Nanofibrous membrane scaffolds of chitosan (CS), silk fibroin (SF) and CS/SF blend were prepared by electrospinning and studied for growth and osteogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs). The morphology and physico-chemical properties of all membrane scaffolds were compared. The influence of CS and SF on cell proliferation was assessed by the MTS assay, whereas osteogenic differentiation was determined from the Alizarin Red staining, alkaline phosphatase activity and expression of osteogenic marker genes. The osteogenic differentiation and proliferation of hMSCs were enhanced by CS and SF nanofibers, respectively. Blending CS with SF retained the osteogenesis nature of CS without negatively influencing the cell proliferative effect of SF. By taking advantage of the differentiation/proliferation cues from individual components, the electrospun CS/SF composite nanofibrous membrane scaffold is suitable for bone tissue engineering. (C) 2014 Elsevier Ltd. All rights reserved.