Synthesis of a Reactive Oxygen Species Responsive Star Polymer for the Controlled Release of Carbendazim

An intelligent responsive pesticide delivery system hasbeen appliedin agriculture to improve the utilization rate of pesticides. Whenplants are affected by fungi, a large number of reactive oxygen species(ROS) are produced rapidly on the wound surface. Based on this, aROS responsive star polymer micellar slow-release system was constructedto load carbendazim (MBC) and improve its bioavailability. The starpolymer was synthesized by using 3-mercaptopropionic acid, acetone,pentaerythritol (PER), epsilon-caprolactone (epsilon-CL), and methoxypolyethyleneglycols (mPEG5000, Mw = 5000) and named PER-PCL-TK-mPEG5000. By loading MBC, the drug loading micelle MBC-loadedPER-PCL-TK-mPEG5000 was obtained. The cumulativerelease amount of MBC-loaded PER-PCL-TK-mPEG5000containing H2O2 is 1.64 times of that without H2O2 after 120 h release.The inhibitory rate of MBC-loaded PER-PCL-TK-mPEG5000containing H2O2 against Rhizoctonia solani (R. solani) was 91.6%. The criticalmicelle concentration (CMC) of PER-PCL-TK-mPEG5000is 4.37 mg/L, and the result showed that PER-PCL-TK-mPEG5000 and MBC-loaded PER-PCL-TK-mPEG5000 havegood stability at 4 degrees C for 14 d. This study proved that the strategyof designing pesticide vectors according to the target environmentcan be widely used to protect crops, improve pesticide utilizationrate, and protect the environment.

Automated summary

An intelligent responsive pesticide delivery system with ROS responsive star polymer micellar slow-release system shows great potential in improving the utilization rate of pesticides in agriculture. The system successfully loaded MBC and demonstrated a 1.64-fold increase in release amount with the presence of H2O2. It also exhibited a high inhibitory rate against R. solani. This study highlights the importance of designing pesticide vectors according to the target environment for crop protection, improved pesticide utilization, and environmental preservation.