Avermectin Research Articles

Ferulic acid alleviates cardiac injury by inhibiting avermectin-induced oxidative stress, inflammation and apoptosis

Avermectin (AVM) is a broad-spectrum antibiotic from the macrolide class, extensively employed in fisheries and aquaculture. Nevertheless, its indiscriminate utilisation has resulted in a substantial accumulation of remnants in the aquatic ecosystem, potentially inflicting significant harm to the cardiovascular system of aquatic species. Ferulic acid (FA) is a naturally occurring compound in wheat grain husks. It possesses potent anti-inflammatory and antioxidant properties, which can help reduce cardiovascular damage. Additionally, its affordability makes it an excellent option for aquaculture usage as a feed additive. This article explored the potential of FA as a feed additive to protect against AVM-induced heart damage in carp. We subjected carp to AVM for 30 days and provided them with a diet of 400 mg/kg of FA. FA substantially reduced the pathogenic damage to heart tissue caused by AVM, as shown through hematoxylin-eosin staining. The biochemical analysis revealed that FA markedly enhanced the activity of antioxidant enzymes catalase (CAT), glutathione (GSH), and total antioxidant capacity (T-AOC) while reducing the malondialdehyde (MDA) content. Furthermore, qPCR analysis demonstrated a substantial increase in the mRNA levels of transforming growth factor-β1 (tgf-β1) and interleukin-10 (il-10) simultaneously, significantly reducing the expression levels of interleukin-10 (il-6), interleukin-1β (il-1β), tumor necrosis factor-α (tnf-α) and inductible nitric oxide synthase (inos). Through the mitochondrial apoptotic route, FA reduced AVM-induced cell death in carp heart cells by upregulating bcl-2 while downregulating the mRNA expression levels of bax, fas, caspase8 and caspase9. In summary, FA alleviated cardiac injury by inhibiting AVM-induced oxidative stress, inflammatory response, and apoptosis in carp heart tissue.

ROS sensitive micelles of carbon dioxide based amphiphilic polymer for delivery of avermectin

A novel amphiphilic polymer, methoxy polyethylene glycols (mPEG)-3, 3′-(propane-2, 2-diylbis (sulfanediyl)) dipropionic acid (TK)-poly (propylene oxide-co-carbon dioxide-co-allyl glycidyl ether) (PPAG) (mPEG2000-TK-PPAG), was successfully synthesized for delivery of avermectin (AVE). The chemical structure was characterized by FTIR. In aqueous medium, mPEG2000-TK-PPAG could self-assembled into micelles. The AVE loaded mPEG2000-TK-PPAG micelles showed a considerable drug-loading content of 19 %. The prepared micelles were spherical morphology with average hydrodynamic diameter 469.4 nm and zeta potential of around –33.6 mv. AVE was released slowly from the AVE loaded mPEG2000-TK-PPAG micelles in a neutral condition and was released rapidly under stimulation of reactive oxygen species (ROS). Therefore, this ROS responsive micelle formulation achieves target control of pests and provides an efficient micelle platform for green agriculture.

Cationic Amphiphilic Comb-Shaped Polymer Emulsifier for Fabricating Avermectin Nanoemulsion with Exceptional Leaf Behaviors and Multidimensional Controlled Release.

