Poly(d,l-Lactic acid) Composite Foams Containing Phosphate Glass Particles Produced via Solid-State Foaming Using CO₂...

Area of Science:

• Biomaterials Science
• Materials Engineering
• Tissue Engineering

Background:

• Biodegradable polymers like poly(d,l-lactic acid) (PDLLA) are promising for bone tissue engineering (BTE).
• Incorporating bioactive fillers can enhance mechanical properties and osteoconductivity of BTE scaffolds.
• Developing efficient fabrication methods for complex composite structures is crucial for BTE.

Purpose of the Study:

• To produce and characterize highly porous composite foams from PDLLA and a calcium phosphate glass particulate (PGP) for BTE.
• To investigate the effect of PGP content on the morphological and mechanical properties of the composite foams.
• To evaluate the suitability of the solid-state foaming (SSF) technique for fabricating BTE scaffolds.

Main Methods:

• Composite materials were fabricated by melt compounding PDLLA with 5-30 vol.% PGP (50P2O5-40CaO-10TiO2 mol.%).
• Porous structures were created using solid-state foaming (SSF) with high-pressure gaseous carbon dioxide.
• Morphological analysis (SEM) and mechanical testing (compressive strength, Young's modulus) were performed on neat and composite foams.

Main Results:

• PGP fillers were well dispersed in the PDLLA matrix.
• Composite foams exhibited significantly improved compressive strength and Young's modulus (>2-fold) compared to neat PDLLA foam.
• High porosity (up to 91%) with well-interconnected macropores (up to 78% open) and reduced pore size (down to 190 µm) were achieved with increasing PGP content.

Conclusions:

• The SSF technique effectively produced highly porous PDLLA-PGP composite foams with tunable characteristics suitable for BTE.
• The incorporation of PGP significantly enhanced the mechanical properties and pore structure of the foams.
• SSF offers advantages in flexibility and high bioactive particle incorporation for designing advanced BTE scaffolds.