Improving the Stability, Foliar Utilization and Biological Activity of Imidacloprid Delivery Systems: Size Effect of Nanoparticles.

Nanotechnology could improve the effectiveness and functionality of pesticides, but the size effect of nanopesticides on formulation performance and the related mechanisms have yet to be explored, hindering the precise design and development of efficient and eco-friendly nanopesticides. In this study, two non-carrier-coated imidacloprid formulations (Nano-IMI and Micro-IMI) with identical composition but varying particle size characteristics were constructed to exclude other interferences in the size effect investigation. Nano-IMI and Micro-IMI both exhibited rod-like structures. Specifically, Nano-IMI had average vertical and horizontal axis sizes of 239.5 nm and 561.8 nm, while Micro-IMI exhibited 6.7 µm and 22.1 µm, respectively. Compared to Micro-IMI, the small size effect of Nano-IMI affected the arrangement of interfacial molecules, reduced surface tension and contact angle, thereby improving the stability, dispersibility, foliar wettability, deposition and retention of the nano-system. Nano-IMI exhibited 1.3 times higher toxicity to Aphis gossypii Glover compared to Micro-IMI, attributed to its enhanced foliar utilization efficiency. Importantly, the Nano-IMI did not intensify the toxicity to non-target organism Apis mellifera L. This study systematically elucidates the influence of size effect on key indicators related to the effectiveness and safety, providing a theoretical basis for efficient and safe application of nanopesticides and critical insights into sustainable agriculture and environmental development.

Size-dependent Effect on Foliar Utilization and Biocontrol Efficacy of Emamectin Benzoate Delivery Systems.

The development of nanopesticides provides new avenues for pesticide reduction and efficiency improvement. However, the size effect of nanopesticides remains unclear, and its underlying mechanisms of influence have become a major obstacle in the design and application of pesticide nanoformulations. In this research, the noncarrier-coated emamectin benzoate (EB) solid dispersions (Micro-EB and Nano-EB) were produced under a constant surfactant-to-active ingredient ratio by a self-emulsifying-carrier solidification technique. The particle size of Micro-EB was 162 times that of spherical Nano-EB. The small size and large specific surface area of Nano-EB facilitated the adsorption of surfactants on the surface of the particles, thereby improving its dispersibility, suspensibility, and stability. The pinning effect of nanoparticles significantly suppressed droplet retraction and rebounding. Moreover, Nano-EB exhibited a 25% higher retention of the active ingredient on cabbage leaves and a 70% higher washing resistance than Micro-EB, and both were significantly different. The improvement of abilities in wetting, spreading, and retention of Nano-EB on crop leaves contributed to the increase in foliar utilization, which further resulted in a 1.6-fold enhancement of bioactivity against target Spodoptera exigua compared to Micro-EB. Especially, Nano-EB did not exacerbate the safety risk to the nontarget organism zebrafish with no significant difference. This study elaborates the size effect on the effectiveness and safety of pesticide formulations and lays a theoretical foundation for the development and rational utilization of efficient and environmentally friendly nanopesticides.

The key factors of solid nanodispersion for promoting the bioactivity of abamectin.

Solid nanodispersion (SND) is an important variety of nanopesticides which have been extensively studied in recent years. However, the key influencing factors for bioactivity enhancement of nanopesticides remain unclear, which not only limits the exploration of relevant mechanisms, but also hinders the precise design and development of nanopesticides. In this study, we explored the potential of SND in enhancing the bioactivity of nanopesticides, specifically focusing on abamectin SND prepared using a self-emulsifying-carrier solidifying technique combined with parameter optimization. Our formulation, consisting of 8% abamectin, 1% antioxidant BHT (2,6-di-tert-butyl-4-methylphenol), 12% complex surfactants, and 79% sodium benzoate, significantly increased the pseudo-solubility of abamectin by at least 3300 times and reduced its particle size to a mere 15 nm, much smaller than traditional emulsion in water (EW) and water-dispersible granule (WDG) forms. This reduction in particle size and increase in surface activity resulted in improved foliar adhesion and retention, enabling a more efficient application without the need for organic solvents. The inclusion of antioxidants also enhanced photostability compared to EW, and overall stability tests confirmed SND's resilience under various storage conditions. Bioactivity tests demonstrated a marked increase in toxicity against diamondback moths (Plutella xylostella L.) with abamectin SND, which exhibited 3.7 and 7.6 times greater efficacy compared to EW and WDG, respectively. These findings underscore the critical role of small particle size, high surface activity, and strong antioxidant properties in improving the performance and bioactivity of abamectin SND, highlighting its significance in the design and development of high-efficiency, eco-friendly nanopesticides and contributing valuably to sustainable agricultural practices.

