Production of ¹⁸F‐Labeled Titanium Dioxide Nanoparticles by Proton Irradiation for Biodistribution and Biological Fate Studies in Rats

Abstract

A simple and straightforward method is presented for the direct proton beam activation of 18 O‐enriched titanium dioxide nanoparticles (TiO 2 NPs) via the 18 O(p,n) 18 F nuclear reaction in order to assess the biological fate of the NPs using positron emission tomography (PET). The radiolabeling of the NPs does not alter their morphological properties as demonstrated by transmission electron microscopy and dynamic light scattering measurements. The simultaneous formation of other radioisotopes by activation of the titanium atom, i.e., 48 V, 47 V, 44g Sc, has been investigated using high‐resolution gamma spectrometry and PET. The labeling of TiO 2 NPs with radioactive 18 F atoms makes it possible to perform short‐term in vivo biodistribution studies of the metal oxide NPs in rats after intravenous and oral administration using PET. The accumulation of NPs in different organs could be quantified during almost 8 h after administration.