ABSTRACT
The first BNCT antitumor effects of BNNTs toward B16 melanoma cells were demonstrated. The use of DSPE-PEG2000 was effective for preparation of the BNNT-suspended aqueous solution. BNNT-DSPE-PEG2000 accumulated in B16 melanoma cells approximately three times higher than BSH and the higher BNCT antitumor effect was observed in the cells treated with BNNT-DSPE-PEG2000 compared to those treated with BSH, indicating that BNNT-DSPE-PEG2000 would be a possible candidate as a boron delivery vehicle for BNCT.
Subject(s)
Antineoplastic Agents/administration & dosage , Boron Compounds/administration & dosage , Boron Neutron Capture Therapy/methods , Melanoma, Experimental/drug therapy , Melanoma, Experimental/radiotherapy , Nanotubes , Animals , Antineoplastic Agents/chemistry , Boron Compounds/chemistry , Cell Survival/drug effects , Cell Survival/radiation effects , Nanotubes/chemistry , Neutrons , Skin Neoplasms/drug therapy , Skin Neoplasms/radiotherapyABSTRACT
closo-Dodecaborate-encapsulating liposomes were developed as boron delivery vehicles for neutron capture therapy. The use of spermidinium as a counter cation of closo-dodecaborates was essential not only for the preparation of high boron content liposome solutions but also for efficient boron delivery to tumors.
Subject(s)
Antineoplastic Agents/administration & dosage , Boron Compounds/administration & dosage , Animals , Antineoplastic Agents/chemistry , Boron/administration & dosage , Boron Compounds/chemistry , Boron Neutron Capture Therapy , Cell Line, Tumor , Cell Survival/drug effects , Female , Liposomes , Mice, Inbred BALB C , Neoplasms/pathology , Neoplasms/therapy , Tumor Burden/drug effectsABSTRACT
Mercaptoundecahydrododecaborate (BSH)-encapsulating 10% distearoyl boron lipid (DSBL) liposomes were developed as a boron delivery vehicle for neutron capture therapy. The current approach is unique because the liposome shell itself possesses cytocidal potential in addition to its encapsulated agents. BSH-encapsulating 10% DSBL liposomes have high boron content (B/P ratio: 2.6) that enables us to prepare liposome solution with 5000 ppm boron concentration. BSH-encapsulating 10% DSBL liposomes displayed excellent boron delivery efficacy to tumor: boron concentrations reached 174, 93, and 32 ppm at doses of 50, 30, and 15 mg B/kg, respectively. Magnescope was also encapsulated in the 10% DSBL liposomes and the real-time biodistribution of the Magnescope-encapsulating DSBL liposomes was measured in a living body using MRI. Significant antitumor effect was observed in mice injected with BSH-encapsulating 10% DSBL liposomes even at the dose of 15 mg B/kg; the tumor completely disappeared three weeks after thermal neutron irradiation ((1.5-1.8) × 10(12) neutrons/cm(2)). The current results enabled us to reduce the total dose of liposomes to less than one-fifth compared with that of the BSH-encapsulating liposomes without reducing the efficacy of boron neutron capture therapy (BNCT).