Preparation and Comprehensive Evaluation of the Efficacy and Safety of Chlorantraniliprole Nanosuspension.

Chlorantraniliprole is a broad-spectrum insecticide that has been widely used to control pests in rice fields. Limited by its low solubility in both water and organic solvents, the development of highly efficient and environmentally friendly chlorantraniliprole formulations remains challenging. In this study, a low-cost and scalable wet media milling technique was successfully employed to prepare a chlorantraniliprole nanosuspension. The average particle size of the extremely stable nanosuspension was 56 nm. Compared to a commercial suspension concentrate (SC), the nanosuspension exhibited superior dispersibility, as well as superior foliar wetting and retention performances, which further enhanced its bioavailability against Cnaphalocrocis medinalis. The nanosuspension dosage could be reduced by about 40% while maintaining a comparable efficacy to that of the SC. In addition, the chlorantraniliprole nanosuspension showed lower residual properties, a lower toxicity to non-target zebrafish, and a smaller effect on rice quality, which is conducive to improving food safety and the ecological safety of pesticide formulations. In this work, a novel pesticide-reduction strategy is proposed, and theoretical and data-based support is provided for the efficient and safe application of nanopesticides.

Design and Synthesis of a Water-Based Nanodelivery Pesticide System for Improved Efficacy and Safety.

Developing an environmentally friendly and safe nanodelivery system is crucial to improve the efficacy of pesticides and minimize environmental and health risks. However, preparing a completely water-based nanopesticide without using harmful solvents is a technical challenge. In this study, a water-based nanodelivery pesticide system was constructed to improve the efficacy and safety of Emamectin Benzoate (EB). A specific surfactant, 29-(4-(5-hydroxynonan-5-yl)phenoxy)-3,6,9,12,15,18,21,24,27-nonaoxanonacosan-1-ol (SurEB) was designed and synthesized to form a water-based nanodelivery system (EBWNS) with EB. Molecular dynamics simulations revealed the self-assembly and interaction forces between SurEB and EB in water, providing insights into the formation mechanism of EBWNS nanoparticles. The nanodelivery system showed the prolonged effectivity of EB with reduced degradation and demonstrated a good control efficacy for multiple target pests, such as red spider mite, beet armyworm larvae (Lepidoptera: Noctuidae), and rice stem borers (Chilo suppressalis). Toxicology tests on various objects demonstrated that the EBWNS has low toxicity for seeds, HaCaT cells, zebrafish, earthworm, and E. coli. This study provides a distinctive perspective for developing environmentally friendly nanopesticide formulations, which clarified a water-based treatment method for specific lipid-soluble pesticides. The water-based nanodelivery pesticide system has the potential to improve the efficacy and safety of pesticides in the process of field applications.

Temperature-Dependent Nanogel for Pesticide Smart Delivery with Improved Foliar Dispersion and Bioactivity for Efficient Control of Multiple Pests.

The use of nanomaterials and nanotechnology to construct a smart pesticide delivery system with target-oriented and controlled-release functions is important to increase the effective utilization rate and minimize environmental residue pollution. A temperature-dependent delivery system can modulate the release of pesticide with temperature to improve the efficacy and precision targeting. A series of poly(N-isopropylacrylamide) (PNIPAM)-based nanogels with high deformability and tunable structure were successfully constructed for smart pesticide delivery and effective pest control. A lambda-cyhalothrin (LC)-loaded Pickering emulsion (LC@TNPE) with a stable gel-like network structure was further formed by the temperature-dependent nanogel to encapsule the pesticide. The foliar wettability, photostability, and controlled-release property of LC@TNPE were effectively enhanced compared to the commercial formulation because of the encapsulation and stabilization of nanogel. The release rate of LC positively correlated with temperature changes and thereby adapted to the trend of pest population increase at higher temperature. The LC@TNPE displayed improved control efficacy on multiple target pests including Plutella xylostella, Aphis gossypii, and Pieris rapae compared with the commercial suspension concentrate and microcapsule suspension, and it showed marked efficacy to control Pieris rapae for an extended duration even at a 40% reduced dosage. Furthermore, the safety was evaluated systematically on cells in vitro and with a nontarget organism. Studies confirmed that the system was relatively safe for HepG2 cells and aquatic organism zebrafish. This research provides an insight into creating an efficient and environmentally friendly pesticide nanoformulation for sustainable agriculture production.

