Collagen-Fibronectin Crosstalk in Engineered Matrices: Synergistic Assembly Orchestrates Fibrillar Morphogenesis and...

The cooperative interplay between type I collagen (COL) and fibronectin (FN) in the extracellular matrix (ECM) guides both matrix organization and cell behavior. While COL-based materials are widely used, their limited capacity to integrate FN-mediated regulatory cues restricts functional biomimicry. Here, we investigate how COL/FN composites in distinct assembly states (monomeric vs fibrillar) differentially regulate cellular responses. Biophysical characterization confirmed FN binding to COL α chains promotes coassembly into hybrid fibrils with accelerated kinetics and enhanced mechanical rigidity. Strikingly, HT1080 cells exhibited opposing adhesion behaviors on monomeric versus fibrillar COL/FN matrices. In monomeric matrices, escalating FN ratios progressively reduced adhesion, while in fibrillar matrices, low-FN ratios enhanced adhesion synergistically. Cell migration followed an inverse pattern, with monomeric hybrids promoting motility and fibrillar matrices suppressing it. Our findings highlight that COL/FN assembly states, independent of compositional changes, dictate cell-matrix reciprocity through structural reconfiguration. This work establishes a paradigm for engineering ECM-inspired materials with phase-specific topographies to guide cellular decision-making, advancing applications in tissue regeneration and mechanobiology studies.