Magnetic bead electrochemical sandwich assay (MBESA) for the inflammatory cytokine interleukin-1β in fetal membrane on-a-chip studies and placental macrophages

Preterm birth (PTB), triggered by preterm premature rupture of membranes (PPROM), remains a global health challenge, often linked to infections like chorioamnionitis. Existing biomarker detection methods, such as ELISAs, are limited by time, cost, and reagent requirements. There is a significant demand for new analytical techniques that identify PTB biomarkers, such as the inflammatory cytokine interleukin-1β (IL-1β), within biological models. In this work, we have quantified IL-1β with our newly developed magnetic bead electrochemical sandwich assay (MBESA), an alternative to traditional ELISAs. We have utilized a fetal membrane organ on-a-chip (FMOC) to mimic the physiological functions of the human fetal membranes during bacterial infections in vitro . The MBESA was optimized to detect IL-1β levels present within a FMOC and lipopolysaccharides (LPS)-infected cell cultures. We present the design of the MBESA, highlighting the high sensitivity of an electrochemical technique and the application of the FMOC in reproductive research. The MBESA was able to reproducibly detect standard IL-1β levels in the physiological ranges of 10 pg/mL to 600 pg/mL. Significant differences were observed in LPS-treated and untreated macrophages samples, but there was no significant difference between the MBESA and ELISA methods when examining LPS-treated and untreated macrophages samples. The MBESA’s reduced reagent use, faster results, and compatibility with organ on-a-chip systems suggest its potential for integration into point-of-care diagnostic tools targeting inflammation-driven PTB. • MBESA detects IL-1β with high sensitivity and reduced reagent requirements • FMOC replicates fetal membrane inflammation for in vitro cytokine analysis • MBESA shows strong agreement with ELISA for LPS-treated macrophage samples • FMOC and MBESA support point-of-care diagnostics for PTB biomarkers