Simple and fast colorimetric detection of lipopolysaccharide based on aptamer and SYBR Green I mediated aggregation of gold nanoparticles.

Lipopolysaccharide (LPS) poses a considerable threat to food safety and human health. A colorimetric assay for LPS detection based on LPS binding aptamer (LBA) and SYBR Green I (SG) mediated aggregation of gold nanoparticles (AuNPs) was established. In the absence of LPS, the LBA was absorbed onto the AuNPs surface which prevented SG-induced aggregation of AuNPs, and the sensing system exhibited red color. When LPS was added, it interacted with the LBA, forming a complex. At higher LPS concentration, many LBAs were exhausted resulting in SG-induced aggregation of AuNPs, and color change from red to blue. The range of colorimetric detection of LPS was linear in 0-12 EU/mL, with a limit of detection of 0.1698 EU/mL. Spiked LPS in real samples and interfering substances were also identified. This assay ingeniously using the fluorescent dye SG as an effective trigger of AuNPs aggregation, is rapid and facile than most of those earlier reported LBA-based LPS assays, and there is potential to be modified to construct assays for other targets.

Construction and Characterization of Novel Hydrophilic Nanospheres Loaded with Lambda-Cyhalothrin via Ultrasonic Emulsification-Solvent Evaporation.

Safe and efficient pesticide formulations have attracted great attention for the prevention and control of diseases and pests. In recent years, improving the effectiveness and duration of pesticides through nanotechnology has become a research hotspot in the field of pesticide formulations. Here, we develop a novel hydrophilic lambda-cyhalothrin nanospheres encapsulated with poly(styrene-co-maleic anhydride) (PSMA) via the ultrasonic emulsification-solvent evaporation method, which exhibited better particle size uniformity and dispersion in comparison with the traditional method. The effects of PSMA content, oil phase/water phase ratio and phacoemulsification time on the particle size and morphology of nanoparticles were investigated to optimize preparation process parameters. Meanwhile, the wettability and adhesion behavior on the leaf surface, the release properties, and the storage stability of nanoparticles were characterized to evaluate the performance of the novel nano-formulation. This work not only establishes a facile and promising method for the applicable of insoluble pesticides, but also develops an innovative nano-formulation with hydrophilicity and high leaf adhesion, which opens a new direction in plant protection and residue reduction.

Development of emamectin benzoate-loaded liposome nano-vesicles with thermo-responsive behavior for intelligent pest control.

Pesticides play an important role in agricultural disease and pest control. However, the low utilization efficiency and environmentally unfriendly disadvantages of conventional pesticide formulations cause substantial environmental and ecological damage. Constructing intelligent controlled-release pesticide systems via nanotechnology is a feasible way to overcome these defects. In this research, an emamectin benzoate-loaded liposome nano-vesicle (EB-Lip-NV) with a multicompartment structure and thermo-responsive characteristics was developed to accurately control nocturnal pests and improve insecticidal activity. EB-Lip-NV is an unusual low-temperature rapid-release system based on phase transitions of the liposome membrane. Compared with the conventional water-soluble granule (SG), the EB-Lip-NV exhibited higher control activity on Spodoptera exigua. More importantly, the control efficacy of Spodoptera exigua at 20 °C was around 1.4 times that at 40 °C because of low temperature-induced rapid release. This controlled-release behavior of EB-Lip-NV in response to temperature change could effectively control the population of nocturnal pests. In addition, the toxicity of the EB-Lip-NV towards zebrafish was lower than that of SG by above 50%. This study provides a new strategy for constructing intelligent controlled-release pesticide systems with improving utilization rate and reducing harm to the environment and non-target organisms.

Construction and characterization of ethyl cellulose-based nano-delivery system for phenamacril.

