Titanium dioxide nanoparticles induce an adaptive inflammatory response and invasion and proliferation of lung epithelial cells in chorioallantoic membrane
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, CP 54059 Estado de México (Mexico)
- Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria AP 70-186, CP 04510 México, DF (Mexico)
- Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, CP 11340 México, DF (Mexico)
- Instituto Nacional de Cancerología, Subdirección de Investigación Básica, San Fernando 22, Tlalpan, CP 14080 México, DF (Mexico)
Titanium dioxide nanoparticles (TiO{sub 2} NPs) studies have been performed using relatively high NPs concentration under acute exposure and limited studies have compared shape effects. We hypothesized that midterm exposure to low TiO{sub 2} NPs concentration in lung epithelial cells induces carcinogenic characteristics modulated partially by NPs shape. To test our hypothesis we synthesized NPs shaped as belts (TiO{sub 2}-B) using TiO{sub 2} spheres (TiO{sub 2}-SP) purchased from Sigma Aldrich Co. Then, lung epithelial A549 cells were low-exposed (10 µg/cm{sup 2}) to both shapes during 7 days and internalization, cytokine release and invasive potential were determined. Results showed greater TiO{sub 2}-B effect on agglomerates size, cell size and granularity than TiO{sub 2}-SP. Agglomerates size in cell culture medium was 310 nm and 454 nm for TiO{sub 2}-SP and TiO{sub 2}-B, respectively; TiO{sub 2}-SP and TiO{sub 2}-B induced 23% and 70% cell size decrease, respectively, whilst TiO{sub 2}-SP and TiO{sub 2}-B induced 7 and 14-fold of granularity increase. NO{sub x} production was down-regulated (31%) by TiO{sub 2}-SP and up-regulated (70%) by TiO{sub 2}-B. Both NPs induced a transient cytokine release (IL-2, IL-6, IL-8, IL-4, IFN-γ, and TNF-α) after 4 days, but cytokines returned to basal levels in TiO{sub 2}-SP exposed cells while TiO{sub 2}-B induced a down-regulation after 7 days. Midterm exposure to both shapes of NPs induced capability to degrade cellular extracellular matrix components from chorioallantoic membrane and Ki-67 marker showed that TiO{sub 2}-B had higher proliferative potential than TiO{sub 2}-SP. We conclude that midterm exposure to low NPs concentration of NPs has an impact in the acquisition of new characteristics of exposed cells and NPs shape influences cellular outcome. - Graphical abstract: (A) Lung epithelial cells were low exposed (below 10 µg/cm{sup 2}) to titanium dioxide nanoparticles (TiO{sub 2}-NPs) shaped as spheres (TiO{sub 2}-SP) and belts (TiO{sub 2}-B) for midterm (7 continuous days) separately. (B) Then, cells from each cell culture were harvested and seeded on the top of the chorioallantoic membrane (CAM) for 5 days and (C) invasion and proliferation of cells were analyzed in CAM sections. - Highlights: • Hydrodynamic size of TiO2- SP was smaller than TiO2-B in cell culture media • TiO2- SP induced higher decrease in cell size than TiO2-B • TiO2-SP induced a transient cytokine release and TiO2-B a downregulation • TiO2-B caused higher proliferative capability than TiO2-SP.
- OSTI ID:
- 22447570
- Journal Information:
- Environmental Research, Vol. 136; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0013-9351
- Country of Publication:
- United States
- Language:
- English
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