Application progress of air-liquid interface exposure technology in respiratory system toxicity induced by diesel exhaust in vitro

Diesel exhaust (DE) is an important pollution source widely existing in the living and production environment, which is closely related to the health of the public and occupational groups. The International Agency for Research on Cancer has classified DE as a Group 1 carcinogen. Considering the negative health impacts on the respiratory system due to DE exposure in vitro, it is crucial to apply reliable test systems allowing accurate assessment of the biological effects of DE. The exposure technology of respiratory system in vitro is considered as one of the feasible measures to implement the 3R (reduce, refine, and replace) principle in animal experiments. Compared with the traditional submerged culture in vitro models, the air-liquid interface (ALI) exposure technology has the advantages including fewer influencing factors, easier exposure condition control, and shorter exposure cycle. ALI has become an important tool to study molecular events associated with physiology and pathology of respiratory system, and action modes and interactions of different cell types. Also, ALI has been increasingly widely used because it can simulate the actual processes of human respiratory system cells and/or tissues to DE exposure. This review was intended to introduce the development and advantages of ALI exposure technology, and further summarized the application progress of ALI exposure technology in studying the respiratory toxicity induced by DE exposure in vitro, so as to provide new ideas and pathways for the use of ALI exposure technology in the study of biomarkers and mechanisms of respiratory toxicity associated with DE exposure, and provide basic data to screen and promote biomarkers for exposed populations.