Chitosan-based composite bilayer scaffold as an in vitro osteochondral defect regeneration model

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Osteochondral tissue damage can lead to osteoarthritis and reduced quality of life.
• Current multiphasic scaffolds face challenges in stable interfacial integration between layers.
• Developing advanced scaffolds is crucial for effective osteochondral defect repair.

Purpose of the Study:

• To fabricate a bilayer scaffold for osteochondral tissue regeneration with seamless interfacial integration.
• To mimic the native osteochondral microenvironment with a mechanical stiffness gradient.
• To evaluate the scaffold's potential for promoting chondrogenesis and osteogenesis.

Main Methods:

• Fabrication of a bilayer scaffold using thermally-induced phase separation (TIPS) of two distinct polymer solutions.
• Optimization of scaffold layers with chitosan, hyaluronic acid (articular cartilage region), and hydroxyapatite (subchondral bone region).
• Co-culture of the scaffold with chondrocyte-like and osteoblast-like cells to assess biocompatibility and regenerative potential.

Main Results:

• The fabricated scaffold exhibited seamless interfacial integration and a mechanical stiffness gradient.
• Chitosan facilitated cell attachment and polyelectrolyte complex formation.
• Co-culture demonstrated significant cell proliferation, migration to the interface, and upregulation of osteogenesis and chondrogenesis markers.

Conclusions:

• The developed bilayer scaffold shows promise for osteochondral tissue regeneration due to its structural integrity and biomimetic properties.
• The scaffold effectively supports cell attachment, proliferation, migration, and differentiation.
• This approach offers a potential solution for treating osteochondral defects and osteoarthritis.