Physico-chemical dynamics of protein corona formation on 3D-bimetallic Au@Pd nanodendrites and its implications on biocompatibility

Abstract Bimetallic nanoparticles present a promising therapeutic platform that offers unique potentials in numerous biomedical applications. However, their interaction with proteins upon contact with biofluids may modulate their biological properties due to adsorbed proteins. Herein, we provide insights on the pattern and mechanism of interactions of gold-core palladium shell dendritic-nanoparticles (Au@PdNDs) with excess morphology in the presence of human blood proteins: bovine serum albumin (BSA), fibrinogen (FBG), and gamma-globulin (γ-GLO). Upon modification with polyethylene glycol (PEG) and protamine sulfate (PS), various techniques such as fluorescence spectroscopy, dynamic light scattering, and circular dichroism spectroscopy were employed to investigate the dynamics of nanodendrite-protein complex formation. It was found that regardless of the surface charge of the bimetallic nanodendrites, FBG was the most adsorbed among the proteins, followed by BSA and γ-GLO. Furthermore, both types of nanodendrites showed selective affinity towards the different proteins based on the calculated number of binding sites (n) and association constants (K). Interestingly, FBG displayed substantial concentration-dependent conformational changes in the presence of both types of nanodendrites while only PS-modified Au@PdNDs showed α-helix and β-strand distortions with γ-GLO. Finally, the nanodendrite-protein complex formation significantly improved the biocompatibility upon the exposure to breast (MCF-7), lung (A549), and kidney embryonic (HEK 293) cell lines and was independent of the surface property as well as the concentration of the biocoronation. Our findings highlighted a critical assessment of relevant considerations towards the deployment of nanodendrites for therapeutic applications.