Facile synthesis of anisotropic porous chitosan/hydroxyapatite scaffolds for bone tissue engineering

This paper reports a facile strategy of integrating composite synthesis and pore fabrication into one step to fabricate anisotropic porous chitosan/hydroxyapatite (CS/HA) scaffolds for the first time. These orientation-structured porous CS/HA scaffolds exhibited highly anisotropic porous structure, uniform and optimal pore sizes (200 similar to 500 mu m), high porosity (ca. 85%), unidirectional interconnected network, and excellent anisotropic mechanical properties. The anisotropic pore architecture of CS/HA scaffolds was formed spontaneously accompanied by a process of in situ precipitation of HA into the CS matrix, and the formation mechanism was also investigated. This novel one-step fabrication method is based on a brand-new principium which is totally different from the traditional ones and has never been reported before. It is a new breakthrough on technical advancement of porous structure fabrication, especially for anisotropic porous structure fabrication. Moreover, the cell biocompatibility with the scaffolds was tested in vitro. The results indicated that excellent cell biocompatibility was observed for the orientation-structured porous CS/HA scaffold (40/60 in weight ratio), in which the MG63 cells could spread and cluster along the macroporous walls of the scaffold, and deeply penetrate into the tube-like pores. This orientation-structured porous scaffold, combining high biocompatibility with high strength, has a better potential for application in bone tissue engineering.