Validation of the Vitrocell® HTP 2.0+ 12-well mammalian module for assessing cigarettes, ENDS and eHTPs: Evaluation of dilution airflow, dose resolution and dose repeatability

Coresta SSPT 2023 -- The present study aimed to validate the performance of the Vitrocell® HTP 2.0+ 12-well mammalian module for assessing three different test articles: cigarettes, electronic nicotine delivery systems (ENDS) and electronic tobacco heated products (eHTPs). Specifically, we investigated the variation within dilution airflow, dose resolution and dose repeatability to ensure the reliability of the experimental setup. To evaluate dilution airflow, measurements were conducted across all test articles, revealing consistently low variation, except for the lowest dilution rates where higher variability was observed. Overall, the dilution airflow showed satisfactory performance, indicating its suitability for use in the experimental system. Dose resolution, a critical parameter for accurate assessment, was assessed for all test articles. The results demonstrated good dose resolution in general, although ENDS exhibited the lowest resolving power among the three tested products. This finding emphasizes the need for careful consideration when evaluating ENDS to ensure accurate dosing and subsequent analysis. Furthermore, the experimental dose repeatability was examined. Notably, the repeatability was highest on test articles that required multiple products per dose, cigarettes and eHTPs, indicating the importance of accounting for pod-to-pod variability when planning exposures using ENDS. In conclusion, the validation of the Vitrocell® HTP 2.0+ 12-well mammalian module demonstrated reliable performance for assessing cigarettes, ENDS and eHTPs. The study findings revealed low variation within dilution airflow, overall good dose resolution and highlighted the significance of considering pod-to-pod variability for ENDS exposures. These findings contribute to the accurate evaluation of aerosol exposures and support the use of this module in relevant toxicological investigations and risk assessments.