Micro- and nanoplastics from dental restorative materials: studies on cell biological effects

• Applicants: Professorin Dr. Olga Polydorou; Professor Dr. Pascal Tomakidi
• Subject Area: Dentistry, Oral Surgery
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 467572288

In the context of nano-safety research, the aspect of bioefficacy of nanoplastics is currently gaining in importance, also from a health policy perspective. So far, there are no results on the cell biological effects of microplastic (MP) and nanoplastic (NP) particles from dental restorative materials on exposure-relevant target cells, including the epithelial keratinocytes of the gingiva (HGK). Against this as yet unexplained background, the hypothesis of the proposal is that MP and NP particles as well as eluates generated from them from dental restorative materials exert biological effects on HGK and that these effects manifest themselves in a modulation of such important cell functions as (i) proliferation and (ii) differentiation as well as (iii) inflammation. To test this hypothesis, MP and NP particles generated from restorative materials by dental grinding processes are first determined in their size distribution and chemical composition and then prepared so that they can be added to monolayer cultures of HGK in different size fractions and concentrations and for different exposure times, together with eluates derived from them. The interaction of MP and NP particles with HGK will be analysed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The evaluation of the modulation of cellular functions will be performed using established, standardised methods for cellular localisation, quantification of gene and protein expression, and activation/phosphorylation of cell function-relevant biomarker molecules. By using specific inhibitors and specific siRNA, the role of the respective signalling molecule for the exposure-induced modulation of the cell function under investigation will be elucidated. Insights into the identification of such hitherto unknown cell biological effects can be of great benefit in the future to better understand and thus better assess the effect of MP and NP particles and their eluates from dental restorative materials on the function of cells and thus the physiology of tissues of the human body.

• DFG Programme: Research Grants