Nanoscale flow cytometry for immunophenotyping and quantitating extracellular vesicles in blood plasma

作者：Nikki Salmond, Karan Khanna, Gethin Owen, Karla C. Williams · 发表于：Nanoscale · 年份：2021 · DOI：10.1039/d0nr05525e · 被引用次数：63 · 研究领域：Extracellular vesicles in disease、Lattice Boltzmann Simulation Studies、Nanopore and Nanochannel Transport Studies

Extracellular vesicles (EVs) are lipid membrane enclosed nano-sized structures released into the extracellular environment by all cell types. EV constituents include proteins, lipids and nucleic acids that reflect the cell from which they originated. The molecular profile of cancer cells is distinct as compared to healthy cells of the same tissue type, and this distinct profile should be reflected by the EVs they release. This makes EVs desirable candidates for blood-based biopsy diagnosis of cancer. EVs can be time consuming to isolate therefore, a technology that can analyze EVs in complex biological samples in a high throughput manner is in demand. Here nanoscale flow cytometry is used to analyze EVs in whole, unpurified, plasma samples from healthy individuals and breast cancer patients. A known breast cancer marker, mammaglobin-a, was evaluated as a potential candidate for expression on EVs and increased levels in breast cancer. Mammaglobin-a particles were abundantly detected in plasma by nanoscale flow cytometry but only a portion of these particles were validated as bona fide EVs. EVs could be distinguish and characterized from small protein clusters and platelets based on size, marker composition, and detergent treatment. Mammaglobin-a positive EVs were characterized and found to be CD42a/CD41-positive platelet EVs, and the number of these EVs present was dependent upon plasma preparation protocol. Different plasma preparation protocols influenced the total number of...