Fabricating oxygen self-supplying 3D printed bioactive hydrogel scaffold for augmented vascularized bone regeneration

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Bone tissue engineering scaffolds face challenges like poor mechanical properties and central necrosis.
• Existing scaffolds often require cells or growth factors, limiting clinical application.

Purpose of the Study:

• To develop a cell/factor-free, self-oxygenated 3D printed bioactive hydrogel scaffold for enhanced bone regeneration.
• To address limitations of current bone tissue engineering scaffolds.

Main Methods:

• Constructed a hybrid double network hydrogel (polyacrylamide and CaCl2-crosslinked sodium carboxymethylcellulose) for mechanical strength and printability.
• Integrated oxygen-generating calcium peroxide (CaO2) nanoparticles encapsulated within ZIF-8 for sustained oxygen release.
• Utilized 3D printing to create a scaffold with pore structures facilitating cell infiltration and nutrient transport.

Main Results:

• The hydrogel scaffold exhibited excellent compressive strength and 3D printability, mimicking extracellular matrix characteristics.
• Sustained oxygen release from CaO2/ZIF-8 nanoparticles promoted in vitro cell viability, proliferation, angiogenesis, and osteogenic differentiation.
• The combination of oxygen and 3D pore structure prevented central necrosis and facilitated cell infiltration, vascularization, and bone regeneration in vivo.

Conclusions:

• The developed self-oxygenated 3D printed hydrogel scaffold offers a promising cell/factor-free approach for bone tissue engineering.
• This innovative scaffold demonstrates significant potential for clinical applications in bone regeneration and repair.