Human Multi-Compartment Airways-on-Chip Platform for Emulating Respiratory Airborne Transmission: From Nose to Pulmonary Acini

Abstract

The past decade has witnessed tremendous endeavors to deliver novel preclinical in vitro lung models for pulmonary research endpoints, including foremost with the advent of organ- and lung-on-chips. With growing interest in aerosol transmission and infection of respiratory viruses within a host, most notably the SARS-CoV-2 virus amidst the global COVID-19 pandemic, the importance of crosstalk between the different lung regions (i.e., extra-thoracic, conductive and respiratory), with distinct cellular makeups and physiology, are acknowledged to play an important role in the progression of the disease from the initial onset of infection. In the present Methods article, we designed and fabricated to the best of our knowledge the first multi-compartment human airway-on-chip platform to serve as a preclinical in vitro benchmark underlining regional lung crosstalk for viral infection pathways. Combining microfabrication and 3D printing techniques, our platform mimics key elements of the respiratory system spanning (i) nasal passages that serve as the alleged origin of infections, (ii) the mid-bronchial airway region and (iii) the deep acinar region, distinct with alveolated airways. Crosstalk between the three components was exemplified in various assays. First, viral-load (including SARS-CoV-2) injected into the apical partition of the nasal compartment was detected in distal bronchial and acinar components upon applying physiological airflow across the connected compartment models. Secondly, nebulized viral-like dsRNA, poly I:C aerosols were administered to the nasal apical compartment, transmitted to downstream compartments via respiratory airflows and leading to an elevation in inflammatory cytokine levels secreted by distinct epithelial cells in each respective compartment. Overall, our assays establish an in vitro methodology that supports the hypothesis for viral-laden airflow mediated transmission through the respiratory system cellular landscape. With a keen eye for broader end user applications, we share detailed methodologies for fabricating, assembling, calibrating, and using our multi-compartment platform, including open-source fabrication files. Our platform serves as an early proof-of-concept that can be readily designed and adapted to specific preclinical pulmonary research endpoints.

In vitro high-content tissue models to address precision medicine challenges

“…The use of lung-on-a-chip technology for the study of various viruses and infectious diseases has previously been disclosed by several reports ( Fig. 2 ) ( Nof et al, 2022 ; Saygili et al, 2021 ; Si et al, 2019 ; Tang et al, 2020 ; Thacker et al, 2021 ; Zhang et al, 2021 ). For instance, the models have been used to investigate the drug-resistant evolution of the influenza virus and identification of new resistance mutations by viral genome sequencing ( Fig.…”

“…Moreover, Nof and coauthors devised a multi-compartment respiratory tract-on-chip model containing nasal-, bronchial-, and acinar airways to study SARS-CoV-2 infections and its transmission from the nose to pulmonay acini ( Fig. 2 d) ( Nof et al, 2022 ). The presented platform allows for the evaluation of the transmission pathway, infectious pathogenesis and host-pathogen interactions and could possibly be employed for drug screening.…”

“…Saygili et al D) Multi-compartment respiratory tract-on-chip model comprising nasal-, bronchial-, and acinar airways for human host-pathogen interaction studies. Reproduced with permission ( Nof et al, 2022 ). Copyright 2022, Nof et al Licensed under A Creative Commons Attribution License (CC BY).…”

PEG-fibrinogen hydrogel microspheres as a scaffold for therapeutic delivery of immune cells

“…To illustrate hydrogel delivery into respiratory airway tracts, we used a recently established a multi-compartment Airway-on-chip model that recapitulates key anatomical and physiological components of the human respiratory tracts ( Nof et al, 2022 ). These include three distinct compartments of nasal passages, bronchial and acinar (alveoli) airways, mimicking the extra-thoracic, conductive and respiratory regions, respectively ( Artzy-Schnirman et al, 2019 ; Elias-Kirma et al, 2020 ; Sznitman, 2021 ).…”

“…To that end we used a pneumonic plague model of mice intranasally infected with Yersinia pestis bacterium to obtain inflamed whole lung extracts and assessed their effects on cell viability, cytokine expression and mobilization from the hydrogel microspheres ex vivo . As a proof of concept for topical delivery of encapsulated cells to human respiratory tracts, we utilized a recently developed multi-component Airways-on-chip models that mimic human nasal, bronchial and alveolar airways ( Nof et al, 2022 ).…”