3D printed scaffolds with multistage osteogenic activity for bone defect repair

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Bone defect repair is complex, involving immune response, stem cell differentiation, and matrix mineralization.
• Existing bone tissue engineering methods often lack adaptability, leading to incomplete healing.
• A dynamic scaffold is needed to support the multiple stages of osteogenesis.

Purpose of the Study:

• To develop a 3D-printed scaffold with multistage osteogenic activity for improved bone defect repair.
• To create a scaffold utilizing shape-memory elastomer and electroactive materials for enhanced functionality.
• To investigate the scaffold's ability to regulate the immune microenvironment and promote stem cell differentiation.

Main Methods:

• Fabrication of a 3D-printed scaffold using shape-memory elastomer and electroactive materials.
• Evaluation of the scaffold's shape-memory properties triggered by physiological temperature for minimally invasive implantation.
• Application of electric field polarization to impart negative surface charge and assess its effects on macrophage polarization and bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation via PI3K/Akt and FAK/ERK pathways.
• Assessment of the scaffold's role in promoting extracellular matrix mineralization through ion attraction.

Main Results:

• The scaffold demonstrated excellent shape-memory performance, enabling temperature-triggered recovery for potential minimally invasive delivery.
• Electrically polarized scaffold surfaces induced M2 macrophage polarization and promoted BMSC osteogenic differentiation by activating PI3K/Akt and FAK/ERK signaling pathways.
• The negatively charged surface facilitated calcium and phosphate ion attraction, promoting mineralization and extracellular matrix formation.

Conclusions:

• A novel 3D-printed scaffold with multistage osteogenic activity was successfully developed.
• The scaffold effectively regulates the immune microenvironment and promotes stem cell osteogenic differentiation and matrix mineralization.
• This innovative scaffold presents a promising strategy for advancing bone defect repair applications.