Fungicide-resistant Fusarium has become a threaten to wheat production. Novel fungicide formulations can improve the efficacy of active ingredient and minimize the emergence of resistance. Encapsulation of fungicides in biodegradable carriers, especially, in polysaccharide, is a feasible approach to develop environment-friendly and efficient formulation. This study focused on the synthesis of ethyl cellulose-based phenamacril nano-delivery system by combining emulsion-solvent evaporation and high-pressure homogenization technology to improve the control of fusarium head blight in wheat. Emulsifier 125 and Tersperse 2500 were screened from eleven commonly used surfactants. Emulsifier 125 and Tersperse 2500 in a ratio of 2:1 and phenamacril nanocapsules with the mean particle size of 152.5 ± 1.3 nm were prepared. These showed excellent storage stability and wettability on crop leaves. A bioassay comparing the nanocapsules with a commercial preparation against Fusarium graminearum showed significantly improved biological activity. This formulation could be used to effectively not only to control fusarium head blight but also delay the occurrence of resistance.

Thermo-Responsive Quaternary Ammonium Chitosan Nanocapsules with On-Demand Controlled Pesticide Release and Maximally Synergistic Biological Activity.

Pesticides play an important role in pest control. However, they can be limited due to low utilization efficiency, causing substantial losses to the environment and ecological damage. Nanotechnology is an active area of research regarding encapsulation of pesticides for sustainable pest control. Here, we developed intelligent formulations of avermectin (Av) quaternary ammonium chitosan surfactant (QACS) nanocapsules (i.e., Av-Th@QACS) with on-demand controlled release properties, toward ambient temperature and maximal synergistic biological activity of Av and QACS. The Av-Th@QACS regulated the quantity of pesticide release in accordance with the ambient temperature changes and, insofar as this release is a means of responding to variations in pest populations, maximized the synergistic activity. In addition, the Av-Th@QACS were highly adhesive to crop leaves as a result of the prolonged retention time on the crop leaves. Therefore, Av-Th@QACS exhibited greater control against aphids at 35 °C than at 15 and 25 °C. Compared with commercial formulations, Av-Th@QACS was more toxic at 35 °C and less toxic at 15 °C. Thus, researchers can apply Av-Th@QACS as intelligent nanopesticides with an on-demand, controlled release and synergistic biological activity and, in so doing, prolong pesticide duration and improve the utilization efficiency.

Nano-EMB-SP improves the solubility, foliar affinity, photostability and bioactivity of emamectin benzoate.

BACKGROUND: Emamectin benzoate (EMB), a frequently used biopesticide, is poorly soluble in water, making it difficult to wet the leaf surface, is prone to degrade in sunlight and readily loses its bioactivity. Traditional methods such as organic solvent application, pH adjustment and addition of photoprotectants either increase the economic and environmental costs or barely achieve the desired goal. We hypothesized that nanotechnology could improve the solubility, foliar affinity, photostability and bioactivity of EMB. This research set out to prepare a nano-EMB solid powder (nano-EMB-SP) and test this hypothesis. RESULTS: Nano-EMB-SP was prepared using a self-emulsifying method combined with carrier solidification. The mean particle size and Polydispersity index (PDI) of nano-EMB-SP were 14.64 nm and 0.24, respectively. A scanning electron microscopy image showed that EMB nanoparticles were mainly spherical or ellipsoidal in shape. Without organic solvent, the aqueous solubility of EMB in nano-EMB-SP was 4500 mg L-1 , at least 14-fold that of the EMB soluble granule (EMB-SG), which is solubilized by pH adjustment. Excellent foliar affinity of EMB was achieved by nano-EMB-SP, which completely wet and penetrated the superhydrophobic surface of cabbage (Brassica oleracea L.) leaf. Without photoprotectants, up to 82% of EMB content can be protected from ultraviolet (UV) damage in nano-EMB-SP. The combined effects of excellent photostability and foliar affinity of nano-EMB-SP led to the bioactivity of EMB being almost unchanged before and after UV radiation. CONCLUSION: Nano-EMB-SP is an eco-friendly and efficient way to improve the solubility, foliar affinity, photostability and bioactivity of EMB. This research provides a good approach to improving the efficacy of poorly soluble and UV-sensitive pesticides. © 2022 Society of Chemical Industry.

