Comparative absorption, distribution, and excretion of titanium dioxide and zinc oxide nanoparticles after repeated oral administration

Table 1 Physicochemical characterization of metal oxide nanoparticles

Particles	Crystallinity	Primary size (nm) measured by		Hydrodynamic size (nm) ^a	Surface area (m ²/g) ^b	Endotoxin (pg/ml) ^c
Particles	Crystallinity	Manufacturer	SEM	Hydrodynamic size (nm) ^a	Surface area (m ²/g) ^b	Endotoxin (pg/ml) ^c
TiO₂	Anatase 80: 20 Rutile	21	26.4 ± 6.1	37.8 ± 0.4	50±15	N.D.
ZnO	Hexagonal	40	89.3 ± 44.7	201.8 ± 17.2	60±10	N.D.

ND not detectable. SEM scanning electron microscopy.
^aNanoparticles were dispersed in DW and measured by a dynamic light scattering method.
^bSpecific surface area by the Brunauer-Emmett-Teller method was provided by the manufacturer.
^cLevels of endotoxin were measured using an Endpoint Chromogenic Limulus Amebocyte Lysate assay (Cambrex, MD, USA).

ISSN: 1743-8977