Tendon Fascicle-Inspired Nanofibrous Scaffold of Polylactic acid/Collagen with Enhanced 3D-Structure and Biomechanical Properties

Surgical treatment of tendon lesions still yields unsatisfactory clinical outcomes. The use of bioresorbable sca olds represents a way forward to improve tissue repair. Sca olds for tendon reconstruction should have a structure mimicking that of the natural tendon, while providing adequate mechanical strength and sti ness. In this paper, electrospun nano bers of two crosslinked PLLA/ Collagen blends (PLLA/Coll-75/25, PLLA/Coll-50/50) were developed and then wrapped in bundles, where the nano bers are predominantly aligned along the bundles. Bundle morphology was assessed via SEM and high-resolution x-ray computed tomography (XCT). The 0.4-micron resolution in XCT demonstrated a biomimetic morphology of the bundles for all compositions, with a predominant nano ber alignment and some scatter (50–60% were within 12° from the axis of the bundle), similar to the tendon microstructure. Human broblasts seeded on the bundles had increased metabolic activity from day 7 to day 21 of culture. The sti ness, strength and toughness of the bundles are comparable to tendon fascicles, both in the as-spun condition and after crosslinking, with moderate loss of mechanical properties after ageing in PBS (7 and 14 days). PLLA/Coll-75/25 has more desirable mechanical properties such as sti ness and ductility, compared to the PLLA/Coll-50/50. This study con rms the potential to bioengineer tendon fascicles with enhanced 3D structure and biomechanical properties.