Effects of gold nanoparticle morphologies on interactions with proteins.

In biological milieu, nanoparticles tend to bind with a variety of biomolecules, particularly proteins, thereby forming an interfacial corona that endows them with a new biological identity. A thorough understanding of these protein coronas is likely to provide insights into nanoparticle biodistribution and nanoparticle-mediated cytotoxicity, leading to the expansion of potential applications and the further elucidation of the biological impacts of nanoparticles in biomedical applications. Herein, three differently shaped AuNPs were synthesized, namely nanospheres (AuNSPs), nanorods (AuNRs), and nanostars (AuNSs). The effects of the morphologies of AuNPs on the structures and functions of adsorbed fibrinogen (FIB) and trypsin (Try) were investigated via circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR). Simultaneously, two different types of proteins were employed to investigate their influences on the stability and aggregation of AuNPs, using UV-vis absorption spectroscopy, transmission electron microscopy (TEM), microscale thermophoresis (MST), and dynamic light scattering (DLS). It was found that, compared to AuNSPs, the irregularly shaped AuNPs (e.g., AuNRs and AuNSs) had the capacity to induce greater changes in the secondary structures of the proteins. Furthermore, it appeared that the differently shaped AuNPs had obvious effects on the secondary structure of Try, and slight effects on the secondary structure of FIB. Consequently, these preliminary results indicated that the formation of protein corona, as well as the aggregation behaviors of the AuNPs was intimately related to the specific shapes of the AuNPs and the unique structures of the proteins.