| 초록 |
New drug delivery system for tumor targeting is needed due to the currently limited therapeutic activity and insolubility of administered anticancer drugs. Thus, this study has been studied the temperature-sensitive liposomes(TSL), which release anticancer drug(doxorubicin, DOX) at the hyperthermia temperature(～40℃). The TSL were carefully modified with a change of phospholipid ratio. Copolymers of N-isopropylacrylamide(NIPAAm) and acrylamide(AAm), which exhibit a lower critical solution temperature at the hyperthermia temperature(～40℃), were prepared by free radical polymerization. The release of DOX from liposomes was determined by measuring the fluorescence intensity with changing temperature and time. The release of DOX from liposomes modified by copolymer was more 30% increased than phospholipid liposomes. The release of DOX might be strongly affected by the copolymer, because the copolymer could undergo the conformational transition of drug in the narrow hyperthermia temperature region(～40±2℃), resulting in a critical increase of the DOX release. Moreover, we have observed that the release time of DOX from liposomes was completed in 5 minutes and its particles size were from 120 to 170 nm. In conclusion, we have prepared TSL which could be controlled by hyperthermia temperature. They can be applied in the field of a drug delivery system for tumor targeting by temperature control.
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