Differences in cytotoxicity of lung epithelial cells exposed to titanium dioxide nanofibers and nanoparticles: Comparison of air-liquid interface and submerged cell cultures

Toxicological effects of zinc oxide nanoparticle exposure: an in vitro comparison between dry aerosol air-liquid interface and submerged exposure systems

“…Increased expression of multiple cytokines, for example IL-8, in hAELVi (human alveolar epithelial lentivirus immortalized) cells was seen in Mills-Goodlet et al, but where similar dose levels as in the current study were used. However, two other studies showed similar cellular responses in both ALI and submerged cultures, except for in the release of LDH, where higher levels were found in the ALI cultures (Cappellini et al 2020;Medina-Reyes et al 2020). These similarities were seen even though several study parameters varied between the two studies.…”

“…To ensure that the ALI exposure systems can be used for NP exposures, each system needs to be evaluated with different categories of NPs, and comparative studies between traditionally submerged and ALI exposure systems need to be performed. Multiple ALI systems have already been used in such comparative studies, for example MINUCELL (Lenz et al 2013), VITROCELL (Xie et al 2012;Panas et al 2014;Mihai et al 2015;Loret et al 2016;Hilton et al 2019;Medina-Reyes et al 2020;Mills-Goodlet et al 2020), XposeALI (Cappellini et al 2020), and ALICE (Lenz et al 2009;Stoehr et al 2015), and most of them have reported more pronounced effects with the ALI exposure systems than with the submerged at similar dose levels. However, a comparison between the NACIVT system and traditional submerged exposure systems has not previously been performed.…”

In Vitro Toxicity of Industrially Relevant Engineered Nanoparticles in Human Alveolar Epithelial Cells: Air–Liquid Interface versus Submerged Cultures

“…Hydrodynamic size and concentration (number of particles/mL) of the aqueous ENP suspensions under study were determined by Dynamic Light Scattering using a ZetaSizer Ultra (Malvern Panalytical, Malvern, UK) and Nanoparticle Tracking Analysis (NTA) using a NanoSight LM20 (NANOSIGHT Ltd., Salisbury, UK), respectively. The effective density of ENP suspensions was determined by measuring the pellet volume of the ENP stock suspensions after centrifugation at 2000× g for 2 h at 20 • C. In addition, the ENP oxidative potential (acellular ROS production) was determined by Electron Spin Resonance (ESR) based on the trapping of NP-induced hydroxyl radicals (OH) generated in the presence of hydrogen peroxide (H 2 O 2 ) using DMPO (5,5-dimethyl-1-pyrroline-N-oxide) as spin trap, as previously described [39]. Briefly, NP suspensions were mixed with 0.5 M H 2 O 2 and 0.05 M DMPO, followed by incubation for 15 min at 37 • C in a heated shaking water bath prior to ESR (MS400, Magnettech GmbH, Berlin, Germany) analysis.…”

“…Cellular models cultured under air-liquid interface (ALI) conditions, where aerosolised particles are directly delivered onto the cells' surface, are regarded as a more realistic and relevant exposure system, offering a valuable alternative to the traditional submerged cultures [33,36], although most of the in vitro toxicology laboratories worldwide are not equipped to conduct these studies as dedicated equipment and aerosol technology is needed. Notwithstanding, several studies to assess the pulmonary toxicity of ENM under submerged and ALI conditions have been already conducted and showed that ENM hazard might be different depending on the exposure conditions [37][38][39][40].…”

Agglomeration State of Titanium-Dioxide (TiO2) Nanomaterials Influences the Dose Deposition and Cytotoxic Responses in Human Bronchial Epithelial Cells at the Air-Liquid Interface

“…However, the entire study was carried out in submerged exposure conditions. While there is only a limited number of toxicological investigations addressing adverse effects of TiO 2 NMs using ALI exposure systems [31,36,37], the impact of agglomeration has not been researched. Here, we prepared TiO 2 NM agglomerates of different sizes and performed toxicological studies employing ALI exposure.…”