Biomimetic patch with gradient-induced regeneration for tendon-bone interface to repair rotator cuff injury

Abstract

Rotator cuff injury is a common shoulder disease, which can lead to severe shoulder pain and functional limitation. The natural healing process of tendon-bone after rotator cuff injury is slow and often ineffective, and the long-term stress concentration at the injured tendon-bone interface will lead to the re-tear of the healed tissue. Therefore, the development of biomaterials that can provide mechanical support and induce synchronous multitissue regeneration at the tendon-bone interface is a priority. In this study, PCL and COL Ⅰ were blended by electrospinning technology to prepare nanofiber patches with bionic mechanical properties, including sufficient tensile strength and significant elasticity, and multifunctional composite patches were prepared by loading CaSiO₃ and CTGF onto the patches through a double-ended loading strategy. The multifunctional patch has good biocompatibility, and has shown significant advantages in promoting multitissue regeneration. The application of multifunctional patch in rat rotator cuff injury model can effectively promote the regeneration of tendon, cartilage and bone at the tendon-bone interface, and simultaneously complete the healing of tendon to bone, which has a significant effect on promoting the repair of rotator cuff injury. Our study demonstrates the great potential of patch materials for gradient tissue repair and provides a feasible strategy for multi-tissue induced electrospinning scaffolds for the regeneration of the soft-hard tissue interface.