In vitro interactions of aerosol formulations with human nasal epithelium using real-time monitoring of drug transport in a nasal mucosa-on-a-chip

The current organ-on-chip platforms used for studying respiratory drug delivery are limited to the administration of drug solutions and suspensions, lacking the in vivo aerosol drug administration and aerosol interaction with the respiratory tract barrier. Moreover, they mostly rely on conventional assays that require sample collection and ‘off the chip’ analyses, which can be labor-intensive and costly. In this study, a human nasal epithelial mucosa (NEM)-on-a-chip is developed that enables the deposition of aerosolized nasal formulations while emulating realistic shear stresses (0.23 and 0.78 Pa), exerted to the inferior and middle turbinate of the human nasal cavity. Under these different dynamic conditions in the donor channel of the NEM-on-a-chip, the deposited dose of aerosols and particle size distributions varied. In addition, the increase in the shear stress to 0.78 Pa adversely affected the cells' viability, reflected by a 36.9 ± 5.4% reduction in the transepithelial electrical resistance. The epithelial transport profiles of aerosolized ibuprofen formulations under 0.23 Pa shear stress were successfully monitored in real-time by an electrochemical sensor embedded in the acceptor channel, where the NEM-on-a-chip was able to monitor the effect of permeation enhancer in the test formulation on the rate of drug transport. The novel NEM-on-a-chip can potentially be a promising physiologically relevant tool for reliable nasal aerosol testing in vitro.