Synthesis of pediculocidal and larvicidal silver nanoparticles by leaf extract from heartleaf moonseed plant, Tinospora cordifolia Miers

Phytosynthesis of zinc oxide nanoparticles for enhanced antioxidant, antibacterial, and photocatalytic properties: A greener approach to environmental sustainability

Multifunctional nanoparticles (NPs) production from phytochemicals is a sustainable process and an eco-friendly method, and this technique has a variety of uses. To accomplish this, we developed zinc oxide nanoparticles (ZnONPs) using the medicinal plant Tinospora cordifolia (TC). Instruments such as UV-Vis, XRD, FTIR, FE-SEM with EDX, and high-resolution TEM were applied to characterize the biosynthesized TC-ZnONPs. According to the UV-vis spectra, the synthesized TC-ZnONPs absorb at a wavelength centered at 374 nm, which corresponds to a 3.2 eV band gap. HRTEM was used to observe the morphology of the particle surface and the actual size of the nanostructures. TC-ZnONPs mostly exhibit the shapes of rectangles and triangles with a median size of 21 nm. The XRD data of the synthesized ZnONPs exhibited a number of peaks in the 2θ range, implying their crystalline nature. TC-ZnONPs proved remarkable free radical scavenging capacity on DPPH (2,2-Diphenyl-1-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), and NO (Nitric Oxide). TC-ZnONPs exhibited dynamic anti-bacterial activity through the formation of inhibition zones against Pseudomonas aeruginosa (18 ± 1.5 mm), Escherichia coli (18 ± 1.0 mm), Bacillus cereus (19 ± 0.5 mm), and Staphylococcus aureus (13 ± 1.1 mm). Additionally, when exposed to sunlight, TC-ZnONPs show excellent photocatalytic ability towards the degradation of methylene blue (MB) dye. These findings suggest that TC-ZnONPs are potential antioxidant, antibacterial, and photocatalytic agents.

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.

Plant-mediated synthesis of silver nanoparticles: unlocking their pharmacological potential-a comprehensive review

In recent times, nanoparticles have experienced a significant upsurge in popularity, primarily owing to their minute size and their remarkable ability to modify physical, chemical, and biological properties. This burgeoning interest can be attributed to the expanding array of biomedical applications where nanoparticles find utility. These nanoparticles, typically ranging in size from 10 to 100 nm, exhibit diverse shapes, such as spherical, discoidal, and cylindrical configurations. These variations are not solely influenced by the manufacturing processes but are also intricately linked to interactions with surrounding stabilizing agents and initiators. Nanoparticles can be synthesized through physical or chemical methods, yet the biological approach emerges as the most sustainable and eco-friendly alternative among the three. Among the various nanoparticle types, silver nanoparticles have emerged as the most encountered and widely utilized due to their exceptional properties. What makes the synthesis of silver nanoparticles even more appealing is the application of plant-derived sources as reducing agents. This approach not only proves to be cost-effective but also significantly reduces the synthesis time. Notably, silver nanoparticles produced through plant-mediated processes have garnered considerable attention in recent years due to their notable medicinal capabilities. This comprehensive review primarily delves into the diverse medicinal attributes of silver nanoparticles synthesized using plant-mediated techniques. Encompassing antimicrobial properties, cytotoxicity, wound healing, larvicidal effects, anti-angiogenesis activity, antioxidant potential, and antiplasmodial activity, the paper extensively covers these multifaceted roles. Additionally, an endeavor is made to provide an elucidated summary of the operational mechanisms underlying the pharmacological actions of silver nanoparticles.

Nano-platform Strategies of Herbal Components for the Management of Rheumatoid Arthritis: A Review on the Battle for Next-Generation Formulations

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that initially affects small joints and then spreads to the bigger joints. It also affects other organs of the body such as lungs, eyes, kidneys, heart, and skin. In RA, there is destruction of cartilage and joints, and ligaments and tendons become brittle. Damage to the joints leads to abnormalities and bone degradation, which may be quite painful for the patient.

METHOD

The nano-carriers such as liposomes, phytosomes, nanoparticles, microcapsules, and niosomes are developed to deliver the encapsulated phytoconstituents to targeted sites for the better management of RA.

RESULTS

The phytoconstituents loaded nano-carriers have been used in order to increase bioavailability, stability and reduce the dose of an active compound. In one study, the curcumin-loaded phytosomes increase the bioavailability of curcumin and also provides relief from RA symptoms. The drug-loaded nano-carriers are the better option for the management of RA.

CONCLUSION

In conclusion, there are many anti-arthritic herbal and synthetic medicine available in the market that are currently used in the treatment of RA. However, chronic use of these medications may result in a variety of side effects. Because therapy for RA is frequently necessary for the rest of ones life. The use of natural products may be a better option for RA management. These phytoconstituents, however, have several disadvantages, including limited bioavailability, low stability, and the need for a greater dosage. These problems can be rectified by using nano-technology.

