Corynoline and Extracellular Vesicles Co-Loaded Scaffold Accelerates Vascularized Bone Regeneration with Photothermal...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Nanotechnology

Background:

• Autologous bone grafting faces limitations like donor site scarcity and immune issues.
• Effective bone defect repair requires strategies beyond traditional grafting.
• Developing advanced scaffolds is crucial for enhanced bone regeneration.

Purpose of the Study:

• To create a multifunctional, NIR-responsive composite scaffold for controlled delivery of corynoline (Cor) and extracellular vesicles (EVs).
• To investigate the scaffold's potential in enhancing bone regeneration by modulating the immune microenvironment and promoting vascularization.
• To address the clinical challenge of bone defect repair with a novel biomaterial solution.

Main Methods:

• Fabrication of a composite scaffold using β-tricalcium phosphate (β-TCP) coated with polydopamine (PDA).
• Immobilization of corynoline (Cor) and extracellular vesicles (EVs) onto the PDA-coated scaffold.
• Utilizing near-infrared (NIR) irradiation to trigger controlled and sustained release of bioactive factors.
• In vitro and in vivo evaluation of the scaffold's efficacy in promoting bone regeneration, vascularization, and immune modulation.

Main Results:

• The PDA coating enabled efficient immobilization and NIR-triggered, sustained release of Cor and EVs for over 14 days.
• Corynoline promoted M2 macrophage polarization, reducing inflammation, while EVs enhanced angiogenesis and osteogenesis.
• NIR stimulation of the scaffold effectively modulated the immune microenvironment and promoted vascularized bone regeneration.
• In vivo studies showed significantly enhanced new bone formation, reduced inflammation, increased cell recruitment, and accelerated vascularization.

Conclusions:

• The developed multifunctional, NIR-responsive scaffold offers a promising strategy for efficient and controlled bone defect repair.
• This approach effectively combines biomaterial design with controlled release of therapeutic agents to enhance bone regeneration.
• The scaffold's ability to modulate the immune microenvironment and promote vascularization represents a significant advancement in regenerative medicine.