Preparation and evaluation of a biomimetic scaffold with porosity gradients in vitro

A novel biodegradable scaffold based on mimetic a natural bone tissue morphology with a porosity gradient structure was prepared in this paper. The result of surface morphology indicated that a graded porous structure was formed in the fabricated scaffold, where the dense layer (0%) was connected with the most porous layer (60%) by a middling porous layer (30%). To evaluate the degradability, graded porous scaffolds compared with homogeneous scaffolds were placed into a Tris-HCl buffer solution (pH = 7.4) for 28 days. It was found that both scaffolds presented the same degradation trend, and the graded porous structure did not change the original degradability of the scaffold. Moreover, the compressive strength of the graded porous scaffold was better than that of conventional homogeneous scaffold with the increase of degradation time, and the graded porous structure can enhanced the mechanical property of the scaffold. These findings suggest that this biodegradable and porosity-graded scaffold may be a new promising scaffold for loaded bone implant.