China
Africa
Explore chapters and articles related to this topic
Reconstituted 2D Cell and Tissue Models
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Nicole Schneider-Daum, Patrick Carius, Justus C. Horstmann, Claus-Michael Lehr
First described some 20 years ago, Cultex Systems have meanwhile developed to a commercially available system for controlled aerosol deposition in ALI conditions. Originally described as an innovative device for cell culture on Transwell inserts at ALI conditions (Aufderheide and Mohr 1999, 2000), the application of gaseous compounds (Ritter et al. 2001), diesel exhaust (Knebel et al. 2002), and cigarette smoke (Aufderheide et al. 2001) were evaluated thereafter. This first generation is made of glass, containing three individual housings for Transwell inserts. Continuous temperature control via water and medium supply are controlled individually. The air flows on cell cultures through a cylindrical structure and exits at the sides to flow back. A second generation device called Cultex Radial Flow System (RFS) generates more consistent particle distribution, as the air flows equally on the cell culture inserts, not in a row like in the first generation (Aufderheide et al. 2017). Experiments have mainly been conducted with different inorganic material, cigarette or e-cigarette aerosol (Aufderheide and Emura 2017). A modified Cultex system presented an enhanced module with hyperboloid-shaped air exposition inlets, improving air flow, and preventing swirls (Aufderheide and Mohr 2004). Later, Vitrocell® developed a range of exposure systems for small to higher throughput. Typical applications are exposure to nanoparticles, gases, and complex mixtures, like in a comparison between cigarette and e-cigarette aerosol (Neilson et al. 2015).
Dihydroxyacetone levels in electronic cigarettes: Wick temperature and toxin formation
Published in Aerosol Science and Technology, 2018
Shawna Vreeke, Tetiana Korzun, Wentai Luo, R. Paul Jensen, David H. Peyton, Robert M. Strongin
The e-cigarette aerosol consists of aerosol droplets suspended in the gas phase (Pankow 2014). The aerosol produced from the e-cigarette was passed through a dry cold trap (−76°C ± 2°C), followed by an impinger of solvent, a 0.45 μm pore size syringe filter, and a CH Technologies single cigarette smoking machine (SCSM-STEP). Each vaping session consisted of 10 puffs. The SCSM-STEP was set to the CORESTA program, which has a square shape puff profile, 3 s puff period, 30 s puff interval, and a 55 mL puff volume. For this study (vide supra), the puff interval was set to 3 min by disconnecting the filter from the smoking machine after each puff. Each device was set at varying wattages, within manufacturer's recommendations. EC1 was tested (at a minimum) in triplicate at 6 watts, 10 watts, and 15 watts. EC2 was tested (at a minimum) in triplicate at 5 watts, 10 watts, and 15 watts. EC3 was tested (at a minimum) in triplicate at 20 watts, 30 watts, 40 watts, and 50 watts. After each puff, the solvent from the impinger was used to collect and rinse the aerosols that had condensed inside the cold trap. For analysis by NMR, the impinger was filled with 0.6 mL DMSO-d6. Post aerosolization, 0.425 mL of the DMSO-d6 rinse was collected into a Wilmad® 400 MHz NMR tube. 20 µL of 9.7 mM 2,3,5,6-tetrachloro-4-nitrobenzene prepared in DMSO-d6 was added as an internal standard. For analysis by GC/MS, the impinger was filled with 2.0 mL HPLC-grade acetone. Post aerosolization, 1.5 mL of acetone from the impinger was used to rinse the cold trap, and 1.0 mL of the rinse was collected into an amber glass screw top vial. 20 µL of 11 mM 1,2,3-trichlorobenzene prepared in HPLC grade isopropanol (IPA) was added as an internal standard.