Robert M. Ta

Date of Award


Degree Type


Degree Name

Master of Science


Medical Biophysics


Robert Bartha, PhD

Second Advisor

Stephen Pasternak, MD, PhD


Alzheimer’s disease is a neurodegenerative disease with no early diagnosis. Neuronal dysfunction is an early indication of Alzheimer’s disease which we can measure by examining the lysosomal protein Cathepsin-D. Molecular imaging of Cathepsin-D using Magnetic Resonance Imaging (MRI) contrast agents could enhance visualization of disease and provide contrast within tissues and cells that are morphologically similar but physiologically distinct. The purpose of our work was to evaluate a novel MRI/fluorescent contrast agent designed to detect Cathepsin-D in early Alzheimer’s disease.

In-vitro MRI and fluorescent sensitivity were characterized in addition to cellular uptake in cells over-expressing Cathepsin-D. Cortical and hippocampal uptake was evaluated following in-vivo injection of contrast agent in mice. The contrast agent exhibited differences in retention and uptake between control and transgenic Alzheimer’s mice. The results demonstrate the potential utility of the contrast agent for in-vivo identification of cathepsin-D upregulation and will continue to be further evaluated and refined in future studies.



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