Potential in vitro model for testing the effect of exposure to nanoparticles on the lung alveolar epithelial barrier

Abstract

Pulmonary barrier function plays a pivotal role in protection from inhaled particles. However, some nano-scaled particles, such as carbon nanotubes (CNT), have demonstrated the ability to penetrate this barrier in animal models, resulting in an unusual, rapid interstitial fibrosis. To delineate the underlying mechanism and specific bio-effect of inhaled nanoparticles in respiratory toxicity, models of lung epithelial barriers are required that allow accurate representation of in vivo systems; however, there is currently a lack of consistent methods to do so. Thus, this work demonstrates a well-characterized in vitro model of pulmonary barrier function using Calu-3 cells, and provides the experimental conditions required for achieving tight junction complexes in cell culture, with trans-epithelial electrical resistance measurement used as a biosensor for proper barrier formation and integrity. The effects of cell number and serum constituents have been examined and we found that changes in each of these parameters can greatly affect barrier formation. Our data demonstrate that use of 5.0 × 104 Calu-3 cells/well in the Transwell cell culture system, with 10% serum concentrations in culture media is optimal for assessing epithelial barrier function. In addition, we have utilized CNT exposure to analyze the dose-, time-, and nanoparticle property-dependent alterations of epithelial barrier permeability as a means to validate this model. Such high throughput in vitro cell models of the epithelium could be used to predict the interaction of other nanoparticles with lung epithelial barriers to mimic respiratory behavior in vivo, thus providing essential tools and bio-sensing techniques that can be uniformly employed.

The Synergistic and Neuroprotective Effects of Alcohol–Antioxidant Treatment on Blood–Brain Barrier Endothelial Cells

“…These control monolayers were not exposed to any of the experimental compounds. The culture media were supplemented with 10% FBS, as TEER values using this concentration of FBS remained consistent for longer in addition to aiding the proliferation of cells (Derk et al, 2015). 1 9 10 6 bEnd5 cells (Sigma, 96091930) were seeded per well on sterile inserts (Microsep, PIHA012) and grown to confluence for 24 hours in clear 24-well tissue culture plates (n = 6).…”

In Vitro Methods for Assessing Nanoparticle Toxicity

“…6. If nanoparticles permeate across the barrier and tear the junctions or if construction of the junction is otherwise impaired, the acquired TEER value is typically observed to decrease from the range of 500-2000 Ω/cm 2 to less than 500 Ω/cm 2 [57]. Isolating the apical and basolateral compartment concentrations of nanoparticles as a function of time following barrier exposure effectively relates the permeability of the epithelial membrane with respect to the tested nanoparticles [58], and incorporation of the particle translocation tendency with TEER results can decide whether the particles are constructed to innately bypass the junction or whether the transmission occurs as a result of nanoparticle-induced membrane rupture.…”

“…Confocal microscopy images of ZO-1 (green) and DAPI (blue) stained junctions and nuclei, respectively, display monolayer formation as a function of increased TEER resistance (b). Reproduced from [57]. https:/creativecommons.org/licenses/by-ncnd/4.0/ Cytotoxicity of curcumin and curcumin nanogels (CNGs) for human umbilical vein endothelial cells (HUVECs) following 24 h of treatment at specified concentrations.…”

The impact of nanomaterial characteristics on inhalation toxicity

“…233,[249][250][251] Recent application fields for BEAS-2B cells cover investigations regarding the toxicity of e-cigarettes and environmental particulate matter. Oeder et al showed with their metabolomics and transcriptomics study that diesel fuel and heavy fuel oil can change many cellular processes like protein biosynthesis, 249 In addition to the above-mentioned cell lines, other bronchial cell lines such as Calu-3 252,253 and 16HBE14o-are also applied to study the interactions of lung cells with nanoparticles. 241,254 Since the deposition of nano-sized airborne material primarily occurs in the alveolar region and subsequent retention or translocation is one of the key factors for toxicological risks of ENMs, alveolar epithelia cell models may represent a suitable model for the toxicity testing of inhalable ENMs.…”