From nature to nanotechnology: The interplay of traditional medicine, green chemistry, and biogenic metallic phytonanoparticles in modern healthcare innovation and sustainability

As we navigate the modern era, the intersection of time-honoured natural remedies and contemporary scientific approaches forms a burgeoning frontier in global healthcare. For generations, natural products have been foundational to health solutions, serving as the primary healthcare choice for 80% to 85% of the world's population. These herbal-based, nature-derived substances, significant across diverse geographies, necessitate a renewed emphasis on enhancing their quality, efficacy, and safety. In the current century, the advent of biogenic phytonanoparticles has emerged as an innovative therapeutic conduit, perfectly aligning with principles of environmental safety and scientific ingenuity. Utilizing green chemistry techniques, a spectrum of metallic nanoparticles including elements such as copper, silver, iron, zinc, and titanium oxide can be produced with attributes of non-toxicity, sustainability, and economic efficiency. Sophisticated herb-mediated processes yield an array of plant-originated nanomaterials, each demonstrating unique physical, chemical, and biological characteristics. These attributes herald new therapeutic potentials, encompassing antioxidants, anti-aging applications, and more. Modern technology further accelerates the synthesis of natural products within laboratory settings, providing an efficient alternative to conventional isolation methods. The collaboration between traditional wisdom and advanced methodologies now signals a new epoch in healthcare. Here, the augmentation of traditional medicine is realized through rigorous scientific examination. By intertwining ethical considerations, cutting-edge technology, and natural philosophy, the realms of biogenic phytonanoparticles and traditional medicine forge promising pathways for research, development, and healing. The narrative of this seamless integration marks an exciting evolution in healthcare, where the fusion of sustainability and innovation crafts a future filled with endless possibilities for human well-being. The research in the development of metallic nanoparticles is crucial for unlocking their potential in revolutionizing fields such as medicine, catalysis, and electronics, promising groundbreaking applications with enhanced efficiency and tailored functionalities in future technologies. This exploration is essential for harnessing the unique properties of metallic nanoparticles to address pressing challenges and advance innovations across diverse scientific and industrial domains.

Unveiling Various Facades of Tinospora cordifolia Stem in Food: Medicinal and Nutraceutical Aspects

Natural products with curative properties are gaining immense popularity in scientific and food research, possessing no side effects in contrast to other drugs. Guduchi, or Tinospora cordifolia, belongs to the menispermaceae family of universal drugs used to treat various diseases in traditional Indian literature. It has received attention in recent decades because of its utilization in folklore medicine for treating several disorders. Lately, the findings of active phytoconstituents present in herbal plants and their pharmacological function in disease treatment and control have stimulated interest in plants around the world. Guduchi is ethnobotanically used for jaundice, diabetes, urinary problems, stomachaches, prolonged diarrhea, skin ailments, and dysentery. The treatment with Guduchi extracts was accredited to phytochemical constituents, which include glycosides, alkaloids, steroids, and diterpenoid lactones. This review places emphasis on providing in-depth information on the budding applications of herbal medicine in the advancement of functional foods and nutraceuticals to natural product researchers.

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.

Magnesium Oxide Nanoparticles: Effective Antilarvicidal and Antibacterial Agents

People are vulnerable to mosquito-borne infections in tropical and subtropical climate countries. Due to resistive issues, vector control is an immediate concern in today's environment. The current study describes the synthesis of magnesium oxide by four different approaches including green, microwave, sol-gel, and hydrothermal methods. The synthesized magnesium oxide (MgO) nanoparticles were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM), and energy-dispersive X-ray analysis (EDAX) techniques. The FT-IR studies reveal the presence of functional groups in the synthesized nanoparticles. The structural and morphological studies were investigated using XRD and HRSEM. EDAX reveals the presence of Mg and O in the prepared samples. The synthesized MgO NPs were screened for antibacterial studies against Gram-positive strains, Enterococcus faecalis and Staphylococcus aureus, two Gram-negative cultures, Escherichia coli and Klebsiella pneumoniae, using different concentrations. The results indicated excellent antibacterial activity against both Gram-positive and Gram-negative bacteria at 50 mg/mL hydrothermally produced MgO nanoparticles, with a maximal zone of inhibition (ZOI) of 5 mm for S. aureus, 7 mm for E. faecalis, and 6 mm for K. pneumoniae. The ZOI of E. coli was found to be the greatest at 9 mm when 50 mg/mL sol-gel-produced MgO nanoparticles were used. The synthesized MgO nanostructures were tested against fourth-instar larvae of Aedes aegypti and Aedes albopictus, and the hydrothermally synthesized MgO nanostructures exhibited better results when compared with other methods of synthesis. The reports show that A. aegypti and A. albopictus mortality rates were reported to be the lowest with green-manufactured MgO nanoparticles (7.5 g mL-1) and the highest with hydrothermally synthesized MgO nanoparticles (120 g mL-1). The research indicates that MgO nanostructures are promising drugs for antibacterial and mosquitocidal larvae control properties.

Emerging Trends in Advanced Translational Applications of Silver Nanoparticles: A Progressing Dawn of Nanotechnology

Nanoscience has emerged as a fascinating field of science, with its implementation in multiple applications in the form of nanotechnology. Nanotechnology has recently been more impactful in diverse sectors such as the pharmaceutical industry, agriculture sector, and food market. The peculiar properties which make nanoparticles as an asset are their large surface area and their size, which ranges between 1 and 100 nanometers (nm). Various technologies, such as chemical and biological processes, are being used to synthesize nanoparticles. The green chemistry route has become extremely popular due to its use in the synthesis of nanoparticles. Nanomaterials are versatile and impactful in different day to day applications, resulting in their increased utilization and distribution in human cells, tissues, and organs. Owing to the deployment of nanoparticles at a high demand, the need to produce nanoparticles has raised concerns regarding environmentally friendly processes. These processes are meant to produce nanomaterials with improved physiochemical properties that can have significant uses in the fields of medicine, physics, and biochemistry. Among a plethora of nanomaterials, silver nanoparticles have emerged as the most investigated and used nanoparticle. Silver nanoparticles (AgNPs) have become vital entities of study due to their distinctive properties which the scientific society aims to investigate the uses of. The current review addresses the modern expansion of AgNP synthesis, characterization, and mechanism, as well as global applications of AgNPs and their limitations.

