Polycaprolactone/Hydroxyapatite composite scaffolds: Preparation, characterization, and in vitro and in vivo biological responses of human primary bone cells

Polycaprolactone (PCL) is a synthetic biodegradable polymer that has been approved for use as bone graft substitutes. In this study, PCL scaffolds incorporating hydroxyapatite (HAp) particles were fabricated by combined solvent casting and particulate leaching techniques. The average pore dimension was in the range of about 480-500 mu m. The porosity, water absorption, and compressive modulus of the scaffold were evaluated. The responses of primary bone cells cultured on the PCL and PCL/HAp scaffolds were examined both in vitro and in vivo. In comparison with the cells grown on the PCL scaffold, those cultured on the PCL/HAp counterpart positively expressed the markers of osteogenic differentiation. Cells increased the mRNA expressions of type I collagen and osteocalcin on day 10 and demonstrated a significant increase in calcium deposition. In coherence with the ill vitro appearance, histomorphometric analysis in a mouse calvarial model showed a significantly greater amount of new bone formation. The results demonstrated that the prepared PCL/HAp scaffold could be a good candidate as synthetic substitute for bone tissue engineering. (C) 2010 Wiley Periodicals, Inc. J Biomed Mater Res 94A: 241-251, 2010