The development of intelligent multifunctional nanopesticides featuring enhanced foliage affinity and hierarchical target release is increasingly pivotal in modern agriculture. In this study, a novel cationic amphiphilic comb-shaped polymer, termed PEI-TA, was prepared via a one-step Michael addition between low-molecular-weight biodegradable polyethylenimine (PEI) and tetradecyl acrylate (TA), followed by neutralization with acetic acid. Using the emulsifier PEI-TA, a positively charged avermectin (AVM) nanoemulsion was prepared via a phase inversion emulsification process. Under optimal formulation, the obtained AVM nanoemulsion (defined as AVM@PEI-TA) demonstrated exceptional properties, including small size (as low as 67.6 nm), high encapsulation efficiency (up to 87.96%), and high stability toward shearing, storage, dilution, and UV irradiation. The emulsifier endowed AVM@PEI-TA with a pronounced thixotropy, so that the droplets exhibited no splash and bounce when they were sprayed on the cabbage leaf. Owing to the electrostatic attraction between the emulsifier and the leaf, AVM@PEI-TA showed improved leaf adhesion, better deposition, and higher washing resistance in contrast to both its negatively charged counterpart and AVM emulsifiable concentrate (AVM-EC). Compared to the large-sized particles, the small-sized particles of the AVM nanoemulsion more effectively traveled long distances through the vascular system of veins after entering the leaf apoplast. Moreover, the nanoparticles lost stability when exposed to multidimensional stimuli, including pH, temperature, esterase, and ursolic acid individually or simultaneously, thereby promoting the release of AVM. The release mechanisms were discussed for understanding the important role of the emulsifier in nanopesticides.

Toxic effects of avermectin on liver function, gut microbiota, and colon barrier in the rat model

Avermectin (AVM), a compound derived from the fermentation of Avermectin Streptomyces, has insecticidal, acaricidal, and nematicidal properties. Widely employed in agriculture, it serves as an effective and broad-spectrum insecticide for pest control. Although the toxicity of AVM at low doses may not be readily apparent, prolonged and extensive exposure can result in poisoning. To investigate the toxic effects of AVM on the body, this study established rat models of AVM poisoning with both low and high concentrations of the compound. Fifteen male rats were randomly assigned to one of three groups (n=5 per group): a control group, a low-concentration group, and a high-concentration group. The low-concentration group was administered an oral dose of 2 mg/kg AVM once daily for a duration of seven days, while the high-concentration group received an oral dose of 10 mg/kg AVM once daily for the same period. This study examined the impact of AVM on liver function and gut microbiota in rats using weight monitoring, liver function indicator detection, liver metabolomics sequencing, colon barrier function testing, and gut microbiota sequencing. The findings of this study demonstrated that exposure to 2 or 10 mg/kg AVM for seven days can lead to a notable decrease in rat weight, as well as induce liver dysfunction and metabolic disturbances. Additionally, AVM exposure can disrupt the composition of the intestinal microbiota and impair the integrity of the colon mucosal barrier, causing downregulation of Occludin expression and upregulation of inflammation-related protein expression levels such as IL-1β, Myd88, and TLR4. Furthermore, bioinformatics analysis revealed a significant association between liver dysfunction and dysbiosis of the gut microbiota. These findings have implications for the agricultural use of AVM and its potential contribution to environmental pollution. Consequently, individuals involved in AVM usage should prioritize safety precautions and monitor liver function.

Long-lasting, UV shielding, and cellulose-based avermectin nano/micro spheres with dual smart stimuli-microenvironment responsiveness for Plutella xylostella control

The requirement to improve the efficiency of pesticide utilization has led to the development of sustainable and smart stimuli-responsive pesticide delivery systems. Herein, a novel avermectin nano/micro spheres (AVM@HPMC-Oxalate) with sensitive stimuli-response function target to the Lepidoptera pests midgut microenvironment (pH 8.0–9.5) was constructed using hydroxypropyl methylcellulose (HPMC) as the cost-effective and biodegradable material. The avermectin (AVM) loaded nano/micro sphere was achieved with high AVM loading capacity (up to 66.8 %). The simulated release experiment proved the rapid stimuli-responsive and pesticides release function in weak alkaline (pH 9) or cellulase environment, and the release kinetics were explained through release models and SEM characterization. Besides, the nano/micro sphere size made AVM@HPMC-Oxalate has higher foliar retention rate (1.6–2.1-fold higher than commercial formulation) which is beneficial for improving the utilization of pesticides. The in vivo bioassay proved that AVM@HPMC-Oxalate could achieve the long-term control of Plutella xylostella by extending UV shielding performance (9 fold higher than commercial formulation). After 3 h of irradiation, the mortality rate of P. xylostella treated by AVM@HPMC-Oxalate still up to 56.7 % ± 5.8 %. Moreover, AVM@HPMC-Oxalate was less toxic to non-target organisms, and the acute toxicity to zebrafish was reduced by 2-fold compared with AVM technical.

