3D-printed airway model as a platform for SARS-CoV-2 infection and antiviral drug testing

We present a bioprinted three-layered airway model with a physiologically relevant microstructure for the study of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection dynamics. This model exhibited clear cell-cell junctions and mucus secretion with an efficient expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). Having infected air-exposed epithelial cells in the upper layer with a minimum multiplicity of infection of 0.01, the airway model showed a marked susceptibility to SARS-CoV-2 within one-day post-infection (dpi). Furthermore, the unique longevity allowed the observation of cytopathic effects and barrier degradation for 21 dpi. The in-depth transcriptomic analysis revealed dramatic changes in gene expression affecting the infection pathway, viral proliferation, and host immune response which are consistent with COVID-19 patient data. Finally, the treatment of antiviral agents, such as remdesivir and molnupiravir, through the culture medium underlying the endothelium resulted in a marked inhibition of viral replication within the epithelium. The bioprinted airway model can be used as a manufacturable physiological platform to study disease pathogeneses and drug efficacy.