Revealing the Binding Structure of the Protein Corona on Gold Nanorods Using Synchrotron Radiation-Based Techniques: Understanding the Reduced Damage in Cell Membranes

TLDR

Limited knowledge exists on the binding structure and stability of protein coronas on nanomaterials and their biological impacts. The study aims to design a BSA protein corona on CTAB‑coated gold nanorods and use synchrotron‑based spectroscopy, CD, and MD simulations to elucidate its structure, thereby improving understanding of protective effects against nanomaterial toxicity. We employed synchrotron radiation X‑ray absorption spectroscopy, microbeam X‑ray fluorescence spectroscopy, circular dichroism, and molecular dynamics simulations to capture the protein adsorption structure on gold nanorods. Protein adsorption involves at least 12 Au–S bonds, stabilizing the corona and reducing CTAB/AuNR cytotoxicity, and these results provide a strategy for studying protein–nanomaterial interactions to guide safer nanomaterial design.

Abstract

Regarding the importance of the biological effects of nanomaterials, there is still limited knowledge about the binding structure and stability of the protein corona on nanomaterials and the subsequent impacts. Here we designed a hard serum albumin protein corona (BSA) on CTAB-coated gold nanorods (AuNRs) and captured the structure of protein adsorption using synchrotron radiation X-ray absorption spectroscopy, microbeam X-ray fluorescent spectroscopy, and circular dichroism in combination with molecular dynamics simulations. The protein adsorption is attributed to at least 12 Au–S bonds and the stable corona reduced the cytotoxicity of CTAB/AuNRs. These combined strategies using physical, chemical, and biological approaches will improve our understanding of the protective effects of protein coronas against the toxicity of nanomaterials. These findings have shed light on a new strategy for studying interactions between proteins and nanomaterials, and this information will help further guide the rational design of nanomaterials for safe and effective biomedical applications.