Phytoconstituents Assisted Biofabrication of Copper Oxide Nanoparticles and Their Antiplasmodial, and Antilarval Efficacy: A Novel Approach for the Control of Parasites

The present work aimed to biofabricate copper oxide nanoparticles (CuO NPs) using Tinospora cordifolia leaf extract. The biofabricated CuO NPs were treated against the malarial parasite of chloroquine-resistant Plasmodium falciparum (INDO) and the antilarval efficacy was evaluated against the malaria vector Anopheles stephensi and dengue vector Aedes aegypti. The prominence at 285 nm in the UV-visible spectrum helped to identify the produced CuO NPs. Based on the XRD patterns, the concentric rings correspond to reflections at 38.26° (111), 44.11° (200), 64.58° (220), and 77.34° (311). These separations are indicative of CuO's face-centered cubic (fcc) structure. The synthesized CuO NPs have FTIR spectra with band intensities of 3427, 2925, 1629, 1387, 1096, and 600 cm^-1. The absorbance band at 3427 cm^-1 is known to be associated with the stretching O-H due to the alcoholic group. FTIR proved that the presence of the -OH group is responsible for reducing and capping agents in the synthesis of nanoparticles (NPs). The synthesized CuO NPs were found to be polymorphic (oval, elongated, and roughly spherical) in form with a size range of 11-47 nm and an average size of 16 nm when the morphology was examined using FESEM and HRTEM. The highest antiplasmodial efficacy against the chloroquine-resistant strain of P. falciparum (INDO) was found in the synthesized CuO NPs, with LC₅₀ values of 19.82 µg/mL, whilst HEK293 cells are the least toxic, with a CC₅₀ value of 265.85 µg/mL, leading to a selectivity index of 13.41. However, the antiplasmodial activity of T. cordifolia leaf extract (TCLE) and copper sulfate (CS) solution showed moderate activity, with LC₅₀ values of 52.24 and 63.88 µg/mL, respectively. The green synthesized NPs demonstrated extremely high antilarval efficacy against the larvae of An. stephensi and Ae. aegypti, with LC₅₀ values of 4.06 and 3.69 mg/L, respectively.

PMMA/ABS/CoCl2 Composites for Pharmaceutical Applications: Thermal, Antimicrobial, Antibiofilm, and Antioxidant Studies

In this study, PMMA/ABS/CoCl₂ ternary composite films were fabricated by the solution casting technique. The different weight ratios of cobalt chloride (≤10 wt) were incorporated into the PMMA/ABS blend (80:20). The chemical structure and thermal properties of the synthesized composites were assessed by FT-IR, TGA, and XRD. The biological properties of ternary composites, such as in vitro antibacterial activity and antioxidant capacity, were investigated. The enhanced thermal stability and promising antibacterial, selective antibiofilm, and potential antioxidant properties of PMMA/ABS/cobalt chloride composites demonstrated that they can be used for high-quality plastics and in many pharmaceutical applications.

Multiplex heteroatoms doped carbon nano dots with enhanced catalytic reduction of ionic dyes and QR code security label for anti-spurious applications

Herein, a simple hydrothermal approach was used to make multiplex heteroatoms doped carbon dots from Tinospora cordifolia miers plant extract. Their ability to the catalytic activity of dyes and anti-spurious applications was evaluated. The formation of NBCNDs and source of (T. cordifolia miers) study the optical properties, and functional groups are investigated using UV-Visible spectroscopy and FT-IR techniques. The synthesized NBCNDs structure and elemental compositions were examined via HR-TEM, XRD, and XPS, respectively. According to the HRTEM images, the average particle size of the NBCNDs was around 4.3± 1 nm, with d-spacing of 0.19 nm. The obtained NBCNDs were exposed under 395 nm UV light to emit bluish-green tuneable fluorescence with QY (quantum yield) of 23.7%. The prepared NBCNDs as a potential catalyst for the AYR and CV dye reduction process using freshly prepared NaBH₄, with determined rate constant values at 0.1220 and 0.1521 min^-1, respectively. Lastly, we constructed a quick response (QR) code security label for anti-spurious applications using stencil techniques. The "confidential info" was encrypted using a QR code digital system, and the decryption was read using a smartphone under 365 nm light irradiation.

Biologically Synthesized Silver Nanoparticles and Their Diverse Applications

Nanotechnology has become the most effective and rapidly developing field in the area of material science, and silver nanoparticles (AgNPs) are of leading interest because of their smaller size, larger surface area, and multiple applications. The use of plant sources as reducing agents in the fabrication of silver nanoparticles is most attractive due to the cheaper and less time-consuming process for synthesis. Furthermore, the tremendous attention of AgNPs in scientific fields is due to their multiple biomedical applications such as antibacterial, anticancer, and anti-inflammatory activities, and they could be used for clean environment applications. In this review, we briefly describe the types of nanoparticle syntheses and various applications of AgNPs, including antibacterial, anticancer, and larvicidal applications and photocatalytic dye degradation. It will be helpful to the extent of a better understanding of the studies of biological synthesis of AgNPs and their multiple uses.

