Comparative assessment of threein vitro exposure methods for combustion toxicity

Abstract

A comparative assessment of three approaches for the use of human cells in vitro to investigate combustion toxicity was conducted. These included one indirect and two direct (passive and dynamic) exposure methods. The indirect method used an impinger system in which culture medium was used to trap the toxicants, whilst the direct exposure involved the use of a Horizontal Harvard Navicyte Chamber at the air/liquid interface. The cytotoxic effects of thermal decomposition products were assessed using the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay (Promega) on a selection of human cells including: HepG2, A549 and skin fibroblasts. A small scale laboratory fire test using a vertical tube furnace was designed for the generation of combustion products. Polymethyl methacrylate (PMMA) was selected as a model polymer to study the cytotoxic effects of combustion products. NOAEC (no observable adverse effect concentration), IC10 (10% inhibitory concentration), IC50 (50% inhibitory concentration) and TLC (total lethal concentration) values were determined from dose response curves. Assessment using the NRU (neutral red uptake) and ATP (adenosine triphosphate) assays on human lung derived cells (A549) was also undertaken. Comparison between in vitro cytotoxicity results against published toxicity data for PMMA combustion and predicted LC50 (50% lethal concentration) values calculated from identified compounds using GCMS (gas chromatography mass spectrometry) was determined. The results suggested that the indirect exposure method did not appear to simulate closely exposure via inhalation, whilst exposure at the air/liquid interface by using the dynamic method proved to be a more representative method of human inhalation. This exposure method may be a potential system for in vitro cytotoxicity testing in combustion toxicity.

Exposure of aerosols and nanoparticle dispersions to in vitro cell cultures: A review on the dose relevance of size, mass, surface and concentration

“…Therefore, additional steps towards mimicking the in vivo exposure have to be taken. In the case of combustion-derived nanoparticles such as diesel soot (Kittelson, 1998), in vitro air-exposure systems are well established (Aufderheide and Mohr, 2000;Gasser et al, 2009;Holder, Lucas, Goth-Goldstein, and Koshland, 2008;Knebel, Ritter, and Aufderheide, 2002;Lestari, Markovic, Green, Chattopadhyay, and Hayes, 2006;Paur, Mulhopt, Weiss, and Diabate, 2008;Seagrave et al, 2007;Tippe, Heinzmann, and Roth, 2002). In addition air-liquid exposure systems for engineered nanoparticles have been very recently developed (Brandenberger et al, 2010;Lenz et al, 2009).…”

In Vitro biological toxicity assessments for fire combustion products

“…The furnace ( Fig. 3,5 The furnace consisted of a vertical furnace, a load cell and a polycarbonate chamber for mixing and measurement.…”

“…3 The combustion products were bubbled through a standard hygiene sampling impinger containing serum-free culture medium at a controlled flow rate using a personal air sampling pump (SKC, USA), usually with a 30 min exposure period. The indirect exposure method uses the culture medium to trap the combustion toxicants.…”

“…The indirect exposure method uses the culture medium to trap the combustion toxicants. 3 Direct exposure (passive and dynamic) 3 The combustion products were bubbled through a standard hygiene sampling impinger containing serum-free culture medium at a controlled flow rate using a personal air sampling pump (SKC, USA), usually with a 30 min exposure period.…”

Development of an in vitro Batch-type Closed Gas Exposure Device with an Alveolar Epithelial Cell Line, A549, for Toxicity Evaluations of Gaseous Compounds

“…[5][6][7][8][9][10][11][12] Some of the devices have been applied to evaluate the toxicities for actual environmental gases, such as cigarette smoke, 8,9 diesel exhaust emission, 10 and combustion gas. 11 However, since most devices reported previously are large scale and continuous flow-based systems, several handled liters of sample gases are necessary. Accordingly, the flexibility of these systems is likely to be low when we consider the evaluation of a wide range of pure gaseous chemicals or samples emitted to various environments.…”