Fabrication of dual responsive microcapsules based on starch with enhanced foliar adhesion and photostability for improving control efficacy and reducing environmental risks

Stimuli-responsive controlled release formulations offer a promising avenue for enhancing effective utilization and mitigating environmental risks of pesticides. Herein, pH and enzyme-responsive pesticide microcapsules (AVE@CPS-Fe-TA) were constructed by encapsulating carboxylated porous starch (CPS) loaded with avermectin (AVE) within tannic acid-iron complexes (Fe-TA) to improve the insecticidal efficacy and reduce toxicity to non-targets of AVE. The results showed that the loading content of AVE in the modified starch-based microcapsules could be precisely adjusted by the enzymatic hydrolysis time of starch. The prepared AVE@CPS-Fe-TA had pH and α-amylase dual responsive release properties and exhibited superior photostability, and its photolysis half-life was extended by 15.57-fold compared to AVE technical. Additionally, the leaf retention rate of AVE@CPS-Fe-TA after being rinsed by simulated rainwater was 6.08 times higher than that of commercial formulation AVE EC. In greenhouse insecticidal activity experiment, AVE@CPS-Fe-TA demonstrated a high control efficacy against Ostrinia furnacalis and had a prolonged effective duration. Moreover, AVE@CPS-Fe-TA significantly reduced the acute toxicity of AVE to zebrafish and promoted the growth of maize seedlings. Therefore, this work would provide eco-friendly stimuli-responsive microcapsules of pesticides for improving the efficiency of utilization and reducing environmental risks.

Protective effects of dietary additive quercetin: Nephrotoxicity and ferroptosis induced by avermectin pesticide

In recent years, contamination of aquatic systems with Avermectin (AVM) has emerged as a significant concern. This contamination poses substantial challenges to freshwater aquaculture. Plant-derived Quercetin (QUE), known for its anti-inflammatory, antioxidant, and ferroptosis-inhibiting properties, is commonly employed as a supplement in animal feed. However, its protective role against chronic renal injury in freshwater carp induced by AVM remains unclear. This study assesses the influence of dietary supplementation with QUE on the consequences of chronic AVM exposure on carp renal function. The carp were subjected to a 30-day exposure to AVM and were provided with a diet containing 400 mg/kg of QUE. Pathological observations indicated that QUE alleviated renal tissue structural damage caused by AVM. RT-QPCR study revealed that QUE effectively reduced the increased expression levels of pro-inflammatory factors mRNA produced by AVM exposure, by concurrently raising the mRNA expression level of the anti-inflammatory factor. Quantitative analysis using DHE tests and biochemical analysis demonstrated that QUE effectively reduced the buildup of ROS in the renal tissues of carp, activity of antioxidant enzymes CAT, SOD, and GSH-px, which were inhibited by AVM, and increased the content of GSH, which was induced by prolonged exposure to AVM. QUE also reduced the levels of MDA, a marker of oxidative damage. Furthermore, assays for ferroptosis markers indicated that QUE increased the mRNA expression levels of gpx4 and slc7a11, which were reduced due to AVM induction, and it caused a reduction in the mRNA expression levels of ftl, ncoa4, and cox2, along with a drop in the Fe2+ concentration. In summary, QUE mitigates chronic AVM exposure-induced renal inflammation in carp by inhibiting the transcription of pro-inflammatory cytokines. By blocking ROS accumulation, renal redox homeostasis is restored, thereby inhibiting renal inflammation and ferroptosis. This provides a theoretical basis for the development of freshwater carp feed formula.

Spherical Assembly of Halloysite Clay Nanotubes as a General Reservoir of Hydrophobic Pesticides for pH-Responsive Management of Pests and Weeds.

