Toxicity assessment of anatase and rutile titanium dioxide nanoparticles: The role of degradation in different pH conditions and light exposure.
Titanium dioxide nanoparticles (TiO2NPs), in the two crystalline forms, rutile and anatase, have been widely used in many industrial fields, especially in cosmetics. Therefore, a lot of details about their safety issues have been discussed by the scientific community. Many studies have led to a general agreement about TiO2NPs toxicity, in particular for anatase form, but no mechanism details have been proved yet. In this study, data confirm the different toxic potential of rutile and anatase TiO2NPs in two cell lines up to 5nM nanoparticles concentration. Moreover, we evaluated the role of titanium ions released by TiO2NPs in different conditions, at pH=4.5 (the typical lysosomal compartment pH) and at pH=5.5 (the skin physiological pH) in conditions of darkness and light, to mimic the dermal exposure of cosmetics. Anatase nanoparticles were proner to degradation both in the acidic conditions and at skin pH. Our study demonstrates that pH and sunlight are dominant factors to induce oxidative stress, TiO2NPs degradation and toxicity effects.
Università del Salento, Dipartimento di Matematica e Fisica "Ennio De Giorgi", Via Arnesano, 73100 Lecce, Italy. Electronic address: valeria.dematteis@unisalento.it.
Valeria
V
De Matteis
Università del Salento, Dipartimento di Matematica e Fisica "Ennio De Giorgi", Via Arnesano, 73100 Lecce, Italy; Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT) of Consiglio Nazionale delle Ricerche (CNR), Institute of Nanoscience, via Arnesano, 73100 Lecce, Italy.
Mariafrancesca
M
Cascione
Center for Biomolecular Nanotechnologies, Istituto Italiano di Tecnologia (CBN-IIT), via Barsanti, 73010, Arnesano, Lecce, Italy.
Virgilio
V
Brunetti
Università del Salento, Dipartimento di Matematica e Fisica "Ennio De Giorgi", Via Arnesano, 73100 Lecce, Italy; Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT) of Consiglio Nazionale delle Ricerche (CNR), Institute of Nanoscience, via Arnesano, 73100 Lecce, Italy.
Chiara Cristina
CC
Toma
Università del Salento, Dipartimento di Matematica e Fisica "Ennio De Giorgi", Via Arnesano, 73100 Lecce, Italy; Euromediterranean Center for Nanomaterial Modelling and Technology (ECMT) of Consiglio Nazionale delle Ricerche (CNR), Institute of Nanoscience, via Arnesano, 73100 Lecce, Italy.
Rosaria
R
Rinaldi
D000072283:A549 Cells; D053148:Caspase 3 / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D061986:MCF-7 Cells; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity*; D018384:Oxidative Stress; D013472:Sunlight; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity*
C009495:titanium dioxide; D014025:Titanium; D007770:L-Lactate Dehydrogenase; D053148:Caspase 3
Cytotoxicity; Ions release; Sunlight exposure; Titanium dioxide; pH