关键词: 运动损伤, 聚氨酯支架, 动态拉伸, 间充质干细胞, Yes相关蛋白信号通路

Abstract: This study developed a polyurethane scaffold featuring aligned nanogrooves (width: 2-3 μm, roughness Ra = 185 ± 32 nm) fabricated based on the Marangoni effect. Its morphology and crystalline structure were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarized light microscopy. Uniaxial tensile and cyclic fatigue tests evaluated its static and dynamic mechanical properties, demonstrating an elastic modulus matching that of natural ligaments and excellent fatigue resistance. Hemolysis assays and Live/Dead staining confirmed its good biocompatibility (hemolysis rate < 5%, high cell viability). Rat bone marrow-derived mesenchymal stem cells (MSCs) were isolated, cultured, and seeded onto the polyurethane scaffold surfaces. The cells were divided into three groups: static smooth surface (SS), static nanogrooved surface (SN), and dynamic stretched nanogrooved surface (DN), with the DN group subjected to dynamic tensile stimulation at 5% strain. Cell migration, proliferation, and adhesion behaviors were analyzed via scratch wound assay, EdU staining, and cytoskeleton/focal adhesion staining. The expression of YAP and integrin pathway-related molecules was detected using qPCR and Western Blot. Experimental results showed that the SN group could guide the alignment and migration of MSCs under static conditions. The DN group, under the synergistic effect of nanotopography and dynamic stretching, exhibited significantly enhanced cell migration speed, proliferation activity, cytoskeletal alignment, and focal adhesion maturation. Molecular mechanistic studies indicated that the combined stimulation synergistically upregulated the gene expression of YAP, CTGF, CYR61, and integrin β1, and promoted YAP protein nuclear translocation. In conclusion, this scaffold successfully drives MSC migration and proliferation by activating the YAP signaling pathway, while possessing biosafety, mechanical compatibility, and dynamic responsiveness.

Key words: Polyurethane scaffold, Nanogroove, Mesenchymal stem cell, Dynamic stretching, Yes-associated protein signaling