Bidirectional Mechanical Stimulation Enables Biomechanical Coupling and Functional Maturation in Arterial Microphysiological Systems

Engineering functional arterial tissues in vitro requires dynamic cues that recapitulate native mechanical environments. A bidirectional stimulation approach, termed blood and tissue side stretch (BTS), is presented, applying cyclic circumferential stretch to drive maturation of arterial microphysiological systems (aMPSs). These stimuli replicate key biomechanical forces present in vivo-cyclic circumferential stretch-enabling a more physiologically relevant tissue architecture. Human umbilical vein endothelial cells (HUVECs) and human smooth muscle cells (SMCs) are co-cultured within a bilayered vessel structure composed of an elastomeric hydrogel that mimics native vessel geometry and compliance. BTS stimulation enhances alignment of collagen fibers, promotes expression of contractile markers in SMCs, and improves barrier function and junctional protein localization in HUVECs. The matured aMPS exhibits vasomotor responsiveness and biomechanical integrity, validating its physiological relevance. Comparative analysis shows that BTS outperforms static and one-directional controls in promoting vascular tissue maturation. This platform provides a scalable and biomimetic solution for vascular tissue engineering and disease modeling. By integrating orthogonal mechanical cues that mimic the in vivo arterial environment, this approach represents a significant step forward in the development of predictive, functional, and high-fidelity vascular models for drug testing and regenerative medicine applications.