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liquid interface cell exposure system
Abstracts / Toxicology Letters 238S (2015) S56–S383
P07-058 Toxicological validation during the development of new catalytic systems using air/liquid interface cell exposure system Y. Landkocz 1,∗ , M. Al Zallouha 1 , J. Brunet 1 , R. Cousin 1 , J.M. Halket 2 , E. Genty 1 , D. Courcot 1 , S. Siffert 1 , P. Shirali 1 , S. Billet 1 1 2
UCEIV, Chemistry and Toxicology, Dunkerque, France King’s College, Mass Spectrometry Facility, London, United Kingdom
Question: Volatile Organic Compounds (VOCs), including Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) are industrial solvents frequently used and emitted into the atmosphere. Toluene is one of the most used despite its major and direct impact on human health. It is therefore fundamental to minimize emissions directly at source. Catalytic oxidation represents an efficient remediation technique in order to reduce its emission directly at the source, but can release byproducts. Catalyst performance is usually evaluated using dedicated analytical chemistry methods measuring VOC conversion or CO2 emission. Methods: In this study, two catalysts Pd/␣-Al2 O3 and Pd/␥-Al2 O3 were toxicologically tested in order to determine the most efficient one for toluene oxidation. The two catalytic systems were thus coupled to Air-Liquid Interface (ALI) system Vitrocell® , to expose human A549 lung cells during 1 h to toluene or to exhaust from toluene catalytic oxidation. Following the exposure, gene expression of nine proteins implied in the organic compounds metabolisation in lung cells were conducted to validate the most effective catalyst for toluene remediation. Results: Both exposure concentrations (i.e. 10 and 100% of catalytic emission) resulted in increased gene expression of Xenobiotic Metabolising Enzymes (XMEs) (CYP2E1, CYP2S1, CYP1A1, CYP1B1, EPHX1 and NQO1). Some of these XMEs are known to be induced by polycyclic organic compounds conventionally not searched during the development of catalysts for VOCs degradation. The increase in gene expression suggests the presence of undetected compounds whose toxicity must be assessed before the adoption of new catalyst. This enhances the relevance of toxicological validation of such systems before scaling-up and marketing. Conclusions: This study validated in a first step the suitability of using Vitrocell® system as an innovative, direct and dynamic model of ALI exposure in the development of new catalysts, showing the presence of chemically undetected byproducts. In a second step, the comparison of the two catalysts showed that less organic compounds metabolizing genes were induced with Pd/␥-Al2 O3 making it more efficient than Pd/␣-Al2 O3 for toluene remediation. http://dx.doi.org/10.1016/j.toxlet.2015.08.556
P07-059 Generation of a reproducible and stable atmosphere charged of VOC mixture suitable for exposure at air–liquid interface B. Gaelle 1,∗ , A. sophie 1 , D. Valérie 2 , I. Momas 1 , S. Nathalie 1 1 2
Public health laboratory, EA 4064, Paris, France Ecole des Mines Alès, Pau, France
Volatile Organic Compounds (VOC) mostly emitted from human activities and building materials are widely present in indoor environments of developed countries. Some evidences highlight associations between indoor VOC exposures and the occurrence of airway disorders, such as asthma. To strengthen biological proofs,
S193
application of realistic atmosphere containing VOCs to in vitro suitable systems able to mimic human exposure reality need to be provided. The main objective of this work was to generate a reproducible and stable atmosphere, charged of a VOC mixture emitted by paints, in order to assess the impact of such environmental mixture on respiratory health using in vitro experiments. The protocol for generation of the VOC mixture atmosphere was adapted from the standard NF EN ISO 16000-11 concerning determination of the emission of VOCs, products of construction and furnishing in indoor air. All parameters (amount of paint, surface deposits) were calculated in accordance with this standard. A commercial aqueous domestic-paint was used in this study. The control of the stability of the generated atmosphere was conducted by sampling using SPME fibers once per day during 7 days and GC–MS analysis. The results indicated that whatever the device used the atmosphere remained stable during six days. This protocol was applied to our in vitro model, a human reconstituted nasal epithelium (hRNE). hRNE were exposed at air-liquid interface twice a week during 1 h at 24 h intervals during