Functionalized Mesoporous Silica Nanoparticles with Redox-Responsive Short-Chain Gatekeepers for Agrochemical Delivery

Abstract

The controlled release of salicylic acid (SA), a key phytohormone, was mediated by using a novel decanethiol gatekeeper system grafted onto mesoporous silica nanoparticles (MSNs). The decanethiol was conjugated only to the external surfaces of the MSNs through glutathione (GSH)-cleavable disulfide linkages and the introduction of a process to assemble gatekeepers only on the outer surface so that the mesopore area can be maintained for high cargo loading. Raman and nitrogen sorption isotherm analyses confirmed the successful linkage of decanethiol to the surface of MSNs. The in vitro release of SA from decanethiol gated MSNs indicated that the release rate of SA in an environment with a certain amount of GSH was significantly higher than that without GSH. More importantly, in planta experiments showed the release of SA from decanethiol gated MSNs by GSH induced sustained expression of the plant defense gene PR-1 up to 7 days after introduction, while free SA caused an early peak in PR-1 expression which steadily decreased after 3 days. This study demonstrates the redox-responsive release of a phytohormone in vitro and also indicates the potential use of MSNs in planta as a controlled agrochemical delivery system.

Green Formation of Robust Supraparticles for Cargo Protection and Hazards Control in Natural Environments

“…The mechanisms of cargo delivery were identified by fitting the release profiles to kinetic models . Elovich and Korsmeyer–Peppas models described the thymol release reasonably well, but the Elovich model was used to fit the cargo release profile from the SPs, as it provided the best coefficients of determination (over 0.95; Table S1, Supporting Information).…”

Mesoporous silica nanoparticles for stimuli-responsive controlled drug delivery: advances, challenges, and outlook

“…To establish redox-responsive DDS, disulfide bonds were absolutely necessary, and the gatekeepers may vary, but mainly based on nanoparticles, 44,45,78,79 supramolecule or biomacromolecule, [80][81][82][83][84][85][86][87][88] and polymers. [89][90][91][92][93][94] Many inorganic nanoparticles have been used as nanovalves to seal the drug molecule into the channels of MSN through covalently functionalizing MSN with disulfide containing linkers, such as CdS, 44 Fe 3 O 4 , 45 gold, 78 and ZnO. 79 Giri et al 45 synthesized a controlled-release delivery system that was based on MCM-41-type MSN capped with superparamagnetic Fe 3 O 4 nanoparticles through disulfide bonds and was stimuli-responsive and chemically inert to guest molecules entrapped in the matrix.…”

Quaternized Chitosan-Capped Mesoporous Silica Nanoparticles as Nanocarriers for Controlled Pesticide Release

“…Yi established functionalized MSNs with redox-responsive, short-chain decanethiol gatekeepers for agrochemical salicylic acid (SA) delivery. The release rate of SA under a certain amount of glutathione (GSH) was obviously higher than that without GSH [28]. …”