Albumin-coated SPIONs: an experimental and theoretical evaluation of protein conformation, binding affinity and competition with serum proteins

Abstract

The variety of nanoparticles (NPs) used in biological applications is increasing and the study of their interaction with biological media is becoming more important. Proteins are commonly the first biomolecules that NPs encounter when they interact with biological systems either in vitro or in vivo. Among NPs, super-paramagnetic iron oxide nanoparticles (SPIONs) show great promise for medicine. In this work, we study in detail the formation, composition, and structure of a monolayer of bovine serum albumin (BSA) on SPIONs. We determine, both by molecular simulations and experimentally, that ten molecules of BSA form a monolayer around the outside of the SPIONs and their binding strength to the SPIONs is about 3.5 × 10(-4) M, ten times higher than the adsorption of fetal bovine serum (FBS) on the same SPIONs. We elucidate a strong electrostatic interaction between BSA and the SPIONs, although the secondary structure of the protein is not affected. We present data that supports the strong binding of the BSA monolayer on SPIONs and the properties of the BSA layer as a protein-resistant coating. We believe that a complete understanding of the behavior and morphology of BSA-SPIONs and how the protein interacts with SPIONs is crucial for improving NP surface design and expanding the potential applications of SPIONs in nanomedicine.

Sensitive Analysis of Protein Adsorption to Colloidal Gold by Differential Centrifugal Sedimentation

“…It should be pointed out, however, that even at the highest BSA concentrations, BSA did not form multilayers on NPs, as had been suggested previously for BSA coronas on a variety of NPs. 22,44 …”

Next‐Generation Polymer Shells for Inorganic Nanoparticles are Highly Compact, Ultra‐Dense, and Long‐Lasting Cyclic Brushes

“…[41] These results were further confirmed by atomic force microscopy (AFM) measurements ( Figure S17 in the Supporting Information) and indicate that despite their high s,l inear PEOXA shells were not able to prevent BSA adsorption. [41] These results were further confirmed by atomic force microscopy (AFM) measurements ( Figure S17 in the Supporting Information) and indicate that despite their high s,l inear PEOXA shells were not able to prevent BSA adsorption.…”

“…In particular, the increase of Z-average D H for NPs bearing linear PEOXA shells corresponded to approximately 15 nm, indicating the formation of aB SA monolayer,w ith proteins adsorbing "side up" on the NPs interface. [41] These results were further confirmed by atomic force microscopy (AFM) measurements ( Figure S17 in the Supporting Information) and indicate that despite their high s,l inear PEOXA shells were not able to prevent BSA adsorption. In accordance to what was observed for PEGylated NPs, [6] small proteins like BSA are capable of overcoming the osmotic barrier generated by the linear brushes and physically interact with NP cores.O nt he contrary,t he combined effects of ultra-high s and enhanced steric stabilization granted by the more compact and uniformly dense cyclic brushes efficiently prevent NP surface contamination by BSA.…”

Insights into switchable thermoresponsive copolymer layers by atmospheric pressure plasma‐initiated chemical vapour deposition

“…Changes in frequency of p(NVCL‐co‐EGDMA)‐coated QCM‐D sensors after BSA injection at 22°C and 50°C with schemes depicting the BSA‐coated surface interactions, BSA adapted from Reference [ 41 ] (a). QCM‐D measurements for estimating adsorbed amounts of BSA to bare and coated QCM‐D sensors.…”