Engineering human peritoneum in vitro: A novel microfluidic platform for modeling peritoneal physiology and pathophysiology.

The peritoneum, the body's largest serous membrane, plays critical roles in abdominal homeostasis and immune defense. When disrupted by surgery or disease, it can lead to devastating complications including peritoneal adhesions-affecting up to 93% of surgical patients-peritonitis, and metastatic spread. Current research models fail to capture the complexity of human peritoneal biology, relying on inadequate animal models or oversimplified 2D cultures. Here, we introduce a PDMS-free microfluidic platform that recreates the structural and functional architecture of human peritoneum. Our system combines immortalized mesothelial cells (MeT5A) with patient-derived peritoneal fibroblasts in a physiologically relevant 3D environment, enabling real-time analysis of peritoneal function and dysfunction. Through systematic evaluation of stromal matrices, we identified fibrin gel as optimal for supporting healthy mesothelial monolayer formation while maintaining excellent cell viability over 14 days. Importantly, we demonstrate the platform's translational potential by successfully modeling peritoneal adhesion formation. This innovative tool may improve the understanding of peritoneal biology, accelerating drug discovery and developing personalized treatment strategies for peritoneal diseases.