Bioinspired Hierarchical Assembly of Poly(L‐Lactic Acid) Nanofiber Bundles Into Native Tendon Fascicle‐Mimicking Textile Yarns via Conjugate Electrospinning

Tendons and ligaments possess a hierarchical bundled architecture but exhibit limited intrinsic healing capacity after injury. Herein, bioinspired poly( l ‐lactic acid) (PLLA) electrospun nanofiber bundle yarns (ENBYs) are fabricated using an integrated conjugate electrospinning and rolling strategy. Key processing parameters are optimized to obtain aligned PLLA nanofiber bundle membranes with average fiber and bundle diameters of 0.73 ± 0.13 μm and 4.06 ± 2.12 μm, respectively. The resulting PLLA ENBYs exhibit highly aligned hierarchical structures and favorable mechanical properties, with the optimal yarn showing a tensile strength of 19.2 MPa, Young's modulus of 297.7 MPa, and elongation at break of 378.5%. Moreover, the yarns demonstrate excellent hemocompatibility and cytocompatibility. Braided scaffolds fabricated from the PLLA ENBYs effectively promote rat tenocyte adhesion, proliferation, elongation, and aligned growth along the fiber direction. This work establishes a feasible strategy for fabricating structurally biomimetic and mechanically robust PLLA yarns as promising building blocks for tendon/ligament tissue engineering scaffolds.