Protein Corona in Response to Flow: Effect on Protein Concentration and Structure

Abstract

Nanoparticles used in cellular applications encounter free serum proteins that adsorb onto the surface of the nanoparticle, forming a protein corona. This protein layer controls the interaction of nanoparticles with cells. For nanomedicine applications, it is important to consider how intravenous injection and the subsequent shear flow will affect the protein corona. Our goal was to determine if shear flow changed the composition of the protein corona and if these changes affected cellular binding. Colorimetric assays of protein concentration and gel electrophoresis demonstrate that polystyrene nanoparticles subjected to flow have a greater concentration of serum proteins adsorbed on the surface, especially plasminogen. Plasminogen, in the absence of nanoparticles, undergoes changes in structure in response to flow, characterized by fluorescence and circular dichroism spectroscopy. The protein-nanoparticle complexes formed from fetal bovine serum after flow had decreased cellular binding, as measured with flow cytometry. In addition to the relevance for nanomedicine, these results also highlight the technical challenges of protein corona studies. The composition of the protein corona was highly dependent on the initial mixing step: rocking, vortexing, or flow. Overall, these results reaffirm the importance of the protein corona in nanoparticle-cell interactions and point toward the challenges of predicting corona composition based on nanoparticle properties.

Protein corona: Dr. Jekyll and Mr. Hyde of nanomedicine

“…Again, Au-coated magnetic NPs were applied in biomarker discovery as tool for preconcentration and separation of proteins from sera of patients with multiple myeloma [96]. These considerations lead to a challenge in the prediction of biocorona composition, strictly related with activity, toxicity, and immunogenicity of NPs [97][98][99].…”

Engineered Polymeric Materials for Biological Applications: Overcoming Challenges of the Bio–Nano Interface

“…Numerous physicochemical factors have been shown to contribute to the accumulation and subsequent composition of the protein corona including chemical composition [22], size [23], curvature [22], rigidity [24], hydrophobicity [22], presence of protein targeting ligands [25], and surface characteristics [10,11,26]. These factors contribute to the unpredictable outcome of interactions between nanoparticles and physiological phenomena, with enhanced variability also arising due to flow rate encountered in different parts of the animal [27], enzymatic modifications [12], glycosylation state [28], as well as localized plasma protein concentration [27] and content [12] within anatomical regions. While the interaction with blood proteins has been profiled for certain kinds of materials (e.g., gold nanoparticles [29] and liposomes [30]), proteomic fingerprinting has not been done for polymeric nanomedicines (at least under conditions that match those present within the blood stream of an animal).…”

Target Site Delivery and Residence of Nanomedicines: Application of Quantitative Systems Pharmacology

“…NP-PC formation depends on NP properties (material, surface properties, size, charge, shape, geometry, curvature), environment (ECM composition, pH, temperature, shear stress, ionic strength), and time (Strojan et al, 2017). High shear flow, by inducing conformational changes of proteins in plasminogen-rich PC, reduces NP binding to plasminogen receptors on cells compared with static shear flow (Jayaram et al, 2018). Surface modifications such as pegylation generally decrease PC formation, enabling the NP to avoid recognition and entrapment in the RES (Nuytten et al, 2010;Dobrovolskaia et al, 2014;Bargheer et al, 2015;Pelaz et al, 2015).…”