Lignin-Modified Electronegative Epoxy Resin Nanocarriers Effectively Deliver Pesticides against Plant Root-Knot Nematodes (Meloidogyne incognita)

Chelation and nanoparticle delivery of monomeric dopamine to increase plant salt stress resistance

Soil salinization hinders sustainable development of global agriculture. Dopamine (DA) delivery is promising for mitigating the detrimental effects of salt on plants. However, self-polymerization limits delivery and effectiveness. Here we chelated DA with ethylenediamine tetraacetic acid and zinc to reduce self-polymerization. To reduce soil adsorption, a sodium lignosulfonate and octadecyl dimethyl benzyl ammonium chloride nanocarrier is made for delivery to the plant. Compared with DA monomer, the soil adsorption rate of the DA in the nanocarrier is 46.02% lower. Salt stress experiments reveal, compared with NaCl and DA groups, the nanocarrier group exhibits significant increases in growth indicators for tomato plants. The beneficial effect is attributed to the increases in proline content, antioxidant capacity, and K+/Na+ ratios in the plants. Similar results are also observed with woody pear seedlings. These findings provide insights into alleviating crop salt stress.

The preparation of an allyl isothiocyanate and avermectin B2 microcapsule suspension against plant root-knot nematodes (Meloidogyne incognita)

BACKGROUND

Root-knot nematodes (Meloidogyne incognita) are one of the main pathogens affecting agricultural production. Conventional fumigants like methyl bromide have been phased out because of environmental risks, while alternatives face challenges of soil toxicity and resistance evolution. This study aims to develop a novel microencapsulated dual-agent system combining allyl isothiocyanate (AITC) and avermectin B2 (AVB2) for sustainable nematode control.

RESULT

Bioassay results showed that AITC and AVB2 had high toxicity against M. incognita with median lethal concentration (LC50) values of 21.44 and 3.06 mg L-1, respectively. The optimal combination of AITC and AVB2 at a ratio (LC50) of 40:60 (mAITC:mAVB2 = 14:3) exhibited significant synergy against M. incognita, with a co-toxicity coefficient of 183.67. The optimum formulation of 5% AITC-AVB2 microcapsule suspension (CS) was obtained by orthogonal test. The efficacy of 5% AITC-AVB2 CS against M. incognita was 82.92% in pot trials at a dosage of 50 mg kg-1.

CONCLUSION

This study initiated a dual-agent microencapsulation system that integrates plant extracts and microbial fermentation compounds for ecologically compatible nematode management. This technology addresses the limitations of fumigants through synergistic action, reduced environmental load and mitigated resistance. The results of the study provide a scalable solution for next-generation agrochemical formulations, balancing efficacy and sustainability. © 2025 Society of Chemical Industry.

Multiresponsive Zein Nanospheres for Avermectin B2 Delivery: Enhancing Root-Knot Nematode Control and Safety to Nontarget Organisms

Root-knot nematodes are globally prevalent plant-parasitic pests, distinguished by their widespread distribution, extensive host range, and challenging control measures. Avermectin B2, one of the few effective nematicides available, faces limitations in efficacy and poses environmental concerns due to its eco-unfriendly composition and poor utilization in traditional emulsifiable concentrate (EC) formulations. In this study, we developed core-shell structured Ave B2-BS@Zein@SC nanospheres, incorporating zein as the carrier, sodium caseinate as the stabilizer, and butyl stearate as the temperature "switch". These nanospheres demonstrated multiresponsive characteristics to temperature, pH, and enzymatic conditions, facilitating rapid pesticide release under elevated temperatures, mildly acidic or alkaline conditions, and in the presence of protease. These controlled-release properties effectively responded to both environmental factors during nematode outbreaks and the intestinal conditions of the nematodes, enhancing pesticide targeting and utilization efficiency. The engineered nanospheres improved the mobility and stability of avermectin B2 in soil, enabling more comprehensive control of nematodes across broader and deeper soil layers. Additionally, the penetration capability of Ave B2-BS@Zein@SC into plant roots effectively eliminated nematodes that had already invaded the root system, thereby strengthening crop protection. Crucially, Ave B2-BS@Zein@SC demonstrated enhanced safety for nontarget organisms. This environmentally conscious, and multiresponsive pesticide nanodelivery system presents a promising strategy for sustainable subterranean pest management.

