Synthesis and Characterization of Stimuli-Responsive Poly(2-dimethylamino-ethylmethacrylate)-Grafted Chitosan Microcapsule for Controlled Pyraclostrobin Release

Abstract

Controllable pesticide release in response to environmental stimuli is highly desirable for better efficacy and fewer adverse effects. Combining the merits of natural and synthetic polymers, pH and temperature dual-responsive chitosan copolymer (CS-g-PDMAEMA) was facilely prepared through free radical graft copolymerization with 2-(dimethylamino) ethyl 2-methacrylate (DMAEMA) as the vinyl monomer. An emulsion chemical cross-linking method was used to expediently fabricate pyraclostrobin microcapsules in situ entrapping the pesticide. The loading content and encapsulation efficiency were 18.79% and 64.51%, respectively. The pyraclostrobin-loaded microcapsules showed pH-and thermo responsive release. Microcapsulation can address the inherent limitation of pyraclostrobin that is photo unstable and highly toxic on aquatic organisms. Compared to free pyraclostrobin, microcapsulation could dramatically improve its photostability under ultraviolet light irradiation. Lower acute toxicity against zebra fish on the first day and gradually similar toxicity over time with that of pyraclostrobin technical concentrate were in accordance with the release profiles of pyraclostrobin microcapsules. This stimuli-responsive pesticide delivery system may find promising application potential in sustainable plant protection.

Chitosan Oligosaccharide Fluorinated Derivative Control Root-Knot Nematode (Meloidogyne incognita) Disease Based on the Multi-Efficacy Strategy

“…This study shows that chitin, chitosan, and COS can be considered good nematode control candidates. As low toxic pesticides, chitosan and COS can be manufactured as sustainable pesticides encapsulating materials [34,35], or modified by grafting functional groups [36]. The methods can be the route to deal with the toxicity of nematicide [7,37].…”

Chitosan-Based Nanofibrous Membrane Unit with Gradient Compositional and Structural Features for Mimicking Calcified Layer in Osteochondral Matrix

“…Chitosan (CH) has many good properties and its chemical structure is similar to that of GAGs that largely exist in native ECM of different body tissues, thus making CH a popular biomaterial for a wide variety of applications in tissue engineering, drug delivery, and gene vectors [ 27 , 28 ]. Despite its merits, CH scaffolds usually have poor wet-state strength and are degraded fast in vivo, which hinder their applicability to situations where the high strength and degradation tolerance are needed.…”

Fabrication a controlled-release pesticide for improving UV-shielding properties and reducing toxicity via coating polydopamine

“…This conclusion was similar to the result reported by Xu et al He used poly(2-dimethylaminoethylmethacrylate) (PDMAEMA) and chitosan (CS) fabricated CSg-PDMAEMA microcapsules. LC 50 (24h) values of Pyr@CS-g-PDMAEMA were 0.1020 mg/L, which was less toxic than the control49 . While, in the next 48 h, the acute toxicity of MC against zebra sh became comparable with that of Pyr EC.…”