Bone-Like Apatite-Coated Chitosan Scaffolds: Characterization and Osteoblastic Activity

In this study, porous scaffolds were prepared from chitosan (2% w/v in acetic acid and deacetylation degree: DD > 85%) by freeze-drying method, and freshly lyophilized scaffolds were stabilized with ethanol solutions. Bone-like apatite formation on chitosan scaffolds was achieved by immersing the scaffolds into a novel concentrated simulated body fluid (10 x SBF-like solution) for different periods, i.e., 6 and 24 h. Scanning electron microscope views showed that the 6-h treatment in 10x SBF-like solution led to the formation of calcium phosphate nucleation sites on chitosan scaffolds, whereas the apatite particles showed characteristic cauliflower-like morphology at the end of 24-h treatment. X-ray diffraction results supported the fact that mineral phase was made of hydroxyapatite. Osteogenic activities of untreated and SBF-treated chitosan scaffolds were examined by preosteoblastic MC3T3 cell culture studies. The mitochondrial activity test showed that apatite-coated scaffolds stimulated cell proliferation compared with uncoated scaffolds. Alkaline phosphatase and osteocalcine levels indicated that the differentiation of the cells on all scaffolds increased significantly from 15th day of culture to the 21th day of culture, especially for the cells on 24-h SBF-treated scaffolds. The results of this study indicated that 10 x SBF-like solution-treated chitosan scaffolds may be evaluated for bone tissue engineering. POLYM. COMPOS., 31:1418-1426, 2010. (C) 2009 Society of Plastics Engineers