The development of smart systems for pesticidal delivery presents a significant advancement in enhancing the utilization efficiency of pesticides and mitigating environmental risks. Here an acid-responsive pesticidal delivery system using microspheres formed by the self-assembly of halloysite clay nanotubes (HNTs) is proposed. Insecticide avermectin (AVM) and herbicide prometryn (PMT) are used as two models of hydrophobic pesticide and encapsulated within the porous microspheres, followed by a coating of tannic acid/iron (TA/FeIII) complex films to generate two controlled-release pesticides, named as HCEAT and HCEPT, resulting in the loading capacity of AVM and PMT being 113.3 and 120.3mgg-1, respectively. Both HCEAT and HCEPT exhibit responsiveness to weak acid, achieving 24h-release ratios of 85.8% and 80.5% at a pH of 5.5. The experiment and simulation results indicate that the coordination interaction between EDTA2- and Ca2+ facilitates the spherical aggregation of HNTs. Furthermore, these novel pesticide formulations demonstrate better resistance against ultraviolet (UV) irradiation, higher foliar affinity, and less leaching effect, with negligible impact of the carrier material on plants and terrestrial organisms. This work presents a promising approach toward the development of efficient and eco-friendly pesticide formulations, greatly contributing to the sustainable advancement of agriculture.

Fabrication and property of the avermectin-attapulgite composites regulated by mixed-surfactants and sodium alginate

OA-AP, DTAB-AP, DDBAB-AP complexes were synthesized by introducing surfactants of OA, DTAB and DDBAB into attapulgite (AP). The complexes were systematically characterized. The appearance of new diffraction peaks at low angle indicated a new lamellar structure of OA (DTAB, DDBAB)-AP complexes. Then, the pesticide avermectin (AV) composites of AV/DTAB-OA-AP, AV/DDBAB-OA-AP, sodium alginate (SA) @AV/DTAB-OA-AP and SA@AV/DDBAB-OA-AP were prepared and investigated detailedly. The basal spacings of AV/DTAB-OA-AP and AV/DDBAB-OA-AP were bigger than those of OA-AP and DTAB(DDBAB)-AP. The existences of AV, surfactants and SA molecules of the composites were further confirmed. Furthermore the effect of SA on AV release behaviors of SA@AV/DTAB (DDBAB)-OA-AP microspheres was investigated and compared. Compared to AV/DTAB (DDBAB)-OA-AP, the released rate of the microspheres decreased remarkably. The AV release behaviors of AV/DTAB (DDBAB)-OA-AP could be fitted with pseudo second-order model, while the first-order model was better to describe those of the microspheres. Finally, the bioassay of the microspheres were studied and analyzed. The microspheres had a longer duration and control effect on Mythimna separata. This study could be helpful to provide a pesticide delivery system to improve the utilization efficiency of pesticides.

Study on Pyrolysis Behavior of Avermectin Mycelial Residues and Characterization of Obtained Gas, Liquid, and Biochar

The proper disposal of antibiotic mycelial residue (AMR) is a critical concern due to the spread of antibiotics and environmental pollution. Pyrolysis emerges as a promising technology for AMR treatment. In this study, we investigated the effect of pyrolysis temperature on the thermal decomposition behavior and product characteristics of avermectin (AV) mycelial residues. Various characterization techniques were employed to analyze thoroughly the compositions and yields of the obtained gas, liquid, and biochar products. The results indicated that most of the organic matter such as protein, carbohydrate, and aliphatic compounds in AV mycelial residues decomposed intensely at 322 °C and tended to end at 700 °C, with a total weight loss of up to 72.6 wt%. As the pyrolysis temperature increased, the biochar yield decreased from 32.81 wt% to 26.39 wt% because of the enhanced degradation of volatiles and secondary reactions of the formed aromatic rings. Accordingly, more gas components were formed with the gas yield increased from 9.76 wt% to 15.42 wt%. For bio-oil, the contents were maintained in the range of 57.43–60.13 wt%. CO and CO2 dominated the gas components with a high total content of almost 62.37–97.54 vol%. At the same time, abundant acids, esters (42.99–48.85%), and nitrogen-containing compounds (32.14–38.70%) such as nitriles, amides, and nitrogenous heterocyclic compounds were detected for the obtained bio-oil. As for the obtained biochars, particle accumulation and irregular pores were presented on their bulk surface, which was primarily composed of calcium oxalate (CaC2O4) and calcium carbonate (CaCO3). This work can provide theoretical insights for the harmless disposal and resource recovery for AMR, contributing significantly to the field of solid waste reuse and management.

