title: Hyperthermia-mediated local drug delivery by a bubble-generating liposomal system for tumor-specific chemotherapy.
abstract: As is widely suspected, lysolipid dissociation from liposomes contributes to the intravenous instability of ThermoDox (lysolipid liposomes), thereby impeding its antitumor efficacy. This work evaluates the feasibility of a thermoresponsive bubble-generating liposomal system without lysolipids for tumor-specific chemotherapy. The key component in this liposomal formulation is its encapsulated ammonium bicarbonate (ABC), which is used to actively load doxorubicin (DOX) into liposomes and trigger a drug release when heated locally. Incubating ABC liposomes with whole blood results in a significantly smaller decrease in the retention of encapsulated DOX than that by lysolipid liposomes, indicating superior plasma stability. Biodistribution analysis results indicate that the ABC formulation circulates longer than its lysolipid counterpart. Following the injection of ABC liposome suspension into mice with tumors heated locally, decomposition of the ABC encapsulated in liposomes facilitates the immediate thermal activation of CO2 bubble generation, subsequently increasing the intratumoral DOX accumulation. Consequently, the antitumor efficacy of the ABC liposomes is superior to that of their lysolipid counterparts. Results of this study demonstrate that this thermoresponsive bubble-generating liposomal system is a highly promising carrier for tumor-specific chemotherapy, especially for local drug delivery mediated at hyperthermic temperatures.
authors.affiliation: Department of Chemical Engineering and Institute of Biomedical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan, ROC.
authors.forename: Ko-Jie
authors.initials: KJ
authors.lastname: Chen
authors.forename: Er-Yuan
authors.initials: EY
authors.lastname: Chaung
authors.forename: Shiaw-Pyng
authors.initials: SP
authors.lastname: Wey
authors.forename: Kun-Ju
authors.initials: KJ
authors.lastname: Lin
authors.forename: Felice
authors.initials: F
authors.lastname: Cheng
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Lin
authors.forename: Hao-Li
authors.initials: HL
authors.lastname: Liu
authors.forename: Hsiang-Wen
authors.initials: HW
authors.lastname: Tseng
authors.forename: Chih-Peng
authors.initials: CP
authors.lastname: Liu
authors.forename: Ming-Cheng
authors.initials: MC
authors.lastname: Wei
authors.forename: Chun-Min
authors.initials: CM
authors.lastname: Liu
authors.forename: Hsing-Wen
authors.initials: HW
authors.lastname: Sung
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry; D001639:Bicarbonates / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D045744:Cell Line, Tumor; D004317:Doxorubicin / Q000737:chemistry; D004337:Drug Carriers; D006358:Hot Temperature; D006801:Humans; D006979:Hyperthermia, Induced; D008081:Liposomes / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D013667:Technetium / Q000737:chemistry; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D001639:Bicarbonates; D004337:Drug Carriers; D008081:Liposomes; D002245:Carbon Dioxide; C027043:ammonium bicarbonate; D013667:Technetium; D004317:Doxorubicin