Characterization of a Vitrocell VC1 Using Nicotine Dosimetry: An Essential Component Toward StandardizedIn VitroAerosol Exposure of Tobacco and Next Generation Nicotine Delivery Products

Abstract

The U.S. Food and Drug Administration has regulatory authority over tobacco products, including conventional cigarettes and next generation products (NGPs) such as e-cigarettes and tobacco heating products (THPs). There is a desire by the industry, regulator and animal, protection organizations to incorporate non-animal test methods for tobacco product and NGP assessment. When assessing respiratory effects in vitro, reliable exposure systems that deliver aerosols to cellular/tissue cultures (such as human reconstructed airways or lung slices) at the air-liquid interface are needed. Using nicotine dosimetry, we report the characterization of a Vitrocell VC1 in our laboratories (IIVS, USA). Nicotine, generated from a 3R4F reference cigarette or NGP (e-cigarette and THP) aerosols at source and the exposure interface (culture media), was assessed using ultra-high-performance liquid chromatographytandem mass spectrometry. These data were compared to published dosimetry data for the same products, generated at a different laboratory (BAT R&D, Southampton, UK), on different exposure systems (VC10 and Borgwaldt RM20S) to confirm repeatability. The nicotine content of 3R4F and NGP aerosols at VC1 source generation was established. Results demonstrated no statistical difference between laboratories (IIVS and BAT; p = 0.903) when comparing puff-by-puff nicotine concentrations from the three products. Culture media nicotine assessment demonstrated no significant difference between replicate wells in the exposure module ( p = 0.855), indicating uniform delivery. This study demonstrates successful Vitrocell VC1 aerosol generation and delivery across multiple nicotine product categories, as characterized using nicotine as a dosimetry marker. The data suggest the VC1 established in our laboratory can reproducibly generate and deliver tobacco product and NGP aerosols for future in vitro assessment and matches the performance of reported exposure systems.

Invited review: human air-liquid-interface organotypic airway tissue models derived from primary tracheobronchial epithelial cells—overview and perspectives

“…Commercial smoking robots, such as Vitrocell® VC1 and VC10 (Adamson et al 2017 ; Keyser et al 2019 ) and Borgwaldt RM20S (Phillips et al 2005 ; Azzopardi et al 2015 ), have been used for exposing cells to freshly generated CS aerosols under ALI conditions and using standard or customized smoke-generating regimens. The Vitrocell® Smoke Exposure Systems allow for consistent and reproducible generation and delivery of CS or e-cig aerosols to ALI cultures (Adamson et al 2014 ; Behrsing et al 2018 ). In general, these systems consist of two main components, i.e., a smoking machine for generating CS or e-cig aerosols and an exposure chamber for diluting and delivering the aerosols to the cells.…”

“…Extensive characterization of the Vitrocell® Smoke Exposure System demonstrated consistent particulate deposition, vapor phase marker CO delivery, and biological responses (Thorne et al 2013 ). In a recent study, nicotine was validated as a CS dosimetry marker for the VC1 smoking robot (Behrsing et al 2018 ). In another study, deposition of CS particles generated by the VC10 smoking robot was measured using QCM and results compared across 6 independent laboratories.…”

Breathing in vitro: Designs and applications of engineered lung models

“…Although smoking machines have been used principally to investigate the effects of cigarette smoke on lung tissues, [120][121][122][123][124][125][126][127][128][129] in the last few years, several research groups have focused their efforts on studying the effects of next generation tobacco and nicotine products, namely e-cigarette aerosols and heated tobacco products. [130][131][132][133][134][135][136][137][138][139][140] Table 4 shows all the commercial technologies mentioned here, which can be considered a good choice for advanced in vitro models if exposure conditions related with inhalation are a crucial aspect of the study.…”

Acute electronic vapour product whole aerosol exposure of 3D human bronchial tissue results in minimal cellular and transcriptomic responses when compared to cigarette smoke

“…Nicotine is often used as a marker of 3R4F smoke and EVP aerosol delivery. 40 Deposited nicotine in PBS following exposure to 100 puffs of undiluted 3R4F smoke and EVP aerosol was quantified. There was significantly (p < 0.05) more nicotine deposited following 100 puffs of 3R4F smoke (69.5 + 4.5 mg/ml) than following the same number of puffs generated from the myblu TM device (28.9 + 4.3 mg/ml).…”

“…The dilution was achieved by adding air perpendicular to the aerosol creating a turbulent and homogenous diluted mix which was pumped through to exhaust. Diluted aerosol was sampled and drawn into the exposure module via negative pressure applied by a vacuum pump 40 and where cells cultured on inserts were housed. All VC1 tubing was replaced prior to both 3R4F smoke and EVP aerosol generation and delivery.…”