RESUMEN
Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between (10)B and thermal neutrons. It is necessary for effective BNCT therapy to accumulate (10)B atoms in the tumour cells. The delivery system consisted of polyethylene-glycol (PEG) binding liposomes (DPPC/cholesterol/DSPC-PEG2000) with an entrapped (10)B-compound and we evaluated the cytotoxic effects of intravenously injected (10)B-PEG-liposomes on human pancreatic carcinoma xenografts in nude mice with thermal neutron irradiation. After thermal neutron irradiation of mice injected with (10)B-PEG-liposomes, growth of AsPC-1 tumours was suppressed relative to controls. Injection of (10)B-PEG-liposomes caused the greatest tumour suppression with thermal neutron irradiation in vivo. These results suggest that intravenous injection of (10)B-PEG-liposomes can increase the retention of (10)B atoms by tumour cells, causing suppression of tumour growth in vivo, after thermal neutron irradiation.
Asunto(s)
Borohidruros/administración & dosificación , Terapia por Captura de Neutrón de Boro , Boro/administración & dosificación , Neoplasias Pancreáticas/radioterapia , Compuestos de Sulfhidrilo/administración & dosificación , Animales , Línea Celular Tumoral , Humanos , Isótopos , Liposomas , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Modelos Animales , Trasplante de Neoplasias , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Polietilenglicoles/químicaRESUMEN
Stacks consisting of thin CR-39 sheets sandwiched between thick lucite and water absorbers were perpendicularly bombarded by 12C ions at 200 and 244 MeV/u. Track radius distributions representing the charge composition of the fragmented beams were automatically measured by a particle track analysis system. After analysis of the nuclear charge distributions, the total charge removal cross-sections and elemental production cross-sections of fragments with atomic numbers from 5 to 3, were obtained down to the lower energies (approximately 50 and 100 MeV/u, respectively). It has been found that the measured total charge removal cross-section agrees with theoretical predictions within approximately 10% and very well with previous experiments in corresponding energy regions. Two model calculations for production of B fragment are in good agreement with our measured data while a third model overestimates it by approximately 12%. Theoretical cross-sections for Be and Li fragments differ strongly among the different models and from measured values.