Promoting the Spreading of Droplets on a Superhydrophobic Surface by Supramolecular Amphiphilic Complex-Based Host-Guest Chemistry

Recent Advances in Stimulus-Responsive Nanocarriers for Pesticide Delivery

In an effort to make pesticide use safer, more efficient, and sustainable, micro-/nanocarriers are increasingly being utilized in agriculture to deliver pesticide-active agents, thereby reducing quantities and improving effectiveness. In the use of nanopesticides, the choice to further design and prepare pesticide stimulus-responsive nanocarriers based on changes in the plant growth environment (light, temperature, pH, enzymes, etc.) has received more and more attention from researchers. Based on this, this paper examines recent advancements in nanomaterials for the design of stimulus-responsive micro-/nanocarriers. It delves into the intricacies of preparation methods, material enhancements, in vivo/ex vivo controlled release, and application techniques for controlled release formulations. The aim is to provide a crucial reference for harnessing nanotechnology to pursue reduced pesticide use and increased efficiency.

An eco-friendly photo-responsive hyaluronic acid-based supramolecular polysaccharide hybrid hydrogels for plant growth regulation and heavy metal ions adsorption

Agrochemicals are widely used in agricultural production, but they may cause agrochemicals residues and environmental pollution. Polysaccharide-based materials have emerged as a promising biopolymer carrier for agrochemicals delivery. Herein, an eco-friendly, photo-responsive supramolecular polysaccharide hybrid hydrogels (HA-AAP-Guano-CD@LP) was constructed from arylazopyrazole-modified hyaluronic acid (HA-AAP), guanidinium functionalized β-cyclodextrin (Guano-CD), and laponite clay (LP) via synergistic host-guest and electrostatic interactions, which could realize the controlled release of plant growth regulators such as naphthalene acetic acid (NAA) and gibberellin (GA) and promote the growth of Chinese cabbage and alfalfa. More interestingly, after releasing the cargo, the hydrogels could be used to capture heavy metal ions via strong complexation between the ions and carboxyl groups. This polysaccharide-based supramolecular hybrid hydrogels may provide a new strategy to realize the precision agriculture by the controlled delivery of plant growth regulators and synergetic adsorption of pollutants.

Controlling high-speed droplet splashing and superspreading behavior on anisotropic superhydrophobic leaf surfaces by ecofriendly Pseudogemini surfactants

BACKGROUND

Efficient deposition of high-speed droplets on superhydrophobic leaf surfaces remains an important challenge. For anisotropic wired superhydrophobic leaf surfaces, the splashing phenomenon is especially serious because it leads to the low effective utilization of pesticides by biological targets. The lost pesticides cause serious ecological environment pollution, therefore there is an urgent need to develop a green and sustainable cost-effective strategy to achieve efficient deposition of high-speed droplets on anisotropic superhydrophobic leaf surfaces at low dosage.

RESULTS

One type of green pseudogemini surfactant is constructed based on fatty acids and hexamethylenediamine by electrostatic interaction to control the splashing and spreading of high-speed droplets on superhydrophobic surfaces. The formed surfactant can not only achieve complete inhibition of the bouncing of droplets, but also promote rapid spreading on superhydrophobic leaf surfaces at very low usage. The efficient deposition and superspreading phenomenon are attributed to the rapid migration and adsorption of the surfactant from the dynamic spherical micelles at the newly formed solid-liquid interface, the network-like aggregated spherical micelles, and the Marangoni effect caused by the surface tension gradient. Moreover, the surfactant shows an excellent synergistic effect with herbicides to control weeds by inhibiting droplet splashing.

CONCLUSION

This work provides a simpler, more effective and sustainable approach to utilize aggregated spherical micelles rather than conventional vesicles or wormlike micelles to improve the droplet deposition on superhydrophobic leaf surfaces and reduce the impact of surfactants and pesticides on the ecological environment.

