Bioprinted Osteogenic and Vasculogenic Patterns for Engineering 3D Bone Tissue.

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Fabricating 3D large-scale bone tissue constructs with functional vasculature is challenging for repairing large bone defects.
• Existing methods struggle to create complex, perfusable vascular networks within engineered bone.
• Need for biomimetic matrices that support cell co-culture and promote osteogenesis and angiogenesis.

Purpose of the Study:

• To develop a direct-writing bioprinting strategy for fabricating microstructured, bone-like tissue constructs with perfusable vascular lumens.
• To create in vitro matrices for co-culturing endothelial cells and mesenchymal stem cells.
• To engineer constructs with controlled physical and chemical microniches and gradients.

Main Methods:

• Utilized extrusion-based direct-writing bioprinting with gelatin methacryloyl (GelMA) hydrogels.
• Printed a central cylinder of low methacryloyl substituted GelMA (GelMA_LOW) to form a vascular lumen.
• Developed cell-laden cylinder elements with silicate nanoplatelets for osteogenesis and synthesized hydrogels with vascular endothelial growth factor for vascularization.

Main Results:

• The bioprinted constructs supported cell survival and proliferation during 21 days of in vitro maturation.
• Engineered constructs demonstrated high structural stability throughout the culture period.
• The method allowed for local control of physical and chemical microniches and gradient establishment.

Conclusions:

• The developed bioprinting strategy successfully fabricated bone-like tissue constructs with perfusable vasculature.
• The engineered constructs are suitable for in vitro co-culture and demonstrate potential for bone defect repair.
• This approach enables precise control over the microenvironment within engineered tissues.