Polylactic acid nanoparticles for co-delivery of dinotefuran and avermectin against pear tree pests with improved effective period and enhanced bioactivity.

Pesticide compounding technology for disease and pest control emerges as an effective way to increase the effectiveness of pesticides while reducing pesticides resistance. Nanomaterials and encapsulation technology have offered a new insight into preparing efficient pesticide formulations, especially constructing a co-delivery nanoparticle for synergistic pesticides. In this study, a dinotefuran/avermectin co-delivery nanoparticles (DACNPs) against pear tree pests with polylactic acid (PLA) as the wall material were constructed by double-emulsion method combined with high-pressure homogenization technique. The drug content of the DACNPs was 39.1% with an average size of 245.7 ± 4.2 nm and the mean polymer dispersity index (PDI) value was 0.123. The DACNPs showed high foliar retention and good spread performance on target leaves due to the nanoscale effect. The obtained DACNPs showed a better control effect on Grapholitha molesta Busck and Psylla chinensis Yang et Li compared with the commercial formulations, which could significantly prolong the effective duration and enhance the bioactivity with lower amounts and application frequency of pesticides. This study may provide new insights into developing novel pesticide formulations to improve the utilization rate of pesticides, reduce environmental pollution and minimize the cost of farming.

Versatile Oral Insulin Delivery Nanosystems: From Materials to Nanostructures.

Diabetes is a chronic metabolic disease characterized by lack of insulin in the body leading to failure of blood glucose regulation. Diabetes patients usually need frequent insulin injections to maintain normal blood glucose levels, which is a painful administration manner. Long-term drug injection brings great physical and psychological burden to diabetic patients. In order to improve the adaptability of patients to use insulin and reduce the pain caused by injection, the development of oral insulin formulations is currently a hot and difficult topic in the field of medicine and pharmacy. Thus, oral insulin delivery is a promising and convenient administration method to relieve the patients. However, insulin as a peptide drug is prone to be degraded by digestive enzymes. In addition, insulin has strong hydrophilicity and large molecular weight and extremely low oral bioavailability. To solve these problems in clinical practice, the oral insulin delivery nanosystems were designed and constructed by rational combination of various nanomaterials and nanotechnology. Such oral nanosystems have the advantages of strong adaptability, small size, convenient processing, long-lasting pharmaceutical activity, and drug controlled-release, so it can effectively improve the oral bioavailability and efficacy of insulin. This review summarizes the basic principles and recent progress in oral delivery nanosystems for insulin, including physiological absorption barrier of oral insulin and the development of materials to nanostructures for oral insulin delivery nanosystems.

Preparation, Characterization, and Evaluation of Pyraclostrobin Nanocapsules by In Situ Polymerization.

In this study, pyraclostrobin nanocapsules were prepared by in situ polymerization with urea-formaldehyde resin as a wall material. The effects of different emulsifiers, emulsifier concentrations, and solvents on the physicochemical properties of pyraclostrobin nanocapsules were investigated. Solvesso™ 100 was selected as the solvent, and Emulsifier 600# was used as the emulsifier, which accounted for 5% of the aqueous phase system, to prepare pyraclostrobin nanocapsules with excellent physical and chemical properties. The particle size, ζ potential, and morphology of the nanocapsules were characterized by a particle size analyzer and transmission electron microscope. The nanocapsules were analyzed by Fourier-transform infrared spectroscopy, and the loading content and sustained release properties of the nanocapsules were measured. The results show that the size of the prepared nanocapsules was 261.87 nm, and the polydispersity index (PDI) was 0.12, presenting a uniform spherical appearance. The loading content of the pyraclostrobin nanocapsules was 14.3%, and their cumulative release rate was 70.99% at 250 h, providing better efficacy and sustainability compared with the pyraclostrobin commercial formulation.

Nanomaterials and nanotechnology for the delivery of agrochemicals: strategies towards sustainable agriculture.

