Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE An integrated conjugate electrospinning and twisting strategy is developed to fabricate PLLA electrospun nanofiber bundle yarns with a tendon fascicle-mimicking hierarchical architecture. The resulting yarns exhibit aligned nanofibrous bundle structures, favorable mechanical properties, and excellent cytocompatibility, providing promising biomimetic textile building blocks for advanced tendon/ligament tissue engineering scaffolds.

ABSTRACT
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.