Biomass-Based, Dual Enzyme-Responsive Nanopesticides: Eco-friendly and Efficient Control of Pine Wood Nematode Disease.

Pine wood nematode (PWN) disease is a globally devastating forest disease caused by infestation with PWN, Bursaphelenchus xylophilus, which mainly occurs through the vector insect Japanese pine sawyer (JPS), Monochamus alternatus. PWN disease is notoriously difficult to manage effectively and is known as the "cancer of pine trees." In this study, dual enzyme-responsive nanopesticides (AVM@EC@Pectin) were prepared using nanocoating avermectin (AVM) after modification with natural polymers. The proposed treatment can respond to the cell wall-degrading enzymes secreted by PWNs and vector insects during pine tree infestation to intelligently release pesticides to cut off the transmission and infestation pathways and realize the integrated control of PWN disease. The LC50 value of AVM@EC@Pectin was 11.19 mg/L for PWN and 26.31 mg/L for JPS. The insecticidal activity of AVM@EC@Pectin was higher than that of the commercial emulsifiable concentrate (AVM-EC), and the photostability, adhesion, and target penetration were improved. The half-life (t1/2) of AVM@EC@Pectin was 133.7 min, which is approximately twice that of AVM-EC (68.2 min). Sprayed and injected applications showed that nanopesticides had superior bidirectional transportation, with five-times higher AVM contents detected in the roots relative to those of AVM-EC when sprayed at the top. The safety experiment showed that the proposed treatment had lower toxicity and higher safety for nontarget organisms in the application environment and human cells. This study presents a green, safe, and effective strategy for the integrated management of PWN disease.

Ecofriendly Controlled-Release Insecticide Carrier: pH-/Temperature-Responsive Rosin-Derived Hydrogels for Avermectin Delivery against Mythimna separata (Walker).

The exploration of environmentally friendly, less toxic, sustained-release insecticide is increasing with the growing demand for food to meet the requirements of the expanding population. As a sustained-release carrier, the unique, environmentally friendly intelligent responsive hydrogel system is an important factor in improving the efficiency of insecticide utilization and accurate release. In this study, we developed a facile approach for incorporating the natural compound rosin (dehydroabietic acid, DA) and zinc ions (Zn2+) into a poly(N-isopropylacrylamide) (PNIPAM) hydrogel network to construct a controlled-release hydrogel carrier (DA-PNIPAM-Zn2+). Then, the model insecticide avermectin (AVM) was encapsulated in the carrier at a drug loading rate of 36.32% to form AVM@DA-PNIPAM-Zn2+. Surprisingly, the smart controlled carrier exhibited environmental responsiveness, strongly enhanced mechanical properties, self-healing ability, hydrophobicity, and photostability to ensure a balance between environmental friendliness and the precision of the drug release. The release experiments showed that the carboxyl and amide groups in the polymer chains alter the intermolecular forces within the hydrogel meshes and ingredient diffusion by changing temperatures (25 and 40 °C) and pH values (5.8, 7.4, and 8.5), leading to different release behaviors. The insecticidal activity of the AVM@DA-PNIPAM-Zn2+ against oriental armyworms was good, with an effective minimum toxicity toward aquatic animals. Therefore, AVM@DA-PNIPAM-Zn2+ is an effective drug delivery system against oriental armyworms. We anticipate that this ecofriendly, sustainable, smart-response carrier may broaden the utilization rosin and its possible applications in the agricultural sector.

