Second Harmonic Generation Nanoparticles for Biomedical Imaging: Synthesis and Interaction with Model Bio-Interfaces

This work investigates the synthesis and characterization of Barium Titanate (BT) nanoparticles, which exhibit non-linear optical properties, with a focus on their potential application in biomedical imaging. BT nanoparticles are active in second harmonic generation (SHG), enabling deep tissue imaging with a high signal-to-noise ratio. A major objective of this study is to advance in the understanding of the interactions between these nanoparticles and model biological systems. To this end, monolayers of 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC) spread on aqueous sub-phase are employed as model bio-interfaces, and the effects of BT nanoparticles on their properties are investigated using physicochemical experimental techniques such as Langmuir trough and Dynamic Light Scattering, also in the presence of albumin, a representative serum protein. The results evidence nanoparticle incorporation into the lipid layer, affecting its phase behavior, as well as the spontaneous formation of protein coronas around NPs, which is further confirmed by super-resolution optical microscopy.