Contact-dependent transfer of TiO₂nanoparticles between mammalian cells

Abstract

Cellular organelles have been shown to shuttle between cells in co-culture. We hereby show that titanium dioxide (TiO2) nanoparticles (NPs) can be transferred in such a manner, between cells in direct contact, along with endosomes and lysosomes. A co-culture system was employed for this purpose and the NP transfer was observed in mammalian cells including normal rat kidney (NRK) and HeLa cells. We found that the small GTPase Arf6 facilitates the intercellular transfer of smaller NPs and agglomerates. Spherical, anatase nano-TiO2 with sizes of 5 (Ti5) and 40 nm (Ti40) were used in this study. Humans are increasingly exposed to TiO2 NPs from external sources such as constituents of foods, cosmetics, and pharmaceuticals, or from internal sources represented by Ti-based implants, which release NPs upon abrasion. Exposure to 5 mg/l of Ti5 and Ti40 for 24 h did not affect cellular viability but modified their ability to communicate with surrounding cells. Altogether, our results have important implications for the design of nanomedicines, drug delivery and toxicity.

TiO2 nanoparticles disrupt cell adhesion and the architecture of cytoskeletal networks of human osteoblast‐like cells in a size dependent manner

“…and ), and the smaller particle, that is, Ti5, was clearly associated with larger agglomerates and more adverse effects indicating that different NP sizes may elicit different toxicity responses. This was consistent with previous reports from our lab with regard to the uptake of Ti5 particles by different cell types . Internalization of both particles was associated with morphological changes in SaOS‐2 and the NP‐treated cells appeared smaller in size and in association with Ti5, the cells had a higher aspect ratio.…”

“…This was consistent with previous reports from our lab with regard to the uptake of Ti5 particles by different cell types. 10,32 Internalization of both particles was associated with morphological changes in SaOS-2 and the NP-treated cells appeared smaller in size and in association with Ti5, the cells had a higher aspect ratio.…”

“…However, upon abrasion of the titanium dioxide (TiO 2 ) layer formed on implants’ surfaces, TiO 2 particles ranging from nano‐ to micron‐sizes can be released, which may lead to adverse effects . Being nondegradable, TiO 2 particles can represent a long‐term hazard when released in tissues and previous reports from our lab reported cellular uptake and transfer of these particles between cells via endosomes and lysosomes . Furthermore, studies have also reported the presence of nano‐TiO 2 in distant sites and organs .…”

“…[5][6][7][8][9] Being nondegradable, TiO 2 particles can represent a long-term hazard when released in tissues and previous reports from our lab reported cellular uptake and transfer of these particles between cells via endosomes and lysosomes. 10 Furthermore, studies have also reported the presence of nano-TiO 2 in distant sites and organs. 11,12 The effects of different nanoparticles (NPs) on cells and their cytoskeletal components have been demonstrated previously in various types of cells, including: mesenchymal stem cells, epithelial cells, fibroblasts, neural cells, and endothelial cells.…”

High throughput toxicity screening and intracellular detection of nanomaterials

“…It was demonstrated that TiO 2 78, 79, 80 and Ag81 NMs induce an increase of SS signal in cell populations after exposure to both NMs. SS indicates the granularity of the cells and is strongly linked to their content of NMs.…”