Preparation and Characterization of Homogeneous Hydroxyapatite/Chitosan Composite Scaffolds via In-Situ Hydration

Abstract

Hydroxyapatite(HAP)/Chitosan(CS) composite is a biocompatible and bioactive material for tissue engineering. A novel homogeneous HAP/CS composite scaffold was developed via lyophilization and in situ hydration. A model CS solution with a Ca/P atom ratio of 1.67 was prepared through titration and stirring so as to attain a homogeneous dispersion of HAP particles. After lyophilization and in situ hydration, rod-shaped HAP particles (5 μm in diameter) within the CS matrix homogeneously scattered at the pore wall of the CS scaffold. X-ray diffraction (XRD) and Fouri-er-Transformed Infrared spectroscopy (FTIR) confirmed the formation of HAP crystals. The compressive strength in the composite scaffold indicated a significant increment over a CS-only scaffold. Bioactivity in vitro was completed by immersing the scaffold in simulated body fluid (SBF), and the result suggested that there was an increase in apatite formation on the HAP/CS scaffolds. Biological in vivo cell culture with MC 3T3-E1 cells for up to 7 days demonstrated that a homogeneous incorporation of HAP particles into CS scaffold led to higher cell viability compared to that of the pure CS scaffold or the HAP/CS scaffold blended. The results suggest that the homogeneous composite scaffold with better strength, bioactivity and biocompatibility can be prepared via in vitro hydration, which may serve as a good scaffold for bone tissue engineering.