Preparation and characterization of osteochondral scaffold

Calcium phosphate was gradiently formed into cartilage-like matrices containing type II collagen using modified alternate soaking process. Characterization of calcium phosphate formed in the type II collagen matrices was performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), and scanning electron microscopy (SEM). The results from XRD and FT-IR analysis indicated that calcium phosphate formed in the matrix was hydroxyapatite (HAp), whose phosphate ions were partially replaced by carbonate ions. TG-DTA analysis showed that HAp content increased with increasing immersion cycle in calcium and phosphate solutions. SEM image showed that a calcium phosphate layer was deposited on one side of type II collagen gels. The type II collagen gel-HAp composite with gradient calcium phosphate crystals should prove useful in regenerating the bone-cartilage interface.