Toxicity of plant-based silver nanoparticles to vectors and intermediate hosts: Historical review and trends

Green nanoparticles (GNPs), mainly green silver nanoparticles (Ag NPs), have been recommended as sustainable and eco-friendly technologies to control vectors and intermediate hosts. The aim of the current study is to carry out a historical and systematic literature review about the use of green plant-based Ag NPs (GP-Ag NPs) to control medically important mosquito, tick and gastropods. Data about the number of studies published per year, geographical distribution of studies (mailing address of the corresponding author), synthesis type (plant species, plant structure and extract types), physicochemical properties of GP-Ag NPs, experimental designs, developmental stages and the toxic effects on mosquitoes, ticks and gastropods were summarized and discussed. Revised data showed that GP-Ag NPs synthesis and toxicity in mosquitoes, ticks and snails depend on plant species, plant part, extract types, exposure condition and on the analyzed species. GP-Ag NPs induced mortality, tissue damage, biochemical and behavioral changes in mosquitoes and reduced their fecundity, oviposition, egg hatching and longevity. Ticks exposed to GP-Ag NPs presented increased mortality and reduced oviposition, while on snails, studies demonstrated mortality, oxidative stress, and DNA damage. Immune responses were also observed in snails after their exposure to GP-Ag NPs. GP-Ag NPs reduced the reproduction and population of several vectors and intermediate hosts. This finding confirms their potential to be used in gastropod control programs. Future studies about current gaps in knowledge are recommended.

Biotechnological applications of mangrove plants and their isolated compounds in medicine-a mechanistic overview

Mangrove plants, also known as halophytes, are ecologically important plants that grow in various tropical and subtropical intertidal regions. Owing to the extreme abiotic and biotic stressful conditions they thrive in, these plants produce unique compounds with promising pharmacological propensities. Mangroves are inhabited by an astronomical number of fungal communities which produce a diverse array of extracellular degradative enzymes, namely: amylase, cellulase, xylanase, pectinase, cholesterol oxidase, etc. Such enzymes can be isolated from the mangrove fungi and harnessed for different biotechnological applications, for example, as replacements for chemical catalysts. Mangrove microbes attract considerable attention as they shelter the largest group of marine microorganisms that are resistant to extreme conditions and can produce novel biogenic substances. Vaccines developed from mangrove microbes may promise a safe future by developing effective immunization procedures with a minimum of economic burden. Interestingly, mangroves offer an exciting opportunity for synthesizing nanoparticles in a greener way as these plants are naturally rich in phytochemicals. Rhizophora mucronata Lam., Avicennia officinalis L. and Excoecaria agallocha L. are capable of synthesizing nanoparticles which have evolved recently as an alternative in various industries and are used for their biomedical application. Besides, the phytoconstituents isolated from mangrove plants, such as: gallic acid, galactose, lupeol, catechins, carotenoids, etc., were explored for various biological activities. These compounds are used in the pharmaceutical and nutraceutical industries to produce antimicrobial, antioxidant, anticancer, antidiabetic, and other therapeutic agents. The present review provides information on the biotechnological potentials of mangrove plants and their bioactive compounds as a new source of novel drugs, enzymes, nanoparticles and therapeutically important microbial pigments. Thus, this review forms a base of support and hasten the urgent research on biomedical applications of mangroves.

Nanopesticides: A Systematic Review of Their Prospects With Special Reference to Tea Pest Management

Background: Tea is a natural beverage made from the tender leaves of the tea plant (Camellia sinensis Kuntze). Being of a perennial and monoculture nature in terms of its cultivation system, it provides a stable micro-climate for various insect pests, which cause substantial loss of crop. With the escalating cost of insect pest management and increasing concern about the adverse effects of the pesticide residues in manufactured tea, there is an urgent need to explore other avenues for pest management strategies. Aim: Integrated pest management (IPM) in tea invites an multidisciplinary approach owing to the high pest diversity in the perennial tea plantation system. In this review, we have highlighted current developments of nanotechnology for crop protection and the prospects of nanoparticles (NPs) in plant protection, emphasizing the control of different major pests of tea plantations. Methods: A literature search was performed using the ScienceDirect, Web of Science, Pubmed, and Google Scholar search engines with the following terms: nanotechnology, nanopesticides, tea, and insect pest. An article search concentrated on developments after 1988. Results: We have described the impact of various pests in tea production and innovative approaches on the use of various biosynthesized and syntheric nanopesticides against specific insect pest targets. Simultaneously, we have provided support for NP-based technology and their different categories that are currently employed for the management of pests in different agro-ecosystems. Besides the broad categories of active ingredients (AI) of synthetic insecticides, pheromones and natural resource-based molecules have pesticidal activity and can also be used with NPs as a carriers as alternatives to traditional pest control agents. Finally, the merits and demerits of incorporating NP-based nanopesticides are also illustrated. Conclusions: Nanopesticides for plant protection is an emerging research field, and it offers new methods to design active ingredients amid nanoscale dimensions. Nanopesticide-based formulations have a potential and bright future for the development of more effective and safer pesticide/biopesticides.

