Air sacs in the lungs called alveoli are the essential site of gas exchange and also an important barrier against inhaled viruses and bacteria that cause respiratory diseases like flu or TB.

Researchers have been working to recreate the battle between human cells and bacteria in the lab by building a lung-on-a-chip: small units of human lung on a plastic chip containing tiny channels and compartments. In this case, they aimed to recreate air sacs to understand how they respond to infection.

Until now, these lung-on-chip devices have been made of a mixture of patient-derived and commercially available cells, meaning they can’t fully replicate the lung function or disease progression of a single individual.