three weeks. The VOC atmosphere was renewed every week. Biological effects of exposures were assessed at different times of the experiment by cytokine production measurements (IL-8, IL-6 and GM-CSF) in the culture medium on basal epithelium side, and Trans Epithelial Electrical Resistance (TEER) measurement as tissular integrity parameter. Interestingly, during all the experimental period, no change was observed in TEER measurements, as well as in cytokine production during VOC exposure compared with air exposure. These results need confirmation and could be related with the composition of the water-based paint that we tested and contained 3 VOC: Propylene glycol, Texanol A and B. The protocol of generation and control of atmosphere with complex VOC mixture could be useful for risk assessment of respiratory effect due to air pollution. http://dx.doi.org/10.1016/j.toxlet.2015.08.557
P07-060 Organotypic in vitro human small intestinal tissue models to assess drug toxicity and permeation S. Ayehunie 1 , Z. Stevens 1 , T. Landry 1 , M. Tami 2 , M. Klausner 1 , P. Hayden 1,∗ 1 2
MatTek Corp, Ashland, United States Cyprotex, Watertown, United States
Development of reliable and reproducible primary human cell based small intestinal (SMI) tissue models that recapitulate in vivo SMI tissue phenotype, structure and function are critically needed to study gastrointestinal (GI) permeation, drug toxicity and inflammation. The validity of commonly used Caco-2 cell models is questionable due to a lack of physiological relevance and animal models often fail to predict human responses. This study describes development of 3D SMI models from primary human SMI epithelial cells and fibroblasts. Long term culture of the models and application for drug toxicity and drug permeation studies are demonstrated. The utility of the reconstructed SMI tissue models for GI drug toxicity studies was evaluated using the GI toxicant drug, indomethacin. Outcome measurements include transepithelial electrical resistance (TEER), histology and apical protein washes (sloughed epithelium). Drug permeation studies were performed using 8 drugs that utilize specific transporters (Pgp, BCRP, MRP-2, etc.). Uptake or efflux transport was analyzed by LC–MS/MS. Specific findings include: 1) The SMI tissue models can be cultured for extended time (up to 28 days) with no significant change in TEER
P07-058 Toxicological validation during the development of new catalytic systems using air/liquid interface cell exposure system Y. Landkocz 1,∗ , M. Al Zallouha 1 , J. Brunet 1 , R. Cousin 1 , J.M. Halket 2 , E. Genty 1 , D. Courcot 1 , S. Siffert 1 , P. Shirali 1 , S. Billet 1 1 2
UCEIV, Chemistry and Toxicology, Dunkerque, France King’s College, Mass Spectrometry Facility, London, United Kingdom
Question: Volatile Organic Compounds (VOCs), including Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) are industrial solvents frequently used and emitted into the atmosphere. Toluene is one of the most used despite its major and direct impact on human health. It is therefore fundamental to minimize emissions directly at source. Catalytic oxidation represents an efficient remediation technique in order to reduce its emission directly at the source, but can release byproducts. Catalyst performance is usually evaluated using dedicated analytical chemistry methods measuring VOC conversion or CO2 emission. Methods: In this study, two catalysts Pd/␣-Al2 O3 and Pd/␥-Al2 O3 were toxicologically tested in order to determine the most efficient one for toluene oxidation. The two catalytic systems were thus coupled to Air-Liquid Interface (ALI) system Vitrocell® , to expose human A549 lung cells during 1 h to toluene or to exhaust from toluene catalytic oxidation. Following the exposure, gene expression of nine proteins implied in the organic compounds metabolisation in lung cells were conducted to validate the most effective catalyst for toluene remediation. Results: Both exposure concentrations (i.e. 10 and 100% of catalytic emission) resulted in increased gene expression of Xenobiotic Metabolising Enzymes (XMEs) (CYP2E1, CYP2S1, CYP1A1, CYP1B1, EPHX1 and NQO1). Some of these XMEs are known to be induced by polycyclic organic compounds conventionally not searched during the development of catalysts for VOCs degradation. The increase in gene expression suggests the presence of undetected compounds whose toxicity must be assessed before the adoption of new catalyst. This enhances the relevance of toxicological validation of such systems before scaling-up and marketing. Conclusions: This study validated in a first step the suitability of using Vitrocell® system as an innovative, direct and dynamic model of ALI exposure in the development of new catalysts, showing the presence of chemically undetected byproducts. In a second step, the comparison of the two catalysts showed that less organic compounds metabolizing genes were induced with Pd/␥-Al2 O3 making it more efficient than Pd/␣-Al2 O3 for toluene remediation. http://dx.doi.org/10.1016/j.toxlet.2015.08.556
