Pectin functionalized metal-organic frameworks as dual-stimuli-responsive carriers to improve the pesticide targeting and reduce environmental risks

Inhibition mechanism of pectin-modified nano-selenium on Phytophthora capsici and the improvement of the resistance in pepper

The principal disease impacting pepper production is Phytophthora blight, which nano‑selenium (nano-Se) controls well but has high storage requirements and low heat resistance. Varying pectin amounts yielded pectin-modified nano-Se (nano-Se@PT) with 0.1 %, 0.5 %, 1 %, and 2 % concentration. As pectin content grew, nano-Se@PT particle size reduced, zeta potential value rose, and thermogravimetric temperature climbed. The incorporation of nano-Se@PT can improve its stability and thermal resistance at 40 °C and 70 °C. Nano-Se@PT outperformed nano-Se in fungicidal and Phytophthora capsici inhibition. In vitro antifungal experiments showed that nano-Se@PT could significantly inhibit mycelium growth with an EC50 of about 4 mg/L. The particles adsorbed on the surface of mycelium, inducing death by destroying cell membranes, mitochondria, and nuclei. Non-targeted metabolomics analysis showed that nano-Se@PT treatment disrupted the mycelium growth and metabolism and changed amino acids, nucleotides, and sugar levels. In vivo experiments, 2 % nano-Se@PT had the lowest disease index and the best preventive therapy. Rhizosphere soil microbial analysis showed that nano-Se@PT recruited beneficial microorganisms such as Bacteroides, Lactobacillus, and Bifidobacterium in pepper plants, improving their Phytophthora capsici resistance and growth. The findings suggest that nano-Se@PT might be a unique pepper disease control technique and shed light on plant fungal disease management.

Degradable mesoporous organosilicon nanoparticles coated with chitosan-Cu2+ complexes with dual stimulus-response for efficient prochloraz delivery

Accurate pesticide application enhances efficiency, reduces usage and minimizes environmental risks. This study employed amino-functionalized degradable mesoporous organosilicon nanoparticles (DMON-N) as a carrier, with chitosan (CS) acting as a capping agent. Chemical cross-linking of CS with Cu2+ through chelation promotes the formation of Cu2+-CS complexes. A pH/redox dual-responsive prochloraz (PRO) delivery system (Cu-CS@PRO-DMON, CCPD) was constructed and evaluated for its potential application in controlling rice sheath blight. The successful preparation of CCPD was confirmed through a series of physicochemical characterizations. The findings demonstrated that CCPD exhibited a high PRO loading capacity (29.09 %) and that PRO could be released from CCPD for an extended duration (up to 144 h) under the influence of acidity and glutathione promotion. Furthermore, CCPD demonstrated excellent wettability (measured contact angle: 63.52 ± 0.42°), adhesion (23.83 ± 2.59 mg/cm2) and resistance to rainfall washout on rice leaves. CCPD demonstrated superior antimicrobial efficacy to prochloraz technical (PRO TC) material and prochloraz emulsion in water (PRO EW). The biosafety assessment revealed that CCPD exhibited minimal acute toxicity to zebrafish, no discernible toxicological effects on human bronchial epithelial cells and no notable impact on rice.

Fe-based metal-organic frameworks modified with carboxymethyl cellulose for targeted pesticide delivery and reducing biotoxicity

Traditional pesticide formulations have issues such as poor targeting, low adhesion performance, and a tendency to leach into the environment, causing pollution. In this study, a pesticide delivery platform (PRO@FeMOFs@CMC) with a dual response was designed by encapsulating prochloraz technical (PRO) within Fe-based metal-organic frameworks (FeMOFs) and using carboxymethyl cellulose (CMC) as the gatekeeper. The results showed that PRO@FeMOFs@CMC exhibited a loading capacity of 28.86 % for PRO and efficient adhesion to wheat and rice leaves. This delivery platform showed a significant increase in the release of PRO under environments similar to that produced by a pathogen infection, involving cellulase and glutathione (GSH). Importantly, compared to prochloraz suspension concentrate (PRO@SC), PRO@FeMOFs@CMC exhibited higher fungicidal efficacy against Rhizoctonia cereali and Rhizoctonia solani and its acute toxicity to zebrafish and earthworms was reduced by 3.7 times and 8.6 times, respectively. Compared to PRO@SC, the cells treated with PRO@FeMOFs@CMC had higher cell viability and a significantly reduced apoptosis rate, demonstrating greater safety. Additionally, FeMOFs@CMC showed no evident toxicity to wheat and rice. In summary, PRO@FeMOFs@CMC is an efficient and safe pesticide controlled-release system for the sustainable management of wheat and rice diseases.

