Fabrication and Characterization of Hydroxyapatite/Wollastonite Composite Bioceramics with Controllable Properties for Hard Tissue Repair
In this study, the hydroxyapatite/wollastonite (Ca10(PO4)6(OH)2/CaSiO3, HAp/CS) composite bioceramics with different weight ratio were fabricated. The effects of composite ratio on sintering behavior, microstructure, mechanical properties, bioactivity, degradability behavior and the bone marrow mesenchymal stem cells (MSC) response to the composites were investigated. When the weight ratio of CS increased, the linear shrinkage of the ceramics decreased, while the porosity increased. The bending strength of the composites could be regulated between 98.06 ± 3.27 and 221.30 ± 15.69 MPa, and increased apparently with the increase of the CS component amount. The elastic modulus of the sintered samples was about 14.88–18.95 GPa, which was similar to that of human cortical bone. The bioactivity of the composites was enhanced with increasing CS content. For composites with more than 30 wt% CS contents, the samples were completely covered by a layer of dense apatite only after 1 day soaking. The dissolution rate of the samples increased with the increase of CS content, which suggested that the degradability of the HAp/CS composite bioceramics could be tailored by adjusting the initial HAp/CS ratio. In addition, the proliferation of MSC on the composites was examined and the results showed that higher content of CS content in composites promoted cell proliferation. When the CS content in the composite increased to 30 wt%, the proliferation rate of MSC cells showed significant higher than that of pure HAp (P<0.05). Therefore, the HAp/CS composites with more than 30 wt% CS content might be promising candidates as load bearing, bioactive, and degradable biomaterials for hard tissue repair applications.
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Document Type: Research Article
Affiliations: State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
Publication date: 2011-01-01