Immobilized amount of NBD-liposomes was calculated by the deviation of fluorescence intensity between liposome suspension added with and without AAO, based on the calibration curve determined from the concentration dependence of NBD-liposomes on the fluorescence intensity in PBS. Released amount was also measured by fluorescence analysis of the supernatant. Fluorescence intensity was measured with JASCO FP-6500 spectrofluorophotometer (Japan Spectroscopic Co. Ltd., Tokyo, Japan) at 25°C, in which polarizers of excitation and emission were set orthogonally to cut off scattered light.