Source: PURDUE UNIVERSITY submitted to NRP
SCALABLE NANOCARRIERS FOR EFFICIENT FOLIAR DELIVERY OF AGROCHEMICALS TO PLANTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030062
Grant No.
2023-67021-39751
Cumulative Award Amt.
$300,000.00
Proposal No.
2022-08572
Multistate No.
(N/A)
Project Start Date
Jul 1, 2023
Project End Date
Jun 30, 2026
Grant Year
2023
Program Code
[A1511]- Agriculture Systems and Technology: Nanotechnology for Agricultural and Food Systems
Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907
Performing Department
College of Agriculture
Non Technical Summary
Problem: Many of the agrochemicals currently in use in agricultural production are inefficient; they do not reach their target plant, or they do not reach the correct part of their target plant, or they do not remain with their target plant for the desired length of time. It has been estimated, for example, that less than 3% of pesticides currently in use actually reach their target site - the rest is lost into soils and water systems, where they can cause unintended environmental damage.Science: We propose to process agrochemicals into microscopic carriers (nanocarriers) that will improve the movement of the active agents in plants. Specifically, we aim to develop nanocarriers that will be uptaken into plant leaves after foliar (leaf) dosing and will then move to specified locations in the plant (e.g. stem or roots or remaining in the leaves). We will encapsulate three representative agrochemicals - an antibiotic, a hormone, and a pesticide - into nanocarriers and track their movement in tomato plants to demonstrate that we can control uptake and trafficking. We will use a large-scale cost-effective method of formulating nanocarriers using biodegradable materials.Impact: A scalable biodegradable nanocarrier formulation applied as a standard agricultural foliar spray that effectively promotes agrochemical uptake through leaves would be a critical breakthrough in the practical and economical administration of agrochemicals. We here will take the first step in developing and validating a system to produce such nanocarriers.
Animal Health Component
10%
Research Effort Categories
Basic
80%
Applied
10%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20514602020100%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
1460 - Tomato;

Field Of Science
2020 - Engineering;
Goals / Objectives
Foliar delivery of bioactive agents to plants is a highly desirable but historically inefficient method of (1) promoting agrochemical internalization or (2) trafficking agrochemicals to specific locations in tissue. Most agrochemicals, when applied foliarly in the form of an aqueous dispersion, are poorly internalized into leaves and do not transit efficiently to other organs, limiting their ability to affect biological activity in the target organism. Water-soluble agents are unable to penetrate the waxy cuticular layer on leaves, and water-insoluble agents are usually dispersed in suspensions with macroscopic particulates, which are too large for internalization by direct penetration or stomatal flooding.The increasing number and variety of fungal, bacterial, viral, and environmental stressors that negatively affect plant health necessitates the development of a cost-effective and scalable delivery system capable of translocating systemically an agrochemical from the exterior of a leaf to the vasculature, roots, other leaves, or combinations of these. In addition to transporting materials to target locations in plants, such a delivery system would potentially reduce the overall quantity of bioactive agents required to have a biological effect on the plant. We here propose developing organic nanocarriers containing representative agrochemicals from three classes - antibiotic, hormone, and pesticide (streptomycin, gibberellic acid, and prochloraz, respectively, or alternatives) - and evaluating their ability to systemically deliver their payload to tomato following foliar administration
Project Methods
Activity 1: Prepare three suites of nanocarrier formulations loaded with streptomycin, gibberellic acid, or prochloraz (or alternatives), and a tracer metal for tracking by ICP-MS.Methods: Nanocarriers will be formulated by Flash NanoPrecipitation with hydrophobic ion pairing. One suite will be prepared for each of the three agrochemical cores of interest. Each formulation will also contain a tracer metal (e.g. Eu or Gd) in the nanocarrier core, which will be incorporated in the form of a hydrophobic oxide that will not release from the nanocarrier core over time. We propose to prepare 2-3 formulations per suite, covering a range of surface stabilizers to demonstrate the flexibility of FNP formulations.Activity 2: Quantify nanocarrier uptake and translocation in tomato to demonstrate proof of principle for improved bioactive uptake and systemic delivery following foliar administration.Methods: We will quantify translocation of organic nanocarriers to phloem, roots, and other plant parts using tomato as a model crop plant. We will also measure particle rainfastness and internalization into dosed leaves to demonstrate efficacy of this administration strategy.

Progress 07/01/24 to 06/30/25

Outputs
Target Audience:The audience for the work at this stage is primarily (1) other researchers, including collaborators at Purdue and elsewhere and (2) agrochemical companies, to whom we have presented our ongoing work and preliminary results. Presentations in this period include: oneinvitedseminar at Corteva on July 18 2024,one invitedseminar at Eastman Chemical on July 24 2024, two presentations at the AIChE annual meeting in October 2024, one invited seminar at LSU on November 11 2024, one invited seminar at Silvek on January 16 2025, and one invited seminar with AgXelerators on April 7 2025. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two graduate students, two undergraduate students, and one research scientist have been working on this project, including formulation development and evaluation, data analysis, report preparation, experimental design, explaining project to collaborators, and presenting results. How have the results been disseminated to communities of interest?Results have been disseminated through research presentations by the PI and students. PI presentations in this period include: oneinvitedseminar at Corteva on July 18 2024,one invitedseminar at Eastman Chemical on July 24 2024, two presentations at the AIChE annual meeting in October 2024, one invited seminar at LSU on November 11 2024, one invited seminar at Silvek on January 16 2025, and one invited seminar with AgXelerators on April 7 2025. Student presentations include an undergraduate poster at the Purdue Research Day in spring 2025, which won first place in the College of Agriculture. What do you plan to do during the next reporting period to accomplish the goals?We plan to complete the proposed studies and publish five manuscripts: 1) One paper will focus on nanocarrier kinetics and dosing strategies (e.g. abaxial versus adaxial foliar dosing) in tomato plants. Drafted; will be submitted by the end of July 2025. 2) One paper will focus onstreptomycin andesfenvalerate nanocarrier transport and biotransformation in tomato plants by tracking both the active ingredient and metal tag on the nanocarrier. 3) One paper will focus on the formulation and application of astaxanthin nanoparticles to modulate reactive oxygen species in tomato plants as a hormonal regulator of stress. 4) One paper will focus on the formulation and application of streptomycin nanoparticles to tomato plants to manage foliar pathogen pseudomonas syringae and soilborne root pathogen ralstoniasolanacearum. 5) One paper will focus on the formulation and application of esfenvalerate and permethrin nanoparticles to celery plants to manage insect pressure by translocating to the plant root tissue.

