Acceleration of osteogenic differentiation of preosteoblastic cells by chitosan containing nanofibrous scaffolds.

To accelerate bone tissue formation, scaffolds better provide stimulatory niches to the residing cells for osteogenic differentiation. In this study, polycaprolactone (PCL) nanofibers containing various amounts of chitosan (0, 3, 9, and 23%) were prepared and evaluated for their osteogenic differentiation of preosteoblasts in 2D and 3D cultures. Characterization of the obtained nanofibers revealed that average fiber diameter, hydrophilicity, Young's modulus, and fiber degradation were closely correlated with the amount of chitosan in PCL nanofibers. Incorporation of chitosan in PCL nanofibers not only improved the adhesion and proliferation of MC 3T3-E1 cells but also elevated calcium deposition, alkaline phosphatase (ALP) activity, and the expression of osteopontin (OPN) compared to PCL alone nanofibers. Culture of cell-rich 3D constructs prepared by layer-by-layer assembling MC 3T3-E1 with chitosan containing PCL nanofibers led to a uniform tissue formation with significant mineralization at 21 days. In all, chitosan containing PCL nanofibers are superior to PCL nanofibers in promoting bone tissue formation.