Bioactivation of biomorphous silicon carbide bone implants

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• 作者：Julia Will ; Alex ; er Hoppe ; Frank A. Mü ; ller ; Carmen T. Raya ; Juliá ; n M. Ferná ; ndez ; Peter Greil
• 关键词：Biomorphous ceramics ; SiC ; Biomimetic ; Hydroxyapatite ; Bioactivity
• 刊名：Acta Biomaterialia
• 出版年：2010
• 出版时间：December 2010
• 年：2010
• 卷：6
• 期：12
• 页码：4488-4494
• 全文大小：882 K

文摘

Wood-derived silicon carbide (SiC) offers a specific biomorphous microstructure similar to the cellular pore microstructure of bone. Compared with bioactive ceramics such as calcium phosphate, however, silicon carbide is considered not to induce spontaneous interface bonding to living bone. Bioactivation by chemical treatment of biomorphous silicon carbide was investigated in order to accelerate osseointegration and improve bone bonding ability. Biomorphous SiC was processed from sipo (Entrandrophragma utile) wood by heating in an inert atmosphere and infiltrating the resulting carbon replica with liquid silicon melt at 1450 °C. After removing excess silicon by leaching in HF/HNO₃ the biomorphous preform consisted of β-SiC with a small amount (approximately 6 wt. % ) of unreacted carbon. The preform was again leached in HCl/HNO₃ and finally exposed to CaCl₂ solution. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared analyses proved that oxidation of the residual carbon at the surface induced formation of carboxyl [COO⁻] groups, which triggered adsorption of Ca²⁺, as confirmed by XPS and inductively coupled plasma optical emission spectroscopy measurements. A local increase in Ca²⁺ concentration stimulated in vitro precipitation of Ca₅(PO₄)₃OH (HAP) on the silicon carbide preform surface during exposure to simulated body fluid, which indicates a significantly increased bone bonding activity compared with SiC.