Selection of Fluorescent, Bioluminescent, and Radioactive Tracers to Accurately Reflect Extracellular Vesicle Biodistribution <i>in Vivo</i>
Elisa Lázaro‐Ibáñez, Farid N. Faruqu, Amer F. Saleh, Andreia Silva, Julie Wang, Janusz Rak, Khuloud T. Al‐Jamal, Niek Dekker
Abstract
imaging of organs and analysis of tissue lysates. Specifically, NanoLuc fused to CD63 altered EV distribution, resulting in high accumulation in the lungs, demonstrating that genetic modification of EVs for tracking purposes may compromise their physiological biodistribution. Blood kinetic analysis revealed that EVs are rapidly cleared from the circulation with a half-life below 10 min. Our study demonstrates that radioactivity is the most accurate EV tracking approach for a complete quantitative biodistribution study including pharmacokinetic profiling. In conclusion, we provide a comprehensive comparison of fluorescent, bioluminescent, and radioactivity approaches, including dual labeling of EVs, to enable accurate spatiotemporal resolution of EV trafficking in mice, an essential step in developing EV therapeutics.