RESUMO
Devastating plant diseases and soil depletion rationalize an extensive use of agrochemicals to secure the food production worldwide. The sustained release of fertilizers and pesticides in agriculture is a promising solution to the eco-toxicological impacts and it might reduce the amount and increase the effectiveness of agrochemicals administration in the field. This review article focusses on carriers with diameters below 1 µm, such as capsules, spheres, tubes and micelles that promote the sustained release of actives. Biopolymer nanocarriers represent a potentially environmentally friendly alternative due to their renewable origin and biodegradability, which prevents the formation of microplastics. The social aspects, economic potential, and success of commercialization of biopolymer based nanocarriers are influenced by the controversial nature of nanotechnology and depend on the use case. Nanotechnology's enormous innovative power is only able to unfold its potential to limit the effects of climate change and to counteract current environmental developments if the perceived risks are understood and mitigated.
Assuntos
Agroquímicos , Plásticos , Agroquímicos/farmacologia , Biopolímeros , Preparações de Ação Retardada , Horticultura , Ciências SociaisRESUMO
The current spraying of agrochemicals is unselective and ineffective, consuming a high amount of fungicides, which endangers the environment and human health. Cellulose-based nanocarriers (NCs) are a promising tool in sustainable agriculture and suitable vehicles for stimuli-responsive release of agrochemicals to target cellulase-segregating fungi, which cause severe plant diseases such as Apple Canker. Herein, cellulose was modified with undec-10-enoic acid to a hydrophobic and cross-linkable derivative, from which NCs were prepared via thiol-ene addition in miniemulsion. During the crosslinking reaction, the NCs were loaded in situ with hydrophobic fungicides, Captan and Pyraclostrobin. NCs with average sizes ranging from 200 to 300 nm and an agrochemical-load of 20 wt% were obtained. Cellulose-degrading fungi, e.g. Neonectria. ditissima which is responsible for Apple Canker, lead to the release of fungicides from the aqueous NC dispersions suppressing fungal growth. In contrast, the non-cellulase segregating fungi, e.g. Cylindrocladium buxicola, do not degrade the agrochemical-loaded NCs. This selective action against Apple Canker fungi, N. ditissima, proves the efficacy of NC-mediated drug delivery triggered by degradation in the exclusive presence of cellulolytic fungi. Cellulose NCs represent a sustainable alternative to the current unselective spraying of agrochemicals that treats many crop diseases ineffectively.
Assuntos
Agroquímicos , Hypocreales , Celulose , Humanos , Doenças das PlantasRESUMO
Herein, we present the synthesis and characterization of poly(thioether-ester) nanoparticles via thiol-ene miniemulsion polymerization using a biobased α,ω-diene diester monomer, namely dianhydro-d-glucityl diundec-10-enoate (DGU), synthesized from 10-undecenoic acid (derived from castor oil) and isosorbide (derived from starch). DGU was copolymerized with 1,4-butanedithiol by thiol-ene miniemulsion polymerization resulting in waterborne poly(thioether-ester) particles with diameter around 200nm. Polymers with number average molecular weight up to 11kDa were obtained via miniemulsion polymerization. DSC and XRD analyses indicated a semi-crystalline polymer with a degree of crystallinity of at least 20% and Tm around 68°C. In addition, Coumarin 6 was encapsulated in the polymer particles with efficiency up to 98%. Nanoparticles presented biocompatibility in murine fibroblast (L929) and uterine colon cancer (HeLa) cells. The substantial cellular uptake of poly(thioether-ester) nanoparticles by HeLa cells suggests a potential use in uterine colon cancer treatment.