Novel polymeric micelles for insect pest control: encapsulation of essential oil monoterpenes inside a triblock copolymer shell for head lice control

Abstract

BackgroundEssential oil components (EOCs) are molecules with interesting application in pest control, these have been evaluated against different insect pest from more than 100 years, but their practical use is rather limited. Thus, the enhancement of their bioavailability and manageability due to their dispersion in water can open new perspective for the preparation of formulations for the control of insect pest. In this work, we studied the encapsulation of different monoterpenes in a poloxamer shell in order to prepare aqueous formulations that can be used for the development of platforms used in pest control.MethodsMicellar systems containing a 5 wt% of poloxamer 407 and 1.25 wt% of the different monoterpenes were prepared. Dynamic Light Scattering (DLS) experiments were carried out to characterize the dispersion of the EOCs in water. The pediculicidal activity of these micellar systems was tested on head lice using an ex vivo immersion test.ResultsThe poloxamers allowed the dispersion of EOCs in water due to their encapsulation inside the hydrophobic core of the copolymer micelles. From this study, we concluded that it is possible to make stable micellar systems containing water (>90 wt%), 1.25 wt% of different monoterpenes and a highly safe polymer (5wt% Poloxamer 407). These formulations were effective against head lice with mortality ranging from 30 to 60%, being the most effective emulsions those containing linalool, 1,8-cineole, α-terpineol, thymol, eugenol, geraniol and nonyl alcohol which lead to mortalities above 50%.DiscussionSince these systems showed good pediculicidal activity and high physicochemical stability, they could be a new route for the green fabrication of biocompatible and biosustainable insecticide formulations.

Association of zein nanoparticles with botanical compounds for effective pest control systems

“…Geraniol is a compound derived from different essential oils (citronella and palmrose, among others) and is classified as an acyclic alcohol having a vapor pressure of 2.21 × 10 −2 mmHg at 25 °C, water solubility of 100 mg L −1 and boiling point at 230 °C. Several applications of geraniol are reported in the literature, including in the control of agricultural pests . Eugenol, the main component of clove essential oil, belongs to the chemical class of phenylpropanoids.…”

Oil-In-Water Microemulsions for Thymol Solubilization

“…Therefore, the use of o/w microemulsions is of particular interest because they provide a protected environment for solubilizing EOCs within oil droplets, favoring the distribution of the solubilized material in an aqueous environment [8,13,14]. Successful EOC solubilization impacts a number of different technological and industrial areas due to the recognized activity of this type of molecule as neurotoxic for a variety of insects and antimicrobial against multi-resistant bacteria or preservatives [15][16][17][18]. Among the application fields of EOCs, one can mention the cosmetic industry (ingredients of fragrances, decorative cosmetics, fine fragrances and flavoring), food industry (aromas and flavors), pharmaceutical industry (active components of medicines and antibacterials/antimicrobials) and aromatherapy.…”

Synthesis of rotenone loaded zein nano-formulation for plant protection against pathogenic microbes

“…The use of different matrices, including biodegradable polymers, lipids, proteins, among others, as carrier agents for targeted delivery of active ingredients toward controlling plant diseases, insects and pests have shown great promises. [11][12][13] Zein is a corn prolamine, rich in amino acids such as proline, leucine, glutamine and alanine. Hydrophobicity makes zein capable of self-association in presence of polar solvents, water, which has already been used to encapsulate essential oils, including oregano, thyme, thymol, curcumin and carvacrol.…”