broad-Spectrum Attenuation of Biofilm and Cytotoxic Properties Against HepG2 Cell Lines

There is grave necessity to counter the menace of drug-resistant biofilms of pathogens using nanomaterials. Moreover, we need to produce nanoparticles (NPs) using inexpensive clean biological approaches that demonstrate broad-spectrum inhibition of microbial biofilms and cytotoxicity against HepG2 cell lines. In the current research work, titanium dioxide (TiO2) NPs were fabricated through an environmentally friendly green process using the root extract of Withania somnifera as the stabilizing and reducing agent to examine its antibiofilm and anticancer potential. Further, X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron micrograph (TEM), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET) techniques were used for determining the crystallinity, functional groups involved, shape, size, thermal behavior, surface area, and porosity measurement, respectively, of the synthesized TiO2 NPs. Antimicrobial potential of the TiO2 NPs was determined by evaluating the minimum inhibitory concentration (MIC) against Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, Listeria monocytogenes, Serratia marcescens, and Candida albicans. Furthermore, at levels below the MIC (0.5 × MIC), TiO2 NPs demonstrated significant inhibition of biofilm formation (43-71%) and mature biofilms (24-64%) in all test pathogens. Cell death due to enhanced reactive oxygen species (ROS) production could be responsible for the impaired biofilm production in TiO2 NP-treated pathogens. The synthesized NPs induced considerable reduction in the viability of HepG2 in vitro and could prove effective in controlling liver cancer. In summary, the green synthesized TiO2 NPs demonstrate multifarious biological properties and could be used as an anti-infective agent to treat biofilm-based infections and cancer.

Synthesis and characterization of crustin capped titanium dioxide nanoparticles: Photocatalytic, antibacterial, antifungal and insecticidal activities

Current scenario of bio-nanotechnology, successfully fabrication of ultrafine titanium dioxide nanoparticles (TiO₂NPs) using various biological protein sources for the multipurpose targets. The present research report involves synthesis of TiO₂NPs using antimicrobial peptide (AMP) crustin (Cr). Crustin previously purified from the blue crab, Portunus pelagicus haemolymph, by blue Sepharose CL-6B matrix assisted affinity column chromatography. Synthesized Cr-TiO₂NPs was physico-chemically characterized by UV-Visible spectroscopy (UV-Visible), X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), High-resolution transmission electron microscopy (HR-TEM) and zeta potential examination. X-ray diffraction analysis for crystalline nature and phase identification of titanium dioxide nanoparticles was absorbed. Functional groups were found through FTIR ranges between 1620 and 1700 cm^-1. HR-TEM analysis showed that the synthesized Cr-TiO₂NPs tetragonal shape and sizes ranging from 10 to 50 nm. Finally, the surface charge of the Cr-TiO₂NPs was confirmed through zeta potential analysis. Furthermore, the characterized Cr-TiO₂NPs exhibited good biofilm inhibition against GPB - S. mutans (Gram Positive Bacteria- Streptococcus mutans), GNB - P. vulgaris (Gram Negative Bacteria- Proteus vulgaris) and fungal Candida albicans. Moreover, photocatalysis demonstrated that the Cr-TiO₂NPs was effectively explored the degradation of dyes. The results suggest that Cr-TiO₂NPs is an excellent bactericidal, fungicidal and photocatalytic agent that can be supportively used for biomedical and industrial applications.

Phytosynthesized metal oxide nanoparticles for pharmaceutical applications

Developments in nanotechnology field, specifically, metal oxide nanoparticles have attracted the attention of researchers due to their unique sensing, electronic, drug delivery, catalysis, optoelectronics, cosmetics, and space applications. Physicochemical methods are used to fabricate nanosized metal oxides; however, drawbacks such as high cost and toxic chemical involvement prevail. Recent researches focus on synthesizing metal oxide nanoparticles through green chemistry which helps in avoiding the involvement of toxic chemicals in the synthesis process. Bacteria, fungi, and plants are the biological sources that are utilized for the green nanoparticle synthesis. Due to drawbacks such as tedious maintenance and the time needed for the nanoparticle formation, plant extracts are widely used in nanoparticle production. In addition, plants are available all over the world and phytosynthesized nanoparticles show comparatively less toxicity towards mammalian cells. Secondary metabolites including flavonoids, terpenoids, and saponins are present in plant extracts, and these are highly responsible for nanoparticle formation and reduction of toxicity. Hence, this article gives an overview of recent developments in the phytosynthesis of metal oxide nanoparticles and their toxic analysis in various cells and animal models. Also, their possible mechanism in normal and cancer cells, pharmaceutical applications, and their efficiency in disease treatment are also discussed.