Dietary additive ferulic acid alleviated oxidative stress, inflammation, and apoptosis induced by chronic exposure to avermectin in the liver of common carp (Cyprinus carpio)

Avermectin (AVM) has been utilized extensively in agricultural production since it is a low-toxicity pesticide. However, the pollution caused by its residues to fisheries aquaculture has been neglected. As an abundant polyphenolic substance in plants, ferulic acid (FA) possesses anti-inflammatory and antioxidant effects. The goal of the study is to assess the FA's ability to reduce liver damage in carp brought on by AVM exposure. Four groups of carp were created at random: the control group; the AVM group; the FA group; and the FA + AVM group. On day 30, and the liver tissues of carp were collected and examined for the detection of four items of blood lipid as well as the activity of the antioxidant enzymes catalase (CAT), glutathione (GSH) and malondialdehyde (MDA) in carp liver tissues by biochemical kits, and the transcript levels of indicators of oxidative stress, inflammation and apoptosis by qPCR. The results showed that liver injury, inflammation, oxidative stress, and apoptosis were attenuated in the FA + AVM group compared to the AVM group. In summary, dietary addition of FA could ameliorate the hepatotoxicity caused by AVM in carp by alleviating oxidative stress, inflammation, apoptosis in liver tissues.

Enhancement of acyl-CoA precursor supply for increased avermectin B1a production by engineering meilingmycin polyketide synthase and key primary metabolic pathway genes.

Avermectins (AVEs), a family of macrocyclic polyketides produced by Streptomyces avermitilis, have eight components, among which B1a is noted for its strong insecticidal activity. Biosynthesis of AVE "a" components requires 2-methylbutyryl-CoA (MBCoA) as starter unit, and malonyl-CoA (MalCoA) and methylmalonyl-CoA (MMCoA) as extender units. We describe here a novel strategy for increasing B1a production by enhancing acyl-CoA precursor supply. First, we engineered meilingmycin (MEI) polyketide synthase (PKS) for increasing MBCoA precursor supply. The loading module (using acetyl-CoA as substrate), extension module 7 (using MMCoA as substrate) and TE domain of MEI PKS were assembled to produce 2-methylbutyrate, providing the starter unit for B1a production. Heterologous expression of the newly designed PKS (termed Mei-PKS) in S. avermitilis wild-type (WT) strain increased MBCoA level, leading to B1a titer 262.2 μg/mL - 4.36-fold higher than WT value (48.9 μg/mL). Next, we separately inhibited three key nodes in essential pathways using CRISPRi to increase MalCoA and MMCoA levels in WT. The resulting strains all showed increased B1a titer. Combined inhibition of these key nodes in Mei-PKS expression strain increased B1a titer to 341.9 μg/mL. Overexpression of fatty acid β-oxidation pathway genes in the strain further increased B1a titer to 452.8 μg/mL - 8.25-fold higher than WT value. Finally, we applied our precursor supply strategies to high-yield industrial strain A229. The strategies, in combination, led to B1a titer 8836.4 μg/mL - 37.8% higher than parental A229 value. These findings provide an effective combination strategy for increasing AVE B1a production in WT and industrial S. avermitilis strains, and our precursor supply strategies can be readily adapted for overproduction of other polyketides.

Ferulic acid alleviates long-term avermectin-induced damage to the spleen of carp and restores its inflammatory response and oxidative balance

Extensive use of avermectin (AVM) in agriculture can seriously contaminate fish in aquaculture. Ferulic acid (FA) is a strong antioxidant sourced from plants and is widely applied in food and medicine, but its protective function on the immunological damage caused by AVM is still lacking. In this study, carp were chronically exposed to (1/10 96 hr LC50) AVM for 30 day(s), with a dietary supplement of FA (400 mg/kg) to assess its effects on carp spleen. The experimental groups (n = 10) included: control, AVM-exposed (2.404 µg/L), FA + AVM co-treated, and FA alone. Long-term AVM exposure altered spleen tissue, reducing serum complement C3 (p < 0.01) and immunoglobulin M levels (p < 0.001), and increasing pro-inflammatory tnf-α (p < 0.001), il-6 (p < 0.001), il-1β (p < 0.001), and inos mRNA levels, whilst down-regulating the anti-inflammatory tgf-β (p < 0.05). Additionally, it disrupted the balance of oxidative stress indicators such as MDA (p < 0.001), T-AOC, GSH, and CAT, leading to spleen tissue apoptosis (42.4%). However, the addition of FA reversed these conditions, elevated the anti-inflammatory factor, and improved spleen immune function following chronic exposure to AVM in carp. Moreover, the ability to restore oxidative homeostasis in carp by adjusting the Nrf2/NQO-1 axis protected the health of spleen tissues. This discovery also supports the development of fish feed for aquaculture.

