Porous zirconia/hydroxyapatite scaffolds for bone reconstruction

摘要

Objective. Highly porous apatite-based bioceramic scaffolds have been widely investigated as three-dimensional (3D) templates for cell adhesion, proliferation, and differentiation promoting the bone regeneration. Their fragility, however, limits their clinical application especially for a large bone defect. Methods. To address the hypothesis that using a ZrO_2/hydroxyapatite (HAp) composite might improve both the mechanical properties and cellular compatibility of the porous material, we fabricated ZrO_2/HAp composite scaffolds with different ZrO_2/HAp ratios, and evaluated their characteristics. In addition, porousZrO_2/HAp scaffolds containing bone marrow derived stromal cells (BMSCs) were implanted into critical-size bone defects for 6 weeks in order to evaluate the bone tissue reconstruction with this material. Results. The porosity of a ZrO_2/HAp scaffold can be adjusted from 72% to 91%, and the compressive strength of the scaffold increased from 2.5 to 13.8 MPa when the ZrO_2 content increased from 50 to 100 wt%. The cell adhesion and proliferation in the ZrO_2/HAp scaffold was greatly improved when compared to the scaffold made with ZrO_2 alone. Moreover, in vivo study showed that a BMSCs-loaded ZrO_2/HAp scaffold provided a suitable 3D environment for BMSC survival and enhanced bone regeneration around the implanted material. Significance. We thus showed that a porous ZrO_2/HAp composite scaffold has excellent mechanical properties, and cellular/tissue compatibility, and would be a promising substrate to achieve both bone reconstruction and regeneration needed in the treatment of large bone defects.