Composite Patch with Heterogeneous Structural Design for Improved Rotator Cuff Repair

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Rotator cuff repair often fails due to postoperative re-tears.
• Current treatments lack strategies for effective tendon-bone interface regeneration.

Purpose of the Study:

• To develop and evaluate a bioactive glass composite patch (BCP) for enhanced rotator cuff tendon-bone healing.
• To promote regeneration and integration at the tendon-bone interface.

Main Methods:

• Fabrication of a BCP with a poly (lactic acid) (PLA) outer layer and a 3D-printed inner core of gelatin methacryloyl (GelMA) hydrogel.
• Differential loading of zinc-doped (ZnBG) and strontium-doped (SrBG) bioactive glasses targeting tendon and bone regions.
• In vitro and in vivo assessments of cell behavior, tissue regeneration, and immune response.

Main Results:

• ZnBG ions promoted tendon-derived stem cell proliferation, migration, matrix expression, and reduced fibrosis.
• SrBG ions enhanced osteogenic differentiation and mineralization of bone marrow mesenchymal stem cells.
• In vivo studies showed organized collagen regeneration, improved bone integration, and a favorable immune microenvironment.

Conclusions:

• The BCP effectively promotes comprehensive structural and functional regeneration of the tendon-bone interface.
• This innovative biomaterial strategy offers a promising solution for challenging rotator cuff injuries.
• The BCP modulates the local microenvironment to support tissue repair and healing.