Low-density electrospun fibrous network promotes mechanotransduction and matrix remodeling in fibroblasts

The mechanical interactions between cells and fiber-dominated extracellular matrix (ECM) are crucial in regulating matrix-remodeling and cellular physiological processes. Electrospun fibers, as a type of biomimicking fibers, provide an ideal platform for engineering a variety of tissues in vitro. However, the mechanisms by which electrospun fibers promote cellular matrix-remodeling, particularly concerning the characteristic mechanical compliance in the fibers, remain inadequately understood due to the crossing and entanglement of electrospun ultrafine fibers in those densely packed fibrous mats. This study devised low-density fibrous network and mechanically sensitive fibroblasts to investigate how cells sense, respond to, and remodel the residing microenvironment at both cellular and molecular levels. The results showed that the fibroblasts cultured on the low-density fibrous network exhibited a contractile phenotype, as evidenced by the upregulated transcription and synthesis of ECM-related proteins as well as fiber recruitment capability, thereby displaying a greater capacity in matrix-remodeling. Analysis of mechanotransduction-related markers revealed that the RhoA-ROCK signaling pathway was activated in the low-density fibrous network-substrated fibroblasts. Additionally, enhanced cytoskeletal assembly, cell contractility, YAP nuclear translocation, and activation of Piezo1 were observed. Inhibition of ROCK disrupted mechanotransduction, consequently impairing the cell's matrix-remodeling capacity. These findings demonstrate that the low-density electrospun fibrous network promotes the cell-mediated matrix-remodeling by facilitating mechanotransduction signaling. This study establishes a theoretical framework for understanding how electrospun fibers regulate cellular function at the micro-mechanical level and may shed insights on the design of biomimetic fibrous scaffolds for promoting tissue regeneration.