In this episode of Behind the Biology, Dr. Carolina Lucchesi explores microphysiological systems (MPS)—advanced bioengineering devices designed to mimic key organ or tissue functions in a more physiologically relevant way than traditional 2D culture, while offering a more human-relevant alternative than many animal models in specific contexts. Dr Lucchesi digs into what it takes to build and run MPS in practice: choosing materials (and understanding tradeoffs like small molecule absorption), selecting the right cell source (primary cells, organoids, iPSC derived cells, or cell lines), accounting for organ specific mechanical forces (like shear stress), and managing biological complexity across multiple cell types, media, and timelines. The episode closes with how cross industry collaboration and protocol harmonization can improve reproducibility and make data more comparable across platforms.