Hydrophobin-Coated Solid Fluorinated Nanoparticles for 19F-MRI

In recent years, fluorine-magnetic resonance imaging (¹⁹F-MRI) has emerged as a promising diagnostic technique, complementary to traditional proton magnetic resonance imaging (¹H-MRI) and easily translatable for clinical use, providing in-depth in vivo quantification without the use of radioactive agents. This creates a need for the development of appropriate delivery systems for highly omniphobic fluorinated probes. The use of the film-forming protein hydrophobin (HFBII) represents a sustainable and simple method to invert the philicity of fluorinated surfaces. Here, the ability of HFBII to form a rigid protein monolayer on superfluorinated coatings rendering them hydrophilic is shown, a property that is also retained in biological environment. This approach is then translated to directly disperse a solid superfluorinated ¹⁹F-MRI probe, PERFECTA, in aqueous solution through the formation of core-shell hydrophobin stabilized PERFECTA nanoparticles (NPs). The obtained NPs are fully characterized in terms of morphology, magnetic properties, colloidal stability, protein corona formation, cellular viability, and imaging performance.