Biomechanical and biomolecular characterization of large extracellular vesicles - PROJECT SUMMARY/ABSTRACT Extracellular vesicles (EVs) are cell-derived, membrane-bound vesicles that carry various biomolecules (proteins, nucleic acids, lipids) and are found in noninvasive liquid biopsies. They play important roles in cell-to- cell communications as molecular messengers, meaning EVs are also attractive circulating biomarkers for molecular diagnosis of various diseases and carriers for therapeutics. Most previous studies have focused on the biomolecular contents of small nanoscale EVs (also called exosomes). There is less understanding of EVs’ mechanical properties and the molecular characteristics of microscale large EVs (L-EVs). EV origins vary widely, and their functions are harder to determine. Investigating EV functions and downstream clinical applications requires rigorous approaches of separating and classifying EVs. The EV field is still determining the characteristics of EV subpopulations and how to best separate them into groups. The overall goal of this project is to investigate L-EV subtypes using our microfluidic technology that will be advanced to measure the biomechanical and biomolecular properties of single L-EVs. The two specific aims propose to investigate L-EV heterogeneity and subtypes from different GBM-associated mutations (e.g., EGFR, EGFRvIII, and IDH1 mutations) and explore the clinical value of multiplex L-EV characterization from plasma samples. The collaborative team has complementary expertise (Dr. Dahl at UMass Boston for microfluidics and biomechanics and Dr. Im at Massachusetts General Hospital for imaging and molecular characterization of EVs). Undergraduate researchers from UMass Boston will be trained in biotechnology lab techniques at both UMass Boston and MGH, acquire and analyze data for this project, and be fully integrated into the collaborative research team through their participation and presentation of their work at biweekly project meetings and twice-a-year in-person project symposiums. This proposed work will deepen our understanding of EV biology, especially with the biomechanical properties of EVs, along with their roles as biomarkers. By correlating L-EV stiffness to its biomolecular content, we seek to explain the biomolecular origins of EV stiffness and assess the feasibility of using both physical and chemical properties as biomarkers to classify cancer subtypes more accurately.
