A user-friendly herbicide derived from photo-responsive supramolecular vesicles

Area of Science:

• Supramolecular chemistry
• Materials science
• Toxicology

Background:

• Paraquat is a widely used herbicide with high human toxicity, causing significant morbidity and mortality.
• Developing safer herbicide formulations is crucial to mitigate risks associated with paraquat exposure.

Purpose of the Study:

• To create a photo-responsive, user-friendly formulation of paraquat-loaded supramolecular vesicles.
• To enhance the safety profile of paraquat while maintaining its herbicidal efficacy.

Main Methods:

• One-pot self-assembly of amphiphilic ternary host-guest complexes involving cucurbit[8]uril, paraquat, and an azobenzene derivative.
• Photo-responsive paraquat release triggered by UV or sunlight-induced trans-to-cis isomerization of the azobenzene derivative.
• Cytotoxicity evaluation using in vitro cell models, in vivo zebrafish, and mouse models.

Main Results:

• Vesicles successfully encapsulated paraquat, releasing it only upon UV or sunlight irradiation.
• The paraquat-loaded vesicles demonstrated an enhanced safety profile across all tested models.
• Herbicidal activity of the vesicles against invasive weeds was comparable to free paraquat under natural sunlight.

Conclusions:

• The developed supramolecular vesicles provide a safe and effective formulation for paraquat.
• Photo-responsive drug delivery systems can be utilized to control herbicide release and reduce toxicity.
• This approach offers a promising strategy for developing safer agrochemical formulations.