P07-059 Generation of a reproducible and stable atmosphere charged of VOC mixture suitable for exposure at air–liquid interface B. Gaelle 1,∗ , A. sophie 1 , D. Valérie 2 , I. Momas 1 , S. Nathalie 1 1 2
Public health laboratory, EA 4064, Paris, France Ecole des Mines Alès, Pau, France
Volatile Organic Compounds (VOC) mostly emitted from human activities and building materials are widely present in indoor environments of developed countries. Some evidences highlight associations between indoor VOC exposures and the occurrence of airway disorders, such as asthma. To strengthen biological proofs,
S193
application of realistic atmosphere containing VOCs to in vitro suitable systems able to mimic human exposure reality need to be provided. The main objective of this work was to generate a reproducible and stable atmosphere, charged of a VOC mixture emitted by paints, in order to assess the impact of such environmental mixture on respiratory health using in vitro experiments. The protocol for generation of the VOC mixture atmosphere was adapted from the standard NF EN ISO 16000-11 concerning determination of the emission of VOCs, products of construction and furnishing in indoor air. All parameters (amount of paint, surface deposits) were calculated in accordance with this standard. A commercial aqueous domestic-paint was used in this study. The control of the stability of the generated atmosphere was conducted by sampling using SPME fibers once per day during 7 days and GC–MS analysis. The results indicated that whatever the device used the atmosphere remained stable during six days. This protocol was applied to our in vitro model, a human reconstituted nasal epithelium (hRNE). hRNE were exposed at air-liquid interface twice a week during 1 h at 24 h intervals during three weeks. The VOC atmosphere was renewed every week. Biological effects of exposures were assessed at different times of the experiment by cytokine production measurements (IL-8, IL-6 and GM-CSF) in the culture medium on basal epithelium side, and Trans Epithelial Electrical Resistance (TEER) measurement as tissular integrity parameter. Interestingly, during all the experimental period, no change was observed in TEER measurements, as well as in cytokine production during VOC exposure compared with air exposure. These results need confirmation and could be related with the composition of the water-based paint that we tested and contained 3 VOC: Propylene glycol, Texanol A and B. The protocol of generation and control of atmosphere with complex VOC mixture could be useful for risk assessment of respiratory effect due to air pollution. http://dx.doi.org/10.1016/j.toxlet.2015.08.557
P07-060 Organotypic in vitro human small intestinal tissue models to assess drug toxicity and permeation S. Ayehunie 1 , Z. Stevens 1 , T. Landry 1 , M. Tami 2 , M. Klausner 1 , P. Hayden 1,∗ 1 2
MatTek Corp, Ashland, United States Cyprotex, Watertown, United States
Development of reliable and reproducible primary human cell based small intestinal (SMI) tissue models that recapitulate in vivo SMI tissue phenotype, structure and function are critically needed to study gastrointestinal (GI) permeation, drug toxicity and inflammation. The validity of commonly used Caco-2 cell models is questionable due to a lack of physiological relevance and animal models often fail to predict human responses. This study describes development of 3D SMI models from primary human SMI epithelial cells and fibroblasts. Long term culture of the models and application for drug toxicity and drug permeation studies are demonstrated. The utility of the reconstructed SMI tissue models for GI drug toxicity studies was evaluated using the GI toxicant drug, indomethacin. Outcome measurements include transepithelial electrical resistance (TEER), histology and apical protein washes (sloughed epithelium). Drug permeation studies were performed using 8 drugs that utilize specific transporters (Pgp, BCRP, MRP-2, etc.). Uptake or efflux transport was analyzed by LC–MS/MS. Specific findings include: 1) The SMI tissue models can be cultured for extended time (up to 28 days) with no significant change in TEER