Breaking the Tendon Repair Barrier: A Biomimetic Soluble Collagen Scaffold Enables Full Functional Regeneration of Achilles Tendon in Rabbits

This groundbreaking research employs biomimetic artificial tendons for the first time globally to successfully regenerate a 2 cm defect in the rabbit Achilles tendon. The artificial tendon, woven by collagen threads derived from soluble collagen, is a biomimetic tendon with a composition, structure and function akin to natural tendons. The biomimetic tendon exhibits exceptional tensile strength of (43.4 MPa), surpassing that of the natural Achilles tendon (39.1MPa). The remarkable mechanical properties, coupled with its favorable biocompatibility and low immunogenicity, underscore the substantial clinical application potential of this biomimetic material. A biomimetic tendon was implanted to repair a rabbit model of a 2 cm tendon defect without employing exogenous cells or growth factors. Twenty weeks after transplantation, the mechanical properties of the regenerated tendon were restored to approximately 80.1% of those of the natural Achilles tendon. This biomimetic tendon not only provides mechanical support during the initial phase of cell recruitment but also sustains strength to facilitate functional tendon reconstruction until material degradation and complete tendon regeneration. The regenerated tendon tissue exhibited regularly arranged dense collagen fibers along the longitudinal axis of the natural tendons, demonstrating high mechanical strength and seamless integration. Histological analysis further revealed a progressive enhancement in collagen fiber diameter, density, and structural integrity within regenerated tendons over time, closely resembling the characteristics of natural Achilles tendons eventually. Notably, there were no apparent immune reactions or inflammatory responses during the experimental cycle. These findings unequivocally demonstrate the remarkable efficacy of biomimetic tendons in facilitating functional tissue regeneration, underscoring their significant medical and scientific value. This study not only presents a novel treatment approach for tendon injury repair but also establishes the foundation for future clinical tendon and ligament regeneration and repair, with extensive clinical application prospects.