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Encapsulation of pesticides in organic nanocarriers via Flash NanoPrecipitation (FNP) for foliar delivery to plants

thesis
posted on 2024-11-29, 16:20 authored by Luiza Stolte Bezerra Lisboa OlLuiza Stolte Bezerra Lisboa Ol

Flash Nanoprecipitation (FNP) is a technique that allows organic nanocarriers (NCs) with core-shell architecture to be prepared reproducibly and at scale. The surface shell may be designed independently of the content in the core. This can allow for encapsulated active ingredients to be delivered to areas of the plant where they naturally would not move to but are needed, the biodistribution becoming a function of NC properties and release of active from the NC. The scalability of FNP is also attractive, since large scale production is ultimately required for commercialization of novel agrochemical solutions. In Chapter 3 scalable NCs encapsulating streptomycin (STP) have been prepared at high encapsulation efficiency (EE) and with controlled release of the antibiotic (< 5%). A surface-similar NC has been shown to translocate (~ 6%) to the roots of citrus trees under controlled conditions after foliar spraying. In vitro efficacy suggests that, if enough NCs containing STP are able to reach the phloem sections of trees where CLas resides at sufficient concentrations under field conditions, then this novel formulation may be able to offer an effective solution for managing the disease. Chapter 4 highlights the challenges in encapsulating weakly hydrophobic fungicides via FNP, the strategies that were employed to module fungicide solubility, and initial quantitative efforts to determine fungicide EE in a reliable and accurate manner. Even without full knowledge about the form in which a particular fungicide, mefentrifluconazole (MFZ), was present in the NCs that were applied to turfgrass during a greenhouse biodistribution test, the novel formulation provided higher MFZ recovery in the lower roots than the conventional treatment 7 days after application. It also presented sustained higher recovery of MFZ on the blades for up to 3 days and after blade clipping at 14 days. These results may indicate that MFZ was present in the vasculature.

Funding

USDA National Institute of Food and Agricultural Citrus Disease Research and Extension (ECDRE) grant number 2022-70029-38668

History

Degree Type

  • Master of Science

Department

  • Agricultural and Biological Engineering

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Kurt D. Ristroph

Additional Committee Member 2

Gerald L. Miller

Additional Committee Member 3

Ganesan Narsimhan