Real-time assessment of cigarette smoke particle deposition in vitro

Jason Adamson,David Azzopardi,Sophie Hughes,John Mcaughey,Marianna D Gaça

doi:10.1186/1752-153x-6-98

Jason Adamson, David Azzopardi + Show 3 more

Open Access

https://doi.org/10.1186/1752-153x-6-98

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Abstract

BackgroundRecently there has been a rapid increase in approaches to assess the effects of cigarette smoke in vitro. Despite a range of gravimetric and chemical methods, there is a requirement to identify simpler and more reliable methods to quantify in vitro whole smoke dose, to support extrapolation and comparisons to human/in vivo dose. We have previously characterised an in vitro exposure system using a Borgwaldt RM20S smoking machine and a chamber exposing cellular cultures to whole smoke at the air-liquid interface. In this study we demonstrate the utility of a quartz crystal microbalance (QCM), using this exposure system, to assess real-time cigarette smoke particulate deposition during a 30 minute smoke exposure. Smoke was generated at various dilutions (1:5–1:400, smoke:air) using two cigarette products, 3R4F Kentucky reference and 1 mg commercially available cigarettes. The QCM, integrated into the chamber, assessed particulate deposition and data generated were compared to traditional chemical spectrofluorometric analysis.ResultsThe QCM chamber was able to detect mass differences between the different products within the nanogram range. 3R4F reference cigarette smoke deposition ranged from 25.75 ±2.30 μg/cm2 (1:5) to 0.22 ±0.03 μg/cm2 (1:400). 1 mg cigarette smoke deposition was less and ranged from 1.42 ±0.26 μg/cm2 (1:5), to 0.13 ±0.02 μg/cm2 (1:100). Spectrofluorometric analysis demonstrated statistically significant correlation of particulate deposition with the QCM (p < 0.05), and regression R2 value were 97.4 %. The fitted equation for the linear model which describes the relationship is: QCM = −0.6796 + 0.9744 chemical spectrofluorescence.ConclusionsWe suggest the QCM is a reliable, effective and simple tool that can be used to quantify smoke particulate deposition in real-time, in vitro and can be used to quantify other aerosols delivered to our chamber for assessment.

Highlights

There has been a rapid increase in approaches to assess the effects of cigarette smoke in vitro
In this study we present a novel application of a quartz crystal microbalance (QCM), to assess the real-time deposition of cigarette smoke in vitro
We have demonstrated repeatable and accurate whole smoke dilution and delivery of cigarette smoke using a commercially available Borgwaldt RM20S smoking machine (Borgwaldt-kc, Hamburg, Germany) [2,6] and successful applications in vitro [7,9,11]

Summary

Introduction

There has been a rapid increase in approaches to assess the effects of cigarette smoke in vitro. Whole smoke dose is dependent on the machine used to generate, dilute and deliver smoke and is variously described as a percentage of smoke, a fraction of smoke, ratios of smoke to air, puff number, total exposure of micrograms per insert, or as a flow rate of mixing air and vacuum applied to a smoke dilutor [2,3,5,6,9,10,11] This is a relatively new and challenging field but is an increasingly important point of discussion within the industry. The need to quantify absolute chemical or particle deposition in in vitro model systems is of increasing importance to scientists and regulators for consistent interpretation of disease model end-points versus a defined biologically effective dose [12,13]

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