Impact of the Nanoparticle–Protein Corona on Colloidal Stability and Protein Structure

Abstract

In biological fluids, proteins may associate with nanoparticles (NPs), leading to the formation of a so-called "protein corona" largely defining the biological identity of the particle. Here, we present a novel approach to assess apparent binding affinities for the adsorption/desorption of proteins to silver NPs based on the impact of the corona formation on the agglomeration kinetics of the colloid. Affinities derived from circular dichroism measurements complement these results, simultaneously elucidating structural changes in the adsorbed protein. Employing human serum albumin as a model, apparent affinities in the nanomolar regime resulted from both approaches. Collectively, our findings now allow discrimination between the formation of protein mono- and multilayers on NP surfaces.

Antibacterial activity of silver nanoparticles: A surface science insight

“…By modifying the surface of nanoparticles, the corona shell can change the interactions they have with cells as well as physical and chemical properties of the systems [146,[151][152][153]. In the specific case of Ag NPs, formation of a corona has been shown to increase their colloidal stability in presence of salts [154] and their resistance toward acidic dissolution [155,156]. In 2013, Gnanadhas et al showed that the presence of proteins in the incubation medium led to a lower antibacterial activity of silver nanoparticles [157].…”

Particle Targeting in Complex Biological Media

“…[89b] Similarly, Gebauer et al reported that the protein corona formed around silver NPs could be utilized to stabilize the particles against agglomeration. [94] In contrast, Au NPs can aggregate when exposed to cellconditioned media (media that has been previously exposed to cells, which alters its composition, for example through growthrelated depletion and secretion of biomolecules). [95] The protein corona therefore affects the physicochemical properties of particles, and can influence their behavior in vivo.…”

“…[15,94,99] Therefore, to retain the targeting ability of particles in a biological environment, the goal is to better understand the formation and effects of protein coronas in order to eliminate their negative impacts on in vivo particle targeting and behavior. [21b,89c,123] Low-fouling materials (e.g., PEG, zwitterionic polymers and carbohydrates) have been extensively used to confer the carrier surface with stealth properties and can significantly reduce the amount of adsorbed proteins on the particle surface.…”

“…Recruiting Method Performance Albumin BSA Non-specific adsorption Improved stability of NPs [161] Specific adsorption Prevented NPs from being filtered by the reticuloendothelial system in vivo [162] HSA Non-specific adsorption Enhanced the accessibility of targeting ligands and targeting results of functionalized polymeric particles; improved stability of NPs [87,94] Apolipo-protein ApoE Specific adsorption Helped particles to cross the BBB and to deliver therapeutics to the brain [104a,163] ApoJ (clusterin) Specific adsorption Created stealth surface of PEG-or PEEP-coated NPs and reduced non-specific cellular uptake of these NPs [59,123b] ApoA4 Specific adsorption Decreased cellular uptake of NPs [93] ApoC3 RBP Specific adsorption Directed NPs to hepatic stellate cells [162] Vitronectin Specific adsorption Promoted efficient uptake of particles in cancer cells expressing high levels of vitronectin α ν β 3 integrin receptor [164] Aβ 1-42 peptide Specific adsorption Captured toxic forms of Aβ 1-42 peptides and improved Alzheimer's disease condition [165] a)…”

Biocatalytic Formation of Gold Nanoparticles Decorated with Functional Proteins inside Recombinant Escherichia coli Cells

“…13 Among these materials, protein-decorated Au NPs are of great importance because they can confer colloidal stability and bioactivity to Au NPs. 14,15 Au NPs can be synthesized by the chemical reduction of gold ions in the presence of a surface-capping ligand. 16 The capping ligand provides particle stabilization and an opportunity for surface modification.…”