Engineering Pro-Osteogenic Poly(l-Lactide-co-ε-caprolactone) Sponges Through Carbonate Apatite Integration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Polymer/ceramic composites show promise as bone grafts, but polymer coating can hinder osteogenesis.
• Developing flexible, osteoconductive bone graft substitutes is crucial for effective bone healing.

Purpose of the Study:

• To fabricate a highly elastic and osteoconductive bone graft sponge.
• To integrate carbonate apatite (CAp) particles within a poly(l-lactide-co-ε-caprolactone) (PLCL) matrix.
• To create a macroporous structure for enhanced bone regeneration.

Main Methods:

• Fabricated a PLCL/CaCO3 sponge via freeze-drying a PLCL and calcium carbonate precursor slurry.
• Converted CaCO3 to CAp and exposed CAp on the surface using a sodium phosphate solution, enhancing hydrophilicity.
• Created interconnected macropores (500-600 μm) by embedding and leaching NaCl crystals.

Main Results:

• In vitro studies showed CAp and macropores significantly enhanced osteoblast adhesion and differentiation.
• In vivo rabbit femoral defect models demonstrated CAp provided osteoconductivity, facilitating bone ingrowth within 4 weeks.
• The macroporous structure supported comprehensive bone regeneration throughout the sponge.

Conclusions:

• The developed PLCL/CAp sponge exhibits significant osteoconductivity and promotes bone regeneration.
• The combination of CAp integration and a macroporous structure enhances the biomaterial's efficacy.
• This PLCL/CAp sponge represents a promising candidate for bone regenerative applications.