Organosilica-based deformable nanopesticides with enhanced insecticidal activity prepared by flash nanoprecipitation

A flash nanoprecipitation technique was developed for the construction of a novel type of deformable hollow organosilica nanoparticle for pesticide delivery.

Supramolecular Biopharmaceutical Carriers Based on Host-Guest Interactions

Traditional drugs have the disadvantages of poor permeability and low solubility, which makes the utilization of pesticides lower and brings many side effects. With the continuous development of supramolecular chemistry in recent years, it has also played an irreplaceable role in the field of pharmaceutical science. Supramolecular macrocycles, such as crown ethers, cyclodextrins, calixarenes, pillararenes and cucurbiturils, are potentially good candidates for drug carriers due to their biocompatibility, hydrophobic cavity and ease of derivatization. The encapsulation of drugs based on host-guest interaction has the advantage of being adjustable and reversible as well as improving the low availability of drugs. Here, the recent advances in methods and strategies for drug encapsulation and release based on supramolecular macrocycles with host-guest interactions have been systematically summarized, laying a bright foundation for the development of novel nanopesticide preparations in the future and pointing out future directions of novel biopesticide research.

Amyloid-Like Protein Aggregation Toward Pesticide Reduction

Pesticide overuse is a major global problem and the cause of this problem is noticeable pesticide loss from undesired bouncing of sprayed pesticide droplets and rain erosion. This further becomes a primary source of soil and groundwater pollution. Herein, the authors report a method that can enhance pesticide droplet deposition and adhesion on superhydrophobic plant leave surfaces by amyloid-like aggregation of bovine serum albumin (BSA). Through the reduction of the disulfide bond of BSA by tris(2-carboxyethyl) phosphine hydrochloride (TCEP), the amyloid-like phase transition of BSA is triggered that rapidly affords abundant phase-transitioned BSA (PTB) oligomers to facilitate the invasion of the PTB droplet into the nanostructures on a leaf surface. Such easy penetration is further followed by a robust amyloid-mediated interfacial adhesion of PTB on leaf surface. As a result, after mixing with pesticides, the PTB system exhibits a remarkable pesticide adhesion capacity that is more than 10 times higher than conventional fixation of commercial pesticides. The practical farmland experiments show that the use of PTB aggregation could reduce the use of pesticides by 70-90% while ensuring yield. This work demonstrates that current pesticide dosage in actual agriculture production may be largely reduced by utilizing eco-friendly amyloid-like protein aggregation.

Pillar[5]arene based glyco-targeting nitric oxide nanogenerator for hyperthermia-induced triple-mode cancer therapy

Nitric oxide (NO)-mediated gas therapy (GT) and alkyl radical (R•) therapy (ART) are emerging cancer therapy modes, and multi-mode therapy has been recognized as an attractive strategy for enhancing anti-cancer efficacy. In this work, a thermal-responsive R• initiator 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIBI)-loaded glycol-targeting NO nanogenerator was constructed by first the covalent conjugation of thermal-responsive NO donor of S-nitrosothiols (RSNO) on the surface of mesoporous silica-coated gold nanorods (AuNRs@MSN), then the coating of a supramolecular complex of amino pillar[5]arene (NP5) and galactose derivative (G), and finally the loading of AIBI. The glycol-targeting NO nanogenerator demonstrated specific targeting ability to HepG2 cells owing to the recognition between galactose residues and asialoglycoprotein receptors (ASGPR). Specially, upon 808 nm near-infrared (NIR) irradiation, the AIBI-loaded NO nanogenerator generated hyperthermia to achieve photothermal therapy (PTT), and further GT and ART resulted from the thermal responsiveness of RSNO and AIBI, respectively. In vitro experiments revealed that the AIBI-loaded glyco-targeting NO nanogenerator had good biocompatibility and exhibited effective inhibition to the proliferation of HepG2 cells. This work provides a novel way to supramolecular hybrid drug delivery systems for triple-mode targeting therapy of PTT/GT/ART.