Nanomaterials (NMs) have received considerable attention in the field of agrochemicals due to their special properties, such as small particle size, surface structure, solubility and chemical composition. The application of NMs and nanotechnology in agrochemicals dramatically overcomes the defects of conventional agrochemicals, including low bioavailability, easy photolysis, and organic solvent pollution, etc. In this review, we describe advances in the application of NMs in chemical pesticides and fertilizers, which are the two earliest and most researched areas of NMs in agrochemicals. Besides, this article concerns with the new applications of NMs in other agrochemicals, such as bio-pesticides, nucleic acid pesticides, plant growth regulators (PGRs), and pheromone. We also discuss challenges and the industrialization trend of NMs in the field of agrochemicals. Constructing nano-agrochemical delivery system via NMs and nanotechnology facilitates the improvement of the stability and dispersion of active ingredients, promotes the precise delivery of agrochemicals, reduces residual pollution and decreases labor cost in different application scenarios, which is potential to maintain the sustainability of agricultural systems and improve food security by increasing the efficacy of agricultural inputs.

Nano Functional Food: Opportunities, Development, and Future Perspectives.

A functional food is a kind of food with special physiological effects that can improve health status or reduce illness. However, the active ingredients in functional foods are usually very low due to the instability and easy degradation of some nutrients. Therefore, improving the utilization rate of the effective ingredients in functional food has become the key problem. Nanomaterials have been widely used and studied in many fields due to their small size effect, high specific surface area, high target activity, and other characteristics. Therefore, it is a feasible method to process and modify functional food using nanotechnology. In this review, we summarize the nanoparticle delivery system and the food nanotechnology in the field of functional food. We also summarize and prospect the application, basic principle, and latest development of nano-functional food and put forward corresponding views.

Application of Non-Viral Vectors in Drug Delivery and Gene Therapy.

Vectors and carriers play an indispensable role in gene therapy and drug delivery. Non-viral vectors are widely developed and applied in clinical practice due to their low immunogenicity, good biocompatibility, easy synthesis and modification, and low cost of production. This review summarized a variety of non-viral vectors and carriers including polymers, liposomes, gold nanoparticles, mesoporous silica nanoparticles and carbon nanotubes from the aspects of physicochemical characteristics, synthesis methods, functional modifications, and research applications. Notably, non-viral vectors can enhance the absorption of cargos, prolong the circulation time, improve therapeutic effects, and provide targeted delivery. Additional studies focused on recent innovation of novel synthesis techniques for vector materials. We also elaborated on the problems and future research directions in the development of non-viral vectors, which provided a theoretical basis for their broad applications.

Advances in Controlled-Release Pesticide Formulations with Improved Efficacy and Targetability.

Pesticides are commonly used in modern agriculture and are important for global food security. However, postapplication losses due to degradation, photolysis, evaporation, leaching, surface runoff, and other processes may substantially reduce their efficacy. Controlled-release formulations can achieve the permeation-regulated transfer of an active ingredient from a reservoir to a target surface. Thus, they can maintain an active ingredient at a predetermined concentration for a specified period. This can reduce degradation and dissipation and other losses and has the potential to improve efficacy. Recent developments in controlled-release technology have adapted the concepts of intelligence and precision from the pharmaceutical industry. In this review, we present recent advances in the development of controlled-release formulations and discuss details of the preparation methods, material improvements, and application technologies.

Development of Chlorantraniliprole and Lambda Cyhalothrin Double-Loaded Nano-Microcapsules for Synergistical Pest Control.

Nanotechnology could greatly improve global agricultural food production. Chlorantraniliprole and lambda cyhalothrin double-loaded nano-microcapsules were fabricated to enhance the control of pests by pesticides and improve the pesticide utilization efficiency. The nano-microcapsules were synthesized using a method involving the solid in oil in water encapsulation technique and solvent evaporation. The nano-microcapsules slowly and simultaneously released lambda cyhalothrin and chlorantraniliprole. The cumulative lambda cyhalothrin and chlorantraniliprole release rates at 40 h were 80% and 70%, respectively. Indoor Spodoptera frugiperda control tests indicated that the double-loaded nano-microcapsules were more toxic than lambda cyhalothrin water-dispersible granules, chlorantraniliprole water-dispersible granules, and a mixture of lambda cyhalothrin water-dispersible granules and chlorantraniliprole water-dispersible granules, indicating that the pesticides in the nano-microcapsules synergistically controlled Spodoptera frugiperda. The results indicated that pesticide nano-microcapsules with synergistic effects can be developed that can improve the effective pesticide utilization efficiency and pesticide bioavailability. This is a new idea for achieving environmentally intelligent pesticide delivery.