Nanoparticle-Coated Sutures Providing Sustained Growth Factor Delivery to Improve the Healing Strengths of Injured Tendons

Tendon injuries are more common, and due to the lack of adequate growth factors, the healing capacity of the injured tendon is limited. The objective of this study is to evaluate the effectiveness of Nanoparticle-coated sutures carrying growth factors on accelerating tendon repair. We found that nanoparticles can adhere uniformly to the surface of the suture modified with polydopamine. After stitching, the nanoparticles remain on the surface of the suture, and its loaded proteins can spread in the tendon tissues. After treatment, in the chicken flexor tendon healing model and the rat Achilles healing model, the ultimate strengths of repaired tendons treated with bFGF and VEGFA-releasing sutures was significantly greater than the tendons repaired with control sutures at multiple time-points. At 6 weeks, adhesion scores in the bFGF and VEGFA-releasing suture group were significantly smaller than those of the control suture group. Tendon gliding excursions were significantly greater in the bFGF and VEGFA-releasing suture group than in the unmodified control sutures. Work of digital flexion was significantly decreased in the bFGF and VEGFA-releasing suture group than in the control group. In a word, we developed a novel platform for local and sustained delivery of growth factors based on the Nanoparticle-coated sutures, which can effectively deliver growth factors to tissues and control the release of growth factors. Dual growth factors loaded Nanoparticle-coated sutures can significantly promote tendon healing. This growth factors delivery system is an attractive therapeutic tool to repair injured tendons.