Preterm birth (PTB; < 37 weeks of gestation) impacts ~ 11% of all pregnancies and contributes to 1 million neonatal deaths worldwide annually. An understanding of the feto-maternal (F-M) signals...

We developed multiple microfluidic organ-on-chip (OOC) devices that represent the structure, functions, and responses of the two feto-maternal interfaces (FMis) in humans (fetal membrane [FMi-OOC] and placenta [PLA-OOC]). Generated by BioRender.

Extracellular vesicles (EVs) play a crucial role in feto-maternal communication and provide an important paracrine signaling mechanism in pregnancy. We hypothesize that fetal cells-derived exosomes and microvesicles (MVs) under oxidative stress carry unique cargo and traffic through feto-maternal interface, which cause inflammation in uterine cells associated with parturition. Exosomes and MVs, from primary amnion epithelial cell (AEC) culture media under normal or oxidative stress (OS)-induced conditions, were isolated by optimized differential centrifugation method followed by characterization for size (nanoparticle tracking analyzer), shape (transmission electron microscopy), and protein markers (western blot and immunofluorescence). Cargo and canonical pathways were identified by mass spectroscopy and Ingenuity Pathway Analysis. Myometrial, decidual, and cervical cells were treated with 1x107 control/OS-derived exosomes/MVs. Pro-inflammatory cytokines were measured using a Luminex assay. Statistical significance was determined by paired T-test (p &lt; 0.05). AEC produced cup-shaped exosomes of 90–150 nm and circular MVs of 160–400 nm. CD9, HSP-70, and Nanog were detected in exosomes while OCT-4, HLA-G, and calnexin were found in MVs. MVs, but not exosomes, were stained for phosphatidylserine. The protein profiles for control versus OS-derived exosomes and MVs were significantly different. Several inflammatory pathways related to OS were upregulated that were distinct between exosomes and MVs. Both OS-derived exosomes and MVs significantly increased pro-inflammatory cytokines (GMCSF, IL-6, and IL-8) in maternal cells compared to control (p &lt; 0.05). Our findings suggest that fetal-derived exosomes and MVs under OS exhibited distinct characteristics and a synergistic inflammatory role in uterine cells associated with the initiation of parturition.