Alginate Nonwoven-Sponge Composite Scaffold for Rotator Cuff Tendon Repair

Growth factor-mediated healing of rotator cuff tendon requires to develop a clinically applicable biomaterial playing roles of mechanical support and growth factor release in vivo. In this study, the alginate (AG) nonwoven-sponge composite scaffold (AGNWSP) was fabricated through the formation of an AG sponge layer on the AG nonwoven scaffold (AGNW) surface, and rotator cuff repair with the AG-based scaffolds containing transforming growth factor-beta 1 (TGF-β1) was investigated with a rabbit model. AGNWSP had higher tensile strength, lower bioabsorbability, and higher sustained TGF-β1 release capacity than AGNW, which were highly correlated with tendon regeneration. AGNW and AGNWSP were fixed to the ruptured tendon-to-bone sites, and fresh solutions of TGF-β1 were injected into the scaffolds. When AGNWSP was applied, the repaired supraspinatus tendon had higher ultimate failure load and stress. In addition, well-organized collagen fibers and fibrocartilages were observed at the tendon-to-bone interface in this case. It is suggested that high degree of ruptured rotator cuff healing could be achieved with AGNWSP in combination with TGF-β1.