Bioactivity of TiO₂/Ti Composite Membrane with Different Crystral Phase

The bioactivity of TiO₂/Ti composite membrane with different crystral phase was studied by the culture of hypothalamic neurons in vitro for the application of immunoisolation. The kind of membrane supported on porous Ti has been prepared by sol-gel technique and the crystral phase was controlled by different sintering temperature. The crystral phase of TiO₂, morphology and function of hypothalamic neurons were observed by X-ray diffraction (XRD), enzyme-linked immunosorbent assay (ELISA) and environmental sanning electron microscope (ESEM). The results showed that neurons could attach well to the TiO₂ /Ti composite membranes with rutile phase and became bipolar. The long axon and dendrite with dendrite spine were interconnected by synapses. A complicated neural net were easily observed. The secretory level of β-endorphine remained between 51.3pmol/L and 40.6pmol/L all the times. However, the neurons in membranes with anatase were transformed into an umbilicate structure without processes. The secretory function of neurons also died out in 4 days. These results indicated that the TiO₂ /Ti composite membranes with rutile phase were propitious to the neuron’s growth than the composite membranes with anatase phase and could be used as immunoisolation membranes.