Salicylic acid functionalized zein for improving plant stress resistance and as a nanopesticide carrier with enhanced anti-photolysis ability

'Microscopic engineering vehicles' for plants under stress combination

The combination of stresses induced by climate change poses significant risks to crop production. We propose using 'microscopic engineering vehicles' in pesticides to mitigate biotic and abiotic stresses on plants. We discuss their customization and potential mode of action, which may help in addressing the crises caused by stress combination.

Engineering Hyaluronic Acid Microneedles Loaded with Mn2+ and Temozolomide for Topical Precision Therapy of Melanoma

Topical therapy has received worldwide attention for in situ tumors owing to its higher efficacy of drug delivery. Herein, this work reports a dissolvable multifunctional hyaluronic acid microneedles (HMNs) patch coloaded with temozolomide (TMZ) and MnCl2 (TMZ/MnCl2@HMN) for chemoimmunotherapy of melanoma. HMNs can ensure the stability of TMZ over time, and exhibit fewer side effects with a localized release way. In particular, TMZ not only promotes dendritic cell maturation by triggering immunogenic cell death in tumor cells, but also induces DNA damage that can further enhance the Mn2+-activated cGAS-STING (stimulator of interferon genes pathway). As a result, the TMZ/MnCl2@HMN multifunctional platform significantly inhibits lung metastases for melanoma, providing a practical strategy for precision therapy of melanoma.

Quaternized chitosan-based organic-inorganic nanohybrid nanoparticles loaded with prothioconazole for efficient management of fungal diseases with minimal environmental impact

Poor foliar deposition and retention of pesticides results in serious pesticide residues and environmental pollution. Organic-inorganic hybridized nanoparticles (OIHN), combining the advantages of organic and inorganic materials, can be used as carriers to load pesticides for efficient and safe application. Herein, a novel multifunctional OIHN composed of mesoporous silica nanoparticles (MSNs) and cationic chitosan quaternary ammonium salt (HACC) was constructed and used as a delivery system for prothioconazole (PTC). The resultant PTC@MSNs-HACC exhibited a remarkable loading capacity of 39.07 wt% and demonstrated enhanced PTC release (31.47 %) under alkaline conditions. The UV-shielding properties of MSNs efficiently shielded PTC from photodegradation, increasing its photostability by over threefold. The strong positive charge of HACC conferred excellent adhesion of PTC@MSNs-HACC to fungal cell membranes, leading to high deposition on wheat leaves with improved rain-wash resistance (increased by 30 %). Consequently, PTC@MSNs-HACC (EC50: 12.48 mg/L) exhibited superior wheat scab control compared to PTC emulsifiable concentrate (EC50: 28.49 mg/L). Additionally, PTC@MSNs-HACC displayed excellent uptake and transport in plants, ensuring plant safety and reducing toxicity to zebrafish by >1-fold. The potential application of the developed PTC@MSNs-HACC in agricultural production holds significant promise and is anticipated to find widespread use in the future.

Encapsulated nanopesticides application in plant protection: Quo vadis?

The increased global food insecurity due to the growing population can be addressed with precision and sustainable agricultural practices. To tackle the issues regarding food insecurity, farmers used different agrochemicals that improved plant growth and protection. Among these agrochemicals, synthetic pesticides used for plant protection in the agricultural field have various disadvantages. Conventional applications of synthetic pesticides have drawbacks such as rapid degradation, poor solubility, and non-target effects, as well as increased pesticide runoff that pollutes the environment. Nanotechnology has evolved as a potential solution to increase agricultural productivity through the development of different nanoforms of agrochemicals such as nanopesticides, nano-fabricated fertilizers, nanocapsules, nanospheres, nanogels, nanofibers, nanomicelles, and nano-based growth promoters. Encapsulation of these pesticides inside the nanomaterials has provided good biocompatibility over conventional application by inhibiting the early degradation of active ingredients (AI), increasing the uptake and adhesion of pesticides, improving the stability, solubility, and permeability of the pesticides, and decreasing the environmental impacts due to the pesticide runoff. In this review, different nanoforms of encapsulated pesticides and their smart delivery systems; nanocarriers in RNA interference (RNAi) based pesticides; environmental fate, practical implications, management of nanopesticides; and future perspectives are discussed.

Preparation of Salicylic Acid-Functionalized Nanopesticides and Their Applications in Enhancing Salt Stress Resistance

Soil salinization is one of the global ecological and environmental problems that are tremendously threatening to the sustainable development of agriculture and food supply. In this work, a facile strategy was proposed to enhance the salt stress resistance of plants by preparing salicylic acid (SA)-functionalized mesoporous silica nanocarriers loaded with emamectin benzoate (EB). The obtained nanopesticides demonstrated a particle size of less than 300 nm. As an endogenous plant hormone, the grafting of SA in this nanopesticide system improved the uptake and translocation of pesticides in cucumber plants by 145.06%, and the applications of such nanopesticides enhanced the salt stress resistance of plants. This phenomenon was accounted for by the SA-functionalized nanopesticides increasing the superoxide dismutase and peroxidase activities (640 and 175%, respectively) and reducing the malondialdehyde content (54.10%), correspondingly alleviating the accumulation of reactive oxygen species and cell damage in plants. The above results were also confirmed by Evans blue staining and NBT staining experiments on cucumber leaves. In addition, these nanopesticides exhibited high insecticidal toxicity, and they also demonstrated biosafety toward nontarget organisms due to their sustained release property. Therefore, this work developed a biosafe SA-functionalized nanopesticide system, and these newly developed nanopesticides have potential in the agricultural field for enhancing salt stress resistance of plants.