Pursuing mechanisms of extracellular vesicle formation. Effects of sample processing

Application of Dynamic and Static Light Scattering for Size and Shape Characterization of Small Extracellular Nanoparticles in Plasma and Ascites of Ovarian Cancer Patients

“…Depending on the driving forces in such self-association, the resulting particles may have either narrow (e.g., micelles) or broad size distributions (e.g., laboratory prepared vesicles in the case that lipid components are left to self-organize into bilayers without some external control over their size, such as extrusion). We also presume that certain subtypes of ENPs can exhibit ellipsoidal or elongated shapes, which is reflected in the value of the shape parameter ρ, which is larger than 1, and is also confirmed by EM images in the literature [47,72,73].…”

Enrichment of plasma in platelets and extracellular vesicles by the counterflow to erythrocyte settling

“…EVs are continuously produced by cells in vivo, therefore some EVs are expected to be naturally present in blood. However, besides these, blood cells shed vesicles also ex vivo, during the sample processing and Enrichment of plasma by erythrocyte settling 5 assessment [16,17]. In all samples, the concentration of platelets and larger EVs (P2* particles) was higher in EPP than in blood, and it further increased in PVRP while it was substantially lower in PPP (Figure 4D).…”

“…Lately, increasing attention is being paid to membrane-enclosed cellular fragments (extracellular vesicles -(EVs)) that have been found abundant in isolates from plasma [15][16][17][18][19]. It has been indicated that EVs are being shed from platelets [19] as well as from other cells [18][19][20].…”

“…PVRP is simple to prepare (only requires a centrifuge and few basic laboratory tools), and with autologous application there is low risk of complications such as infection or immune rejection [1]. However, the preparation procedure can significantly impact blood cells and EVs [16,17] and therefore also the composition of PVRP. Besides EVs that are already present in plasma in vivo, the preparation contains also EVs that are formed during the sample storage [19][20][21] and processing due to the temperature change and shear stress imposed upon blood cells and their fragments [16,17].…”

“…However, the preparation procedure can significantly impact blood cells and EVs [16,17] and therefore also the composition of PVRP. Besides EVs that are already present in plasma in vivo, the preparation contains also EVs that are formed during the sample storage [19][20][21] and processing due to the temperature change and shear stress imposed upon blood cells and their fragments [16,17]. The composition of PVRP that determines its biological activity is therefore influenced by the sample handling throughout the processing.…”