Experimental set up for the irradiation of biological samples and nuclear track detectors with UV C

AimIn this work we present a methodology to produce an “imprint” of cells cultivated on a polycarbonate detector by exposure of the detector to UV C radiation.BackgroundThe distribution and concentration of 10B atoms in tissue samples coming from BNCT (Boron Neutron Capture Therapy) protocols can be determined through the quantification and analysis of the tracks forming its autoradiography image on a nuclear track detector. The location of boron atoms in the cell structure could be known more accurately by the simultaneous observation of the nuclear tracks and the sample image on the detector.Materials and MethodsA UV C irradiator was constructed. The irradiance was measured along the lamp direction and at different distances. Melanoma cells were cultured on polycarbonate foils, incubated with borophenylalanine, irradiated with thermal neutrons and exposed to UV C radiation. The samples were chemically attacked with a KOH solution.ResultsA uniform irradiation field was established to expose the detector foils to UV C light. Cells could be seeded on the polycarbonate surface. Both imprints from cells and nuclear tracks were obtained after chemical etching.ConclusionsIt is possible to yield cellular imprints in polycarbonate. The nuclear tracks were mostly present inside the cells, indicating a preferential boron uptake

Assessment of biological effectiveness of boron neutron capture therapy in primary and metastatic melanoma cell lines

Purpose: In order to optimize the effectiveness of Boron Neutron Capture Therapy (BNCT), Relative Biological Effectiveness (RBE) and Compound Biological Effectiveness (CBE) were determined in two human melanoma cell lines, M8 and Mel-J cells, using the amino acid p-boronophenylalanine (BPA) as boron carrier. Materials and methods: The effects of BNCT on the primary amelanotic cell line M8 and on the metastatic pigmented melanoma cell line Mel-J were studied using colony formation assay. The RBE values were determined using both a gamma ray source, and the neutron beam from the Nuclear Reactor of the National Atomic Energy Commission (RA-3). For the determination of the RBE, cells were irradiated with increasing doses of both sources, between 1 and 8 Gy; and for the determination of CBE factors, the cells were pre-incubated with BPA before irradiation. Afterwards, the cell surviving fraction (SF) was determined for each treatment. Results: Marked differences were observed between both cell lines. Mel-J cells were more radioresistant than the M8 cell line. The clonogenic assays showed that for a SF of 1%, the RBE values were 1.3 for M8 cells and 1.5 for Mel-J cells. Similarly, the CBE values for a 1% SF were 2.1 for M8 and 3 for Mel-J cell lines. For the endpoint of 0.1% of SF the RBE values obtained were 1.2 for M8 and 1.4 for Mel-J cells. Finally, CBE values calculated for a 0.1% were 2 and 2.6 for M8 and Mel-J cell lines respectively. In order to estimate the uptake of the non-radioactive isotope Boron 10 (10B), a neutron induced autoradiographic technique was performed showing discrepancies in 10B uptake between both cell lines. Conclusions: These obtained in vitro results are the first effectiveness factors determined for human melanoma at the RA-3 nuclear reactor and show that BNCT dosimetry planning for patients could be successfully performed using these new factors.Fil: Rossini, Andrés Eugenio. Comisión Nacional de Energía Atómica; ArgentinaFil: Dagrosa, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Portu, Agustina Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Saint Martin, María Laura Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Thorp, Silvia Inés. Comisión Nacional de Energía Atómica; ArgentinaFil: Casal, Mariana. Comisión Nacional de Energía Atómica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Navarro, Aime. Autoridad Regulatoria Nuclear; ArgentinaFil: Juvenal, Guillermo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Pisarev, Mario Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentin

Simultaneous Observation of Cells and Nuclear Tracks from the Boron Neutron Capture Reaction by UV-C Sensitization of Polycarbonate