Impacts
What was accomplished under these goals? We have made progress encapsulating six agrochemicals of interest: Streptomycin: ~40 working nanocarrier formulations with 100% encapsulation efficiency; sizes from 70-350nm, various stabilizers. Release in apoplastic fluid: days/weeks time scale.We have measured the translocation of streptomycin nanoparticles in tomato plants following foliar administration; and measured the fate of streptomycin payload compared to nanocarrier to give insight into the biotransformation of the NPs in planta. Rainfastness has been assessed, and translocation results have been corroborated by confocal microscopy. Esfenvalerate: 10 working nanocarrier formulations with 100% encapsulation efficiency, 25-50% esfenvalerate by mass. Demonstrated esfenvalerate can be co-encapsulated with metalloporphyrins. Demonstrated that particles can be spray dried to form a water-dispersible powder that recovers the nano-size of the particles on resuspension. We have measured the translocation of esfenvalerate nanoparticles in celery and carrot plants following foliar administration.We have measured the translocation of esfenvalerate nanoparticles in tomato plants following foliar administrationand measured the fate of esfenvaerate payload compared to nanocarrier to give insight into the biotransformation of the NPs in planta. Permethrin: 3 working nanocarrier formulations with 100% encapsulation efficiency, 50% permethrin by mass. Demonstrated esfenvalerate can be co-encapsulated with metalloporphyrins. Astaxanthin: 10 working nanocarrier formulations with 100% encapsulation efficiency, 50% astaxanthin by mass. Tebuconazole: Using Flash NanoPrecipitation with hydrophobic ion pairing, developed three stable formulations so far, >94% encapsulation efficiency. Established protocol to measure encapsulation using mass spectrometry. Salicylic acid: Established separation + HPLC method to measure encapsulation efficiency. Highest EE currently only 14%; additional formulation optimization (counterion choice; hydrophobic co-core) underway. Nanocarriers containing a tracer metal and no agrochemical active have also been assessed for translocation after foliar application to adaxial or abaxial leaf surfaces; and measured the translocation of particles over time, to inform other tests above.

Publications


    Progress 07/01/23 to 06/30/24

    Outputs
    Target Audience:The audience for the work at this stage is primarily other researchers, including (1) collaborators at Purdue and elsewhere and (2) the attendees of the Nanoscale Science and Engineering for Agriculture and Food Systems Gordon Research Conference held in June 2024, which I attended and presented a poster on this ongoing work. No research manuscripts have been published from this work yet. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two graduate students and two undergraduate students have been working on this project, including formulation development and evaluation, data analysis, report preparation, experimental design, and explaining project to collaborators. How have the results been disseminated to communities of interest?Attended and presented poster at 2024Nanoscale Science and Engineering for Agriculture and Food Systems Gordon Research Conference in Southern New Hampshire University, June 2024. What do you plan to do during the next reporting period to accomplish the goals?Next steps are to continue optimizing formulations for encapsulation efficiency and number of surface stabilizer options; co-encapsulate metalloporphyrins and actives; measure leaf internalization, rainfastness, and translocation of actives after foliar administration. Translocation will be measured bydigestion + ICP-MS (metal tracing, to track the metalloporphyrin / NC itself) or extraction + LC-MS (direct detection of active).

    Impacts
    What was accomplished under these goals? We have made progress encapsulating four agrochemicals of interest: Streptomycin:16 working nanocarrier formulations with 100% encapsulation efficiency; sizes from 70-350nm, various stabilizers. Release in apoplastic fluid: days/weeks time scale. Esfenvalerate: 3 working nanocarrier formulations with 100% encapsulation efficiency,50% esfenvalerate by mass. Demonstrated esfenvalerate can be co-encapsulated with metalloporphyrins. Tebuconazole: Using Flash NanoPrecipitation with hydrophobic ion pairing, developed three stable formulations so far, >94% encapsulation efficiency. Established protocol to measure encapsulation using mass spec. Salicylic acid: Established separation + HPLC method to measure encapsulation efficiency. Highest EE currently only 14%; additional formulation optimization (counterion choice; hydrophobic co-core) underway. In addition, we have demonstrated that metalloporphyrin molecules containing chelated rare earth metals (e.g. palladium) are suitable for encapsulation using our technique and do not leak their metals over time.

    Publications

    • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Luke Johnson, Caleb Fretz, Luiza Oliveira, Kurt Ristroph. "2022-08572: Scalable nanocarriers for efficient foliar delivery of agrochemicals to plants." Nanoscale Science and Engineering for Agriculture and Food Systems Gordon Research Conference, Southern New Hampshire University, June 2024.