Heat-sensitive liposomes containing cisplatin and localized hyperthermia in treatment of murine tumor.

Combined therapy with heat-sensitive liposomes as carriers for drugs and local hyperthermia is thought to improve the local control rate. I studied the antitumor effects and concentrations of CDDP encapsulated in heat-sensitive liposomes (LIP-CDDP) in vivo. LIP-CDDP or CDDP-solution was given to 8 week-old male C3H/He mice bearing SCC VII tumors by tail vein injection, and tumors were heated at 40 degrees C or 42 degrees C. The concentration of LIP-CDDP in blood was significantly higher than that of CDDP-solution. The concentration in tumors after heating at 42 degrees C increased with heating time, but the concentration in tumors without heating or after heating at 40 degrees C did not show these changes. After heating at 42 degrees C, antitumor effects of LIP-CDDP were significantly better than those obtained with the use of CDDP-solution. Heating at 40 degrees C did not alter the antitumor effect of LIP-CDDP. Therefore, LIP-CDDP proved to be very effective when combined with local hyperthermia at 42 degrees C.