Biological impact of modified inhalable carbon black nanoparticles assessed in cell and tissue culture models

Carbon black nanoparticles (CBNP) have a large surface area to volume ratio and potentially cause adverse health effects after inhalative exposure. Biological effects of four CBNP modifications with different surface properties were assessed in human pulmonary cell lines (16HBE14o-, Calu-3, A549) and precision cut lung slices (PCLS) of mice, rats and humans. Viability was assessed by LIVE/DEAD® staining and WST-1/8 assay. Pro-inflammatory immune responses in PCLS were quantified using ELISA. CBNP-induced formation of reactive oxygen species (ROS) was assessed by flow cytometry using the DCFH-DA assay. The effect of CBNP exposure on transepithelial electrical resistance (TEER) was investigated in Calu-3 cells. CBNP Printex® 90, acetylene soot, and benzo[a]pyrene nanoparticles were nearly non toxic in cell lines and PCLS. However, the dose-response relationships varied considerably between cell lines. 9-Nitroanthracene Printex 90 showed a toxic effect at 50 g/ml in PCLS. The inflammatory response was assessed in tissue lysate and decreased intracellular cytokine concentration. Increased ROS formation was observed in cell lines with all CBNP tested. TEER reduction was observed with all CBNP tested with acetylene soot particles being most effective. The combination of cell and tissue culture models is useful to assess the acute effects of nanomaterials on lungs.