In vitro permeation of nicotine and tobacco specific nitrosamines from smokeless tobacco product extracts in a 3D buccal tissue model.

Tobacco product use is a risk factor in the development of oral cancer, although epidemiology studies show this risk is far less with smokeless tobacco product use than cigarette smoking. While smokeless tobacco contains harmful and potentially harmful constituents (HPHCs), the oral permeation of HPHCs in oral tobacco products is not completely understood. To improve the understanding, three different extract concentrations of the CORESTA reference products (CRP) for snus (CRP1.1) and moist snuff (CRP2.1) were applied to cellular tissue derived from two donors of EpiOral™ model, a 3D human buccal model, and permeation of nicotine and tobacco-specific nitrosamines (TSNAs) were measured over two hours. Permeation of 0.15% caffeine in complete artificial saliva and cell viability were also measured. Results showed that a consistent and concentration dependent cumulative permeation of nicotine and TSNAs was observed with high percent recovery in all conditions. A high degree of sensitivity was seen for all analytes, with minimal cytotoxicity for both CRPs. The data presented here show the EpiOral™ model is fit-for-purpose to evaluate the permeation of nicotine and TSNAs in nicotine-containing snus and moist snuff oral tobacco.

Characterization of smoke and aerosol deliveries from combustible cigarettes, heated tobacco products and electronic nicotine delivery systems in the Vitrocell® Mammalian 6/48 exposure module.

The rapid development associated with Next Generation Tobacco Products (NGTP) has necessitated the development of high throughput methodologies to test their genotoxic potential in vitro when compared to conventional cigarette smoke (CS). An assessment of two Vitrocell® Mammalian 6/48 exposure modules in three independent experiments was made by comparing results from multiple dosimetric techniques applied to aerosol generated from 3R4F Kentucky Reference cigarettes, commercially available electronically heated tobacco product (eHTP) and Electronic Nicotine Delivery System (ENDS) using the Vitrocell® VC10®. Real-time aerosol particle concentration was assessed by means of light scattering photometers and expressed as area under the curve (∑AUC). Nicotine concentrations were determined analytically by LC/MS. Humectant amount and distribution was assessed for eHTP and ENDS by the quantification of free glycerol in a phosphate buffered saline (PBS) trap, whereas total particulate matter (TPM) was assessed in the 3R4F cigarettes by the fluorescence of the particulate at 485 nm in anhydrous dimethyl sulfoxide (DMSO) trap within the exposure. Dose was adjusted by means of the addition of ambient air to dilute the whole smoke/aerosol in L/min and sampled into the system at a rate of 5 mL/min. Dilution of CS ranged from 8.0 to 0.5 L/min and for the eHTP and ENDS ranged from 4 to 0 L/min (undiluted). Dosimetric analysis of the system showed good concordance within replicates (p-values ranged from p = 0.3762 to p = 0.8926) and showed that the Vitrocell® Mammalian 6/48 is a viable means for genotoxic assessment of aerosol generated from both conventional cigarettes and NGTP. Results demonstrate the need to tailor dosimetry approaches to different aerosols due to variations in the physio-chemical composition, with a multi-dosimetry approach recommended.

Enamel staining with e-cigarettes, tobacco heating products and modern oral nicotine products compared with cigarettes and snus: An in vitro study.

PURPOSE: To evaluate the effect of cigarette smoke, smokeless tobacco (e.g. snus), tobacco heating products (THP), electronic cigarettes (EC), and modern oral nicotine products on tooth staining. METHODS: In this in vitro study, staining was assessed for 86 days following exposure of bovine enamel samples to a scientific reference cigarette (1R6F), a THP (glo), an EC (ePen 3), a reference snus product (CRP1.1), and a modern oral product (LYFT). Red wine and coffee were used as positive controls and DMSO and complete artificial saliva as negative controls. Whether brushing could reduce staining levels was also assessed. Changes in staining levels were assessed using the Commission Internationale de L'éclairage L*a*b* method. RESULTS: Enamel staining increased with incubation time, and cigarette smoke, snus, coffee and wine induced statistically higher staining levels. THP, EC and modern oral exposure induced minimal staining levels that were also comparable to negative control samples. At day 86, ΔE mean and SD values were 28.50 ± 3.14, 19.76 ± 1.26, 17.35 ± 3.44, 16.22 ± 2.07, 18.30 ± 3.82, 4.10 ± 1.99, 11.30 ± 2.60, 49.56 ± 2.44 for cigarette, glo, EC with blended tobacco, EC with rich tobacco, reference snus product, modern oral product, coffee or wine. The control ΔE mean and SD values at day 86 were 18.68 ± 3.89 for DMSO and 2.17± 0.78 for complete artificial saliva. The ΔE values for all DMSO extracted samples and control increased from day 1 to 86, which suggests that the DMSO used to extract the samples contributes to the enamel sample staining levels. Staining levels were reduced by brushing. CLINICAL SIGNIFICANCE: Cigarette smoke, red wine, snus and coffee stained enamel. Exposure to THP, EC or modern oral product extracts for 86 days resulted in minimal enamel staining. Further studies are required to assess the long-term impact on staining and the oral cavity following consumer exclusive use of EC, THP or modern oral products.