Researchers from the University of Twente (Netherlands) and Bayreuth (Germany) Develop Microplastic-Free Encapsulation for Crop Protection Agents. They recently published their findings in the scientific journal Advanced Materials
The sustainable application of crop protection agents such as pesticides is one of the greatest challenges in modern agriculture. A significant advancement has now been made by a team of researchers from the University of Twente and Bayreuth (Germany), who have developed a promising solution.
Under the leadership of Prof. André Gröschel and Prof. Frederik Wurm, the researchers successfully synthesized fully degradable block copolymers, which are a type of polymer made up of different segments (the ‘blocks’) of repeating units. From these polymers, based on polyphosphoesters, the researchers created so-called polymer cubosomes – microscopically small cubic particles with a high internal order and pores of approximately 20 nanometers in diameter.
Fighting plant disease
"During the production process, we loaded these polymer cubosomes with fungicides," explains Prof. Gröschel. "The loaded cubosomes exhibit high antifungal activity against grey mould, a common plant disease." Gray mold, also known as Botrytis, is particularly damaging in strawberry and grape cultivation. Notably, the cubosomes remain adhered to grapevine leaves even after multiple simulated rain events and continuously release the fungicide over several days. "For over 10 years, we have been using DNA-inspired polyphosphoesters for drug delivery in medicine, and now we have applied these biodegradable materials for plant protection for the first time. This allows us to avoid microplastics in the environment," explains Prof. Frederik Wurm.
Suna Azhdari, whose doctoral research enabled this breakthrough, emphasizes, "Compared to conventional, solid particles without pores, our polymer cubosomes show a significantly faster release of the active substance. This suggests a more effective application of crop protection agents, while simultaneously reducing the leaching of unused substances into the soil."
Completely degradable
A particularly important aspect of this innovation is the complete degradability of the cubosomes. "Our polymer cubosomes fully degrade into harmless lactic acid and phosphate derivatives," emphasizes Prof. Wurm. "This makes them a promising, microplastic-free carrier system for crop protection agents and highlights their potential for sustainable agriculture."
This groundbreaking development could make a significant contribution to more environmentally friendly and efficient agriculture, while also offering a solution to the problem of microplastic pollution in agricultural applications.
Figure on the left: Shows a Riesling plant with biodegradable polyphosphoester cubosomes on its surface (scanning electron microscopy image on the right). These cubosomes degrade into harmless substances while releasing a fungicide to protect the plant.
More information
The now completed project is part of a doctoral thesis funded by Evonik Industries AG since 12/2021 and carried out by M.Sc. Suna Azhdari. The project was also supported by the German Research Foundation (Project number 445740352). The researchers published their work in an article, titled ‘Fully Degradable Polyphosphoester Cubosomes for Sustainable Agrochemical Delivery’, in the scientific journal Advanced Materials. Authors are: Suna Azhdari, Jürgen Linders, Deniz Coban, Tim Julian Stank, Carina Dargel, Hubert Gojzewski, Thomas Hellweg, André H. Gröschel, Frederik R. Wurm.
