Preparation and characterization of dexamethasone-immobilized chitosan scaffold.

Chitosan film (CSF), 2-dimensional scaffold, was modified with dexamethasone (DEX) in the present work via amino-alcohol forming reaction between amino group of chitosan and carbonyl group of DEX. Successful immobilization was identified by ATR-FTIR spectroscopy and, the immobilized amounts were determined by weighting methods (WM) and integrated area analysis method (AM) of HPLC. For experiments of cell culture of osteogenic differentiation, our results showed that DEX immobilization has more efficiency than the other group (such as both groups of CSF and CSF with free DEX, CSF/fDEX), which was demonstrated as indicated by cell image analysis and ALP activity assay. The results show, as AD-MSCs cultured on DEX-CSF, its shape of cell transformed to polygonal or cubical. The ALP activity assay indicates that of DEX-CSF increase about 3.5 folds than that of CSF's. The results suggest that immobilization of DEX can make chitosan scaffolds to induce differentiation of AD-MSCs toward osteoblastic lineage for bone tissue engineering application.