Size characterization of extracellular vesicles (EVs) and drug delivery liposomes is of great importance in their applications in diagnosis and therapy of diseases. There are many different size characterization techniques used in the field, which often report different size values. Besides technological biases, these differences originate from the fact that various methods measure different physical quantities to determine particle size. In this study, the size of synthetic liposomes with nominal diameters of 50nm and 100nm, and red blood cell-derived EVs (REVs) were measured with established optical methods, such as dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA), and with emerging non-optical methods such as microfluidic resistive pulse sensing (MRPS) and very small-angle neutron scattering (VSANS). The comparison of the hydrodynamic sizes obtained by DLS and NTA with the sizes corresponding to the excluded volume of the particles by MRPS enabled the estimation of the thickness of the hydration shell of the particles. The comparison of diameter values corresponding to the boundary of the phospholipid bilayer obtained from VSANS measurements with MRPS size values revealed the thickness of the polyethylene glycol-layer in case of synthetic liposomes, and the thickness of the protein corona in case of REVs.
Bibliographical noteFunding Information:
This work was supported by the National Research, Development and Innovation Office NKFIH, Hungary under grant numbers PD 121326 and NVKP_16-1-2016-0007 . ZV was supported by the János Bolyai Research Fellowship . Part of this work is based upon experiments performed at the KWS-3 instrument operated by JCNS at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany. ZV gratefully acknowledges the financial support provided by JCNS to perform the neutron scattering measurements at MLZ.
- liposomal drug delivery
- microfluidic resistive pulse sensing
- small-angle neutron scattering
PubMed: MeSH publication types
- Journal Article