NLRP3 and bronchopulmonary dysplasia: Therefore, this study hopes to systematically explore the effects of hUCMSC-Exos on NLRP3 inflammasome activation and endoplasmic reticulum stress, as well as its mechanism in regulating macrophage function and inflammatory response by constructing an in vitro model of BPD (such as pulmonary macrophage model under high oxygen exposure).