Protein Nanoparticle Charge and Hydrophobicity Govern Protein Corona and Macrophage Uptake

Protein
nanoparticles are biomaterials composed entirely of proteins, with
the protein sequence and structure determining the nanoparticle physicochemical
properties. Upon exposure to physiological or environmental fluids,
it is likely that protein nanoparticles, like synthetic nanoparticles,
will adsorb proteins and this protein corona will be dependent on
the surface properties of the protein nanoparticles. As there is little
understanding of this phenomenon for engineered protein nanoparticles,
the purpose of this work was to create protein nanoparticles with
variable surface hydrophobicity and surface charge and establish the
effect of these properties on the mass and composition of the adsorbed
corona, using the fetal bovine serum as a model physiological solution.
Albumin, cationic albumin, and ovalbumin cross-linked nanoparticles
were developed for this investigation and their adsorbed protein coronas
were isolated and characterized by gel electrophoresis and nanoliquid
chromatography mass spectrometry. Distinct trends in corona mass and
composition were identified for protein nanoparticles based on surface
charge and surface hydrophobicity. Proteomic analyses revealed unique
protein corona patterns and identified distinct proteins that are
known to affect nanoparticle clearance in vivo. Further,
the protein corona influenced nanoparticle internalization in vitro in a macrophage cell line. Altogether, these results
demonstrate the strong effect protein identity and properties have
on the corona formed on nanoparticles made from that protein. This
work builds the foundation for future study of protein coronas on
the wide array of protein nanoparticles used in nanomedicine and environmental
applications.