Yu Chong,†,Cuicui Ge,†,Zaixing Yang,†,Jose Antonio Garate,‡Zonglin Gu,†Jeffrey K. Weber,‡Jiajia Liu,†and Ruhong Zhou*,†,‡,§

Abstract

The advent and pending wide use of nanoscale materials urges a biosafety asses**ent and safe design of nanomaterials that demonstrate applicability to human medicine. In biological microenvironment, biomolecules will bind onto nanoparticles forming corona and endow nanoparticles new biological identity. Since bloodcirculatory system will most likely be thefirst interaction organ exposed to these nanomaterials, a deep understanding of the basic interaction mechani**s between serum proteins and foreign nanoparticles may help to better clarify the potential risks of nanomaterials and provide guidance on safe design of nanomaterials. In this study, the adsorption of four high-abundance blood proteins onto the carbon-based nanomaterial graphene oxide (GO) and reduced GO (rGO) were investigatedviaexperimental (AFM,florescence spectroscopy, SPR) and simulation-based (molecular
dynamics) approaches. Among the proteins in question, we observe competitive binding to the GO surface that features a mélange of distinct packing modes. Our MD simulations reveal that the protein adsorption is mainly enthalpically driven through strongπ
πstacking interactions between GO and aromatic protein residues, in addition to hydrophobic interactions. Overall, these results were in line with previousfindings related to adsorption of serum proteins onto single-walled carbon nanotubes (SWCNTs), but GO exhibits a dramatic enhancement of adsorption capacity compared to this one-dimensional carbon form. Encouragingly, protein-coated GO resulted in a markedly less cytotoxicity than pristine and protein-coated SWCNTs, suggesting a useful role for this planar nanomaterial in biomedical applications.