Chitosan nanoparticles functionalized with β-cyclodextrin: a promising carrier for botanical pesticides

Abstract

Carvacrol and linalool are natural compounds extracted from plants and are known for their insecticidal and repellent activities, respectively. However, their low aqueous solubility, high photosensitivity, and high volatility restrict their application in the control of agricultural pests. The encapsulation of volatile compounds can be an effective way of overcoming such problems. Inclusion complexes between beta-cyclodextrin (β-CD) and carvacrol (CVC) or linalool (LNL) were investigated. Inclusion complexes were prepared by the kneading method. Both complexes presented 1:1 host:guest stoichiometry and the highest affinity constants were observed at 20 °C for both molecules. The nanoparticles containing carvacrol and linalool had mean diameters of 175.2 and 245.8 nm, respectively and high encapsulation efficiencies (<90%) were achieved for both compounds. Biological assays with mites (Tetranychus urticae) showed that the nanoparticles possessed repellency, acaricidal, and oviposition activities against this organism. Nanoencapsulated carvacrol and linalool were significantly more effective in terms of acaricidal and oviposition activities, while the unencapsulated compounds showed better repellency activity. The nanoformulations prepared in this study are good candidates for the sustainable and effective use of botanical compounds in agriculture, contributing to the reduction of environmental contamination, as well as promoting the effective control of pests in agriculture.

Synthesis of Chitosan Nanoparticles for Controlled Release of Amiodarone

“…There were no endothermic peak for AMD in loaded NPs, which showed that AMD had been incorporated with β-CD [50] . Similar results were obtained in the literature [52] .…”

Safe nanotechnologies for increasing the effectiveness of environmentally friendly natural agrochemicals

“…However, it can be used as a carrier for pesticides when synthesized in the form of nanoparticles, either alone or in combination with other polymers . This double function as nanocarrier and active substance itself, in addition to its origin from a waste by‐product from the fishing industry, turns chitosan into a promising material for nanoformulating natural compounds …”

“…They have a hydrophobic core and a hydrophilic shell, and they self‐assemble in aqueous solutions with other components to form nanoparticles and aggregates. In addition, cyclodextrins can be conjugated with other nanomaterials, enhancing their characteristics as nanocarriers . They have been successfully loaded with fungicides and tested for treatment of fungal plant diseases in the field, or have been combined with fungicidal natural compounds such as geraniol…”

“…57 This double function as nanocarrier and active substance itself, in addition to its origin from a waste by-product from the fishing industry, turns chitosan into a promising material for nanoformulating natural compounds. 58 Alginate is another linear -linked polysaccharide isolated form the brown algae group, Phaeophyceae, commonly known as seaweed. It can be treated in several ways to produce hydrogels, microspheres, nanoparticles and nanocapsules, 59 and can be combined with other polymers such as chitosan, 57 producing a highly versatile system for nanoformulation of agrochemicals.…”

“…In addition, cyclodextrins can be conjugated with other nanomaterials, enhancing their characteristics as nanocarriers. 58,61 They have been successfully loaded with fungicides 62 and tested for treatment of fungal plant diseases in the field, 63 or have been combined with fungicidal natural compounds such as geraniol. 64 wileyonlinelibrary.com/journal/ps Plants store energy in the form of starch and, starch being one of the most abundant biomass materials in nature, it has multiple applications in industry.…”