SDSL-EPR as a tool for grasping topological information on the interaction between proteins and nanoparticles

The main event associated with the interaction of nanoparticles with biological fluids is the formation of a protein corona. Predicting the fate of NPs in biological environments implies a thorough characterization of such protein layer in terms of chemical composition of the NP surface as well as structural characterization. Both the changes in protein fold and the selective orientation of proteins onto NPs may influence the final outcome of NP in the body. In this paper we provide some examples of how EPR spectroscopy coupled to site-directed spin-labeling (SDSL) may shed light on these specific aspects related to the protein adsorption mechanisms.