Paraquat is a fast-killing herbicide and is widely used as the world's second largest tonnage herbicide variety. However, paraquat is severely toxic to human beings, and there is no effective treatment. About 20 per million people die from paraquat poisoning worldwide. Thus, a user-friendly paraquat formulation that is nontoxic or much less toxic than paraquat with strong evidence from systemic safety evaluations in vivo, but with comparable herbicidal effects with that of paraquat, is highly desirable. This project developed a sunshine-responsive paraquat-loaded nanovesicles via self-assembly of amphiphilic ternary host-guest complexes. This user-friendly herbicide, under natural sunlight, imposes its herbicidal effects that are comparable to that of free paraquat, whereas the safety evaluation on cell, zebrafish and mouse affords much safer toxicity profile than that of free paraquat, which will reduce the injury or casulties caused by accidental contact or ingestion of paraquat. The intelligent drug delivery strategy involved in this project brings the technical change in green agriculture and user-friendly herbicide, offers a new insight on green pesticide preparation, and provides guidance on the developmental direction for future pesticide products.

Fig 1 High biocompatibility and safety of user-friendly paraquat formulation evaluated in zebrafish and mouse models. 

Fig 2 The weed control effects of user-friendly paraquat formulation and free paraquat under sunshine.