Ting Ting Yan

Preparation and Characterization of Hydroxyapatite Whiskers

Hydroxyapatite whiskers were prepared with diammonium hydrogen phosphate, calcium nitrate, nitric acid, sorbitol, HAP seed and carbamide by hydrothermal homogeneous precipitation. The HAP seeds served as whiskers nuclei and sorbitol served as template. The prepared hydroxyapatite whiskers were characterized by XRD,SEM and FTIR. It was indicated that hydroxyapatite whiskers with high crystallinity grew alone Z axis with carbonated trend, and the appearance of HAP was smooth, less magazine and no reunion, the length-diameter ratio of the whiskers was in range of 125-8 with the average is 32.78.

Porous Calcium Sulfate/Hydroxyapatite Whiskers Scaffold for Bone Tissue Engineering

Porous calcium sulfate/hydroxyapatite whiskers composites scaffold is possible to be used in bone tissue engineering, for its biocompatibility, controllable degradation, and good mechanical properties. In this study, porous calcium sulfate/hydroxyapatite whisker composite scaffolds were fabricated by adding pore-forming agent and were characterized. The characteristics of the porous scaffolds were assessed by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and immersing testing techniques. It is shown that the scaffolds prepared in this article have the porous structure with the content of CaSO4 and HA. The scaffolds prepared in this article have been confirmed to be ideally used as biodegradable implants.

A Novel Biodegradable Phosphate Coating on AZ31B Alloy

Mg and its alloys draw more and more attentions to be used as biodegradable medical materials. But the rapid degradation of those materials limits their clinical applications. In this article, a phosphate coating was prepared on AZ31B magnesium alloy to improve its anti-corrosion property. Morphology, composition and corrosion resistance of the coating were studied. The SEM research showed that the coating that composed of rod-like phosphates with small amount of random distributed micro-voids was approximately10-20μm in thickness. The XRD analysis indicated that the coating was mainly composed of MgO, Mg3(PO4)2and Zn3(PO4)2·xH2O. Electrochemical test showed the phosphate treatment could significant improve the corrosion resistance of AZ31B.

Biodegradability of AZ31B Magnesium Alloy with a Permanganate Conversion Coating

Magnesium alloy has been considered as a revolutionary biodegradable material, but the fast degradation limits its development. A permanganate conversion coating for AZ31B magnesium alloy prepared, in order to improve its anti-corrosion property. The morphology and composition of the coating were characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersion spectroscopy (EDS), which showed that the coating was 40-170μm in thickness, with net-like micro-cracks, and was tightly combined with AZ31B magnesium alloy matrix. The main compositions of the coating were Mg and a series of oxides of Mn. Observed by the tests of electrochemical and immersion,the corrosion resistance of AZ31B magnesium alloy can be improved significantly through the permanganate conversion treatment

Prepartion and Properties of Zinc-Doped Hydroxyapatite Whisker

Hydroxyapatite is well used as bone repair materials. Degradation property and biological activity can be further improved by addition Zn into the HAP crystals. Zinc-doped hydroxyapatite whiskers with different content of Zn were prepared with calcium nitrate, Zinc nitrate and diammonium phosphate at the degree of 95°C. Zinc-doped hydroxyapatite whiskers were characterized by XRD, FT-IR, SEM and EDS. It was indicated that zinc can be doped in hydroxyapatite with proper process and zinc-doped hydroxyapatite whiskers were produced successfully.

Research of Preparation and Properties of CaSO4/HAw Bone Graft Substitute

Calcium sulfate/hydroxyl apatite whiskers composite is possible to be used as bone graft substitute, for its biocompatibility, controllable degradation, and suitable mechanical properties. In this study, calcium sulfate/hydroxyl apatite whisker composites were fabricated and characterized. The characteristics of the composites were assessed by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and immersing testing techniques. The composites prepared in this article have been confirmed to be ideally used as biodegradable implants.

Preparation and Research of Porous Hydroxyapatite Whiskers/KGM Composite Bone Scaffolds

Sol-gel method and freeze-drying method were adopted to prepare the porous HAPw/KGM composite bone scaffolds and ammonia was used as a crosslinking agent. The porosity, average pore diameter, compressive strength and degradation rate in vitro were measured according to the related standard. The curves of each factor and lever affecting comprehensive properties were drew through the orthogonal design L9 (34) experiment. SEM and XRD were applied in characterization. The results show that the optimal preparation program of the composite scaffolds is KGM (2g), HAPw (4.5g), ammonia (0.1 ml) and the freeze temperature (-20 ° C); the prepared scaffolds are porous three-dimensional network structures; the porosity of optimal scaffold is more than 90%; the average pore diameter is between 200-300μm; the compressive strength is about 0.8Mpa and the degradation rate is about 50% within 9 weeks.

Preparation and Characterization of Calcium Sulfate Spherical Particles for Dentistry

In this article, calcium sulfate spherical particles were prepared to be used in alveolar bone defect repairing. We used α-calcium sulfate hemihydrate powder to prepare spherical particles of calcium sulfate with stir pelletizing method. The effect of powder addition, pelletizing time and concentration of water-glass on properties of the spherical particles were studied. It was indicated that with increasing of the powder addition, the particle size of the spherical particles was decreased. Prolonging the pelletizing time can improve the compression strength in certain conditions. With increasing of the concentration of water-glass used in preparation process, the shape of the spherical particles becomes non-circular, the granulous stem yield was decreased and the compression strength of the spherical particles was improved.

Study on the Preparation of Strontium-Doped Hydroxyapatite Whisker

Hydroxyapatite is well used as bone repair materials, due to its properties that can be combined with strontium to improve mechanical property and degradation property. In this article, hydroxyapatite whiskers with different amount of doped strontium were prepared with diammonium phosphate, calcium nitrate and strontium nitrate at 94 °C. Fourier transform infrared spectroscopy (FTIR) was used to identify the functional groups. X-ray diffraction (XRD) analysis was carried out to study the phase composition and crystallinity of the whisker. The morphology of the whiskers was characterized by scanning electron microscope (SEM). It was indicated that strontium can be doped in hydroxyapatite with proper process and then the strontium-doped hydroxyapatite whiskers were produced successfully.

Biological Performances Investigation of KGM/SH Fiber Membranes

Fiber woven membranes were prepared with konjac glucomannan (KGM) and sodium hyaluronate (SH). Glycerol was added as plasticizer and lactic acid as modifier. After treatment with microwave,wet spinning method and the programmable 2D mobile platform were used to prepare the KGM/SH fiber woven membranes. The in vitro degradability of the fiber membranes was tested by PBS immersion. The biological activity of the fiber woven membranes was observed by SBF mineralization experiments. The cytocompatibility was also investigated via co-culture of stem cells. It was revealed that the fiber woven membranes had good biological activity, degradation rate and cytocompatibility, which indicated that the membrane has a good prospect as a potential cartilage scaffold.