A Collagen-based Scaffold Supports Tendon-to-bone Healing After Rotator Cuff Repair: An Integrated Translational Study.

Rotator cuff tears are highly prevalent among elderly individuals and athletes. They often lead to persistent pain and restricted mobility, and frequently necessitate surgical intervention. Despite advances in repair techniques, the reattachment of tendon to bone remains a major clinical challenge, with high failure rates primarily attributed to poor regeneration of the tendon-to-bone interface. In this study, we evaluated a collagen-based porous scaffold to support tendon-to-bone healing after rotator cuff repair. First, analysis of public transcriptomic datasets from human lesional tendons identified a "failed healing" state characterized by disorganized fibrosis and activation of inflammatory pathways. Subsequently, MC3T3-E1 and TTD6 cells were cultured on the scaffold to evaluate scaffold-cell interactions. Transcriptomic analysis was performed to explore scaffold-associated cellular responses, and the results suggested changes related to matrix interaction, cell adhesion, and repair-associated remodeling. To evaluate the in vivo performance, a rotator cuff repair model in beagle dogs was established, and the scaffold was implanted at the injury site. Magnetic resonance imaging, biomechanical testing, and histological analyses showed improved tissue integration, mechanical performance, and histological organization. These findings suggest that the scaffold may support tendon-to-bone healing and has translational potential as a collagen-based augmentation patch for rotator cuff repair.