Biofabrication of multiscale bone extracellular matrix scaffolds for bone tissue engineering

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Interconnected porosity is crucial for regenerative scaffolds, enabling cell migration, vascularization, and nutrient diffusion.
• 3D printing offers precise control over scaffold architecture, including pore size, porosity, and interconnectivity.

Purpose of the Study:

• To develop a mechanically functional, multiscale porous scaffold for bone regeneration.
• To enhance vascularization and osteogenic differentiation of stem cells using biofabrication strategies.

Main Methods:

• Functionalizing polycaprolactone (PCL) with decellularised bone extracellular matrix (ECM) to create osteoinductive filaments for 3D printing.
• Integrating freeze-drying of solubilised bone ECM within 3D-printed scaffolds to create a microscale porous network.
• Evaluating scaffold properties, cellular attachment, osteogenesis (in vitro), and vascularization/bone formation (in vivo).

Main Results:

• PCL-ECM filaments improved mechanical properties, cellular attachment, and osteogenesis of mesenchymal stem cells (MSCs).
• Larger scaffold pore sizes (filament spacing) accelerated vascularization and new bone formation in vivo.
• The microscale porous network enhanced cellular attachment, vessel infiltration, and bone regeneration.

Conclusions:

• An "off-the-shelf" multiscale bone-ECM scaffold was successfully developed.
• The scaffold is mechanically stable and promotes vascularization and bone regeneration in vivo.
• This approach offers a promising strategy for bone tissue engineering and regenerative medicine.