150243 20251017144546.0 doi 10.1021/acsnano.5b01326 sideral 91614 ART-2015-91614 eng Pelaz, B. Surface Functionalization of Nanoparticles with Polyethylene Glycol: Effects on Protein Adsorption and Cellular Uptake 2015 Access copy available to the general public Unrestricted Here we have investigated the effect of enshrouding polymer-coated nanoparticles (NPs) with polyethylene glycol (PEG) on the adsorption of proteins and uptake by cultured cells. PEG was covalently linked to the polymer surface to the maximal grafting density achievable under our experimental conditions. Changes in the effective hydrodynamic radius of the NPs upon adsorption of human serum albumin (HSA) and fibrinogen (FIB) were measured in situ using fluorescence correlation spectroscopy. For NPs without a PEG shell, a thickness increase of around 3 nm, corresponding to HSA monolayer adsorption, was measured at high HSA concentration. Only 50% of this value was found for NPs with PEGylated surfaces. While the size increase clearly reveals formation of a protein corona also for PEGylated NPs, fluorescence lifetime measurements and quenching experiments suggest that the adsorbed HSA molecules are buried within the PEG shell. For FIB adsorption onto PEGylated NPs, even less change in NP diameter was observed. In vitro uptake of the NPs by 3T3 fibroblasts was reduced to around 10% upon PEGylation with PEG chains of 10 kDa. Thus, even though the PEG coatings did not completely prevent protein adsorption, the PEGylated NPs still displayed a pronounced reduction of cellular uptake with respect to bare NPs, which is to be expected if the adsorbed proteins are not exposed on the NP surface. info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 13.334 2015 CHEMISTRY, PHYSICAL 6 / 144 = 0.042 2015 Q1 T1 NANOSCIENCE & NANOTECHNOLOGY 4 / 82 = 0.049 2015 Q1 T1 CHEMISTRY, MULTIDISCIPLINARY 8 / 162 = 0.049 2015 Q1 T1 MATERIALS SCIENCE, MULTIDISCIPLINARY 9 / 270 = 0.033 2015 Q1 T1 6.712 2015 Engineering (miscellaneous) 2015 Q1 Physics and Astronomy (miscellaneous) 2015 Q1 Nanoscience and Nanotechnology 2015 Q1 Materials Science (miscellaneous) 2015 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Del Pino, P. (orcid)0000-0002-1477-5259 Maffre, P. Hartmann, R. Gallego, M. Rivera-Fernández, S. (orcid)0000-0003-0616-4383 Fuente, De La Nienhaus, G. U. Parak, W. J. 9, 7 (2015), 6996-7008 ACS Nano ACS NANO 1936-0851 4654499 http://zaguan.unizar.es/record/150243/files/texto_completo.pdf Postprint 1692187 http://zaguan.unizar.es/record/150243/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:150243 articulos driver 2025-10-17-14:09:49 ARTICLE