Directed biomechanical compressive forces enhance fusion efficiency in model placental trophoblast cultures

BeWo choriocarcinoma trophoblasts exposed to equibiaxial compression (10% strain, 1 Hz, 2 days) in the MechanoCulture FX showed enhanced fusion efficiency, while uniaxial compression did not affect fusion. Mechanical compression induced upregulation of Syndecan-1 and downregulation of E-cadherin, mirroring fusion markers seen in vivo. Low compressive stresses (~2 kPa) in 3D BeWo spheroids also enhanced fusion without forskolin induction, demonstrating that directed mechanical stress alone can stimulate syncytialization.