Differentiation of mesenchymal stem cells in chitosan scaffolds with double micro and macroporosity. 
Bone Marrow mesenchymal stem cells can be induced to differentiate into osteoblasts to regenerate damaged bone tissue using tissue engineering techniques.  In this study, we examine the use of chitosan scaffolds with double pore structure prepared by an innovative method that combines freeze gelation (that produces micropores) and particle leaching out technique (that produces interconnected spherical macropores) seeking to enhance the osteogenic differentiation of goat bone marrow stromal cells (GBMSCs).  The double pore architecture of the scaffold was characterized by scanning electron microscopy (SEM), microcomputed tomography and confocal laser scanning microscopy.  The obtained hierarchical pore structure allowed very efficient seeding of GBMSCs that are able to occupy the whole volume of the scaffold, showing good adhesion and proliferation.  GBMSCs were differentiated into osteoblasts as indicated by alkaline phosphatase activity and osteocalcin expression.  The results of this study demonstrate that chitosan scaffold may be promising biomaterial for bone regeneration.