Event
PhD Dissertation Defense Announcement: Katherine Pendragon
Friday, July 21, 2023
2:00 p.m.
AJC 3104 (3rd floor conference room)
Rachel Chang
301 405 8268
rachel53@umd.edu
Title: Functionalized Nanoparticles for the Controlled Modulation of Cellular Behavior
Committee members:
Dr. James Delehanty, Co-Chair
Dr. John Fisher, Co-Chair
Dr. Ian White
Dr. Srinivasa Raghavan
Dr. Paul Paukstelis, Dean's Representative
Abstract:
The ability to control cellular behavior at the single-cell level is of great importance for gaining a nuanced understanding of cellular machinery. This dissertation focuses on the development of novel bioconjugate hard nanoparticle (NP) materials, specifically gold nanoparticles (AuNPs) and quantum dots (QDs), for the controlled modulation of cellular behavior. These hard NPs offer advantages such as small size on the order of 1 – 100 nm, high stability, unique optical properties, and the ability to load cargo on a large surface area to volume ratio, making them ideal tools for understanding and controlling cell behavior. First, we demonstrate the use of AuNPs to manipulate cellular biological functions, specifically the modulation of membrane potential. We present the conception of anisotropic-shaped AuNPs, known as gold nanoflowers (AuNFs), which exhibit broad absorption extending into the near-infrared region of the spectrum. We demonstrate the effectiveness of utilizing the plasmonic properties AuNFs for inducing plasma membrane depolarization in rat adrenal medulla pheochromocytoma (PC-12) neuron-like cells. Importantly, this is achieved with temporal control and without negatively impacting cellular viability. Secondly, we explore the use of QDs as an optical, trackable scaffold for the multivalent display of growth factors, specifically erythropoietin (EPO), for the enhanced induction of protein expression of aquaporin-4 (AQPN-4) within human astrocytes. This results in enhanced cellular water transport within human astrocytes, a critical function in the brain's glymphatic system. We show that EPO-QD-induced augmented AQPN-4 expression does not negatively impact astrocyte viability and augments the rate of water efflux from astrocytes by approximately two-fold compared to cells treated with monomeric EPO, demonstrating the potential of EPO-NP conjugates as research tools and prospective therapeutics for modulating glymphatic system function. Overall, this body of work develops new NP tools, namely solid anisotropic AuNFs and growth factor-delivering QDs, for the understanding and control of cell function. These new functional nanomaterials pave the way for the continued development of novel NP-based tools for the precise modulation of cellular physiology.