The distribution of boron in tissue samples coming from boron neutron capture therapy protocols can be determined through the analysis of its autoradiography image on a nuclear track detector. A more precise knowledge of boron atom location on the microscopic scale can be attained by the observation of nuclear tracks superimposed on the sample image on the detector. A method to produce an imprint of cells cultivated on a polycarbonate detector was developed, based on the photodegradation properties of UV-C radiation on this material. Optimal conditions to generate an appropriate monolayer of Mel-J cells incubated with boronophenylalanine were found. The best images of both cells and nuclear tracks were obtained for a neutron fluence of 1013 cm-2, 6 h UV-C (254 nm) exposure, and 4 min etching time with a KOH solution. The imprint morphology was analyzed by both light and scanning electron microscopy. Similar samples, exposed to UV-A (360 nm) revealed no cellular imprinting. Etch pits were present only inside the cell imprints, indicating a preferential boron uptake (about threefold the incubation concentration). Comparative studies of boron absorption in different cell lines and in vitro evaluation of the effect of diverse boron compounds are feasible with this methodology.Fil: Portu, Agustina Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; ArgentinaFil: Rossini, Andrés Eugenio. Autoridad Regulatoria Nuclear; ArgentinaFil: Thorp, Silvia Inés. Comisión Nacional de Energía Atómica; ArgentinaFil: Curotto, Paula. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Gerencia de Ingenieria Nuclear (cab). Departamento de Reactores de Investigacion.; ArgentinaFil: Pozzi, Emiliano César Cayetano. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Gerencia de Ingenieria Nuclear (cab). Departamento de Reactores de Investigacion.; ArgentinaFil: Granell, Pablo Nicolás. Instituto Nacional de Tecnología Industrial. Centro de Micro y Nanoelectrónica del Bicentenario; ArgentinaFil: Golmar, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial. Centro de Micro y Nanoelectrónica del Bicentenario; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Cabrini, Romulo Luis. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; ArgentinaFil: Saint Martin, María Laura Gisela. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina. Gobierno de la Provincia de Buenos Aires. Ministerio de Produccion Ciencia E Innovacion Tecnologica. Subsecretaria de Politicas Culturales. Biblioteca Central de la Provincia de Buenos Aires Ernesto Sabato.; Argentin

Experimental set up for the irradiation of biological samples and nuclear track detectors with UV C

Aim: In this work we present a methodology to produce an ?imprint? of cells cultivated on a polycarbonate detector by exposure of the detector to UV C radiation.Background: The distribution and concentration of10B atoms in tissue samples coming from BNCT (Boron Neutron Capture Therapy) protocols can be determined through the quantification and analysis of the tracks forming its autoradiography image on a nuclear track detector. The location of boron atoms in the cell structure could be known more accurately by the simultaneous observation of the nuclear tracks and the sample image on the detector.Materials and Methods: A UV C irradiator was constructed. The irradiance was measured along the lamp direction and at different distances. Melanoma cells were cultured on poly-carbonate foils, incubated with borophenylalanine, irradiated with thermal neutrons and exposed to UV C radiation. The samples were chemically attacked with a KOH solution.Results: A uniform irradiation field was established to expose the detector foils to UV C light.Cells could be seeded on the polycarbonate surface. Both imprints from cells and nuclear tracks were obtained after chemical etching.Fil: Portu, Agustina Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); ArgentinaFil: Rossini, Andrés Eugenio. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gadan, Mario Alberto. Comisión Nacional de Energía Atómica; ArgentinaFil: Bernaola, Omar Alberto. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); ArgentinaFil: Thorp, Silvia Inés. Comisión Nacional de Energía Atómica; ArgentinaFil: Curotto, Paula. Comisión Nacional de Energía Atómica; ArgentinaFil: Pozzi, Emiliano César Cayetano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Cabrini, Romulo Luis. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); ArgentinaFil: Saint Martin, María Laura Gisela. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Radiobiología (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Experimental studies of boron neutron capture therapy (BNCT) using histone deacetylase (HDACI) sodium butyrate, as a complementary drug for the treatment of poorly differentiated thyroid cancer (PDTC)

