Advanced Materials Research Vols. 311-313

Abstract: The polycaprolactone (PCL)/chitosan (CS) scaffolds were prepared by the freeze-solvent extraction method using glacial acetic acid with little water as a common blend system. The effect of different solvents on the crystallinity, the morphology, the structure and the mechanical properties of the scaffolds was studied. The results indicate that alkaline solvent favors the deposition of CS, solvent extraction in the frozen condition perfects the crystal of PCL and improves the crystallinity of PCL/CS scaffolds, in the mean while, the compression property enhances. The porosity of PCL/CS reaches 81%, when immersed in water solvent.

Abstract: The coating preparation of HA on the surface of Mg-4.0Zn-1.0Ca-0.6Zr alloy sheet is carried out through a technique combining of pre-alkali-heat-solution-treatment, electro-deposition and post-alkali-heat-solution-treatment. The microstructure and appearance of the coatings are observed and analyzed by means of scan electron microscope. As well as with help of spectrophotometer, the antihemolytic ability of the alloy with HA coated in blood has been studied. The results indicate that the available ageing treatment of the alloy sheet is at 175 °C for 12 hours, and as the rule, the yield strength σ0.2 and elongation rate δ % is reached 320 MPa and 18.75 % respectively. The HA coated with a desirable microstructure is achieved under the technique parameter of the temperature 50 °C and the voltage nearly 10 V, as well as it’s ratio of Ca and P is 1.72 which is close to the human bone tissue of 1.67. The concentration of [Mg²⁺] in leaching liquor is depressed as the using of the alloy with HA coated so that the adverse reaction caused by higher concentration of [Mg2+] in the parts of the body position can be avoided. The value of hemolysis ratio of the alloy with HA coated is 4.06 % less than that of the alloy with un-coated which is 4.35 %, therefore the antihemolytic ability of alloy with HA coated is increased, and the phenomena of hemolysis is not taken place when it is used as one of human body planting material.

Abstract: Purposes: antioxidation of Extract of Chinese Quince on Oil was studied in this paper. Methods: the extract of Chinese Quince was prepared first, then to mixed with lard or peanut oil, in order to determinate their antioxidation. Results: the results showed that the extract of water, 50%alcohol,50% methanol and acetic ester had antioxidation on lard and peanut oil. Conclusion: in comparison, it was found that the effect of antioxidation of 50% methanol and water were preferably, and water was the premium. Chinese Quince is the fruit of Common Floweringquince that belongs to family of Rosaceae. Its Chinese name Mugua was first found in , also called Mao or Tiejiaoli in several other Chinese traditional medicine books such as and . For example, Li shizhen said that according to Mao is another name of Mugua. Guopu commented that Mugua is like a small melon which is eatable and that is what the name is after. wrote as ”Mugua is nowadays very popular, while it is of the best type in the city of XuanCheng. Its tree is like a nai tree. Its flowers are in dark red and blossom in the late spring. Its fruits are of size up to water mellon and down to fist. The people in Xuanzhou are good at cultivating Mugua. They plant Mugua in the valleys. When the fruits are ripe they will put them under sunlight and the fruits will turn into red.” Mugua tastes sore and are tender in character. It is good for liver and spleen. It can be used for relaxing muscles, removing body moist and tending stomach [1-5]. Recently the research on its effective factors and the corresponding development of functional food has become an important area. Although the wine making by fermentation of Chinese quince has been reported, the research on the antioxidation effects of extract of Chinese Quince on oil is rather limited. Therefore, we are aiming at providing more theoretical support for discovering the resource of Chinese Quince by focusing on the antioxidation effects of Chinese Quince.

Abstract: Hydroxyapatite (HA) and Hydroxyapatite/Chitosan (HA/CS) composite were prepared through neutralization method. The results indicate that the way of adding phosphorous acid solution is a key factor to obtain pure HA product, and that prolonged stirring time only promote the entry of CO₃^2- into the lattice of HA crystal. The addition of chitosan can overcome those factors which hamper the formation of pure HA particles, thus optimizing the whole reaction system.

