Preparation and Characterization of β-TCP/CS Scaffolds by Freeze-extraction and Freeze-gelation

The freeze-extraction and freeze-gelation methods were used to prepare highly porous beta-TCP/CS scaffolds with different beta-TCP/CS ratio. In these methods, the suspending mixture of beta-TCP and chitosan was frozen, the frozen mixture was immersed in a non-solvent(0.05 mol/L NaOH/ehanol aqueous) bath to allow the exchange between solvent(acetic-acid aqueous) and non-solvent at a temperature lower than the freezing point of the acetic-acid. Then, the beta-TCP/CS scaffolds were formed and dried at room temperature. Scanning electron microscopy (SEM), X-ray diffraction (XRD), gas chromatography (GC) and omnipotence material testing machine were employed to characterize the beta-TCP/CS scaffolds. The results of GC show that the freeze extraction of the beta-TCP/chitosan scaffolds was completed when the extraction time is above 24 h. The SEM results show that the beta-TCP/CS scaffolds are composed of interconnected pore network. The porosity of the beta-TCP/CS scaffolds decrease with the increase of the content of the beta-TCP. The beta-TCP/CS scaffolds have a highest compressive strength when the chitosan/beta-TCP ratio is 30:70. The present work displays that the beta-TCP/CS composite scaffolds with appropriate mechanical properties and high porosity can be successfully prepared by the freeze-extraction and freeze-gelation methods.