Photocatalytic Fe-doped n-TiO 2 : From synthesis to utilization of in vitro cell models for screening human and environmental nanosafety

Abstract

The utilization of different types nanomaterials (NMs) in environmental remediation and wastewatertreatment requires information on the potential harmful effects on human and environmental health. Inthis light, the utilization of human cell models together with cells from lower organisms, representativeof different environmental compartments, could represent a valuable tool for the in vitro screening of thepotential toxicity of different NMs used in nanoremediation. Among NMs, n-TiO 2 , because of its peculiaroptical and chemical properties, is widely applied for photosensitized UV oxidation of organic pollutants.Moreover, development in design of metal- and non metal- doped TiO 2 with extended photocatalyticactivity in the visible region represents the subject of ongoing research.In this work, the cytotoxic effects of three different types of recently synthetized Fe-doped n-TiO 2were compared in two cell models widely utilized for screening cellular toxicity of NMs in humans andaquatic organisms, human vascular endothelial cells (HECV) and immune cells (hemocytes) of the marineinvertebrate, the mussel Mytilus spp , respectively. Parallel studies were carried out using N-doped n-TiO 2 .The results indicate both distinct and common behavior (agglomeration state) in different media (humancell culture medium and mussel hemolymph serum) and biological effects (cytotoxicity, nitric oxide production)of different types of doped- n-TiO 2 in different cell models. Although in vitro studies represent a first step in the toxicological assessment of NMs, studies comparing their effects on human and aquatic invertebrate cells that take into account the effects of different exposure media represent an useful tool for evaluating potential cytotoxicity of those NMs, like TiO 2 -based photocatalytic NMs, widely applied in environmental remediation, and whose potential risks are poorly understood.