Fig. 2

Nanoparticle characterization in cell medium. Nanoparticle behavior in cell medium (BEGM) was examined by photon cross-correlation spectroscopy (PCCS) and inductively coupled plasma mass spectrometry (ICP-MS). a The PCCS density distribution histograms are presented as density distribution by volume multiplied with corresponding scattered light intensities and indicate the hydrodynamic size distribution of the particles directly after dispersion (0 h), after 2 h, as well as 24 h at a concentration of 10 μg/mL, and (b) corresponding PCCS scattered light intensities. c The amount of Ni released in cell medium after 4, 24 and 48 h was determined by ICP-MS and expressed as % Ni released in cell medium from the total amount of added Ni (determined experimentally) for Ni (gray) and NiO (black)