Medina-Reyes EI1, Delgado-Buenrostro NL2, Leseman DL3, Déciga-Alcaraz A2, He R4, Gremmer ER3, Fokkens PHB3, Flores-Flores JO5, Cassee FR4, Chirino YI2.
1 Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico. Electronic address: firstname.lastname@example.org.
2 Laboratorio de Carcinogénesis y Toxicología, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Estado de México, Mexico.
3 National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.
4 National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute of Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands.
5 Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Coyoacán, CP 04510 Ciudad de México, Mexico
The Air-liquid interface (ALI) model has emerged as a closer physiological system that mimics exposure in gaseous and liquid phases. This Study shows that the exposure to TiO2 nanofibers and nanoparticles displays similar toxicity both the ALI and submerged cell cultures, using lung epithelial A549 cells. Additionally, they detected for the first time that TiO2 nanofibers were located into the nucleus.
Air Liquid Interface (ALI) system has emerged as a useful tool for toxicity evaluation of nanomaterials related to inhalation since the system mimics the aerosol exposure. We compared the biological responses of lung epithelial cells exposed to titanium dioxide (TiO2) nanofibers and nanoparticles in ALI and submerged cell cultures systems. Cells were exposed to 2 and 10 μg/cm2 for 24 h, 48 h and 72 h and LDH release, TiO2 internalization, DNA-double strand breaks (DSBs) and ROS production were assessed. LDH release was similar in both systems and particles had higher cytoplasmic uptake in submerged systems. Both TiO2 types were located in the cytoplasm but nanofibers had nuclear uptake regardless to the system tested. Cells exposed to TiO2 nanofibers had higher DSBs in the ALI system than in submerged cell cultures but cells exposed to TiO2 nanoparticles had similar DSBs in both systems. ROS production was higher in cells exposed to TiO2 nanofibers compared to cells exposed to TiO2 nanoparticles. In conclusion, cytotoxicity of lung epithelial cells was similar in ALI or submerged cell cultures, however cells exposed to TiO2 nanofibers displayed higher toxicity than cells exposed to TiO2 nanoparticles.
Correction by Vitrocell: The VITROCELL Cloud 12 was used in this study and not the VITROCELL Automated Exposures Station