Abstract: Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO₃)₂•4H₂O and (NH₄)₂HPO₄ as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).

Abstract: In this study, ZTA powder is modified by SA with different concentrations (0wt%, 1wt%, 2wt%, 3wt%, 4wt%) for the purpose of improving its properties. The effects of SA on microstructure, particle size distribution and flowability of the ZTA powder are investigated by scanning electron microscope(SEM), laser diffraction analyzer and self-made testing device of the angle of repose. After treatment, the average diameter of the powder decreases, the powder shows better dispersibility and flowability especially when the content of SA is 3wt%. FTIR spectroscopy is employed to evaluate the effect of SA coating on ZTA powder. The results indicate that a covalent bond is formed by the reaction between the hydroxyl group of ZTA surface and carboxyl group of stearic acid. Moreover, the changing of the polarity of ZTA powder can result in a stable dispersion in organic solvents.

Abstract: Sand-blasting treatment and chemically biomimetic growth are important methods improving the interface adhesion strength and formation of osteoconductive coatings for implants. In the present study, these methods were employed to generate bone-like apatite coating on Ti6Al4V spinal fusion devices. The surface morphology, elements and microstructure were analyzed using SEM, AFM, EDS, XRD and TEM. The results showed that bone-like apatite layer formed after sand blasting treatment and chemically biomimetic growth. Also the dimensional accuracy of device after the treatment could meet the implantation requirement of the device. The coating adhesion test suggests that rough surface after sand-blasting can improve the coating adhesion strength. The study will facilitate further the engineering application of chemically biomimetic growth in surface modification of Ti6Al4V implants and the medical application of spinal fusion device.

Abstract: PAN-based carbon fiber (CF) was modified in different ways by authors. The current multiple modification treatment composed of surface oxidation, maleic anhydride (MA) graft and metalion-adsorption was regarded to be a favorable surface treatment for CF carrier. The CF surface morphology and natures were characterized by specific facilities, such as laser confocal microscopy (LCM), X-ray photoelectron spectroscopy (XPS) and the degree of moisture. On the other hand, the biocompatibility nature was indicated by immobilization results of microorganisms on CF. The results show that the surface hydrophilicity and roughness of CF, and the metalion adsorbed on the CF surface would contribute greatly to biofilm formation and improve the immobilization ability of microorganisms on CF surface. Furthermore, the configurations and the adhesion forms of cells were obviously affected by the properties of CF surface.

Abstract: Mg-1Zn-0.5Ca alloy was prepared by casting technology. The as-cast alloy was solution treated at 470°C for 24 h and aged at 175°C for 0-50 h. The microstructure, mechanical properties and electrochemical corrosion behavior of the alloys were investigated. The results showed that the average grain size of the as-cast alloy was 120-150 μm, and the precipitated phases were distributed uniformly in α-Mg grain. The as-cast alloy showed good mechanical properties. The tensile strength was 186 MPa, and ductility was 23%. A typical age softening responses was obtained during the aging treatment. In the electrochemical corrosion tests, corrosion of the alloys is improved in Hank’s solution and 3.5wt% NaCl solution after the solution and aged treatment. However, the aged treated alloys showed the better electrochemical corrosion resistance.

Abstract: Poly (lactic acid) (PLA) scaffolds with different sizes are often fabricated for various requirements. A cellular automaton simulation was used to investigate the effect of the size on the degradation behaviors of porous PLA scaffolds. Four porous PLA scaffolds with 90% initial porosity and different sizes were established by a novel repeat unit method. Mass loss and the change in molecular weight during the degradation were simulated. The results indicate that mass loss is related to the size of the porous scaffold while molecular weight change is independent on the size. With the size of the porous scaffold increasing, the mass loss increases while the difference in mass loss between the scaffolds with different sizes decreases. All these changes can be attributed to the difference in the autocatalytic effect and corresponding oligomer diffusion ability of the porous scaffolds with different sizes.