Surface Curvature Relation to Protein Adsorption for Carbon-based Nanomaterials

Area of Science:

• Materials Science
• Biophysics
• Computational Chemistry

Background:

• Protein adsorption on carbon-based nanomaterials (CBNs) is governed by hydrophobic and π-π interactions.
• Surface topology, specifically curvature, is hypothesized to influence protein adsorption capacity.

Purpose of the Study:

• To investigate the relationship between surface curvature of CBNs and protein adsorption capacity using bovine serum albumin (BSA) as a model protein.
• To reconcile discrepancies between computational simulations and experimental observations regarding protein adsorption on different carbon nanostructures.

Main Methods:

• Coupling Molecular Dynamics (MD) simulations with fluorescence spectroscopy experiments.
• Studying BSA adsorption on carbon nanotubes (CNTs) with varying radii and flat graphene sheets.
• Performing additional MD simulations on multi-walled carbon nanotubes (MWCNTs) to match experimental conditions.

Main Results:

• Protein adsorption capacity increases as the surface curvature of CBNs decreases (i.e., on flatter surfaces).
• Initial experiments with MWCNTs showed an opposing trend, suggesting complexities beyond simple curvature.
• MD simulations revealed that higher mass-to-surface area ratios in MWCNTs explain the experimental discrepancies.

Conclusions:

• The study confirms an inverse relationship between protein adsorption capacity and surface curvature on CBNs.
• Subtle considerations in experimental and simulation design, such as mass-to-surface area ratios in MWCNTs, are crucial for accurate interpretation of protein-nanomaterial interactions.