Fibronectin-derived protein forms a protein corona on gold nanoparticles: synthesis, Raman and optical properties of a new plasmonic nanocarrier

Synthetic fibronectin III-derived protein scaffolds represent a new generation of proteins that can overcome some clinical limitations of therapeutic monoclonal antibodies. However, one major disadvantage of smaller protein scaffolds is their rapid renal clearance and correspondingly short circulating serum half-lives. A complex formation of these protein scaffolds with nanoparticles can be a valuable route to overcome the short half-life in human serum. Here we present the synthesis and characterization of a first example of fibronectin III, 14th domain-derived scaffold, called Pronectin™, with gold nanoparticle of around 30-nm diameter to form a protein corona. The obtained functionalized nanoparticles were characterized by Raman spectroscopy and electron microscopy. Their plasmonic properties, due to the gold core, and the luminescence, attributed to the protein, were measured in two cases (nanoparticles with albumin or Pronectin™), and confirmed that the formation of a protein corona induces some form of denaturation of the proteins themselves. Graphical abstract