Force spectroscopy with BSA functionalized cantilevers on TiO2 nanoparticles

Abstract

AbstractThe contact of nanoparticle surfaces with biomolecules often results in interactions. Proteins as one of the most important biomolecules adsorb on nanoparticle surfaces and can affect the way of recognition or of uptake in the cell. Even inhaled nanoparticles can be found on the luminal side of airways and alveoli, major lung tissue compartment or cells and within capillaries. They cross the cell membrane not by endocytotic processes, but by diffusion or adhesive interactions. Due to the possible interaction after inhalative exposure of inorganic nanoparticles with blood biomolecules we investigated the adhesion properties between different TiO2 nanoparticles and commercial silicon or BSA (as a model protein) modified cantilevers with atomic force microscopy (AFM). The characterization of the nanoparticles was done using laser doppler electrophoresis (LDE), dynamic light scattering (DLS) and transmission electron microscopy (TEM) for zeta potential and size. AFM was used to perform force measurements with unmodified tips and BSA functionalized tips. Adhesion measurements showed differences between the inorganic nanoparticles, regarding their ability to interact with the major serum compound BSA.magnified image Scheme of the adhesion measurements on TiO2 nanoparticles performed with unmodified and BSA modified cantilevers.