Lignin-Based Functional Materials in Agricultural Application: A Review

The demand for biodegradable, sustainable, and eco-friendly alternatives is growing in crop production and protection, which forces an urgent need for society to shift toward more sustainable agricultural development. In recent years, the development and research of lignin-based functional materials have gained increasing attention and impetus, and their use has become more widespread in sustainable agriculture. This review covers the latest research on the potential applications of lignin-based functional materials in plant protectants, sensors for pollutant detection, toxic element removal in soil and water, enzyme immobilization, plant growth regulators/biostimulants, hydrogels, and mulching films. Finally, future challenges and perspectives of lignin-based functional materials are discussed to provide a new strategy for the promotion of sustainable agriculture.

Thermoresponsive lignin-based polyelectrolyte complexes for the preparation of spherical nanoparticles: Application in pesticide encapsulation

Lignin-based nanoparticles hold tremendous potential for various applications. This study proposes an innovative and straightforward method for the synthesis of spherical hybrid lignin nanoparticles (hy-LNPs) with a tunable pore structure. The approach involves blending lignin with 20 wt% polyamide-epichlorohydrin, resulting in the formation of thermoresponsive lignin-based polyelectrolyte complexes. Upon heating to 80 °C, the complexes undergo self-assembly into uniform spherical nanoparticles, achieving a minimum polydispersity index (PDI) as low as 0.08. The study reveals that nanoparticle formation involves simultaneous collapse and growth. During collapse, hy-LNPs become more compact, increasing their elastic behavior and inhibiting particle coalescence, which is critical for the formation of stable, low-dispersibility nanoparticles. Contrary to the expectation that collapse would reduce pore size, the average pore size of the hy-LNPs increases from 24.9 nm to 35.8 nm, likely due to the coalescence of smaller pores into larger ones. Furthermore, this straightforward method was applied to encapsulation β-cypermethrin, achieving an encapsulation efficiency of up to 95 % and reducing the release rate in an ethanol-water solution from 90.6 % to 63.1 % over 5 h. The thermoresponsive lignin-based polyelectrolyte complexes provide a new pathway for the controlled preparation of lignin-based nanoparticles. These nanoparticles demonstrate promising potential for applications such as drug encapsulation.

Nanocarriers boost non-systemic fluazinam transportation in plants and microbial community enrichment in soil

Utilizing nanotechnology for pesticide delivery can enhance their uptake and distribution in plants, thereby boosting pesticide efficiency. Fluazinam, a highly effective broad-spectrum fungicide with unique mode of action, is hindered by its poor systemic conductivity, limiting its field control efficacy. In this study, fluazinam-loaded nanocapsules were developed, which exhibited significantly higher inhibitory activity against various Phytophthora species compared to the commercial suspension concentrate. Notably, the nanocapsules demonstrated pronounced effects on reducing ATP content in Phytophthora capsici and effectively controlled pepper blight and cucumber downy mildew. Tracking the distribution of fluorescein isothiocyanate (FITC) fluorescein-labeled fluazinam nanocapsules revealed their presence in roots seven days after treatment. High-performance liquid chromatography (HPLC) analysis confirmed the easy absorption and transport of fluazinam nanocapsules by pepper plants. Moreover, treatment with fluazinam nanocapsules significantly increased the expression of two exocytosis genes, FACP and RABF2a, in pepper tissues. Lastly, fluazinam nanocapsules were found to enhance the relative abundance of beneficial bacteria in the soil microbial community. This study presents a promising approach to enhance the upward transport capability of non-systemic pesticides, offering novel insights into their application and improved efficacy.

Sustainable lignin-modified epoxy nanocarriers for enhanced foliar insecticide efficacy and food safety

Reducing pesticide residues while extending their efficacy period is a critical challenge in the development of controlled-release pesticides. This study focuses on loading avermectin onto lignin-modified epoxy resin nanocarriers via the creation of photostable nanocapsules (NCs) for evaluating their efficacy against Plutella xylostella. This study also assesses the NCs' resistance to water scour on plant leaves by comparing them with traditional preparations. These NCs feature a stable core-shell structure, an encapsulation efficiency of 92.90 % and slow-release properties. Compared to emulsifiable concentrate (EC) and microemulsion (ME) under UV irradiation, the loading of nanocarriers significantly prolonged the degradation time of avermectin by fivefold. The Nano-formula demonstrated enhanced insecticidal activity in comparison to traditional preparations. Field tests revealed that the efficacy of the NCs on Day 7 (92.55 %) and Day 14 (78.54 %) significantly surpassed that of traditional preparations. Additionally, NCs are more readily washed off cabbage leaves by water than EC and ME, aiding in the reduction of pesticide residues. This technology is particularly suitable for leafy vegetable crops in arid regions or greenhouses, enhancing effectiveness period while minimizing pesticide residues. This research offers novel insights and directions for the development of controlled-release pesticides.

Multi-Stimuli-Responsive, Topology-Regulated, and Lignin-Based Nano/Microcapsules from Pickering Emulsion Templates for Bidirectional Delivery of Pesticides

The increasing demand for improving pesticide utilization efficiency has prompted the development of sustainable, targeted, and stimuli-responsive delivery systems. Herein, a multi-stimuli-responsive nano/microcapsule bidirectional delivery system loaded with pyraclostrobin (Pyr) is prepared through interfacial cross-linking from a lignin-based Pickering emulsion template. During this process, methacrylated alkali lignin nanoparticles (LNPs) are utilized as stabilizers for the tunable oil-water (O/W) Pickering emulsion. Subsequently, a thiol-ene radical reaction occurs with the acid-labile cross-linkers at the oil-water interface, leading to the formation of lignin nano/microcapsules (LNCs) with various topological shapes. Through the investigation of the polymerization process and the structure of LNC, it was found that the amphiphilicity-driven diffusion and distribution of cyclohexanone impact the topology of LNC. The obtained Pyr@LNC exhibits high encapsulation efficiency, tunable size, and excellent UV shielding to Pyr. Additionally, the flexible topology of the Pyr@LNC shell enhances the retention and adhesion of the foliar surface. Furthermore, Pyr@LNC exhibits pH/laccase-responsive targeting against Botrytis disease, enabling the intelligent release of Pyr. The in vivo fungicidal activity shows that efficacy of Pyr@LNC is 53% ± 2% at 14 days postspraying, whereas the effectiveness of Pyr suspension concentrate is only 29% ± 4%, and the acute toxicity of Pyr@LNC to zebrafish is reduced by more than 9-fold compared with that of Pyr technical. Moreover, confocal laser scanning microscopy shows that the LNCs can be bidirectionally translocated in plants. Therefore, the topology-regulated bidirectional delivery system LNC has great practical potential for sustainable agriculture.

The combination of chemical fertilizer affected the control efficacy against root-knot nematode and environmental behavior of abamectin in soil

Chemical fertilizer and pesticide are necessary in agriculture, which have been frequently used, sometimes even at the same time or in combination. To understand the interactions of them could be of significance for better use of these agrochemicals. In this study, the influence of chemical fertilizers (urea, potassium sulfate, ammonium sulfate and superphosphate) on the control efficacy and environmental behavior of abamectin was investigated, which could be applied in soil for controlling nematodes. In laboratory assays, ammonium sulfate at 1 and 2 g/L decreased the LC50 values of abamectin to Meloidogyne incognita from 0.17 mg/L to 0.081 and 0.043 mg/L, indicating it could increase the contact toxicity. In greenhouse trial, ammonium sulfate at 1000 mg/kg increased the control efficacy of abamectin by 1.37 times. Meanwhile, the combination of abamectin with ammonium sulfate could also promote the tomato seedling growth as well as the defense-related enzyme activity under M. incognita stress. The persistence and mobility of abamectin in soil were significantly elevated by ammonium sulfate, which could prolong and promote the control efficacy against nematodes. These results could provide reference for reasonable use of abamectin and fertilizers so as to increase the control efficacy and minimize the environmental risks.

Ascendancy of pyraclostrobin nanocapsule formulation against Rhizoctonia solani: From a perspective of fungus

High-performance pesticide formulations are essential for sustainable agriculture. Among these, nano-pesticides exhibit great advantages in pest control because of their unique size effects. However, the direct effects of nano-formulation fungicides on fungal pathogens remain largely unexplored. In this study, three qualified formulations, suspension concentrate (SC), microcapsules (CS), and nanocapsules (NCS) of pyraclostrobin (PYR) were prepared and utilized to reveal their biocontrol activities against Rhizoctonia solani. Among these three formulations, NCS exhibited notable biocontrol efficacy against R. solani exemplified by an EC50 of 0.319 mg/L for mycelia, distortion of mycelia and abnormalities in cell ultrastructure. Moreover, NCS displayed excellent internalization within R. solani mycelia, contributing to severe damage to cell membrane permeability. Importantly, an equivalent quantity of NCS-PYR showed potent inhibitory effects on the target pathogen, as indicated by reduced adenosine triphosphate (ATP) content and mitochondrial Complex III activity. The NCS consistently exhibited superior in vivo protective and curative activities against R. solani compared to those of CS and SC in rice and faba bean. In summary, we uncovered the strength of rapid efficacy and biocontrol activity of NCS against R. solani and elucidated the advantages of NCS-PYR from the perspective of the target pathogen in agriculture.

One-pot construction of epoxy resin nanocarrier delivering abamectin and its efficacy on plant root-knot nematodes

BACKGROUND

The complex preparation process and storage instability of nanoformulations hinders their development and commercialization. In this study, nanocapsules loaded with abamectin were prepared by interfacial polymerization at room temperature and ordinary pressure using the monomers of epoxy resin (ER) and diamine. The potential mechanisms of primary amine and tertiary amine in influencing the shell strength of the nanocapsules and the dynamic stability of abamectin nanocapsules (Aba@ER) in the suspension system were systematically researched.

RESULTS

The tertiary amine catalyzed the self-polymerization of epoxy resin into linear macromolecules with unstable structures. The structural stability of the diamine curing agent with a primary amine group played a key role in enhancing the structural stability of the polymers. The intramolecular structure of the nanocapsule shell formed by isophorondiamine (IPDA) crosslinked epoxy resin has multiple spatial conformations and a rigid saturated six-membered ring. Its structure was stable, and the shell strength was strong. The formulation had stable dynamic changes during storage and maintained excellent biological activity. Compared with emulsifiable concentrate (EC), Aba@ER/IPDA had superior biological activity, and the field efficacy on tomato root-knot nematode was enhanced by approximately 31.28% at 150 days after transplanting.

CONCLUSION

Aba@ER/IPDA, which has excellent storage stability and simple preparation technology, can provide a nanoplatform with industrial prospects for efficient pesticide delivery. © 2023 Society of Chemical Industry.

Nano-based smart formulations: A potential solution to the hazardous effects of pesticide on the environment

Inefficient usage, overdose, and post-application losses of conventional pesticides have resulted in severe ecological and environmental issues, such as pesticide resistance, environmental contamination, and soil degradation. Advances in nano-based smart formulations are promising novel methods to decrease the hazardous impacts of pesticide on the environment. In light of the lack of a systematic and critical summary of these aspects, this work has been structured to critically assess the roles and specific mechanisms of smart nanoformulations (NFs) in mitigating the adverse impacts of pesticide on the environment, along with an evaluation of their final environmental fate, safety, and application prospects. Our study provides a novel perspective for a better understanding of the potential functions of smart NFs in reducing environmental pollution. Additionally, this study offers meaningful information for the safe and effective use of these nanoproducts in field applications in the near future.

Preparation of enzyme-responsive composite nanocapsules with sodium carboxymethyl cellulose to improve the control effect of root-knot nematode disease

Developing an efficient drug delivery system to mitigate the harm caused by root-knot nematodes is crucial. In this study, enzyme-responsive release abamectin nanocapsules (AVB1a NCs) were prepared using 4, 4-diphenylmethane diisocyanate (MDI) and sodium carboxymethyl cellulose as response release factors. The results showed that the average size (D₅₀₎ of the AVB1a NCs was 352 nm, and the encapsulation efficiency was 92 %. The median lethal concentration (LC₅₀) of AVB1a NCs for Meloidogyne incognita activity was 0.82 mg L^-1. Moreover, AVB1a NCs improved the permeability of AVB1a to root-knot nematodes and plant roots and the horizontal and vertical soil mobility. Furthermore, AVB1a NCs greatly reduced the adsorption of AVB1a by the soil compared to AVB1a emulsifiable concentrate (EC), and the effect of the AVB1a NCs on controlling root-knot nematode disease was increased by 36 %. Compared to the AVB1a EC, the pesticide delivery system significantly reduced the acute toxicity to the soil biological earthworms by approximately 16 times that of the AVB1a and had a lower overall impact on the soil microbial communities. This enzyme-responsive pesticide delivery system had a simple preparation method, excellent performance, and high level of safety, and thus has great application potential for plant diseases and insect pests control.

Dual-functional lignin-based hydrogels for sustained release of agrochemicals and heavy metal ion complexation

An effective way of improving the efficiency of agrochemicals and improving crop yield and quality is by slow or sustained release, which is conducive to environmental protection. Meanwhile, the excessive amount of heavy metal ions in soil can create toxicity in plants. Here, we prepared lignin-based dual-functional hydrogels containing conjugated agrochemical and heavy metal ligands through free-radical copolymerization. The content of the agrochemicals (including plant growth regulator 3-indoleacetic acid (IAC) and herbicide 2,4-dichlorophenoxyacetic acid (DCP)) in the hydrogels were tuned by changing the hydrogel composition. The conjugated agrochemicals could slowly release through the gradual cleavage of the ester bond. As a result of the release of the DCP herbicide, the growth of lettuce was effectively regulated, thus confirming the feasibility and effectiveness of this system in application. At the same time, due to the presence of metal chelating groups (such as COOH, phenolic OH, and tertiary amine) the hydrogels could act as adsorbents or stabilizers towards heavy metal ions for improving the soil remediation and preventing the adsorption of these toxic metals by plant roots. Specifically, Cu(II) and Pb(II) could be adsorbed >380 and 60 mg/g, respectively.

Advances in stimuli-responsive systems for pesticides delivery: Recent efforts and future outlook

Effective pest management for enhanced crop output is one of the primary goals of establishing sustainable agricultural practices in the world. Pesticides are critical in preventing biological disasters, ensuring crop productivity, and fostering sustainable agricultural production growth. Studies showed that crops are unable to properly utilize pesticides because of several limiting factors, such as leaching and bioconversion, thereby damaging ecosystems and human health. In recent years, stimuli-responsive systems for pesticides delivery (SRSP) by nanotechnology demonstrated excellent promise in enhancing the effectiveness and safety of pesticides. SRSP are being developed with the goal of delivering precise amounts of active substances in response to biological needs and environmental factors. An in-depth analysis of carrier materials, design fundamentals, and classification of SRSP were provided. The adhesion of SRSP to crop tissue, absorption, translocation in and within plants, mobility in the soil, and toxicity were also discussed. The problems and shortcomings that need be resolved to accelerate the actual deployment of SRSP were highlighted in this review.

Biorefining waste into nanobiotechnologies can revolutionize sustainable agriculture

Modern agriculture has evolved technological innovations to sustain crop productivity. Recent advances in biorefinery technology use crop residue as feedstock, but this raises carbon sequestration concerns as biorefining utilizes carbon that would otherwise be returned to the soil, thus causing a decline in crop productivity. Furthermore, biorefining generates abundant lignin waste that significantly impedes the efficiency of biorefineries. Valorizing lignin into advanced nanobiotechnologies for agriculture provides a unique opportunity to balance bioeconomy and soil carbon sequestration. Integration of agricultural practices such as utilization of agrochemicals, fertilizers, soil modifiers, and mulching with lignin nanobiotechnologies promotes crop productivity and also enables advanced manufacturing of high-value bioproducts from lignin. Lignin nanobiotechnologies thus represent state-of-the-art innovations to transform both the bioeconomy and sustainable agriculture.

Metolachlor metal-organic framework nanoparticles for reducing leaching, ecotoxicity and improving bioactivity

BACKGROUND

The adverse effects of pesticides has led to a series of ecological, environmental and public health issues. Amide herbicides are an important agrochemical, yet many are prone to leach and pollute the environment, which limits their further application. In this study, metolachlor (METO) was selected as a model pesticide and a controlled released nanoparticle (NP) system was constructed employing a zeolitic imidazolate framework-8 hybrid inorganic-organic porous material (METO@ZIF-8).

RESULTS

The synthesis parameters of METO@ZIF-8 were optimized, and the loading content of METO@ZIF-8 was maximized by a central composite design of response surface test. The NPs were regular dodecahedron with uniform size (mostly 54.3 nm diameter). METO@ZIF-8 had high specific surface area and good dispersal in water. Moreover, it endowed the active ingredient with a pH-responsive release property. The nanocarrier effectively improved the adsorption capacity of METO in soil and reduce the leaching by 10.3-21.7%. Pot experiments suggested that the control effect of METO@ZIF-8 was 16.6 and 48.4% higher than that of METO emulsifiable concentrate (EC) and METO technical concentration (TC) at the recommended dose. Based on the excellent controlled release profiles, METO@ZIF-8 did not affect corn plant growth and significantly reduced the risk of phytotoxicity induced by METO. METO@ZIF-8 effectively reduced acute toxicity in zebrafish compared with METO EC.

CONCLUSION

This study explored the fabrication of a nanocarrier for improving the efficacy and promoting the environmental safety of leachable amide herbicides. © 2022 Society of Chemical Industry.

Lignin-based non-crosslinked nanocarriers: A promising delivery system of pesticide for development of sustainable agriculture

Lignin sulfonate (LS), a waste material from the paper pulping, was modified with benzoic anhydride to obtain benzoylated lignin sulfonates of adjustable hydrophilicity (BLS). When BLS was combined with difenoconazole (Di), a broad-spectrum fungicide, lignin-based, non-crosslinked nanoparticles were obtained either by solvent exchange or solvent evaporation. When a mass ratio of 1:5 LS: benzoic anhydride was used, the Di release from Di@BLS₅ after 1248 h was ca. 74 %, while a commercial difenoconazole microemulsion (Di ME) reached 100 % already after 96 h, proving the sustained release from the lignin nanocarriers. The formulation of Di in lignin-based nanocarriers also improved the UV stability and the foliar retention of Di compared to the commercial formulation of the fungicide. Bioactivity assay showed that Di@BLS₅ exhibited high activities and duration against strawberry anthracnose (Colletotrichum gloeosporioides). Overall, the construction of fungicide delivery nano-platform using BLS via a simple non-crosslinked approach is a novel and promising way to develop new formulations for nanopesticide and the development of sustainable agriculture.

The Practical Utility of Imidazolium Hydrogen Sulfate Ionic Liquid in Fabrication of Lignin-Based Spheres: Structure Characteristic and Antibacterial Activity

In this study, lignin-based spherical particles (Lig-IL) with the use of 1-(propoxymethyl)-1H-imidazolium hydrogen sulfate were prepared in different biopolymer and ionic liquid (IL) weight ratios. The application of IL during the preparation of spherical particles is an innovative method, which may be beneficial for further applications. The particles were obtained with the use of the soft-templating method and their chemical, structural and morphological characterization was performed. The spherical shape of products and their size (91–615 nm) was confirmed with the use of scanning electron microscopy (SEM) images and the particle size distribution results. The attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra were analyzed to identify functional groups of all precursors and produced material and it was confirmed, that all materials exhibit characteristic hydroxyl and carboxylic groups, but the presence of carbonyl group was detected. Moreover, the zeta potential analysis was performed to evaluate the electrokinetic behavior of obtained materials. It was confirmed, that all materials are colloidally stable in pH above 4. Produced lignin-based spherical particles were used for evaluation of their antibacterial properties. Particles were tested against Staphylococcus aureus (S. aureus), a gram-positive bacterium, and Escherichia coli (E. coli), a gram-negative one. It was observed, that only the material with the highest addition of IL showed the antibacterial properties against both strains. A reduction of 50% in the number of microorganisms was observed for particles with the addition of hydrogen sulfate ionic liquid in a 1:1 ratio after 1 h. However, all prepared materials exhibited the antibacterial activity against a gram-positive bacterium.

Lambda-cyhalothrin-loaded nanocapsules pose an unacceptable acute toxicological risk to zebrafish (Danio rerio) at the adult and larval stages but present an acceptable risk to embryos

Recently, size-controlled pesticide microcapsule (MC) delivery systems have played an important role in precision farming development; however, the potential environmental hazards of MCs with different particle sizes have not been fully characterized. In this study, we prepared a series of lambda-cyhalothrin (LC)-MCs with nano and micron-scale capsule sizes (average diameters of 209.4 nm, MC-N; 2.41 µm, MC-S; 4.87 µm, MC-M; and 12.41 µm, MC-L). The assessment results showed that the release and sedimentation behavior of LC-MCs in water and toxicity to zebrafish at three life stages were all particle size-dependent. As the diameter distribution of approximately 100 nm extended to the micron scale (~27 µm), the capsules released more slowly and sunk more quickly in water. In addition, micron-sized LC-MC exposure resulted in significantly less fish mortality and malformations of larvae and embryos compared with nanosized LC-MC exposure. The highest accumulation of MC-N in the gill and the severest toxicity to larvae suggested that the smaller size and stronger permeability of nanocapsules would pose unpredictable consequences for nontargeted organisms. The obvious toxicological differences of LC-MCs toward aquatic organisms implies that regulating MC production in an appropriate size range is an important prerequisite for achieving efficient but safe pesticide applications.

Lignin-based nano-enabled agriculture: A mini-review

Nowadays sustainable nanotechnological strategies to improve the efficiency of conventional agricultural practices are of utmost importance. As a matter of fact, the increasing use of productive factors in response to the growing food demand plays an important role in determining the environmental impact of agriculture. In this respect, low-efficiency conventional practices are becoming obsolete. On the other hand, the exploitation of nanoscaled systems for the controlled delivery of fertilizers, pesticides and herbicides shows great potential towards the development of sustainable, efficient and resilient agricultural processes, while promoting food security. In this context, lignin - especially in the form of its nanostructures - can play an important role as sustainable biomaterial for nano-enabled agricultural applications. In this review, we present and discuss the current advancements in the preparation of lignin nanoparticles for the controlled release of pesticides, herbicides, and fertilizers, as well as the latest findings in terms of plant response to their application. Special attention has been paid to the state-of-the-art literature concerning the release performance of these lignin-based nanomaterials, whose efficiency is compared with the conventional approaches. Finally, the major challenges and the future scenarios of lignin-based nano-enabled agriculture are considered.

Recent Advances on Lignocellulosic-Based Nanopesticides for Agricultural Applications

Controlled release systems of agrochemicals have been developed in recent years. However, the design of intelligent nanocarriers that can be manufactured with renewable and low-cost materials is still a challenge for agricultural applications. Lignocellulosic building blocks (cellulose, lignin, and hemicellulose) are ideal candidates to manufacture ecofriendly nanocarriers given their low-cost, abundancy and sustainability. Complexity and heterogeneity of biopolymers have posed challenges in the development of nanocarriers; however, the current engineering toolbox for biopolymer modification has increased remarkably, which enables better control over their properties and tuned interactions with cargoes and plant tissues. In this mini-review, we explore recent advances on lignocellulosic-based nanocarriers for the controlled release of agrochemicals. We also offer a critical discussion regarding the future challenges of potential bio-based nanocarrier for sustainable agricultural development.

Emamectin benzoate nanogel suspension constructed from poly(vinyl alcohol)-valine derivatives and lignosulfonate enhanced insecticidal efficacy

To reduce the negative impact of nanopesticide carriers of on the environment, a greener nanodelivery system is necessary. Nanogels are nontoxic and degradable carriers, however, the potential of nanogels for delivering pesticides has not been proven. In this study, poly(vinyl alcohol)-valine, an ecofriendly polymer, was synthesized and used to fabricate emamectin benzoate nanogel suspension (EB NS). The nanoformulation showed favorable stability at low temperature, high temperature or one year storage, and in water with different hardnesses. The retention of the EB NS solution on leaves was higher than that of an EB emulsifiable concentrate (EC) by approximately 9% at a concentration of 10 mg L^-1. The half-life of EB nanogels under Ultra Violet irradiation was prolonged by 3.3-fold. Moreover, the bioactivity of the EB NS against Plutella xylostella was higher than that of the EB EC. These advantages resulted in a relatively long duration of pest control. The response of nanogels to laccase, a digestive enzyme in the digestive tract of lepidopteran pests, enables pesticide release on demand. Nanogels have the advantages of being ecofriendly carriers, exhibiting higher utilization, and prolonged pest control periods, and they have a brilliant future in pesticide delivery.

Using a reactive emulsifier to construct simple and convenient nanocapsules loaded with lambda-cyhalothrin to achieve efficient foliar delivery and insecticidal synergies

Nanocapsules are a promising controlled release formulation for foliar pest control. However, the complicated process and high cost limit widespread use in agriculture, so a simpler and more convenient preparation system is urgently needed. Meanwhile, under complex field conditions, the advantageous mechanism of the nanosize effect and sustained release have no quantitative and detailed study. In this study, a reactive emulsifier (OP-10) is used to participate in the interfacial polymerization of the nanoemulsion, and polymer nanocapsules loaded with lambda-cyhalothrin (NCS@LC) are quickly and easily prepared to study the efficacy and synergistic mechanism of foliar pest control. As a result, the nanocapsule is about 150 nm with a stable core-shell structure. The nanoscale state increases the distribution and adhesion of the particles on the leaf surface, which increases the contact efficiency of pesticides under the different physiological stages and behavioral activities of the target organism. The shell structure provides sustained release characteristics and increases the UV resistance by about 2.5 times for pesticides. Compared with microcapsules loaded with lambda-cyhalothrin (CS@LC), NCS@LC not only shows rapid and synergistic insecticidal efficacy but also provides sustained insecticidal efficacy. The mortality of NCS is 3.4 times that of the nanosized emulsion in water (NEW) at the lowest concentration (0.5 mg L^-1), and the control efficacy remained 77.3% after 7 days. Compared with NEW, NCS@LC provides excellent field efficacy, while LC₅₀ for zebrafish is only 0.68 times without increasing the aquatic toxicity risk.

Self-Assembled Degradable Nanogels Provide Foliar Affinity and Pinning for Pesticide Delivery by Flexibility and Adhesiveness Adjustment

At present, it is highly important to develop a simple and compatible nano delivery system for pesticides for foliar application, which can improve their insecticidal efficacy and resistance to adverse climates while reducing the environmental risks. Polyethylene glycol and 4,4-methylenediphenyl diisocyanate are used as hydrophilic soft and hydrophobic hard segments, respectively, for polymer self-assembly and polyurethane gelation in a nanoreactor. The nanocarrier synthesis and the pesticide loading are realized by a one-step integration procedure and suited well for hydrophobic active compounds. Modifying the molecular structure of the soft segment can adjust the flexibility of the nanocarriers and result in viscosity and deformation characteristics. After foliar spray application, the foliar flattening state of the nanogels increases the foliar protection area by 2.21 times and improves both pesticide exposure area and target contact efficiency. Concurrently, the flexibility and viscosity of the nanogels increase the washing resistance and the retention rate of the pesticide by approximately 80 times under continuous washing. The encapsulation of the nanogels reduces the foliar ultraviolet (UV) degradation and aquatic pesticide exposure, which increase the security of λ-cyhalothrine by 9.33 times. Moreover, the degradability of nanogels is beneficial for pesticide exposure and reducing pollution. This system has simple preparation, good properties, and environmental friendliness, making the nanocarriers promising for delivering pesticides.