Research on Dual-Phase Composite Forming Process and Platform Construction of Radial Gradient Long Bone Scaffold

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Additive Manufacturing

Background:

• Natural bone exhibits gradient changes in structure and composition.
• Existing bone scaffolds often lack the complexity to fully address bone defect repair needs.
• Mimicking natural bone's gradient properties is crucial for effective bone tissue engineering.

Purpose of the Study:

• To develop a new bone scaffold preparation technology, the dual-phase composite forming process.
• To design a bionic bone scaffold with radial gradient changes in pore structure and material concentration.
• To evaluate the performance and biocompatibility of the gradient bone scaffolds.

Main Methods:

• Utilized a dual-phase composite forming process for continuous 3D printing of bone scaffolds.
• Controlled material extrusion speeds into a single nozzle mixing chamber to achieve material concentration gradients.
• Prepared radial gradient long bone scaffolds (BS-G) and compared them to traditionally fabricated scaffolds (BS-T).
• Conducted morphological characterization, mechanical property analysis, in vitro cell culture, and in vivo animal studies.

Main Results:

• The dual-phase composite forming process successfully created bone scaffolds (BS-G) with continuous radial pore structure and material concentration gradients.
• BS-G exhibited superior compressive strength (1.00 ± 0.19 MPa) compared to BS-T, meeting bone defect repair requirements.
• In vitro and in vivo studies demonstrated no cytotoxicity and good biocompatibility of the BS-G scaffolds.
• BS-T showed discontinuous gradients with distinct boundaries between material regions.

Conclusions:

• The dual-phase composite forming process is an effective method for fabricating biomimetic bone scaffolds with continuous radial gradients.
• The developed gradient bone scaffolds (BS-G) possess enhanced mechanical properties and excellent biocompatibility.
• This technology provides a foundation for advancing bone tissue engineering and the repair of large bone defects.