Researcher Highlight: Marsalas Whitaker
Marsalas Whitaker, 2nd year Biomedical Engineering graduate student in the Giorgio Lab
The level of epidermal growth factor receptor (EGFR) activation is reflected in subpopulations of extracellular vesicles (EVs) originating from cancerous tissue that contain EGFR. Such EVs can be assessed using methods like immunoblots and flow cytometry. One pitfall of current EV purification techniques is reliance on size and density-based purification of small-EVs that are labor intensive. Additionally, other affinity-based techniques lack the ability to release captured EVs in a non-destructive manner.
My research project is the “Affinity Purification of Small Extracellular Vesicles using Bio-Functionalized Magnetic Particles.” This project is collaborative with Dr. Bob Coffey (VUMC Associate Professor in Cell and Developmental Biology), who focuses on the study of biomarkers for Colorectal Cancer. In the Giorgio lab, we have developed antibody-conjugated superparamagnetic microparticles with cleavable DNA linkers to enable the capture and non-destructive release of EGFR-enriched EVs. Superparamagnetic microparticles are decorated with different concentrations of CTX-DNA to test conditions leading to efficient purification and release of EGFR+ EVs from complex biological samples. We utilize DNA linkers via conventional copper-free “click” chemistry synthesis methods to generate cetuximab-DNA (CTX-DNA) conjugates. These DNA linkers contain two unique restriction sites to provide selective labeling and liberation of EVs mediated by restriction enzyme cleavage.
I joined VINSE to receive training to use high-level technologies like the Dynamic Light Scattering (DLS), Electron Microscopy, and the Nanosight instruments to help characterize bio-conjugated particles synthesized in the Giorgio Lab. VINSE is always very helpful in the step-by-step walkthrough instructions given to use all equipment. VINSE has been impactful in my research and will continue to be a key resource for my future thesis research.
Outside of research, I serve as the President of the Nashville Chapter of NOBCChE (National Organization for the Professional Advancement of Black Chemists and Chemical Engineers). We help support underrepresented scientists (from undergraduate and graduate students through professional scientists) with all the tools needed to complete their degrees; connect these students to professional opportunities; and enrich the professional development of all members. I also mentor local athletes in the Nashville area, where I get to help them in math and science and provide advice on navigating college recruitment and application. As a result, I attend several sporting events throughout the year to watch my young athletes.