Integration of Fibroblast-Populated Collagen Lattices and Perfusable Micro-Physiological Systems: A Mechanobiologically Unified Framework for Living Devices

This review proposes mechanical crosstalk between stromal tension and vascular shear/flow as a unifying principle for integrating fibroblast-populated collagen lattices (FPCLs) with perfusable micro-physiological systems (MPSs). We argue that current in vitro platforms either emphasize fibroblast-driven matrix contraction (as with FPCLs) or flow-mediated vascular dynamics (as with MPSs) but rarely consider the reciprocity between these forces. By defining a mechanobiological framework that couples cellular contractility, extracellular matrix (ECM) remodeling, and shear-dependent endothelial responses, we reframe FPCL-MPS hybrids as "living devices" capable of capturing mechano-transduction across stromal and vascular compartments. This review (1) delineates the mechanobiology of FPCLs, highlighting their tension generation, matrix remodeling, and disease relevance; (2) surveys perfusable MPS design principles, focusing on shear stress, barrier function, and multicellular integration; (3) formulates a crosstalk paradigm in which stromal tension and vascular shear coregulate tissue physiology; (4) synthesizes engineering strategies for integrating FPCLs into MPSs; and (5) outlines challenges and future directions involving multiscale measurements, multi-omics, artificial intelligence, and regulatory standardization. To our knowledge, this review is among the first to explicitly frame stromal tension and vascular shear as a unified mechanobiological axis.