ANGELICA BUENO BARBEZAN

ANGELICA BUENO BARBEZAN

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Gold radioactive nanoparticles for brachytherapy
2023 - ROSERO, WILMMER A.A.; BARBEZAN, ANGELICA B.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.
The development of new materials emerges as an alternative to the treatment of cancer, Nanobrachytherapy is born from the union of nanotechnology and brachytherapy being a modality of radiotherapy in which the nanosources are placed close to or in contact with the region to be treated. In nanoparticle synthesis, a key role is played by coatings, certain sizes of uncoated nanoparticles tend to accumulate in tumors due to vessel irregularities. When coated with gum arabic, the size of the nanoparticles is controlled, allowing the particles to properly penetrate the vasculature. The choice of radionuclide depends on the radiobiology of the cancer and the dose deposited in the tissue, which takes into account the type of decay (beta particles penetrate less into the tissue than X-rays and gamma rays), energy and half-life time (which influence the deposited dose per duration of radioisotope). In this work, 198Au will be used, which presents Beta as the main type of emission with an energy of 314.55 KeV, gamma 411.8 KeV, and a half-life of 2.7 days. The synthesis of radioactive nanoparticles is carried out in a closed chemical reactor, developed during the tests. The chemical reactor gold nanoparticles and precursor chloroauric acid are obtained. The morphology of nanoparticles and their size is guaranteed cold by TEM and radioactive by DLS. With an average diameter (TEM) of 5 nm, gum arabic nanoparticles have a curious property, when solution they form stable agglomerates of 45 nm (DLS), optimal size for in vitro and in vivo tests. They were tested with cancer cells of prostate and mice. In one of the evaluated LNCaP strains, 11% cytotoxicity was observed at the lowest concentration (0.9 μCi/well). At the concentration of 1.8 μCi/well, there was cell proliferation and at the highest concentration (2.7 μCi/well) it showed 32% cytotoxicity. After statistical analysis, the results revealed that although none of the animals showed regression of tumor mass. Tumor growth was slower at treated animals when compared to the tumor growth of the control animals (zero dose). Signaling us then that there is a positive effect on therapeutic efficacy, but these data suggest that the activity used was relatively low to achieve the regression of this mass. In the next experiments we will increase the injected radioactive activity to confirm these results and evaluate its real therapeutic potential.
Development of radioactive nanoparticles functionalized with gum arabic to be used in nanobrachytherapy
2023 - ROSERO, WILMMER A.A.; BARBEZAN, ANGELICA B.; RIGO, MARIA E.Z.; RODRIGUES, PRISCILA S.; TEODORO, LARA E.H.; TALACIMON, CRISTHIAN F.; ZEITUNI, CARLOS A.; ROSTELATO, MARIA E.C.M.
The development of new materials emerges as an alternative to the treatment of cancer, from the combination of nanotechnology and brachytherapy a new area of research was born, Nanobrachytherapy, which through the properties of nanometric materials can achieve better results in the fight against cancer. The objective of this work is classified as radiotherapy, which consists of the use of ionizing radiation to destroy or inhibit the growth of abnormal cells that form a tumor. [1] The ability to integrate NPsAu into biological systems is due to the nanometric dimensions of NPsAu probes which facilitate their incorporation into biological systems, as well as their bioconjugation and non-cytotoxic potential. [2] Taking into account the previous objective, gold was selected as the base element for obtaining nanometric systems, which due to its chemical richness and especially due to the intrinsic properties of one of its radioisotopes, which would allow us in theory to meet the stated objective. . Initially, it was based on the knowledge of the literature, and non-radioactive nanometric systems were obtained, and after a series of stability, characterization and application tests, the radioactive nanometric systems were obtained. Working with radioactive systems posed a great challenge, and up to now it presents us with situations to solve, but we have managed to create a methodology for obtaining, characterizing and applying radioactive gold nanoparticles, and also obtaining positive results from their application.
Synthesis, activation and application testing of gold nanoparticles for nanobrachytherapy
2023 - ROSERO, WILMMER A.A.; BARBEZAN, ANGELICA B.; ROSTELATO, MARIA E.C.M.; SOUZA, CARLA D. de; NOGUEIRA, BEATRIZ R.; ZEITUNI, CARLOS A.
