The Competitive Dynamic Binding of Some Blood Proteins Adsorbed on Gold Nanoparticles

Abstract

Nanoparticle (NP) surfaces are modified immediately by the adsorption of proteins when injected into human blood, leading to the formation of a protein corona. The protein-coated NPs may be recognized by living cells. Furthermore, the adsorption of serum proteins is a continuous competitive dynamic process that is the key to exploring the bioapplication and biosafety of NPs. In this study, the competitive dynamic adsorption of some serum proteins on gold nanoparticles (AuNPs) is investigated by fluorescence emission, dynamic light scattering, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Serum proteins with different AuNPs binding affinities are used to address the competitive dynamic process of protein-AuNP interactions in vitro. The results show that more abundant serum proteins, such as human serum albumin, adsorb on AuNPs first, and then the higher binding affinity and lower concentration serum proteins, such as fibrinogen (FIB), replace the abundant and lower binding affinity serum proteins. However, the lower binding affinity serum proteins, such as hemoglobin, do not replace the higher binding affinity proteins from the protein-AuNP conjugates. During the dynamic exchange process, the larger the binding affinities difference between two proteins, the faster the exchange rate. This dynamic exchange process usually takes longer in inner protein-AuNP conjugates (hard corona) than the external surface of protein-AuNP conjugates (soft corona).