The Effects of Titanium Dioxide Nanoparticles on Osteoblasts Mineralization: A Comparison between 2D and 3D Cell Culture Models

Gabriela de Souza Castro; Wanderson de Souza; Thais Suelen Mello Lima; Danielle Cabral Bonfim; Jacques Werckmann; Braulio Soares Archanjo; José Mauro Granjeiro; Ana Rosa Ribeiro; Sara Gemini-Piperni

doi:10.3390/nano13030425

The Effects of Titanium Dioxide Nanoparticles on Osteoblasts Mineralization: A Comparison between 2D and 3D Cell Culture Models

Nanomaterials (Basel). 2023 Jan 20;13(3):425. doi: 10.3390/nano13030425.

Authors

Gabriela de Souza Castro¹, Wanderson de Souza², Thais Suelen Mello Lima², Danielle Cabral Bonfim³, Jacques Werckmann⁴, Braulio Soares Archanjo⁵, José Mauro Granjeiro², Ana Rosa Ribeiro⁶, Sara Gemini-Piperni^{1

7}

Affiliations

¹ Postgraduate Program in Odontology, Unigranrio, Duque de Caxias 25071-202, Brazil.
² Directory of Life Sciences Applied Metrology, National Institute of Metrology Quality and Technology, Rio de Janeiro 25250-020, Brazil.
³ LabCeR Group, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro 21941-901, Brazil.
⁴ Visitant Professor at Brazilian Center for Research in Physics, Rio de Janeiro 22290-180, Brazil.
⁵ Materials Metrology Division, National Institute of Quality and Technology, Rio de Janeiro 25250-020, Brazil.
⁶ NanoSafety Group, International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal.
⁷ Labεn Group, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro 21941-901, Brazil.

Abstract

Although several studies assess the biological effects of micro and titanium dioxide nanoparticles (TiO₂ NPs), the literature shows controversial results regarding their effect on bone cell behavior. Studies on the effects of nanoparticles on mammalian cells on two-dimensional (2D) cell cultures display several disadvantages, such as changes in cell morphology, function, and metabolism and fewer cell-cell contacts. This highlights the need to explore the effects of TiO₂ NPs in more complex 3D environments, to better mimic the bone microenvironment. This study aims to compare the differentiation and mineralized matrix production of human osteoblasts SAOS-2 in a monolayer or 3D models after exposure to different concentrations of TiO₂ NPs. Nanoparticles were characterized, and their internalization and effects on the SAOS-2 monolayer and 3D spheroid cells were evaluated with morphological analysis. The mineralization of human osteoblasts upon exposure to TiO₂ NPs was evaluated by alizarin red staining, demonstrating a dose-dependent increase in mineralized matrix in human primary osteoblasts and SAOS-2 both in the monolayer and 3D models. Furthermore, our results reveal that, after high exposure to TiO₂ NPs, the dose-dependent increase in the bone mineralized matrix in the 3D cells model is higher than in the 2D culture, showing a promising model to test the effect on bone osteointegration.

Keywords: 3D spheroids; TiO2 NPs; osteoblasts; titanium dental implants.

Grants and funding

This work was supported by National Council for Scientific and Technological Development (CNPq) with grants 405030/2015-0, 306672/2016-2, and 467513/2014-7. J.M.G. thanks the Cientista do Nosso Estado award from FAPERJ and CNPq/Faperj—National Institute of Science and Technology in Regenerative Medicine (INCT-Regenera, process n. 465656/2014-5). A.R.R. thanks the Sinfonia project H2020 of the European Union (N.857253).