Fractal Design Boosts Extrusion-Based 3D Printing of Bone-Mimicking Radial-Gradient Scaffolds

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Additive Manufacturing

Background:

• Extrusion-based three-dimensional (EB-3D) printing is widely used for bone tissue-engineered scaffolds.
• Creating natural bone-like radial-gradient scaffolds with EB-3D printing remains a significant challenge.

Purpose of the Study:

• To present a novel fractal-like porous scaffold with a controllable hierarchical gradient in the radial direction.
• To mimic the natural bone's gradual porosity decrease from cancellous to cortical bone using EB-3D printing.

Main Methods:

• Developed a design-to-fabrication workflow embedding fractal design data into digital processing for EB-3D printing.
• Utilized a combination of suitable extruded inks to fabricate fractal-like scaffolds.
• Fabricated scaffolds with a 3-iteration fractal-like structure.

Main Results:

• Successfully created fractal-like porous scaffolds with a controllable radial hierarchical gradient.
• Demonstrated radial porosity mimicking natural bone.
• Achieved superior mechanical properties and permeability compared to conventional scaffolds.

Conclusions:

• The study presents a robust strategy to overcome EB-3D printing limitations for functionally graded scaffold fabrication.
• The fractal-designed scaffolds show great potential for bone tissue engineering applications.
• This approach enables the creation of bone-mimicking scaffolds with tailored properties.