title: Pitfalls and novel applications of particle sizing by dynamic light scattering.
abstract: After briefly introducing the theoretical equations for DLS based particle size analysis, the need for angular dependent DLS investigations is emphasized to obtain correct particle sizes. Practical examples are given that demonstrate the possible magnitudes of errors in particle size if DLS is measured at one large scattering angle, only, as done by essentially all, most frequently utilized commercial "single angle" particle sizers. The second part is focused on a novel DLS application to sensitively trace (nano)particle interactions with concentrated blood serum or plasma that leads to the formation of large aggregates in a size regime of ≫100 nm. Most likely, such aggregates originate from protein induced bridging of nanoparticles, since it is well known that serum proteins adsorb onto the surface of essentially all nanoparticles utilized in medical applications. Thus, the protein corona around nanoparticles does not only change their biological identity but to a large extend also their size, thus possibly affecting biodistribution and in vivo circulation time.
authors.affiliation: Institute for Physical Chemistry, University Mainz, Welder Weg 11, 55099, Mainz, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Fischer
authors.affiliation: Institute for Physical Chemistry, University Mainz, Welder Weg 11, 55099, Mainz, Germany. Electronic address: mschmidt@uni-mainz.de.
authors.forename: Manfred
authors.initials: M
authors.lastname: Schmidt
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000378:metabolism; D004058:Diffusion; D000067493:Dynamic Light Scattering / Q000379:methods*; D018014:Gene Transfer Techniques; D006801:Humans; D008081:Liposomes / Q000737:chemistry; D000080385:Nanogels; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: D001798:Blood Proteins; D008081:Liposomes; D000080385:Nanogels; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C413692:polyethylene glycol polyethyleneimine nanogel; D011092:Polyethylene Glycols; D011094:Polyethyleneimine
keywords: Aggregation in blood plasma; Dynamic light scattering; Nanoparticle-blood serum interaction; Particle sizer