The microstructure of antigen-extracted heterologous bone

Cui Jie; Li Zheng; He Hui-yu; Hu Yang

doi:10.3969/j.issn.2095-4344.2013.42.001

Abstract：BACKGROUND:Different methods to remove immunogenicity have different effects on the spatial microstructure of antigen-extracted heterologous bone. <br> OBJECTIVE:To compare the microstructure of the antigen-extracted heterologous bone via different methods to provide experimental data for tissue engineering industrialization. <br> METHODS:Fresh cancellous bones extracted from adult sheep vertebrae were prepared into cylinders. Their long axis direction was the same with orientation of the trabeculae. After vibration washing and different-frequency ultrasound rinsing, the cylinder samples were randomly divided into three groups:in physical calcined group, the samples were defatted, decellularized and deproteinized sequential y using methanol/chloroform and hydrogen peroxide, then bathed in sodium pyrophosphate and directly calcined at 1 000 ℃ for 3 hours;in chemical group, the samples were defatted, decellularized and deproteinized sequential y using methanol/chloroform and hydrogen peroxide;in control group, the samples were dried natural y at room temperature. Microstructure of the samples in each group was analyzed and compared through determination of porosity, scanning electron microscopy observation, X-ray diffraction analysis, X-ray atomic spectroscopy elemental analysis microscopic spatial structure. <br> RESULTS AND CONCLUSION:The physical calcined and chemical groups maintained natural network pore system to different extents. The size of the large pore was 50-600μm and that of the smal one was about 2μm. The porosity was 55%to 70%. Hydroxyapatite was the main component of the physical calcined group which was determined by X-ray diffraction, and a smal amount of theβ-Tricalcium phosphate was also determined. In the chemical group, the main component was only hydroxyapatite. The three-dimensional spatial structures of the deproteinized cancellous bones were not damaged greatly, and they had a natural pore network system. Antigen component of xenogeneic cancellous bone can be more thoroughly removed by physical calcination step. The scaffold material made by antigen-extracted heterologous bone may satisfy the demands for bone tissue-engineering scaffolds.