Use of cell media nicotine concentration as a marker to predict cells surface deposited nicotine in transwells after fresh smoke/aerosol exposure
Exposure of organotypic 3D lung models at the air liquid interface (ALI) to fresh whole smoke/aerosol provides a more human relevant exposure assessment of combustible cigarettes and e-vapour products.
The aim of this study is to present a method for determination of nicotine deposition at the 3D MucilAir™ tissues surface, in transwells of 24 MWP after repeated exposure to 30, 60 or 90 puffs of tobacco cigarette (3R4F, 1:17 dilution) or undiluted myblu™ e-vapour aerosol over four weeks. Exact measurement of nicotine deposited at the cell surface is difficult due to absorption of nicotine into the cells. The nicotine serves as a general marker of exposure.
We wanted to determine if cell media nicotine concentration was correlated with cell surface deposition. To measure this, the deposition efficiency onto a glass plate inserted directly into the transwell was determined and was compared to glass discs with cells grown on the surface (BEAS-2B, V79).
During the four weeks of repeated exposure of MucilAir™ tissues at ALI to 3R4F smoke and myblu™ aerosol, basal culture media were collected for nicotine quantification. Additionally nicotine deposition on to glass discs representing the cell surface area was measured. Nicotine based toxicological effects observed over the exposure time in comparison to the puff numbers were compared.
Nicotine deposition on glass discs in the transwells correlated well with the deposited nicotine in the cell media, with increasing puff numbers, dilution factors and the surface area of the glass plates. Therefore, the nicotine concentration measured (using LC-MS/MS) in exposed basal medium can be considered as a proxy in relation to nicotine deposition on the cell surface. As expected, due to different physical characteristics of the products, smoke from 3R4F and aerosol from myblu™, relationship cell media and nicotine deposition had different correlation coefficients.