Figure 1From: Comparative absorption, distribution, and excretion of titanium dioxide and zinc oxide nanoparticles after repeated oral administration SEM and TEM of TiO 2 and ZnO nanoparticles. SEM (A) and TEM (B) images of TiO2 nanoparticles show spherical shape. SEM (C) and TEM (D) images of ZnO nanoparticles show hexagonal shape.Back to article page