Bone Regeneration in SLS-Manufactured Resorbable 3D-Scaffolds-An Experimental Pilot Study in Minipigs.

Area of Science:

• Biomaterials Science
• Orthopedic Research
• Tissue Engineering

Background:

• Resorbable scaffolds are crucial for bone regeneration.
• Poly-L-lactide (PLLA) scaffolds incorporating CaCO3 and CaP were investigated.
• Understanding scaffold properties' impact on bone ingrowth is essential.

Purpose of the Study:

• To evaluate how pore volume and material composition affect bone ingrowth in PLLA-CaCO3/CaP scaffolds.
• To assess bone formation and pore fill in a minipig tibial defect model.

Main Methods:

• Selective laser sintering (SLS) produced PLLA scaffolds with varying porosity and CaP surface modification.
• Scaffolds were implanted into minipig tibial defects for 4 and 13 weeks.
• Micro-computed tomography (µCT) and histomorphometry analyzed bone ingrowth and osteocalcin expression.

Main Results:

• After 4 weeks, bone formation and pore fill were limited but increased significantly by 13 weeks, reaching ~96% pore fill.
• Newly formed bone contacted scaffold walls.
• No significant differences in bone formation were observed between scaffolds with varying pore volumes or CaP addition.

Conclusions:

• SLS-produced PLLA scaffolds effectively support bone ingrowth, achieving substantial pore volume fill within 13 weeks.
• Pore volume and CaP surface modification did not significantly influence bone regeneration in this model.
• Limited CaP availability may explain its lack of enhanced bone formation effect.