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

In parallel to medical treatment of ovarian cancer, methods for the early detection of cancer tumors are being sought. In this contribution, the use of non-invasive static (SLS) and dynamic light scattering (DLS) for the characterization of extracellular nanoparticles (ENPs) in body fluids of advanced serous ovarian cancer (OC) and benign gynecological pathology (BP) patients is demonstrated and critically evaluated. Samples of plasma and ascites (OC patients) or plasma, peritoneal fluid, and peritoneal washing (BP patients) were analyzed. The hydrodynamic radius (R-h) and the radius of gyration (R-g) of ENPs were calculated from the angular dependency of LS intensity for two ENP subpopulations. R-h and R-g of the predominant ENP population of OC patients were in the range 20-30 nm (diameter 40-60 nm). In thawed samples, larger particles (R-h mostly above 100 nm) were detected as well. The shape parameter rho of both particle populations was around 1, which is typical for spherical particles with mass concentrated on the rim, as in vesicles. The R-h and R-g of ENPs in BP patients were larger than in OC patients, with rho approximate to 1.1-2, implying a more elongated/distorted shape. These results show that SLS and DLS are promising methods for the analysis of morphological features of ENPs and have the potential to discriminate between OC and BP patients. However, further development of the methodology is required.