Plant celluloses, hemicelluloses, lignins, and volatile oils for the synthesis of nanoparticles and nanostructured materials

A huge variety of plants are harvested worldwide and their different constituents can be converted into a broad range of bionanomaterials. In parallel, much research effort in materials science and engineering is focused on the formation of nanoparticles and nanostructured materials originating from agricultural residues. Cellulose (40-50%), hemicellulose (20-40%), and lignin (20-30%) represent major plant ingredients and many techniques have been described that separate the main plant components for the synthesis of nanocelluloses, nano-hemicelluloses, and nanolignins with divergent and controllable properties. The minor components, such as essential oils, could also be used to produce non-toxic metal and metal oxide nanoparticles with high bioavailability, biocompatibility, and/or bioactivity. This review describes the chemical structure, the physical and chemical properties of plant cell constituents, different techniques for the synthesis of nanocelluloses, nanohemicelluloses, and nanolignins from various lignocellulose sources and agricultural residues, and the extraction of volatile oils from plants as well as their use in metal and metal oxide nanoparticle production and emulsion preparation. Furthermore, details about the formation of activated carbon nanomaterials by thermal treatment of lignocellulose materials, a few examples of mineral extraction from agriculture waste for nanoparticle fabrication, and the emerging applications of plant-based nanomaterials in different fields, such as biotechnology and medicine, environment protection, environmental remediation, or energy production and storage, are also included. This review also briefly discusses the recent developments and challenges of obtaining nanomaterials from plant residues, and the issues surrounding toxicity and regulation.

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.

Biocontrol of mosquito vectors through herbal-derived silver nanoparticles: prospects and challenges

Mosquitoes spread several life-threatening diseases such as malaria, filaria, dengue, Japanese encephalitis, West Nile fever, chikungunya, and yellow fever and are associated with millions of deaths every year across the world. However, insecticides of synthetic origin are conventionally used for controlling various vector-borne diseases but they have various associated drawbacks like impact on non-targeted species, negative effects on the environment, and development of resistance in vector species by alteration of the target site. Plant extracts, phytochemicals, and their nanoformulations can serve as ovipositional attractants, insect growth regulators, larvicides, and repellents with least effects on the environment. Such plant-derived products exhibit broad-spectrum resistance against various mosquito species and are relatively cheaper, environmentally safer, biodegradable, easily accessible, and are non-toxic to non-targeted organisms. Therefore, in this review article, the current knowledge of phytochemical sources exhibiting larvicidal activity and their variations in response to solvents used for their extraction is underlined. Also, different methods such as physical, chemical, and biological for silver nanoparticle (AgNPs) synthesis, their mechanism of synthesis using plant extract, their potent larvicidal activity, and the possible mechanism by which these particles kill mosquito larvae are discussed. In addition, constraints related to commercialization of nanoherbal products at government and academic or research level and barriers from laboratory experiments to field trial have also been discussed. This comprehensive information can be gainfully employed for the development of herbal larvicidal formulations and nanopesticides against insecticide-resistant vector species in the near future. Graphical abstract.

Silica Nanoparticles for Insect Pest Control

To date, control strategies used against insect pest species are based on synthetic insecticide applications. In addition, the efficacy of these treatments could be decreased due to insecticide resistance in insect populations. Also, the irrational use of chemical control strategies has negative consequences of non-target organisms and threatening human health. Designing nanomaterial for pest insect control is a promising alternative to traditional insecticide formulations. In particular, it has been proven that silica nanoparticles have the potential for molecules delivery, release control improvement and also their toxicity as insecticide alone. In this work, we summarized the state of knowledge on silica nanoparticles (SiNPs) used in pest insect management. Besides, aspects of their synthesis, mode of action, and toxic effects on non-target organisms and environment are reviewed.

Helminthicidal and Larvicidal Potentials of Biogenic Silver Nanoparticles Synthesized from Medicinal Plant Momordica charantia

BACKGROUND

The drug formulations used to control mosquito vectors and helminth infections have resulted in the development of resistance, and negative impact on non-target organisms and environment.

OBJECTIVE

Plant-mediated synthesis of silver nanoparticles (P-AgNPs) using aqueous fruit peel extract of M. charantia, applications of P-AgNPs for helminthicidal activity against Indian earthworms (P. posthuma) and larvicidal activity against larvae of mosquito A. albopictus and A. aegypti.

METHODS

Aqueous fruit peel extract of Momordica charantia was used to reduce silver ions to silver nanoparticles (P-AgNPs). UV-Visible (UV-Vis) Spectroscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy and Transmission Electron Microscopy characterize synthesized P-AgNPs. The motility and survival rate of the worms were recorded for the helminthicidal activity. Percent mortality of larvae of A. albopictus and A. aegypti was recorded for larvicidal activity.

RESULTS

The UV-Vis absorption spectrum of P-AgNPs showed a strong surface plasmon absorption band in the visible region with a maximum absorption at 445 nm indicating the synthesis of silver nanoparticles by the addition of aqueous fruit peel extract. The XRD spectrum of P-AgNPs showed Bragg's reflection peaks 2θ value characteristics for the Face-Centered Cubic (FCC) structure of silver. The sharp absorption peak in FTIR at 1659 cm-1 assigned to C=O stretching vibration in carbonyl compounds represents terpenoids, flavonoids and polyphenols in the corona of PAgNPs; a 2 mg/mL of P-AgNPs. The concentration aqueous extract and P-AgNPs showed complete death of worms (the morphological alteration/coiling of body). A 20 ppm concentration of PAgNPs showed 85% mortality in larvae of Ae. albopictus and Ae. aegypti. P-AgNPs were nontoxic at low concentrations.

CONCLUSION

The aqueous extracts played a dual role as reducing and capping agent during the biosynthesis of AgNPs as per FTIR and XRD results. The surface reactivity facilitated by biomolecule corona attached to silver nanoparticles can further help to functionalize AgNPs in various pharmaceuticals, biomedicals, and environmental applications.