Mosquito control with green nanopesticides: towards the One Health approach? A review of non-target effects

The rapid spread of highly aggressive arboviruses, parasites, and bacteria along with the development of resistance in the pathogens and parasites, as well as in their arthropod vectors, represents a huge challenge in modern parasitology and tropical medicine. Eco-friendly vector control programs are crucial to fight, besides malaria, the spread of dengue, West Nile, chikungunya, and Zika virus, as well as other arboviruses such as St. Louis encephalitis and Japanese encephalitis. However, research efforts on the control of mosquito vectors are experiencing a serious lack of eco-friendly and highly effective pesticides, as well as the limited success of most biocontrol tools currently applied. Most importantly, a cooperative interface between the two disciplines is still lacking. To face this challenge, we have reviewed a wide number of promising results in the field of green-fabricated pesticides tested against mosquito vectors, outlining several examples of synergy with classic biological control tools. The non-target effects of green-fabricated nanopesticides, including acute toxicity, genotoxicity, and impact on behavioral traits of mosquito predators, have been critically discussed. In the final section, we have identified several key challenges at the interface between "green" nanotechnology and classic biological control, which deserve further research attention.

Low-temperature biosynthesis of silver nanoparticles using mango leaf extract: catalytic effect, antioxidant properties, anticancer activity and application for colorimetric sensing

Aqueous mango leaf extract was used as a reducing and capping agent for the biosynthesis of silver nanoparticles (AgNPs)viaa single-step, low cost and green process.

Green chemical synthesis of gold nanoparticles by using Penicillium aculeatum and their scolicidal activity against hydatid cyst protoscolices of Echinococcus granulosus

Hydatid disease is a helminth infection with various clinical complications caused by the larval stage of the dog tapeworm Echinococcus granulosus. The scolicidal agents have been broadly applied for inactivation of the fertile cysts up to now, but these scolicidal agents have several side effects on patients. Therefore, this study aimed to explore the scolicidal activity of green synthesized gold nanoparticles (AuNPs) utilizing mycelia-free culture filtrate of Penicillium aculeatum against hydatid cyst protoscolices of E. granulosus. The size and morphology of AuNPs were affirmed by UV-visible spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic light scattering (DLS) analysis. The Fourier transform infrared (FT-IR) analysis of AuNPs showed the presence of possible functional groups responsible for the bioreduction and capping. The AuNPs were formed relatively uniform with spherical shape and superior monodispersity with the average diameter of 60 nm. Consequently, various concentrations (0.05, 0.1, 0.2, and 0.3 mg/mL) of green synthesized AuNPs and different exposure times (10, 30, 60, and 120 min) were used against hydatid cyst protoscolices. Statistically, the difference between the scolicidal effects of AuNPs were seen extremely significant for all four concentrations and at various exposure times in comparison to the control group (P < 0.0001). The most mean protoscolex elimination ratio was 94% (0.3 mg/mL AuNPs and 120-min exposure time). The current investigation indicated that applying biogenic AuNPs may be considered as a potential scolicidal agent for cystic hydatid disease. However, further studies are required to evaluate the efficacy of AuNPs in vivo.

The standard aqueous stem bark extract of Mangifera indica L. inhibits toxic PLA2 - NN-XIb-PLA2 of Indian cobra venom

The aqueous extract of Mangifera indica is known to possess diverse medicinal properties, which also includes anti-snake venom activities. However, its inhibitory potency and mechanism of action on multi-toxic snake venom phospholipases A₂s are still unknown. Therefore, the objective of this study was to evaluate the modulatory effect of standard aqueous bark extract of M. indica on NN-XIb-PLA₂ of Indian cobra venom. The in vitro sPLA₂, in situ hemolytic and in vivo edema inhibition effect were carried out as described. Also the effect of substrate and calcium concentration was carried out. M. indica extract dose dependently inhibited the GIA sPLA₂ (NN-XIb-PLA₂) activity with an IC₅₀ value of 7.6 μg/ml. M. indica extract effectively inhibited the indirect hemolytic activity up to 98% at ∼40 μg/ml concentration. Further, M. indica extract (0–50 μg/ml) inhibited the edema formed in a dose dependent manner. When examined as a function of increased substrate and calcium concentration, there was no relieve of inhibitory effect of M. indica extract on the NN-XIb-PLA₂. Further, the inhibition was irreversible as evident from binding studies. The in vitro inhibition is well correlated with in situ and in vivo edema inhibiting activities of M. indica. As the inhibition is independent of substrate and calcium and was irreversible, it can be concluded that M. indica extract mode of inhibition could be due to direct interaction of components present in the extract with the PLA₂ enzyme. The aqueous extract of M. indica effectively inhibits svPLA₂ enzymatic and its associated toxic activities, which substantiate their anti-snake venom properties. Further in-depth studies on the role and mechanism of the principal constituents present in the extract, responsible for the anti-PLA₂ activity will be interesting to develop them into potent antisnake component and also as an anti-inflammatory agent.