Nanoparticles as delivery systems

Jalomo, Catherine A

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https://hdl.handle.net/2142/130112 Copy

Description

Title

Nanoparticles as delivery systems

Author(s)

Jalomo, Catherine A

Issue Date

2025-07-18

Director of Research (if dissertation) or Advisor (if thesis)

Murphy, Catherine J

Doctoral Committee Chair(s)

Murphy, Catherine J

Committee Member(s)

• Guironnet, Damien
• Leal, Cecilia
• Rodriguez-Lopez, Joaquin

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• nanomaterials
• hydrogels
• hydrogel nanoparticles
• controlled release

Abstract

Nanomaterials have been studied as drug delivery systems due to their tunable properties, including size and surface chemistry. Engineered nanomaterials can also be loaded with species that act as therapeutic agents. Loading and release of active agents from nanoparticles have been studied to optimize targeted delivery of pharmaceuticals, but less research has been done to apply nanocarriers to agrochemical delivery. In both human and plant pathology, controlled release systems have been used to mitigate the toxicity and side effects of treatment while maintaining a therapeutic dose. Hydrogels are used as a hydrophilic, biocompatible polymer matrix that can load both metal cations and small molecules, and release is closely tied to inter- and intramolecular interactions. Adapting hydrogels on the nanoscale can expand applications to delivery of both pharmaceuticals and agrochemicals. The work presented in this dissertation investigates the synthesis of hydrogel nanoparticles for controlled release of active agents, including the modification of polymeric matrices to tune delivery. In Chapter 1, the use of nanomaterials as delivery systems for therapeutic agents is discussed in detail. Background on the use of nanoparticles for controlled release, as well as an overview of the advantages of using hydrogel-based nanoparticles will be provided. Insights into the nanoparticle design and mechanisms of controlled release are also presented. The work presented in Chapter 2 examines the design and tunability of alginate-based hydrogel nanoparticles for release of copper (II), a micronutrient required for plant health that can improve crop yield of infected tomato plants. A small library of hydrogel nanoparticles with different polymer compositions was prepared to investigate the relationship between polymer matrix and both copper loading and release. The best performing hydrogel nanoparticles were composed of alginate, which coordinates Cu2+, and non-crosslinking biopolymer chitin. Chapter 3 discusses efforts to improve copper loading in and release from hydrogel nanoparticles. First, copper content in hydrogel nanoparticles was increased by incubating copper crosslinked hydrogel nanoparticles in an additional copper (II) sulfate treatment. Hydrogel nanoparticles that were twice loaded with Cu2+ contained and released more copper than nanoparticles without secondary treatment. In addition, unmodified hydrogel nanoparticles were exposed to a photoactive small molecule that competitively binds to copper coordination sites to displace Cu2+. Chapter 4 introduces greenhouse experiments that investigate the effects of copper-crosslinked hydrogel nanoparticles on diseased tomato plants. Tomato plants suffering from fungal infection can benefit from application of copper (II), but benefits are dose-dependent. In the greenhouse studies performed in this study, hydrogel nanoparticles were applied foliarly to infected tomato plants and the effects on biomass, enzymatic activity, and chlorophyll content were observed. Treating diseased tomato plants with hydrogel nanoparticles resulted in an increase in crop yield, indicating that hydrogel nanoparticles can be an effective delivery method for copper (II) and can reduced the effects of fungal infection. Preliminary efforts to expand encapsulation of active agents to include small molecules antifungals are outlined in Chapter 5. Incorporation of hydrophobic small molecules in biopolymeric hydrogels is a challenge for hydrophilic controlled release materials, and this trend is also observed on the nanoscale. While further optimization is needed improve encapsulation efficiency, hydrogel nanoparticles can incorporate the hydrophobic fungicides pydiflumetofen and fluopyram. Finally, Chapter 6 presents hydrogel-wrapped gold nanoparticles for photothermal therapy and delivery of anticancer agents. In this work, a hydrogel-based nanoparticle with a gold nanorod core is discussed as a plasmonic-enabled nanocarrier for targeted drug delivery. This system differs from previously discussed alginate hydrogel nanoparticles because it relies on thermally-responsive synthetic polymers derived from poly(N-isopropylacrylamide) and poly(ethylene glycol).

Graduation Semester

2025-08

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/130112

Copyright and License Information

Copyright 2025 Catherine Jalomo

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