One-step Synthesis of Silver Nanoparticles Using Saudi Arabian Desert Seasonal Plant Sisymbrium irio and Antibacterial Activity Against Multidrug-Resistant Bacterial Strains

Globally, antimicrobial resistance has grown at an alarming rate. To combat the multidrug-resistant (MDR) superbugs, silver nanoparticles (Ag NPs) were synthesized using an aqueous leaf extract of seasonal desert plant Sisymbrium irio obtained from the central region of Saudi Arabia by a simple one-step procedure. The physical and chemical properties of the Ag NPs were investigated through ultraviolet visisble analysis (UV-vis), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) analysis. The UV-vis spectrum showed an absorption band at 426 nm. The XRD results showed a highly crystalline face-centered cubic structure. The surface morphology analyzed using SEM and TEM analyses showed the particle size to be in the range 24 nm to 50 nm. Various concentrations of Ag NPs were tested against MDR Pseudomonas aeruginosa and Acinetobacter baumanii that cause ventilator-associated pneumonia (VAP). American Type Culture Collection (ATCC) Escherichia coli-25922 was used as the reference control strain. The Ag NPs effectively inhibited tested pathogens, even at the lowest concentration (6.25 µg) used. The bacterial inhibitory zone ranged from 11–21 mm. In conclusion, the newly synthesized Ag NPs could be a potential alternative candidate in biomedical applications in controlling the spread of MDR pathogens.

Plant extracts for developing mosquito larvicides: From laboratory to the field, with insights on the modes of action

In the last decades, major research efforts have been done to investigate the insecticidal activity of plant-based products against mosquitoes. This is a modern and timely challenge in parasitology, aimed to reduce the frequent overuse of synthetic pesticides boosting resistance development in mosquitoes and causing serious threats to human health and environment. This review covers the huge amount of literature available on plant extracts tested as mosquito larvicides, particularly aqueous and alcoholic ones, due to their easy formulation in water without using surfactants. We analysed results obtained on more than 400 plant species, outlining that 29 of them have outstanding larvicidal activity (i.e., LC₅₀ values below 10 ppm) against major vectors belonging to the genera Anopheles, Aedes and Culex, among others. Furthermore, synergistic and antagonistic effects between plant extracts and conventional pesticides, as well as among selected plant extracts are discussed. The efficacy of pure compounds isolated from the most effective plant extracts and - when available - their mechanism of action, as well as the impact on non-target species, is also covered. These belong to the following class of secondary metabolites: alkaloids, alkamides, sesquiterpenes, triterpenes, sterols, flavonoids, coumarins, anthraquinones, xanthones, acetogenonins and aliphatics. Their mode of action on mosquito larvae ranges from neurotoxic effects to inhibition of detoxificant enzymes and larval development and/or midugut damages. In the final section, current drawbacks as well as key challenges for future research, including technologies to synergize efficacy and improve stability - thus field performances - of the selected plant extracts, are outlined. Unfortunately, despite the huge amount of laboratory evidences about their efficacy, only a limited number of studies was aimed to validate their efficacy in the field, nor the epidemiological impact potentially arising from these vector control operations has been assessed. This strongly limits the development of commercial mosquito larvicides of botanical origin, at variance with plant-borne products developed in the latest decades to kill or repel other key arthropod species of medical and veterinary importance (e.g., ticks and lice), as well as mosquito adults. Further research on these issues is urgently needed.

Silver nanomaterials in the natural environment: An overview of their biosynthesis and kinetic behavior

Silver nanomaterials (Ag NMs) are fabricated by many biological components in our environment. Recently, research on their biosynthesis and reactions has become a focus of attention. Due to the complexity of biological systems and samples, specific processes and mechanisms involving Ag NMs are difficult to identify and elucidate on the molecular and chemical-bond level. The microorganisms and composite components of plant extracts are of great interest in many biological syntheses. Although potential biomolecules have been shown to play essential roles in biological systems in Ag NM biosynthesis, the detailed mechanism of the electron transfer process and crucial molecules that control this reaction have only recently come into focus. The reactive behavior of the Ag NMs is of great significance for understanding their overall behavior and toxicity. Additionally, only limited knowledge is available about their kinetics. All reactions involve chemical bond formation, electron transfer, or electrostatic interactions. An overview is presented of the biosynthesis of Ag NMs based on molecular supports including a nitrate reductase/NADH oxidase-involved electron transfer reaction and their mechanisms in Ag⁺ reduction: quinol-mediated mechanism and superoxide-dependent mechanism, and molecular supports in plant extracts, is presented. The environmental reaction kinetics and mechanisms of the interactions of Ag NMs with substances are introduced based on the formation and classification of chemical bonds. The particle-particle reaction kinetics of Ag NMs in the environment are discussed to directly explain their stability and aggregation behavior. The toxicity of Ag NMs is also presented. In addition, future prospects are summarized. This review is the first to provide an insight into the mediating molecules and chemical bonds involved in the biosynthesis, kinetics, and mechanisms of action of Ag NMs.

