Engineered Composite Bilayer Scaffold with Functional Osteogenic and Chondrogenic Potential to Repair Articular...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Osteochondral defects (OCDs) result from trauma, aging, arthritis, and sports injuries, posing significant health and economic challenges.
• Repairing osteochondral tissue is complex due to its avascular nature and distinct cartilage and subchondral bone layers.
• Current treatments for OCDs face limitations in fully restoring native tissue structure and function.

Purpose of the Study:

• To fabricate a biomimetic bilayer scaffold designed for effective osteochondral defect regeneration.
• To mimic the native extracellular matrix (ECM) by creating distinct subchondral bone and cartilage layers.
• To evaluate the scaffold's potential for restoring both chondral and subchondral bone regions.

Main Methods:

• Constructed a bilayer scaffold with an inorganic subchondral layer (hydroxyapatite-graphene oxide) and an organic cartilage layer (collagen type I-fibrin).
• Characterized the scaffold's structure, physicochemical properties, mechanical strength, biocompatibility, and cellular adhesion.
• Assessed the osteoinductive and chondroinductive potential in vitro and evaluated regeneration in vivo using a rat model over 12 weeks.

Main Results:

• The bilayer scaffold exhibited appropriate pore sizes, high porosity, and optimal mechanical strength with integrated layers.
• In vitro studies confirmed high biocompatibility and cellular adhesion, along with osteoinductive and chondroinductive properties.
• In vivo studies demonstrated significant osteochondral defect regeneration, including complete defect closure, bone, and cartilage formation, confirmed by imaging and histological analyses.

Conclusions:

• The developed cell-free bilayer scaffold effectively mimics native osteochondral tissue architecture.
• The scaffold demonstrates excellent biocompatibility and promotes significant bone and cartilage regeneration in vivo.
• This biomimetic scaffold represents a promising therapeutic material for addressing osteochondral defects.