Calcium phosphate precursory powders containing Na and Mg have been prepared by the citric acid sol-gel combustion method. The elements of Na and Mg were introduced from component of CaO-P2O5-Na2O-MgO. The effect of sintering additives on the phase composition was characterized by XRD. The effect of sintering additives on sintering of materials was also characterized by linear shrinkage, TEM and SEM. Finally the microstructure of porous calcium phosphate ceramic was determined by SEM.
The microstructure of the prepared porous bioceramic material, including surface porosity and apparent contact area with the artificial mucus film are computed and analyzed. The surface micro-configurations of the porous material before and after sliding on the mucus film are observed in 2D and 3D by digital microscopy. We describe how much mucus enters and stays within different pores, and how the porous material with rough/porous surface contacts with the mucus film (elastic surface/gel). The presented results illustrate that the material with different porous structure can lead to different mucus suction, surface scraping and changes of contact area and condition during sliding, which will be active for high friction of robotic endoscope with the intestinal wall for intestinal locomotion.
The reinforcing effects on hydroxyapatite (abbreviated HA) of phosphate glass additives were researched. The samples of reinforced HA (abbreviated RHA) and control material were prepared and then percutaneously implanted in the skin of experiment animal. The histomorphology of the part skin tissue were observed. By a biomimetic process,the method and conditions of forming HA coating on the surface of medical silicon rubber (abbreviated MSR) were studied. The results illustrate that the phosphate glass additives have obvious reinforcing effects on HA. In the percutaneous implantation test, neither clear infiltration of inflammatory cells nor marked downgrowth of epidermis was observed for the part tissue surrounded RHA. The surface modification of MSR for percutaneous access could be attained by biomimetic synthesis of HA coating.
