A piece of cleaned AAO membrane (10 mg) was added into 500 L of the liposome suspension, followed by gentle agitation for overnight at room temperature. Then, liposomeimmobilized AAO was washed with 500 L of PBS for three times. Liposome-immobilized AAO were stored in PBS buffer at room temperature in dark. In order to release liposomes from AAO, ultrasonic irradiation was applied to liposome-immobilized AAO in 500 L of PBS using a bath sonicator (T103, Honda Electronics, Toyohashi, Japan, power: 30W, frequency: 45 kHz).