Studying the Interaction Behavior of Protein Coronated Gold Nanorods with Polystyrene Nanoplastics

Abstract The formation of protein corona and their modulatory effects on the physicochemical and biological activity of the nanomaterial is well established. The active protein corona on the nanoparticles can further mediate interactions with trace amounts of exogenous entities present in the systemic circulation. In the present study, we utilize an in vitro simulation system wherein, protein corona is strategically engineered by varying the serum concentration on a model nanoparticle i. e. cationic‐gold nanorods (GNRs). Quantitative analysis indicated that the 4 nm cationic GNRs can accumulate as high as ∼1 mg/mL protein corona upon incubation with serum. The size distribution pattern of the bound corona and their subsequent impact on the physicochemical properties of GNRs were determined. To understand how these coronated nanorods would interact with a potent pollutant, the second layer of interaction was further introduced by interacting the coronated‐GNRs with 1 ppm nanoplastic. The impact of differently functionalized polystyrene beads (plain, aminated, and carboxylated) on the core size, hydrodynamic diameter, surface charge, and optical properties of the coronated GNRs is highlighted. A complex interplay of several interactive forces and amino acid‐mediated binding of the GNRs to the styrene and benzene rings of the nanoplastic leads to the formation of a coronated‐GNR‐PS complex (>400 nm). Further, upon subjecting the hybrid‐conjugate system to acidic pH conditions (pH‐5.6 and 4.3), a considerable increase in protein leaching was observed. The novel approach of the present study aims to look into the layered interactive patterns for nanomaterials that are utilized for in vivo applications.