The dissolution behavior of hydroxyapatite (HA) in a hydrothermal solution was investigated using a Morey-type autoclave over a range of 150-350℃ and a pH value range of 5-9. The results showed that the dissolubility of HA powder was determined as a function of temperature and time under constant pressure, and the temperature coefficient for the solubility of HA powder was positive. The rate of dissoluion of HA in the hydrothermal aqueous solution was mainly controlled by a polynuclear mechanism. The dissolution behavior of HA was affected mainly by the hydrothermal temperature and the dissolving activation energy. The effect of temperature was obviously more than that of the pH value of the solution. All rights reserved.

The metabolic way of calcium ions which was released due to in vivo degradation of porous β2TCP ceramics was studied by using the radioisotope 45Ca as tracer. The result shows that some of the calcium ions enter blood and take part in the circulation. These calcium ions distribute into organs and tissues (such as liver, kidney, brain, heart, lung, spleen and stomach) and participate in the metabolisms of body. There is neither the accumulation of calcium ions, nor the lesion or pathologic calcification of the organs and tissues. Some of the calcium ions that enter the near-end femur, ulna and skull are reused by bony tissue to take part in both local mineralization processes during bone healing, or are stored in calcium pool which can participate in the whole body circulating. In the cyclical process, other calcium ions are excreted with urine and feces through kidney and liver. It is indicated that the degradation products of β2TCP ceramics can take part in the physiological metabolic process of normal bone and tissue.

Biornedical nanometer materials are a new field of biomaterials. In this work, CaCo2 and TiO2 nanomete partcles were prepared by sol-gel and chemical homogencous precipitation reaction with ultrasonic wave irradiation. Cell proliferation was measured by MTT method. It is shown that in vitro CaCo3 particles in hibited significantly on growh and proliferation of lung cancer cells A549, but improved slightly the growth of L929 Cells. On the other hand, TiO2 Particles had the same effect of inhibition on A549 cells, however, it obviously restrained the growht of L929 SEM observation demonstrated that L929 cells fadd somehow after treatment of TiO2 particles, but the morphology of L929 cells was not changed after treatment of CaCO3 particles, A549 cells became the typical apoptosis body after treated by TiO2 and CaCO3 particels.