Investigation of temperature sensitive liposome encapsulated adriamycin injected into hepatic artery for targeted behavior and cancer therapy

Temperature sensitive liposome entrapped adriamycin was injected into the hepatic artery of Wistar rats bearing implanted hepatic tumor. Two hours after the injection, the liver was heated to 42 degrees C and maintained at that temperature for 6 minutes using a local hyperthermia. The variation in the pattern of the concentration of the liposomal drug in circulation, and the drug distribution in tissues were investigated. Results indicated that adriamycin was released from the liposomes with the drug concentration peaking in circulation at 30 minutes after heating. Following the hyperthermia treatment, the total amount of drug in the liver decreased, while that in the tumor and urine increased. The 14C labeled liposome track test showed that a parallel relationship between the lipid and the drug was maintained for 8 hours after the hepatic injection, and physiological environment was a determinant of change and existence of liposomal carrier. However, the drug encapsulated in the liposomes can be controlled by hyperthermia to target the tumor. Therapeutic experiments showed that in the group treated with the hepatic artery-injected liposome plus hyperthermia control, the liver tumor growth of the rats administered at 7 days after W256 carcinosarcoma implantation on liver was notably inhibited and the life-span of the animal was greatly extended compared with those of aqueous administration groups and iv injected liposome group.