Zein/sodium abietate complex stabilized pickering emulsion as a delivery system for controlled release of hydrophobic photosensitive pesticide

Inefficient use of pesticides and the consequent environmental problems have led to the development of low-cost, environment-friendly and efficient pesticide delivery systems. Pickering emulsions (PK) stabilized by zein are considered to have many application prospects in the delivery of pesticides. Herein, the function of zein was improved by non-covalent binding with sodium abietate (RA-Na). Tea tree oil (TTO) was used as the solvent for hydrophobic photosensitive pesticide, avermectin (AVM), and also as a component of the oil phase of emulsion. The emulsion AVM@PK was oil in water (O/W) type that had certain foliar affinity. Under the same conditions of UV irradiation, the AVM residual rate of AVM@PK system was 2.4 times that of commercial emulsion (EC), showing superior UV resistance. AVM@PK released AVM at a faster rate under acidic/ basic conditions in vitro than under neutral conditions, with a certain pH response. In vitro bioactivity tests showed that AVM@PK had good antibacterial activity and insecticidal activity equivalent to EC. This system is expected to be used to prevent some plant pests while also preventing or treating some bacterial diseases. It is a simple, environment-friendly, low-cost, effective, and practical strategy for pesticide delivery.

Photothermal controlled-release microcapsule pesticide delivery systems constructed with sodium lignosulfonate and transition metal ions: construction, efficacy and on-demand pesticide delivery.

Widespread application of controlled-release pesticide delivery systems is a feasible and effective method to improve the utilization efficiency of pesticides. However, owing to the high cost and complicated preparation technologies of controlled-release pesticide delivery systems, their applications in agricultural production have been seriously hindered. This study aimed to construct inexpensive photothermally controlled-release pesticide delivery systems using chitosan (CS) and sodium lignosulfonate (LS) as the wall materials, and a coordination assembly strategy of LS with transition metal ions to encapsulate a model pesticide, avermectin (AVM). The resulting complex or nanoparticle photothermal layers in these systems effectively achieved photothermal conversions, and replaced the use of common photothermal agents. In the prepared pesticide-delivery systems, two systems had remarkable photothermal conversion performance and photothermal stabilities with a photothermal conversion efficiency (η) of 24.03% and 28.82%, respectively, under 808 nm, 2 W near-infrared irradiation. The slow-release and ultraviolet-shielding performance of these two systems were markedly enhanced compared with other formulations. The insecticidal activities of these two systems against Plutella xylostella under irradiation with light-emitting diode (LED)-simulated sunlight were also enhanced by 5.20- and 5.06-fold, respectively, compared with that without irradiation of LED-simulated sunlight. Because of their convenient preparations, inexpensive and renewable raw materials, and excellent photothermally controlled-release performance, these on-demand pesticide delivery systems might have significant potential in improving the utilization efficiency of pesticides in modern agriculture. © 2024 Society of Chemical Industry.

