Injectable Zein-Based Photothermal Composite Hydrogel Enhances Osteoporotic Tendon-Bone Healing

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Osteoporotic rotator cuff tears present significant healing challenges due to compromised tendon-bone interface (TBI) integration.
• Current treatments often yield suboptimal outcomes in osteoporotic bone environments.

Purpose of the Study:

• To engineer an injectable Zein-based composite hydrogel (ZDC hydrogel) for enhanced osteoporotic rotator cuff tear repair.
• To investigate the hydrogel's potential for photothermal regulation, niacin release, and promotion of TBI healing.

Main Methods:

• Fabrication of ZDC hydrogel using electron-beam irradiation with niacin-loaded mesoporous carbon nanospheres.
• In vitro assessment of hydrogel properties, cell differentiation (osteogenic and tenogenic), and mechanistic pathways (NAD+, ROS, cell cycle regulators).
• In vivo evaluation in an osteoporotic rat rotator cuff repair model and a rat skin wound model.

Main Results:

• ZDC hydrogel demonstrated favorable self-assembly, mechanical properties, photothermal activity, degradability, and biosafety.
• In vitro studies showed enhanced osteogenic and tenogenic differentiation, increased NAD+ levels, and reduced ROS accumulation.
• In vivo, ZDC hydrogel with near-infrared irradiation (NIR) improved bone formation, TBI reconstruction, biomechanical strength, angiogenesis, and reduced inflammation.

Conclusions:

• The injectable ZDC hydrogel is a promising therapeutic strategy for osteoporotic rotator cuff tears.
• The hydrogel's combination of photothermal properties and niacin release effectively promotes tissue regeneration and healing.
• Further research is warranted to explore its clinical applicability in orthopedic regenerative medicine.