Protein-nanoparticle interactions: Opportunities and challenges

The significant role of protein nanoparticle interactions in nanomedicine and nanotoxicity is emerging recently through the identification of the nanoparticles (NP) protein (biomolecule) corona. The dynamic layer of proteins and/or other biomolecules adsorbed to the nanoparticle surface determines how a NP interacts with living systems and thereby modifies the cellular responses to the NP. Ehrenberg and co-workers used cultured endothelium cells as a model for vascular transport of polystyrene NP with various functional groups, which showed that the capacity of the various NP surfaces to adsorb proteins was indicative of their tendency to associate with cells. The quantification of the adsorbed proteins showed that high-binding NP were maximally coated within seconds to minutes, indicating that proteins on the surface of NP could mediate cell association over much longer time scales. The adsorption or covalent binding of a protein onto a NP's surface can strongly alter the physio-chemical and structural properties of both of them.