Shape and surface properties of titanate nanomaterials influence differential cellular uptake behavior and biological responses in THP-1 cells

Abstract

We investigated cellular uptake behavior and biological responses of spherical and fibrous titanate nanomaterials in human monocyte THP-1 cells. Two titanate nanofibers (TiNFs), namely TF-1 and TF-2, were synthesized from anatase TiO2 nanoparticles (TNPs) via hydrothermal treatment. The synthesized TiNFs and TNPs were thoroughly characterized for their size, crystallinity, surface area and surface pH. TF-1 (∼2 µm in length) was amorphous with an acidic surface, while TF-2 (∼7 µm in length) was brookite with a basic surface. The results demonstrated that none of these titanate nanomaterials resulted in significant cytotoxicity, even at the highest doses tested (50 µg/ml), consistent with an absence of ROS generation and lack of change of mitochondrial membrane potential. While no cytotoxic effect was found in the titanate nanomaterials, TF-2 tended to decrease the proliferation of THP-1 cells. Furthermore, TF-2 resulted in an inflammatory cytokine response, as evidenced by dramatic induction of IL-8 and TNF-α release in TF2 but not TF-1 nor TNPs. These results suggest that shape of titanate nanomaterials plays an important role in cellular internalization, while surface pH may play a prominent role in inflammatory response in THP-1 cells.

Metal nanomaterials: Immune effects and implications of physicochemical properties on sensitization, elicitation, and exacerbation of allergic disease

“…Subsequent activation of the p38 MAPK signaling pathway, alterations in expression of HMOX1 and other oxidative stress genes have also been used as in vitro biomarkers suggestive of sensitizing potential. Numerous metal nanomaterials have been associated with these effects on THP-1 cells, which suggests their potential to activate DC and promote sensitization (Mohamed et al 2011; Khatri et al 2013; McConnachie et al 2013; Boonrungsiman et al 2017).…”

Nanoparticles: a Novel Approach for Sustainable Agro-productivity

“…So, these nanomaterials could be released into the soils, waters, air, and interact with the biological tissues because of their small size as well as the high surface activity (Holden et al 2013). Therefore, there is an urgent need to follow different biological responses related to both human health and the ecological safety (Oomen et al 2014;Syberg and Hansen 2016;Boonrungsiman et al 2017). Different investigations regarding the adverse effects of nanomaterials have been carried out including the biological, medical and terrestrial environments (Hu et al 2016;Kwak and An 2016;Mattsson and Simkó 2016).…”

Strategies for the enhanced intracellular delivery of nanomaterials

“…In addition, the surface pH influences the affinity, agglomeration, and aggregation of nanomaterials. According to some results, surface pH affects phagocytosis and cellular homeostasis, whereby TF-2 was able to trigger inflammatory responses at acid pH whereas TF-1, with a basic pH, suppressed the release of cytokines [86]. In terms of cellular internalization, nanocrystals enter cells through passive diffusion [87] or even by endocytosis [88,89].…”