Formation of a Monolayer Protein Corona around Polystyrene Nanoparticles and Implications for Nanoparticle Agglomeration. Issue 22 (25th April 2019)

• Record Type: Journal Article
• Authors: Wang, Haixia; Ma, Rui; Nienhaus, Karin; Nienhaus, Gerd Ulrich
• Is Part Of: Small. Volume 15:Issue 22(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-04-25
• Subjects: conformational changes -- nanoparticle agglomeration -- nanoparticles -- protein adsorption -- quantitative fluorescence microscopy; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201900974
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Nanoparticle (NP) interactions with cells and organisms are mediated by a biomolecular adsorption layer, the so‐called "protein corona." An in‐depth understanding of the corona is a prerequisite to successful and safe application of NPs in biology and medicine. In this work, earlier in situ investigations on small NPs are extended to large polystyrene (PS) NPs of up to 100 nm diameter, using human transferrin (Tf) and human serum albumin (HSA) as model proteins. Direct NP sizing experiments reveal a reversibly bound monolayer protein shell (under saturating conditions) on hydrophilic, carboxyl‐functionalized (PS‐COOH) NPs, as was earlier observed for much smaller NPs. In contrast, protein binding on hydrophobic, sulfated (PS‐OSO3 H) NPs in solvent of low ionic strength is completely irreversible; nevertheless, the thickness of the observed protein corona again corresponds to a protein monolayer. Under conditions of reduced charge repulsion (higher ionic strength), the NPs are colloidally unstable and form large clusters below a certain protein–NP stoichiometric ratio, indicating that the adsorbed proteins induce NP agglomeration. This comprehensive characterization of the persistent protein corona on PS‐OSO3 H NPs by nanoparticle sizing and quantitative fluorescence microscopy/nanoscopy reveals mechanistic aspects of molecular interactions occurring during exposure of NPs to biofluids. Abstract : Serum protein adsorption onto large polystyrene nanoparticles is quantitatively assessed via in situ nanoparticle sizing and fluorescence imaging. Under saturating conditions, proteins bind reversibly and form a monolayer on carboxyl‐functionalized nanoparticles with hydrophilic surfaces. In contrast, hydrophobic, sulfated nanoparticles are enwrapped by monolayers of irreversibly bound proteins, which can cause nanoparticle agglomeration below a certain threshold coverage.