Poroelastic mechanical loading disrupts cytoskeletal symmetry in 3D architected scaffolds

Cells in load-bearing tissues experience both solid deformation and interstitial fluid flow during physiological loading, but the mechanisms by which they integrate these poroelastic mechanical signals remain poorly understood. Here, we develop a porous, nanoarchitected 3D scaffold that allows simultaneous delivery and control of matrix strain and fluid shear stress. We validated the platform through cyclic loading experiments and simulations of fluid-structure interactions. In static, stress-free culture mechanical environments, osteoblast-like cells adopted shapes, cytoskeletal architectures, and focal adhesion patterns templated by the 3D scaffold geometry. Under cyclic compression, the combined influence of matrix deformation and induced fluid flow disrupted this alignment, producing disordered actin structures and reduced focal adhesion eccentricity. These changes emerged even under low-frequency loading, within the drained poroelastic regime, indicating a high sensitivity of cytoskeletal organization to fluid-solid coupling. Our findings establish a tractable and tunable platform to investigate how cells sense and respond to dynamic poroelastic mechanical environments in 3D.