An in-depth review: Unraveling the extraction, structure, bio-functionalities, target molecules, and applications of pectic polysaccharides

Pectic polysaccharides have long been a challenging subject of research in the field of macromolecular science, given their complex structures and wide range of biological effects. However, the extensive exploration of pectic polysaccharides has been limited due to the intricacy of their structures. In this comprehensive review, we aim to provide a thorough summary of the existing knowledge on pectic polysaccharides, with a particular focus on aspects such as classification, extraction methodologies, structural analysis, elucidation of biological activities, and exploration of target molecules and signaling pathways. By conducting a comprehensive analysis of existing literature and research achievements, we strive to establish a comprehensive and systematic framework that can serve as a reference and guide for further investigations into pectic polysaccharides. Furthermore, this review delves into the applications of pectic polysaccharides beyond their fundamental attributes and characteristics, exploring their potential in fields such as materials, food, and pharmaceuticals. We pay special attention to the promising opportunities for pectic polysaccharides in the pharmaceutical domain and provide an overview of related drug development research. The aim of this review is to facilitate a holistic understanding of pectic polysaccharides by incorporating multifaceted research, providing valuable insights for further in-depth investigations into this significant polymer.

Metal-Organic Frameworks for Sustainable Crop Disease Management: Current Applications, Mechanistic Insights, and Future Challenges

Efficient management of crop diseases and yield enhancement are essential for addressing the increasing food demands due to global population growth. Metal-organic frameworks (MOFs), which have rapidly evolved throughout the 21st century, are notable for their vast surface area, porosity, and adaptability, establishing them as highly effective vehicles for controlled drug delivery. This review methodically categorizes common MOFs employed in crop disease management and details their effectiveness against various pathogens. Additionally, by critically evaluating existing research, it outlines strategic approaches for the design of drug-delivery MOFs and explains the mechanisms through which MOFs enhance disease resistance. Finally, this paper identifies the current challenges in MOF research for crop disease management and suggests directions for future research. Through this in-depth review, the paper seeks to enrich the understanding of MOFs applications in crop disease management and offers valuable insights for researchers and practitioners.

Microencapsulation of multi-component traditional Chinese herbs extracts and its application to traditional Chinese medicines loaded textiles

Extracts of traditional Chinese herbs (TCH) contain a variety of anti-allergic, anti-inflammatory and other bioactive factors. However, the defect of easy degradation or loss of active ingredients limits its application in traditional Chinese medicines (TCM) loaded textiles. In this work, TCH extracts containing different active ingredients were innovatively proposed as the core material of microcapsules. The feasibility of microencapsulation of multi-component TCH extracts in the essential oil state was initially demonstrated. Polyacrylate was also used as a binder to load the microcapsules onto the fabric to improve the durability and wash resistance of the treated fabric. Modeling the oil release of microcapsules for controlled release under different conditions may provide new possible uses for the materials. Results show that the constructed microcapsule has a smooth surface without depression and can be continuously released for over 30 days. The release behavior of microcapsules follows different release mechanisms and can be modulated by temperature and water molecules. The incorporation of microcapsules and polyacrylate does not significantly change the fabric's air permeability, water vapor transmission and hydrophilicity. The washing durability and friction properties of the microcapsule-based fabric are greatly improved, and it can withstand 30 washing tests and 200 friction tests. Moreover, the results of methyl thiazolyl tetrazolium (MTT) release assay using human dermal papilla cells (HDP) as an in vitro template confirm that the microcapsule has no toxic effects on human cells. Therefore, the successful microencapsulation of multi-component TCH extracts indicates their potential application in the field of TCM-loaded textiles.

Exploring the potential of waste biomass-derived pectin and its functionalized derivatives for water treatment

Environmental pollution remains a constant challenge due to the indiscriminate use of fossil fuels, mining activities, chemicals, drugs, aromatic compounds, pesticides, etc. Many emerging pollutants with no fixed standards for monitoring and control are being reported. These have adverse impacts on human life and the environment around us. This alarms the wastewater management towards developing materials that can be used for bulk water treatment and are easily available, low cost, non-toxic and biodegradable. Waste biomass like pectin is extracted from fruit peels which are a discarded material. It is used in pharmaceutical and nutraceutical applications but its application as a material for water treatment is very limited in literature. The scientific gap in literature review reports are evident with discussion only on pectin based hydrogels or specific pectin derivatives for some applications. This review focuses on the chemistry, extraction, functionalization and production of pectin derivatives and their applications in water treatment processes. Pectin functionalized derivatives can be used as a flocculant, adsorbent, nano biopolymer, biochar, hybrid material, metal-organic frameworks, and scaffold for the removal of heavy metals, ions, toxic dyes, and other contaminants. The huge quantum of pectin biomass may be explored further to strengthen environmental sustainability and circular economy practices.

Green synthesized lignin nanoparticles for the sustainable delivery of pyraclostrobin to control strawberry diseases caused by Botrytis cinerea

Lignin, renowned for its renewable, biocompatible, and environmentally benign characteristics, holds immense potential as a sustainable feedstock for agrochemical formulations. In this study, raw dealkaline lignin (DAL) underwent a purification process involving two sequential solvent extractions. Subsequently, an enzyme-responsive nanodelivery system (Pyr@DAL-NPs), was fabricated through the solvent self-assembly method, with pyraclostrobin (Pyr) loaded into lignin nanoparticles. The Pyr@DAL-NPs shown an average particle size of 250.4 nm, demonstrating a remarkable loading capacity of up to 54.70 % and an encapsulation efficiency of 86.15 %. Notably, in the presence of cellulase and pectinase at a concentration of 2 mg/mL, the release of Pyr from the Pyr@DAL-NPs reached 92.66 % within 120 h. Furthermore, the photostability of Pyr@DAL-NPs was significantly improved, revealing a 2.92-fold enhancement compared to the commercially available fungicide suspension (Pyr SC). Bioassay results exhibited that the Pyr@DAL-NPs revealed superior fungicidal activity against Botrytis cinerea over Pyr SC, with an EC50 value of 0.951 mg/L. Additionally, biosafety assessments indicated that the Pyr@DAL-NPs effectively declined the acute toxicity of Pyr towards zebrafish and posed no negative effects on the healthy growth of strawberry plants. In conclusion, this study presents a viable and promising strategy for developing environmentally friendly controlled-release systems for pesticides, offering the unique properties of lignin.

A dew-responsive pectin-based herbicide for enhanced photodynamic inactivation

5-aminolevulinic acid (5-ALA) has been fully demonstrated as a biodegradable, without resistance, and pollution-free pesticide. However, the lack of targeting and the poor adhesion result in a low utilization rate, limiting its practical application. Herein, a dew-responsive polymer pro-pesticide Pec-hyd-ALA was successfully synthesized by grafting 5-ALA onto the pectin (PEC) backbone via acid-sensitive acylhydrazone bonds. When the pro-pesticide is exposed to acid dew on plant surfaces at night, 5-ALA is released and subsequently converted to photosensitize (Protoporphyrin IX, PpIX)in plant cells, leading to its accumulation and promoting photodynamic inactivation (PDI). An inverted fluorescence microscope has verified the accumulation of tetrapyrrole in plant cells. In addition, the highly bio-adhesive PEC backbone effectively improved the wetting and retention of 5-ALA on leaves. The pot experiment also demonstrated the system's control effect on barnyard grass. This work provides a promising approach to improving the herbicidal efficacy of 5-ALA.

Smart controlled-release nanopesticides based on metal-organic frameworks

The practical utilization rates of conventional pesticide formulations by target organisms are very low, which results in the pollution of ecological environments and the formation of pesticide residues in agricultural products. Water-based nanopesticide formulations could become alternative and effective formulations to eventually resolve the main issues of conventional pesticide formulations. In this feature article, we describe the design concept of smart (stimuli-responsive) controlled-release nanopesticides, which are created toward hierarchical targets (pests, pathogens, and foliage) in response to multidimensional stimuli from physiological and environmental factors (such as sunlight) of target organisms and plants, for achieving enhanced insecticidal and fungicidal efficacies. The pore sizes and functionalities of metal-organic frameworks (MOFs) can be fine-tuned through the choice of metal-containing units and organic ligands. Tailor-made MOF nanoparticles with large microporous or mesoporous sizes, as well as good biocompatibility and high thermal, mechanical, and chemical durabilities, are used to load pesticides within these pores followed by coating of plant polyphenols and natural polymers for stimuli-responsive controlled pesticide release. This feature article highlights our works on smart controlled-release MOF-based nanopesticides and also includes related works from other laboratories. The future challenges and promising prospects of smart controlled-release MOF-based nanopesticides are also discussed.

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.

Pectin-Coated Iron-Based Metal-Organic Framework Nanoparticles for Enhanced Foliar Adhesion and Targeted Delivery of Fungicides

Conventional agrochemicals are underutilized due to their large particle sizes, poor foliar retention rates, and difficult translocation in plants, and the development of functional nanodelivery carriers with high adhesion to the plant body surface and efficient uptake and translocation in plants remains challenging. In this study, a nanodelivery system based on a pectin-encapsulated iron-based MOF (TF@Fe-MOF-PT NPs) was constructed to enhance the utilization of thifluzamide (TF) in rice plants by taking advantage of the pectin affinity for plant cell walls. The prepared TF@Fe-MOF-PT NPs exhibited an average particle size of 126.55 nm, a loading capacity of 27.41%, and excellent dual-stimulus responses to reactive oxygen species and pectinase. Foliar washing experiments showed that the TF@Fe-MOF-PT NPs were efficiently adhered to the surfaces of rice leaves and stems. Confocal laser scanning microscopy showed that fluorescently labeled TF@Fe-MOF-PT NPs were bidirectionally delivered through vascular bundles in rice plants. The in vitro bactericidal activity of the TF@Fe-MOF-PT NPs showed better inhibitory activity than that of a TF suspension (TF SC), with an EC50 of 0.021 mg/L. A greenhouse test showed that the TF@Fe-MOF-PT NPs were more effective than TF SC at 7 and 14 d, with control effects of 85.88 and 78.59%, respectively. It also reduced the inhibition of seed stem length and root length by TF SC and promoted seedling growth. These results demonstrated that TF@Fe-MOF-PT NPs can be used as a pesticide nanodelivery system for efficient delivery and intelligent release in plants and applied for sustainable control of pests and diseases.

Bidirectional Uptake, Transfer, and Transport of Dextran-Based Nanoparticles in Plants for Multidimensional Enhancement of Pesticide Utilization

The development of effective multifunctional nano-delivery approaches for pesticide absorption remains a challenge. Here, a dextran-based pesticide delivery system (MBD) is constructed to deliver tebuconazole for multidimensionally enhancing its effective utilization on tomato plants. Spherical MBD nanoparticles are obtained through two-step esterification of dextran, followed by tebuconazole loading using the Michael addition reaction. Confocal laser scanning microscopy shows that fluorescein isothiocyanate-labeled MBD nanoparticles can be bidirectionally transported in tomato plants and a modified quick, easy, cheap, effective, rugged, and safe-HPLC approach demonstrates the capacity to carry tebuconazole to plant tissues after 24 h of root uptake and foliar spray, respectively. Additionally, MBD nanoparticles could increase the retention of tebuconazole on tomato leaves by up to nearly 2.1 times compared with the tebuconazole technical material by measuring the tebuconazole content retained on the leaves. In vitro antifungal and pot experiments show that MBD nanoparticles improve the inhibitory effect of tebuconazole against botrytis cinerea by 58.4% and the protection against tomato gray molds by 74.9% compared with commercial suspensions. Furthermore, the MBD nanoparticles do not affect the healthy growth of tomato plants. These results underline the potential for the delivery system to provide a strategy for multidimensional enhancement of pesticide efficacy.

Sodium alginate-carboxymethyl chitosan hydrogels loaded with difenoconazole for pH-responsive release to control wheat crown rot

Increasing concern about environmental pollution has driven the development of controlled release formulations for agrochemicals. Due to the advantages of degradability and responsiveness to environmental stimuli, polysaccharide-based hydrogel is an ideal carrier for agrochemicals controlled release. In this study, a method-easy polysaccharide hydrogel for controlled release of difenoconazole (DZ) was prepared with sodium alginate (SA) and carboxymethyl chitosan (CMCS). Due to its three-dimensional crosslinked mesh structure, the prepared hydrogels (CSDZ) showed an agrochemical load capacity of 9.03 % and an encapsulation efficiency of 68.64 %. The release rate is faster in alkaline solution, followed by neutral solution, and slowest in an acid environment, which is consistent with the swelling behavior. Furthermore, leaching studies showed that CSDZ hydrogels have excellent protective properties for encapsulated agrochemicals. Compared with technical DZ, the results of in vitro and pot antifungal testing showed that CSDZ had a better control effect against wheat crown rot (Fusarium pseudograminearum). Safety assessment studies indicated that CSDZ hydrogels exhibit good biocompatibility on nontargeted organisms (Daphnia magna, zebrafish and Eisenia fetida) and wheat. This study aims to provide a potentially promising approach for the preparation and application of biocompatible polysaccharide-based hydrogels for agrochemical-controlled release in sustainable disease management.

Preparation of Azoxystrobin-Zinc Metal-Organic Framework/Biomass Charcoal Composite Materials and Application in the Prevention and Control of Gray Mold in Tomato

In order to reduce the use of fungicide and ensure food safety, it is necessary to develop fungicide with low toxicity and high efficiency to reduce residues. Azoxystrobin (AZOX), which is derived from mushrooms, is an excellent choice. However, conventional AZOX release is difficult to regulate. In this paper, a pH-responsive fungicide delivery system for the preparation of AZOX by impregnation method was reported. The Zinc metal-organic framework/Biomass charcoal (ZIF-8/BC) support was first prepared, and subsequently, the AZOX-ZIF-8/BC nano fungicide was prepared by adsorption of AZOX onto ZIF-8/BC by dipping. Gray mold, caused by Botrytis cinerea, is one of the most important crop diseases worldwide. AZOX-ZIF-8/BC could respond to oxalic acid produced by Botrytis cinerea to release loaded AZOX. When pH = 4.8, it was 48.42% faster than when pH = 8.2. The loading of AZOX on ZIF-8/BC was 19.83%. In vitro and pot experiments showed that AZOX-ZIF-8/BC had significant fungicidal activity, and 300 mg/L concentration of AZOX-ZIF-8-BC could be considered as a safe and effective control of Botrytis cinerea. The above results indicated that the prepared AZOX-ZIF-8/BC not only exhibited good drug efficacy but also demonstrated pH-responsive fungicide release.

MOF-based stimuli-responsive controlled release nanopesticide: mini review

By releasing an adequate amount of active ingredients when triggered by environmental and biological factors, the nanopesticides that respond to stimuli can enhance the efficacy of pesticides and contribute to the betterment of both the environment and food safety. The versatile nature and highly porous structure of metal-organic frameworks (MOFs) have recently garnered significant interest as drug carriers for various applications. In recent years, there has been significant progress in the development of metal-organic frameworks as nanocarriers for pesticide applications. This review focuses on the advancements, challenges, and potential future enhancements in the design of metal-organic frameworks as nanocarriers in the field of pesticides. We explore the various stimuli-responsive metal-organic frameworks carriers, particularly focusing on zeolitic imidazolate framework-8 (ZIF-8), which have been successfully activated by external stimuli such as pH-responsive or multiple stimuli-responsive mechanisms. In conclusion, this paper presents the existing issues and future prospects of metal-organic frameworks-based nanopesticides with stimuli-responsive controlled release.

Recent advances in stimuli-response mechanisms of nano-enabled controlled-release fertilizers and pesticides

Nanotechnology-enabled fertilizers and pesticides, especially those capable of releasing plant nutrients or pesticide active ingredients (AIs) in a controlled manner, can effectively enhance crop nutrition and protection while minimizing the environmental impacts of agricultural activities. Herein, we review the fundamentals and recent advances in nanofertilizers and nanopesticides with controlled-release properties, enabled by nanocarriers responsive to environmental and biological stimuli, including pH change, temperature, light, redox conditions, and the presence of enzymes. For pH-responsive nanocarriers, pH change can induce structural changes or degradation of the nanocarriers or cleave the bonding between nutrients/pesticide AIs and the nanocarriers. Similarly, temperature response typically involves structural changes in nanocarriers, and higher temperatures can accelerate the release by diffusion promoting or bond breaking. Photothermal materials enable responses to infrared light, and photolabile moieties (e.g., o-nitrobenzyl and azobenzene) are required for achieving ultraviolet light responses. Redox-responsive nanocarriers contain disulfide bonds or ferric iron, whereas enzyme-responsive nanocarriers typically contain the enzyme's substrate as a building block. For fabricating nanofertilizers, pH-responsive nanocarriers have been well explored, but only a few studies have reported temperature- and enzyme-responsive nanocarriers. In comparison, there have been more reports on nanopesticides, which are responsive to a range of stimuli, including many with dual- or triple-responsiveness. Nano-enabled controlled-release fertilizers and pesticides show tremendous potential for enhancing the utilization efficiency of nutrients and pesticide AIs. However, to expand their practical applications, future research should focus on optimizing their performance under realistic conditions, lowering costs, and addressing regulatory and public concerns over environmental and safety risks.

Research Progress of a Pesticide Polymer-Controlled Release System Based on Polysaccharides

In recent years, with the development of the nanomaterials discipline, many new pesticide drug-carrying systems-such as pesticide nano-metal particles, nano-metal oxides, and other drug-carrying materials-had been developed and applied to pesticide formulations. Although these new drug-loading systems are relatively friendly to the environment, the direct exposure of many metal nanoparticles to the environment will inevitably lead to potential effects. In response to these problems, organic nanomaterials have been rapidly developed due to their high-quality biodegradation and biocompatibility. Most of these organic nanomaterials were mainly polysaccharide materials, such as chitosan, carboxymethyl chitosan, sodium alginate, β-cyclodextrin, cellulose, starch, guar gum, etc. Some of these materials could be used to carry inorganic materials to develop a temperature- or pH-sensitive pesticide drug delivery system. Herein, the pesticide drug-carrying system developed based on polysaccharide materials, such as chitosan, was referred to as the pesticide polymer drug-carrying system based on polysaccharide materials. This kind of drug-loading system could be used to protect the pesticide molecules from harsh environments, such as pH, light, temperature, etc., and was used to develop the function of a sustained release, targeted release of pesticides in the intestine of insects, and achieve the goal of precise application, reduction, and efficiency of pesticides. In this review, the recent progress in the field of polysaccharide-based polymer drug delivery systems for pesticides has been discussed, and suggestions for future development were proposed based on the current situation.

Carboxymethyl β-cyclodextrin grafted hollow copper sulfide@mesoporous silica carriers for stimuli-responsive pesticide delivery

Stimuli-responsive controlled release systems have received extensive attention to improve the pesticide bioavailability and minimize environmental pollution. Herein, a multiple stimuli-responsive IMI@HCuS@mSiO₂ @ -ss-CβCD delivery system was constructed using modified carboxymethyl β-cyclodextrin (CβCD-ss-COOH) as sealing materials, hollow copper sulfide nanoparticles with amino-functionalized mesoporous silica shell (HCuS@mSiO₂-NH₂) as carriers and imidacloprid (IMI) as the model drug. The cavity structure of HCuS@mSiO₂-NH₂ would provide a large space for pesticide loading. The results revealed that HCuS@mSiO₂-ss-CβCD was approximately 230 nm in size and the loading efficiency for IMI was 25.7%, and exhibited better biosafety on bacteria and seed. HCuS carriers were also served as photothermal agent and possessed high photothermal conversion effect (η = 38.4%). IMI@HCuS@mSiO₂ @ -ss-CβCD displayed excellent foliage adhesion and multiple stimuli-responsive release properties to pH, α-amylase, GSH, and NIR. The photostability of IMI embedded in CuS@mSiO₂ @ -ss-CβCD was approximately 10 times that of IMI solution. This work provides an efficient nanoplatform for realizing pesticide delivery.

A pectin-based photoactivated bactericide nanosystem for achieving an improved utilization rate, photostability and targeted delivery of hematoporphyrin

Photoactivated pesticides have many advantages, such as high activity, low toxicity, and no drug resistance. However, poor photostability and a low utilization rate limit their practical application. Herein, the photosensitizer hematoporphyrin (HP) was used as a photoactivated pesticide, covalently linked with pectin (PEC) via ester bonds, to prepare an amphiphilic polymer pro-bactericide, and subsequently self-assembled in aqueous solutions to obtain an esterase-triggered nanobactericide delivery system. The fluorescence quenching effect due to the aggregation of HP in nanoparticles (NPs) enabled the inhibition of photodegradation of HP in this system. Esterase stimulation could trigger HP release and increase its photodynamic activity. Antibacterial assays have shown that the NPs had potent antibacterial capacity, almost completely inactivating bacteria after 60 min of exposure to light. The NPs had good adherence to the leaves. Safety assessment indicated that the NPs have no obvious toxic effects on plants. Antibacterial studies on plants have shown that the NPs have excellent antibacterial effects on infected plants. These results provide a new strategy for obtaining a photoactivated bactericide nanosystem with a high utilization rate and good photostability and targeting ability.

Construction and formulation optimization of prothioconazole nanoemulsions for the control of Fusarium graminearum: Enhancing activity and reducing toxicity

In this study, the optimal emulsifier for prothioconazole nanoemulsions was initially screened based on appearance, microscopic observation, mean droplet size and polydispersity index (PDI). In addition, the BoxBehnken design method is adopted, and the optimal formula is screened with an emulsification time, emulsifier content, and solvent content as a single factor. On this basis, the nanoemulsion meets FAO standards for various indicators. The contact angle of droplets on wheat leaves was significantly reduced. This nanoemulsion also showed good inhibitory activity against Fusarium graminearum (EC₅₀ =1.94 mg L^-1), low acute toxicity to zebrafish (LC₅₀ =26.35 mg L^-1) and good biosafety to BEAS-2B cells. The nanoemulsion reduced the adverse effects of pesticide on wheat seed germination and growth. This study can help promote the design and manufacture of stable, efficient and safe agricultural nanoemulsions, and is expected to benefit the sustainable development of green plant protection.

Polydopamine-encapsulated cap-like mesoporous silica based delivery system for responsive pesticide release and high retention

Nanopesticides formulation has been applied in modern agriculture, but the effective deposition of pesticides on plant surfaces is still a critical challenge. Here, we developed a cap-like mesoporous silica (C-mSiO₂) carrier for pesticide delivery. The C-mSiO₂ carriers with surface amino groups present uniform cap-like shape and have an mean diameter of 300 nm and width of 100 nm. This structure would reduce the rolling and bouncing of carriers on plant leaves, leading to improving the foliage deposition and retention. After loading dinotefuran (DIN), polydopamine (PDA) was used to encapsulate the pesticide (DIN@C-mSiO₂@PDA). The C-mSiO₂ carriers exhibit high drug loading efficiency (24.7%) and benign biocompatibility on bacteria and seed. Except for pH/NIR response release, the DIN@C-mSiO₂@PDA exhibited excellent photostability under UV irradiation. Moreover, the insecticidal activity of DIN@C-mSiO₂@PDA was comparable to that of pure DIN and DIN commercial suspension (CS-DIN). This carrier system has the potential for improving the foliage retention and utilization of pesticides.

Nanoparticles: A Potential and Effective Method to Control Insect-Borne Diseases

Insects act as vectors to carry a wide range of bacteria and viruses that can cause multiple vector-borne diseases in humans. Diseases such as dengue fever, epidemic encephalitis B, and epidemic typhus, which pose serious risks to humans, can be transmitted by insects. Due to the absence of effective vaccines for most arbovirus, insect control was the main strategy for vector-borne diseases control. However, the rise of drug resistance in the vectors brings a great challenge to the prevention and control of vector-borne diseases. Therefore, finding an eco-friendly method for vector control is essential to combat vector-borne diseases. Nanomaterials with the ability to resist insects and deliver drugs offer new opportunities to increase agent efficacy compared with traditional agents, and the application of nanoagents has expanded the field of vector-borne disease control. Up to now, the reviews of nanomaterials mainly focus on biomedicines, and the control of insect-borne diseases has always been a neglected field. In this study, we analyzed 425 works of the literature about different nanoparticles applied on vectors in PubMed around keywords, such as"nanoparticles against insect," "NPs against insect," and "metal nanoparticles against insect." Through these articles, we focus on the application and development of nanoparticles (NPs) for vector control, discussing the lethal mechanism of NPs to vectors, which can explore the prospect of applying nanotechnology in the prevention and control of vectors.

Encapsulation of Imazalil in HKUST-1 with Versatile Antimicrobial Activity

Based on high surface areas, adjustable porosity and microbicide activity, metal-organic frameworks (MOFs) HKUST-1 are widely used as drug release carriers for their slow degradation characteristics under slightly acidic conditions. In this work, porous HKUST-1 was reacted rapidly by cholinium salt (as the deprotonation agent and template) in an aqueous solution at room temperature. A novel antimicrobial system based on an imazalil encapsulated metal organic framework (imazalil IL-3@HKUST-1) was established. Imazalil IL-3@HKUST-1 could achieve synergism in inhibiting pathogenic fungi and bacteria. Moreover, six days after treatment, the slow and constant release of imazalil from imazalil IL@HKUST-1 exhibited better sustainability and microbicidal activity than imazalil. We believe that the method may provide a new strategy for related plant diseases caused by bacteria or fungi.

Zeolitic Imidazole Framework-90-Based Pesticide Smart-Delivery System with Enhanced Antimicrobial Performance

Multimodal antimicrobial technology is regarded as a promising strategy for controlling plant diseases because it enhances antimicrobial efficacy by blocking multiple pesticide-resistance pathways. In this work, a pH-responsive multimodal antimicrobial system was constructed based on ZIF-90 for the controlled release of kasugamycin (KSM). A series of physicochemical characterizations confirmed the successful fabrication of ZIF-90-KSM. The results indicated that the loading capacity of ZIF-90-KSM for KSM was approximately 6.7% and that the ZIF-90 nanocarriers could protect KSM against photodegradation effectively. The acid pH at the site of disease not only decompose the Schiff base bonds between KSM and ZIF-90, but also completely dissolved the nanocarriers. The simultaneous release of KSM and Zn²⁺ ions was able to achieve multimodal antimicrobial functions during disease occurs. A bioactivity survey indicated that ZIF-90-KSM had superior fungicidal activity and longer duration against Magnaporthe oryzae than KSM aqueous solution. In addition, the phytotoxicity assessment of ZIF-90-KSM on rice plants did not reveal any adverse effects. Therefore, ZIF-90-KSM prepared by Schiff base reaction has great potential for achieving synergistic antifungal functions and provides an eco-friendly approach to manage rice diseases.