Bone tissue engineering is an interdisciplinary field which is emerged for the development of viable substitutes that restore and maintain the function of human bone tissues. The success of bone tissue engineering depends on designing of the scaffolds. The polymer-based composite scaffolds containing micro- and nano-structures could provide a platform influencing osteoblastic cell adhesion, spreading, proliferation, and differentiation. Osteoblasts may adhere strongly to the nano-structures than micro-structures in the scaffolds due to the large surface area, better osteo-integrative property and mechanical reliability etc. In this review we are focusing the factors such as pore size, surface topography and roughness, protein adsorption and wettability of nano-structures and their interaction with cell surface integrins molecules. A better understanding of the interactions of nano-structures with osteoblastic cells will have potential applications in the regeneration of bone.