Enhanced SERS-based vertical flow assay for high sensitivity multiplex analysis of antibiotics

Vertical flow assay (VFA) is of great significance in food safety and environmental monitoring for rapid and highly sensitive detection of a variety of antibiotics. Herein, an enhanced surface-enhanced Raman scattering (SERS)-based VFA (eSERS-VFA) was proposed for multiplex determination of avermectin (AVM) and streptomycin (STR) through SERS nanotag recognition, and gold-core silver-shell nanocube was employed as the enhanced substrate of nanotag. A polyethylene terephthalate (PET) membrane with the hydrophobic property was inserted into the interface of nitrocellulose (NC) membrane and absorbent pad to increase immunoreaction time of SERS nanotags and antigens fixed on the NC membrane. The experimental results indicate that the as-developed eSERS-VFA possessed extraordinary properties for antibiotics analysis with excellent sensitivity, wide quantitative detection range, and short analysis time less than 15 min. The limits of detection (LODs) for AVM and STR reached 38.9 and 29.1 fg mL−1, respectively, and the linear dynamic detection ranges (LDRs) were all from 1 pg mL−1 to 100 ng mL−1. We believe that this eSERS-VFA will open a bright window for VFA-based scheme design, and support potential application prospects in the detection of trace antibiotics.

Hepatotoxicity of the Pesticide Avermectin Exposure to Freshwater-Farmed Carp: Evidence from In Vivo and In Vitro Research.

Avermectin (AVM) is presently one of the most extensively employed insecticides across the globe. A number of toxicity research studies of AVM have been carried out in freshwater-farmed carp; however, there are currently no toxicity studies on the liver. This investigation aims to replicate an acute liver injury model induced by AVM in carp, subsequently analyzing the adverse effects imposed on the nontarget species while delving into potential mechanisms underlying its toxicity. In this study, we found that AVM-exposed carp liver tissue showed cellular hydration degeneration and necrosis and reduced the viability of hepatocyte L8824. Second, AVM induced oxidative stress in carp, and AVM stimulation led to reactive oxygen species (ROS) accumulation and Ca2+ overload in hepatocyte L8824, suggesting that AVM exposure induces mitochondrial dysfunction in hepatocytes. AVM induced inflammation in carp liver tissue by inducing mitochondrial kinetic disruption, which triggered hepatic tissue injury. AVM induced autophagy and apoptosis in carp liver tissue and ROS mediated AVM-induced autophagy and apoptosis. The formation of autophagy attenuated the AVM-induced liver injury. In conclusion, the present study elucidated the hepatotoxicity and potential mechanisms of freshwater aquaculture carp exposed to the pesticide AVM, emphasized the importance of monitoring pesticide AVM contamination in freshwater aquaculture aquatic environments, and provided theoretical references for the targeted prevention of AVM-induced toxicity in carp.

Redox/Near-Infrared Dual-Responsive Hollow Mesoporous Organosilica Nanoparticles for Pesticide Smart Delivery.

Extremely inefficient utilization of pesticides has prompted a study of low-cost, sustainable, and smart application systems. Herein, as a promising pesticide nanocarrier, hollow mesoporous organosilica nanoparticles (HMONs) were first synthesized by using inexpensive CaCO3 nanoparticles as the hollow templates. A redox/near-infrared light dual-triggered pesticide release system was further achieved via loading avermectin (AVM) into the HMONs and coating a layer of polydopamine (PDA). The as-prepared AVM@HMONs@PDA displays a favorable pesticide load capability (24.8 wt %), outstanding photothermal performance, and high adhesion to leaves. In addition, with glutathione (GSH), the AVM cumulative release from AVM@HMONs@PDA was 3.5 times higher than that without GSH. Under ultraviolet light irradiation, the half-life of AVM@HMONs@PDA was prolonged by 17.0-fold compared to that of the AVM technical. At day 21 after treatment in the insecticidal activity, the median lethal concentrations (LC50) values displayed that the toxicity of AVM@HMONs@PDA for Panonychus citri (McGregor) was enhanced 4.0-fold compared with the commercial emulsifiable concentrate. In the field trial, at day 28 after spraying, AVM@HMONs@PDA was significantly more control effective than AVM-EC in controlling the P. citri (McGregor), even at a 50% reduced dosage. Moreover, HMONs@PDA was safe for crops. This research presents a novel preparation approach for HMONs, and it also offers a promising nanoplatform for the precise release of pesticides.