Electronic Theses and Dissertations

Date

2021

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Chemistry

Committee Chair

Xiaohua Huang

Committee Member

Yongmei Wang

Committee Member

Paul Simone Jr

Committee Member

Tomoko Fujiwara

Abstract

Cases of cancer are on the rise, and cancer continues to be the major cause of death in the world. It has been known for years that the survival rate and possible recovery depend on early diagnosis and personalized treatment. However, tumors are in most cases almost undetectable until cancer has already invaded the surrounding tissue and begins to metastasize to distant organs at which point the treatment is significantly less effective or completely ineffective. And even if the tumor is detected, its analysis requires a tissue biopsy, which in many instances is a risky invasive procedure that does not allow regular monitoring of the effectiveness of treatment. Therefore, any strategy for early cancer identification will be based on the correct identification of cancer detection markers found in body fluids in various forms such as proteins, RNAs, and DNA. Emerging evidence points to extracellular vesicles, more precisely their subgroup - exosomes, as an abundant source in proteins and nucleic acids that reflects the state of the parental cell. In this dissertation, we summarize the exosomal biogenesis and composition, the influence of exosomes on cancer development and progression with emphasis on breast cancer, and major analytical methods applied to exosomal protein detection. Further, we report our take on exosomal protein detection as a form of novel bulk detection and single vesicle profiling techniques, which are designed for liquid biopsy in a clinical environment. Our approaches are based on optical spectroscopy and imaging such as surface enhanced Raman scattering (SERS), fluorescence, and dark-field light scattering imaging, and are designed to operate with small amounts (8-50 L) of already diluted samples. We demonstrated the potential of 3D printing and its applicability to create a miniaturized device that made it possible to customize detection conditions for nanosized exosomes and microvolume samples. Additionally, we developed a simple, fast, and inexpensive bulk method for detection of exosomal surface proteins using quantum dots in conjunction with fluorescent spectroscopy and we demonstrated its clinical potential on detection of HER2 cancer marker in plasma samples from a breast cancer patient. Lastly, we report single vesicle technology (SVT) based on dual fluorescent and dark-field imaging to achieve protein profiles at a single exosome level. Our SVT can overcome many obstacles that bulk technologies cannot and can bring long-sought-after early cancer detection into the clinical setting.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest

Notes

embargoed

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