Characterization of IgG-protein-coated polymeric nanoparticles using complementary particle sizing techniques

When nanoparticles are introduced into biological media, they acquire a protein corona. The thickness of immunoglobulin G protein on 105 nm polystyrene particles has been determined by dynamic light scattering (DLS), differential centrifugal sedimentation (DCS) and small-angle X-ray scattering (SAXS). All three techniques measured an increase of the protein shell thickness with increasing concentration of the proteins during incubation with the nanoparticles. DLS measurements showed the highest increase, indicating a possible effect of particle agglomeration on the DLS results. DCS accuracy critically depends on the knowledge of the protein shell density but the data allows an estimation of the effective shell density when the thickness was independently determined. SAXS measurements revealed the complex core/shell structure of the bare polystyrene particles. (C) 2014 Crown Copyright. Surface and Interface Analysis (C) 2014 John Wiley & Sons Ltd.