The potential effects of silver and gold nanoparticles as molluscicides and cercaricides on Schistosoma mansoni

Schistosomiasis seriously affects human health in tropical regions. Its prevention is more important than treatment, raising the need for effective control methods. Recently, the role of nanomaterials in medical science has been growing. The present study aimed to evaluate the potential effects of silver (Ag) and gold (Au) nanoparticles (NPs) on Biomphalaria alexandrina snails and Schistosoma mansoni cercariae in vitro and to assess their effects on the infectivity of cercariae in vivo. The in vitro study proved that Ag and Au NPs were effective in killing B. alexandrina snails, with 30 μg/ml Ag and 160 μg/ml Au causing 100% mortality. The LC₅₀ of 9.68 μg/ml for Ag NPs and 133.7 μg/ml for Au NPs prevented snail infection with S. mansoni miracidia. Furthermore, Ag NPs at 50 μg/ml and Au NPs at 100 μg/ml increased the mortality of S. mansoni cercariae in a dose- and time-dependent manner, reaching 100% mortality after 1 h. The in vivo study found that Ag NPs prevented the occurrence of infection when cercariae were treated before the infection by either the tail immersion (TI) or subcutaneous (SC) route, as proven by parasitological parameters and by the absence of granuloma formation in hepatic tissue. Meanwhile, infection of mice by untreated cercariae followed by treatment with NPs 1 h post-infection (PI) caused a decrease in egg count/g intestine and egg count/g liver in the TI-infected group only. The oogram patterns and granuloma formation results were similar between infection control and the SC-infected group. On the other hand, Au NPs led to a decrease in total worm burden (TWB) in all tested groups, with a decrease in egg count/g intestine and egg count/g liver in TI-infected groups with either pre-treated or post-treated cercariae, in contrast to SC-infected groups. However, the oogram patterns and granuloma formation showed similar results to infection control. Ag and Au NPs have potential as molluscicides and cercaricides in vitro and can prevent or modulate the infectivity of cercariae in vivo.

Nanoparticle-plant interaction: Implications in energy, environment, and agriculture

In the recent techno-scientific revolution, nanotechnology has gained popularity at a rapid pace in different sectors and disciplines, specifically environmental, sensing, bioenergy, and agricultural systems. Controlled, easy, economical, and safe synthesis of nanomaterials is desired for the development of new-age nanotechnology. In general, nanomaterial synthesis techniques, such as chemical synthesis, are not completely safe or environmentally friendly due to harmful chemicals used or to toxic by-products produced. Moreover, a few nanomaterials are present as by-product during washing process, which may accumulate in water, air, and soil system to pose serious threats to plants, animals, and microbes. In contrast, using plants for nanomaterial (especially nanoparticle) synthesis has proven to be environmentally safe and economical. The role of plants as a source of nanoparticles is also likely to expand the number of options for sustainable green renewable energy, especially in biorefineries. Despite several advantages of nanotechnology, the nano-revolution has aroused concerns in terms of the fate of nanoparticles in the environment because of the potential health impacts caused by nanotoxicity upon their release. In the present panoramic review, we discuss the possibility that a multitudinous array of nanoparticles may find applications convergent with human welfare based on the synthesis of diverse nanoparticles from plants and their extracts. The significance of plant-nanoparticle interactions has been elucidated further for nanoparticle synthesis, applications of nanoparticles, and the disadvantages of using plants for synthesizing nanoparticles. Finally, we discuss future prospects of plant-nanoparticle interactions in relation to the environment, energy, and agriculture with implications in nanotechnology.

Assessment of oxidative/nitrosative stress biomarkers and DNA damage in Haemonchus contortus, following exposure to zinc oxide nanoparticles

Drug resistance in helminth parasites has incurred several difficulties to livestock industry and ranked among the top public health concerns. Therefore, seeking for new agents to control parasites is an urgent strategy. In the recent years, metallic nanoparticles have been considerably evaluated for anthelmintic effects. The current research was conducted to assess possible anthelmintic impacts of zinc oxide nanoparticles (ZnO-NPs) on a prevalent gastrointestinal nematode, H. contortus. Moreover, several biomarkers of oxidative/nitrosative stress and DNA damage were measured. Various concentrations of the nanoparticle were prepared and incubated with the worms for 24 hours. The parasite mobility, mortality rate, antioxidant enzymes activities (SOD, Catalase and GSH-Px), lipid peroxidation, total antioxidant status as well as nitric oxide (NO) contents and DNA damage were determined. ZnO-NPs exerted significant wormicidal effects via induction of oxidative/nitrosative stress and DNA damage. Conclusively, ZnO-NPs can be utilized as a novel and potential agent to control and treatment of helminth parasitic infections.

Secondary Metabolites in the Green Synthesis of Metallic Nanoparticles

The ability of organisms and organic compounds to reduce metal ions and stabilize them into nanoparticles (NPs) forms the basis of green synthesis. To date, synthesis of NPs from various metal ions using a diverse array of plant extracts has been reported. However, a clear understanding of the mechanism of green synthesis of NPs is lacking. Although most studies have neglected to analyze the green-synthesized NPs (GNPs) for the presence of compounds derived from the extract, several studies have demonstrated the conjugation of sugars, secondary metabolites, and proteins in these biogenic NPs. Despite several reports on the bioactivities (antimicrobial, antioxidant, cytotoxic, catalytic, etc.) of GNPs, only a handful of studies have compared these activities with their chemically synthesized counterparts. These comparisons have demonstrated that GNPs possess better bioactivities than NPs synthesized by other methods, which might be attributed to the presence of plant-derived compounds in these NPs. The ability of NPs to bind with organic compounds to form a stable complex has huge potential in the harvesting of precious molecules and for drug discovery, if harnessed meticulously. A thorough understanding of the mechanisms of green synthesis and high-throughput screening of stabilizing/capping agents on the physico-chemical properties of GNPs is warranted to realize the full potential of green nanotechnology.