For more than 50 years, the Energy and Nuclear Research Institute IPEN, has been offering solutions to Brazil through nuclear technology. Thus, one of the main areas where IPEN has contributed assertively is medicine. Reaching the level of 32 radiopharmaceuticals and radioactive sources intended both for therapy and for the diagnosis of several pathologies, including cancer, which are obtained with the help of the two nuclear reactors and two cyclotrons present in the institution. The Institute has a team for the development, production and distribution of radioactive sources for brachytherapy, such as 192 Ir wires and 125 I seeds. Brachytherapy is a cancer treatment technique where the radioactive source is placed close to or in contact with the lesion. The great advantage of the technique is to save healthy tissues. Currently, we are working on obtaining nanometric materials that can be applied in the emerging nano brachytherapy, because of its properties and characteristics at the nanometric level, gold has been the subject of studies and tests. Elemental Au gold can be activated 198 Au inside a nuclear reactor, and has β- decay and a half-life of 2.7 days, which makes it ideal for short-term irradiations. In addition, gold in the form of nanoparticles has a completely different chemistry, with gold nanoparticles (AuNPs) being easily functionalized by a large part of molecular and polymeric binders, which may present favorable characteristics for the studies, and together with AuNPs they are able to work synergistically to achieve greater efficiencies. Currently, AuNPs have been successfully functionalized with gum arabic (GA), a coating widely used in the cosmetic and food industry, which is low cost and along with nanoparticles has shown biocompatibility with different cell groups and has been shown to be very stable over time. The project includes studies regarding the synthesis of nanoparticles, coating, cytotoxicity of AuNPs in vitro "cold" (non-radioactive) and the development of activation protocols in the nuclear reactor. In the next phase, after activation, in the reactor, "hot" tests will be performed in vitro and in vivo.
Characterization of FXG dosimeters with gold nanoparticles for brachytherapy applications
2023 - RODRIGUES, PRISCILA; BURIN, ANA; BARBEZAN, ANGELICA; TALACIMON, CRISTHIAN; ILCA, MEDEIROS; TEODORO, LARA E.H.; RIGO, MARIA; GESSERAME, MAYSA; TAVARES, PAULO; NOGUEIRA, THUANY; ROSERO, WILMMER; RODRIGUES JUNIOR, ORLANDO; ZEITUNI, CARLOS; ROSTELATO, MARIA
Potential evaluation of cytotoxic 2-tetradecylcyclobutanone lineage in cellular BRL 3A - studies in vitro
2016 - BARBEZAN, A.B.; SALES, B.R.; MARTINS, R.; BUENO, J.B.; SANTELLI, G.M.M.; VILLAVICENCIO, A.L.C.H.
Potential evaluation of mutagenic compounds 2-dodecylcyclobutanone and 2-tetradecylcyclobutanone through the Ames test
2016 - BARBEZAN, ANGELICA B.; BISPO, ANA C.A.; MENDES, BRUNO M.; MARTINS, REGIANE; VILLAVICENCIO, ANNA L.C.H.
Food irradiation is an effective and safe method for preservation and long-term storage for various applications in a wide variety of food products. This process is performed by the use of accelerated electron beams, X-rays or gamma radiation. The 2-Alkylcyclobutanones (2-ACBs) are the only known radiolytic products generated in foods that have fatty acids and were subjected to irradiation. In this study, the stearic and palmitic acid was analyzed when irradiated medium 2-Tetradecylcyclobutanone (2-tDCB) and 2-Dodecylcyclobutanone (2-dDCB). Since the 1990s toxicological safety studies of 2-ACBs have been conducted extensively through synthetic compounds. Additionally, tests to determine if the compounds have any mutagenic activity are strictly necessary. The Ames test was the test choosen for assessing the genotoxicity of both 2- dDCB and 2tDCB compounds. It was used five different bacterial strains TA-1535, TA-1537, TA 98 and TA 100 Salmonella typhimurium, to detect mutations in specific sites Guanine-Cytosine (GC) and WP2 uvrA, Escherichia coli was used to detect point mutations at sites of Adenine- Thymine (AT). This research, unlike those undertaken by other authors up to now, presents some particularities in their factors for a more complete assessment, such as the use of all necessary cell lines to identify possible mutations in specific sites, changes in solvent commonly used, appropriate plates and the investigation of possible mutagenic effects on two important compounds 2-dDCB and 2-tDCB simultaneously. The study revealed no mutagenic activity in any of the cell lines and concentrations evaluated. In conclusion, the compounds 2-dDCB and 2tDCB showed no mutagenic effect in concentrations detectable by the AMES test.
Avaliação do potencial citotóxico da 2-tetradecilciclobutana em células hepáticas linhagem HepG2– estudos in vitro
2016 - BARBEZAN, A.B.; SALES, B.R.; MARTINS, R.; BUENO, J.B.; SANTELLI, G.M.M.; VILLAVICENCIO, A.L.C.H.