Microporous Scaffolds from Poly(Lactide-Co-∊-Caprolactone) Composites with Hydroxyapatite and Tricalcium Phosphates Using Supercritical CO2 for Bone Tissue Engineering

Abstract
A copolymer of L-lactide and ∊-caprolactone ( M n:73,523, M w: 127,990 and PI: 1.74) was synthesized by ring-opening polymerization and confirmed by FTIR, 1 H-NMR and DSC. The copolymer ratio of L-lactide to ∊-caprolactone, determined by 1H-NMR, was 89/11. Specific amounts of hydroxyapatite or tricalcium phosphate were blended in the copolymer matrix to form new composites. Films were made by solvent casting the copolymer and the composite materials. The films were subjected to supercritical CO2 at 3300psi and 70°C to create porous structures. The pore sizes were in the range of 40–80 μm. The porous films (both copolymer and composite) degraded in Ringer solutions much faster than corresponding untreated non-porous films.