title: Cryogenic transmission electron microscopy nanostructural study of shed microparticles.
abstract: Microparticles (MPs) are sub-micron membrane vesicles (100-1000 nm) shed from normal and pathologic cells due to stimulation or apoptosis. MPs can be found in the peripheral blood circulation of healthy individuals, whereas elevated concentrations are found in pregnancy and in a variety of diseases. Also, MPs participate in physiological processes, e.g., coagulation, inflammation, and angiogenesis. Since their clinical properties are important, we have developed a new methodology based on nano-imaging that provides significant new data on MPs nanostructure, their composition and function. We are among the first to characterize by direct-imaging cryogenic transmitting electron microscopy (cryo-TEM) the near-to-native nanostructure of MP systems isolated from different cell types and stimulation procedures. We found that there are no major differences between the MP systems we have studied, as most particles were spherical, with diameters from 200 to 400 nm. However, each MP population is very heterogeneous, showing diverse morphologies. We investigated by cryo-TEM the effects of standard techniques used to isolate and store MPs, and found that either high-g centrifugation of MPs for isolation purposes, or slow freezing to -80 °C for storage introduce morphological artifacts, which can influence MP nanostructure, and thus affect the efficiency of these particles as future diagnostic tools.
authors.affiliation: Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Liron
authors.initials: L
authors.lastname: Issman
authors.affiliation: The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel ; Thrombosis and Hemostasis Unit, Department of Hematology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Brenner
authors.affiliation: Department of Chemical Engineering and The Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Talmon
authors.affiliation: The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel ; Thrombosis and Hemostasis Unit, Department of Hematology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Aharon
mesh_terms: D002460:Cell Line; D055252:Cell-Derived Microparticles / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D005434:Flow Cytometry; D006801:Humans; D046529:Microscopy, Electron, Transmission