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Hydroxyapatite and fluoride-substituted hydroxyapatite powders are synthesized by wet method, compacted into pellets and subjected to heat treatment at 300, 600, 900 degrees C respectively. Analysis of the fluoride-substituted hydroxyapatites and HA by FTIR spectroscopy indicated that with the increasing of sintering temperatures, the phase-pure fluoride-substituted hydroxyapatite and stoichiometric hydroxyapatite could be got. According to the X-ray diffraction analysis, the fluoride-substituted hydroxyapatite is less stable for decomposing into beta-Ca3(PO4)2 at the temperature of 900 degrees C. The in vitro bioactivity of the fluoride-substituted hydroxyapatites and hydroxyapatite heat treated at 900 degrees C was assessed by immersion testing in simulated body fluid (SBF). Both scanning electron microscopy (SEM) analysis and ionic solution changes (Ca2+) demonstrated that the low fluoride content apatite could induce a surface bonelike apatite layer formation.

The biomimetic method, which mimics the natural deposition of biologic apatite, has opened up a new way to develop biomaterials. This paper gives a brief introduction of various biomimetic methods to deposit apatite coatings, and the mechanical and biological properties of the coatings.

This paper has studied the dissolution behavior of the plasma sprayed and electrochemically prepared hydroxyapatite(HA) biocoatings in the simulated body fluid. XRD and SEM show that the plasma sprayed coating and post-heat treated HA coatings are more soluble, and CaO and alpha-TCP in the coatings gradually disappear and CaCO3 forms during the immersion. The composition of the electrocrystallized and alkaline-treated HA coatings is basically unchanged, and the coatings are more stable in the simulated body fluid.

A novel idea in developing cardiopulmonary-cerebral resuscition(CPCR) device has been developed, using a combination of membrane artificial lung(oxygenator), mild-hypothermia, and centrifugal blood pump technologies. A control system for the CPCR has been introduced, using converter control and sensor monitor, with 8031 chips as the controller. Pressure, flow rate and temperature monitors were installed in the system. Two modes of blood pump regulation have been adopted, i.e. continous flow and pulsatile flow. The in vitro evaluation tests showed that the two modes were reasonable and feasible.

Morphology of inorganic material powders before and after being treated by ultrafine crush was observed by transformite electron microscope. The length and diameter of granules were measured. Polymers inorganic material powders before and after being treated by ultrafine crush were used for preparing radiological equivalent materials. Blending compatibility of inorganic meterials with polymer materials was observed by scanning electron microscope. CT values of tissue equivalent materials were measured by X-ray CT. Distribution of inorganic materials was examined. The compactness of materials was determined by the water absorbed method. The elastic module of materials was measured by laser speckle interferementry method. The results showed that the inorganic material powders treated by the ultrafine crush blent well with polymer and the distribution of these powders in the polymer was homogeneous. The equivalent errors of linear attenuation coefficients and CT values of equivalent materials were small. Their elastic modules increased one order of magnitude from 6.028 x 10(2) kg/cm2 to 9.753 x 10(3) kg/cm2. In addition, the rod inorganic material powders having rod granule blent easily with polymer. The present study provides a theoretical guidance and experimental basis for the design and synthesis of radiological equivalent materials.