Functional bone engineering using ex vivo gene therapy and topology-optimized, biodegradable polymer composite...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Bone tissue engineering offers alternatives for bone defects like fracture nonunion and pathological bone loss.
• Current challenges include creating biocompatible scaffolds for cell delivery, tissue invasion, and load-bearing capacity during regeneration.

Purpose of the Study:

• To engineer a biodegradable composite scaffold for bone regeneration.
• To evaluate the scaffold's ability to support cell integration, new bone formation, and mechanical properties during degradation.

Main Methods:

• Utilized topology-optimized design and solid free-form fabrication to create poly(propylene fumarate)/beta-tricalcium phosphate composite scaffolds.
• Seed scaffolds with human fibroblasts genetically modified to express bone morphogenetic protein-7.
• Implanted scaffolds subcutaneously in mice and assessed via microcomputed tomography, compressive testing, and histology.

Main Results:

• New bone formation was observed on the scaffold surface, conforming to the designed architecture.
• Scaffold stiffness was maintained for up to 12 weeks post-implantation.
• Scaffold degradation correlated with successful tissue invasion and regeneration.

Conclusions:

• Topology-optimized, fabricated composite scaffolds show promise for bone tissue engineering.
• These scaffolds effectively support new bone formation and retain mechanical integrity during the regeneration process.
• This approach could advance treatments for significant bone defects and injuries.