Biophysical characterization of Acacia caesia-fabricated silver nanoparticles: effectiveness on mosquito vectors of public health relevance and impact on non-target aquatic biocontrol agents

Mosquito-borne diseases lead to serious public health concerns in tropical and sub-tropical countries worldwide, due to development of mosquito resistance to synthetic pesticides, non-target effects of pesticides, and socioeconomic reasons. Currently, green nanotechnology is a promising research field, showing a wide range of potential applications in vector control programs. The employ of natural products as reducing agents to fabricate insecticidal nanocomposites is gaining research attention worldwide, due to low costs and high effectiveness. Interestingly, biophysical features of green-synthesized nanoparticles strongly differ when different botanicals are employed for nanosynthesis. In this study, a cheap Acacia caesia leaf extract was employed to fabricate silver nanoparticles (Ag NPs) with ovicidal, larvicidal, and adulticidal toxicity against three mosquito vectors, Anopheles subpictus, Aedes albopictus, and Culex tritaeniorhynchus. Ag NPs were analyzed by various biophysical methods, including spectroscopy (UV-visible spectrophotometry, XRD, FTIR, EDX) and microscopy (SEM, TEM, AFM) techniques. High acute larvicidal potential was observed against larvae of An. subpictus (LC₅₀ = 10.33 μg/ml), Ae. albopictus (LC₅₀ = 11.32 μg/ml), and Cx. tritaeniorhynchus (LC₅₀ = 12.35 μg/ml). Ag NPs completely inhibited egg hatchability on three vectors at 60, 75, and 90 μg/ml, respectively. In adulticidal assays, LD₅₀ values were 18.66, 20.94, and 22.63 μg/ml. If compared to mosquito larvae, Ag NPs were safer to three non-target aquatic biocontrol agents, with LC₅₀ ranging from 684 to 2245 μg/ml. Overall, our study highlights the potential of A. caesia as an abundant and cheap bioresource to fabricate biogenic Ag NPs effective against mosquito young instars and adults, with moderate impact on non-target aquatic biocontrol agents.

Toxicity studies of nanofabricated palladium against filariasis and malaria vectors

The present study was carried out to establish the biofabrication of palladium nanoparticles (PdNPs) using the plant leaf extract of Tinospora cordifolia Miers and its toxicity studies on the larvae of filariasis vector, Culex quinquefasciatus Say and malaria vector, Anopheles subpictus Grassi. The biofabricated PdNPs were characterized by using UV-visible spectrum, FTIR, XRD, FESEM, EDX and HRTEM. HRTEM confirmed the PdNPs were slightly agglomerated and spherical in shape and the average size was 16 nm. Gas chromatography and mass spectrometry analysis result revealed that the major constituent present in the T. cordifolia leaf extract is 2,4-di-tert-butylphenol (31.79%) whereas the minor compounds are 1-hexadecanol (7.97%), 1-octadecanol (7.70%), 1-eicosanol (6.85%), behenic alcohol (5.36%), 1-tetradecene (6.22%), cyclotetradecane (6.23%), 1-hexadecene (7.97%), 1-octadecene (7.70%), 1-eicosene (6.85%), and 1-docosene (5.36%). T. cordifolia leaf extract exhibited the larvicidal activity against the fourth instar larvae of C. quinquefasciatus and A. subpictus with the values of LC₅₀ = 59.857 and 54.536 mg/L; LC₉₀ = 113.445 and 108.940 mg/L, respectively. The highest toxicity was observed in the biofabricated PdNPs against the fourth instar larvae of C. quinquefasciatus and A. subpictus with the values of LC₅₀ = 6.090 and 6.454 mg/L; LC₉₀ = 13.689 and 13.849 mg/L, respectively. Concerning non-target effects, Poecilia reticulata were exposed to PdNPs for 24 h and did not exhibit any noticeable toxicity. Overall, our findings strongly suggest that PdNPs is a perfect ecological and inexpensive approach for the control of filariasis and malaria vectors.

Environmentally benign nanometric neem-laced urea emulsion for controlling mosquito population in environment

The increasing risk of vector-borne diseases and the environmental pollution in the day-to-day life due to the usage of the conventional pesticides makes the role of nanotechnology to come into the action. The current study deals with one of the applications of nanotechnology through the formulation of neem urea nanoemulsion (NUNE). NUNE was formulated using neem oil, Tween 20, and urea using the microfluidization method. Prior to the development of nanoemulsion, the ratio of oil/surfactant/urea was optimized using the response surface modeling method. The mean droplet size of the nanoemulsion was found to be 19.3 ± 1.34 nm. The nanoemulsion was found to be stable for the period of 4 days in the field conditions which aids to its mosquitocidal activity. The nanoemulsion exhibited a potent ovicidal and larvicidal activity against A. aegypti and C. tritaeniorhynchus vectors. This result was corroborated with the histopathological analysis of the NUNE-treated larvae. Further, the effect of NUNE on the biochemical profile of the target host was assessed and was found to be efficacious compared to the bulk counterpart. The nanoemulsion was then checked for its biosafety towards the non-target species like plant beneficial bacterium (E. ludwigii), and phytotoxicity was assessed towards the paddy plant (O. sativa). Nanometric emulsion at the concentration used for the mosquitocidal application was found to be potentially safe towards the environment. Therefore, the nanometric neem-laced urea emulsion tends to be an efficient mosquito control agent with an environmentally benign property.