Study on hepatic artery chemoembolization using temperature-sensitive liposome or lipiodol emulsion.

As a novel method for the medical application of liposomes, we have tried hepatic artery chemoembolization using temperature-sensitive liposomes with hyperthermia for the treatment of hepatic tumors. In this study, the effect of temperature-sensitive liposomes was compared with that of Lipiodol emulsion, which has been used clinically. The temperature-sensitive liposomes, consisting of dipalmitoylphosphatidylcholine or Lipiodol emulsions entrapping doxorubicin, were administered into the hepatic artery of hepatic tumor-bearing rats via a cannula. Doxorubicin administered in a liposomal form showed a high accumulative property toward tumors, with heating, while that in the emulsion form showed a slow release property toward tumors. Not only was tumor growth inhibited, but also, an actual diminishing of the tumor was observed in each form. Side effects were also examined: an abnormal rise in GPT, or necrosis of the normal tissues in liver, which was often observed in hepatic artery chemoembolization using Lipiodol emulsion, was remarkably reduced in the liposomal chemoembolization.