Papers by Author: Da Li Zhou

Abstract: Quantitative evaluation of repairing effect of bone grafting material is one of the essential studying subjects. However, traditional evaluation methods are subjective and qualitative. In this paper, the region of new bone from a bone repairing biomaterial planted image is extracted based on color image segmentation and then statistically analyzed to evaluate the property of bone grafting material quantitatively. HSI color model, which corresponds with people’s vision system for color is used to achieve ideal segmental results and effective utilization of color information. The S and I variable are used as thresholding condition for image segmentation, thereby obtaining the area of new bone. The effect of BMP contained in BMP/α-TCP is estimated furthermore. Experimental results show that the composite BMP/α-TCP induce more bone than pure α-TCP in virtue of BMP. This study provides theoretical and experimental suggestions for clinical applications of BMP/α-TCP.

Abstract: A co-precipitation preparation method and the properties of an ultraviolet (UV)-attenuating agent are described in this paper. The composite particles of ultra-fine zinc oxide and titanium oxide are used to attenuate UV radiation. Preparation of TiOSO4, ZnCl2 solution and the co-precipitation of the composite particles by alkali are included during the process. Various types of surfactants have been used to modify the composite particles. Particle sizes are determined by laser particle analyzer, and reflectance and absorption coefficient are determined by UV-VIS spectrophotometer. Results show that particle size of the composite particles as well as total reflectance and absorption coefficient depend on the surfactants, pH value, and carline temperature. The average sizes of zinc oxide and titanium oxide ultra-fine particles range from39 to 65 nm. Attenuation capability of ultraviolet radiation becomes stronger when the particle average sizes becomes smaller. Composites less than 40 nm with titanium oxide of rutile phase attenuate most effectively the ultraviolet radiation ranging from 280 nm to 390 nm.

Abstract: Bioactive composite of apatite-wollastonite(AW)/β-tricalcium phosphate (β-TCP) was prepared. The nucleation and growth of bio-apatite on the surface of AW/β-TCP ceramic in simulated body fluid (SBF) were investigated. The surface morphological structure, phase compositions and microstructure of the materials were characterized by scan electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR); Results show that the surfaces of the AW/β-TCP composite ceramic are covered with a layer of carbonate hydroxyapatite (HCA) when soaked in SBF, which indicates their bioactivity; Such HCA layer is composed of fine ball-like HA granules. With excellent bioactivity and bio-absorption, AW/β-TCP bioactive composite ceramic is expected to be a good candidate for bone substitutes and bone tissue engineering scaffolds.

Abstract: The porous apatite-wollastonite bioactive glass-ceramic (AW-GG) was made from nano-precursor powders derived from sol-gel process, and shaped by dipping method with polymer foam. The physical-chemical properties, bioactivity and biocompatibility of the materials were studied by means of TG, XRD, SEM, TEM and so on. The bioactivity was investigated in simulated body fluid (SBF) and the biocompatibility was evaluated by co-culturing with marrow stromal cells (MSCs). The result shows that: the particle size of the AW precursor powders is 40~100nm; porous AW GC has three-dimensional pored structure with 300~500um macropores and 2~5um micropores; the materials possess high bioactivity and biocompatibility. Porous AW GC may therefore have great potential application as bone tissue engineering scaffold.

Abstract: Merwinite powders were synthesized by a sol-gel process. The bioactivity in vitro of merwinite was investigated by soaking the powders in simulated body fluid (SBF), the growth of hydroxyapatite(HAp) on the surface of the powder was evaluated in various time. It was found that hydroxyapatite was formed after soaking for 14 days. The results indicate that merwinite possessed apatite-formation ability might be a potential candidate biomaterial for hard tissue repair.