Biocompatible and Multifunctional Trityl Spin Probes for Electron Paramagnetic Resonance Spectroscopy

Abstract

The primary objective of my thesis was to develop and utilize a biocompatible multifunctional trityl spin probe for concurrent measurement of pO2, pHe, and [Pi] in vivo by electron paramagnetic resonance (EPR) spectroscopy (Chapter 2). My first goal was to synthesize the proposed probe we are terming HOPE71. Secondly, HOPE71 was characterized by X-band and L-band EPR spectroscopy. Next, the biocompatibility of HOPE71 was assessed through an albumin binding test, cytotoxicity assays, and in vivo intravenous tolerance. Then, the use of HOPE71 to measure the target parameters was demonstrated in a breast cancer mouse model. In tandem, I developed an application for user friendly fitting of the EPR spectrum of HOPE71 and the related monophosphated probe, pTAM (Chapter 3). Lastly, to demonstrate further skill in synthesis of trityl spin probes, I worked in collaboration with the Saxena lab at the University of Pittsburgh to develop a hydrophilic spin probe with a maleimide linker for structural biology studies using site directed spin labeling and dipolar EPR spectroscopy (Chapter 4).