Purpose: The present study analyzed different protocols of administration of boronophenylalanine (BPA) and sodium butyrate (NaB) to increase the BNCT efficacy for poorly differentiated thyroid cancer (PDTC). Materials and methods: Nude mice implanted with human PDTC cells (WRO) were distributed into four protocols: 1) BPA; 2) BPA + ip NaB; 3) BPA + oral NaB; 4) Control. Biodistribution and histologic studies were performed. LAT (BPA transporter) isoforms gene expression was assessed by RT-PCR. Results: Tumor growth delay was observed in animals of the Protocol #3 (p < 0.05). NaB (Protocol #2) increased tumor boron uptake 2-h post BPA injection (p < 0.05). On the other hand, NaB upregulated the expression of all the isoforms of the LAT transporter in vitro. Histologic studies showed a significant decrease of mitotic activity and an increase of vacuoles in tumors of Protocol #3. Neutrons alone or combined with NaB caused some tumor growth delay (p < 0.05), while in the BNCT and BNCT + NaB groups, there was a halt in tumor growth in 70 and 80% of the animals, respectively. Conclusions: Intraperitoneally administration of NaB increased boron uptake while oral administration for a longer period of time induced tumor growth delay previous to BPA administration. The use of NaB via ip would optimize the irradiation results.Fil: Perona, Marina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Majdalani, Eduardo Enrique. Comisión Nacional de Energía Atómica; ArgentinaFil: Rodríguez, Carla. Comisión Nacional de Energía Atómica; ArgentinaFil: Nievas, Susana Isabel. Comisión Nacional de Energía Atómica; ArgentinaFil: Carpano, Marina. Comisión Nacional de Energía Atómica; ArgentinaFil: Rossini, Andrés Eugenio. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Longhino, Juan Manuel. Comisión Nacional de Energía Atómica; ArgentinaFil: Cabrini, Romulo Luis. Comisión Nacional de Energía Atómica; ArgentinaFil: Pisarev, Mario Alberto. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Juvenal, Guillermo Juan. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dagrosa, María Alejandra. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Departamento de Radiobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Detailed dosimetry calculation for in-vitro experiments and its impact on clinical BNCT

Purpose: Boron Neutron Capture Therapy (BNCT) is a form of hadrontherapy based on the selective damage caused by the products of neutron capture in 10B to tumour cells. BNCT dosimetry strongly depends on the parameters of the dose calculation models derived from radiobiological experiments. This works aims at determining an adequate dosimetry for in-vitro experiments involving irradiation of monolayer-cultured cells with photons and BNCT and assessing its impact on clinical settings. M&M: Dose calculations for rat osteosarcoma UMR-106 and human metastatic melanoma Mel-J cell survival experiments were performed using MCNP, transporting uncharged particles for KERMA determinations, and secondary particles (electrons, protons, 14C, 4He and 7Li) to compute absorbed dose in cultures. Dose-survival curves were modified according to the dose correction factors determined from computational studies. New radiobiological parameters of the photon isoeffective dose models for osteosarcoma and metastatic melanoma tumours were obtained. Dosimetry implications considering cutaneous melanoma patients treated in Argentina with BNCT were assessed and discussed. Results: KERMA values for the monolayer-cultured cells overestimate absorbed doses of radiation components of interest in BNCT. Detailed dose calculations for the osteosarcoma irradiation increased the relative biological effectiveness factor RBE1% of the neutron component in more than 30%. The analysis based on melanoma cases reveals that the use of survival curves based on KERMA leads to an underestimation of the tumour doses delivered to patients. Conclusions: Considering detailed dose calculation for in-vitro experiments significantly impact on the prediction of the tumor control in patients. Therefore, proposed methods are clinically relevant.Fil: Dattoli Viegas, Ana Mailen. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Postuma, Ian. Universita degli Studi di Pavia; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Bortolussi, Silva. Universita degli Studi di Pavia; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Guidi, Claretta. Universita degli Studi di Pavia; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Riback, Jessica Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Provenzano, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Marcaccio, Barbara. Universita degli Studi di Pavia; ItaliaFil: Rossini, Andrés Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Autoridad Regulatoria Nuclear; ArgentinaFil: Ferrari, Cinzia. Universita degli Studi di Pavia; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Cansolino, Laura. Universita degli Studi di Pavia; Italia. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Ferrari, Matteo. Cern - European Organization for Nuclear Research; SuizaFil: Portu, Agustina Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: González, Sara Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentin