MARIA JOSE ALVES DE OLIVEIRA

MARIA JOSE ALVES DE OLIVEIRA

Página do item completo

Resultados de Busca

Agora exibindo 1 - 4 de 4

Synthesis of polymeric gels crosslinked by ionizing radiation for treatment of cutaneous leishmaniasis
2019 - OLIVEIRA, MARIA J.A. de; MOREIRA, EDSON G.; SALVADOR, PABLO A.V.; ALCANTARA, MARA T.S.; LUGAO, ADEMAR B.
Ionizing radiation is a very efficient, versatile and clean tool for modifying polymers for various applications, including in the biomedical area. The advantages of using radiation include the ability to process materials in any physical form, at a convenient temperature, often at room temperature. There is no need for the use of initiators or other chemicals and it is easily carried out with high reliability and does not generate any waste. In the research support area, several materials have been treated in order to find correlations between the applied dose and some property of the material susceptible to be modified with gamma radiation. This study proposes the development of polymeric gels (cream) with Glucantime (Sb V) and gel (cream) with silver nanoparticles, for alternative treatment of cutaneous Leishmaniasis. A cobalt-60 gamma irradiation source was used for crosslinking the polymers, forming the silver nanoparticles and simultaneous sterilization, leaving the product ready for use. Polymeric gels were characterized by physico-chemical techniques, instrumental nêutron activation analysis (INAA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).
Effect of gamma irradiation on polymeric gel with glucantime and silver for the alternative treatment of cutaneous leishmania
2018 - OLIVEIRA, M.J.A.; VASQUEZ, P.A.S.; ALCANTARA, M.T.S.; LUGAO, A.B.
The drugs used to treat leishmania are in injectable form and the applications are painful that many patients give up during the treatment. The treatment requires hospitalization to monitor the side effects caused by the drugs, such as cardiac arrhythmia, renal dysfunction, among others. In addition to this situation, if the patient has symptoms such as cardiac arrhythmia, renal dysfunction they can not make use of the treatment. For these reasons finding new forms of treatments with minor side effects as alternative treatments for leishmaniasis has been the object of study of many research laboratories. The objective of this work was to analyze the effects of gamma irradiation on polymeric gel with glucantime and silver as the alternative treatment of cutaneous leishmania. In this case, the polymeric gel prevents the drug from falling directly into the bloodstream, avoiding the side effects, which would make unnecessary the patient's hospitalization. For the development of the gels was used, alginate, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), laponite clay, silver ions, and glucantime. The cobalt-60 source gamma irradiation was used for gel formation, silver nanoparticles and simultaneous sterilization. The physico-chemical characterizations were elemental analysis for quantification of Sb(V) and Sb(III) antimoniate, infrared spectroscopy (FTIR), dispersive energy spectrometry (EDS), transmission electron microscope (TEM). The results are promising, they show that the irradiation does not interfere with the drug's active principle, as expected in this study.
Effect of gamma radiation on polyvinylpyrrolidone hydrogels
2017 - OLIVEIRA, M.J.A.; VASQUEZ, P.A.S.; ALCANTARA, M.T.S.; MUNHOZ, M.M.L.; LUGAO, A.B.
Polyvinylpyrrolidone (PVP) hydrogels have been investigated as drug delivery matrices for the treatment of wounds, such as cutaneous leishmaniasis, and matrices with silver nanoparticles for chronic wounds and burns. The preparation of such hydrogels can occur by various cross-linking methods, such as gamma, chemical, physical, among others. The most feasible for wound dressings is gamma irradiation from cobalt-60, because gamma irradiation simultaneously promotes crosslinking and sterilization, leaving the wound dressing ready for use. The objective of this work was to investigate the effect on physico- chemical properties of gamma radiation on PVP hydrogel according to the radiation absorbed dose variation. The PVP hydrogels were irradiated with doses of 5, 15, 25, 35, 45, 55, 65, 75 and 95kGy at dose rate of 5 kGy/h and characterized by swelling, thermogravimetric and mechanical analysis. Results shown a favorable dose range window for processing of these hydrogels related to the application. The results showed that mechanical strength was affected at doses starting at 25 kGy.
Preservation of photographic and cinematographic films by gamma radiation- preliminary analyses
2017 - NAGAI, MARIA L.E.; SANTOS, PAULO S.; OTUBO, LARISSA; OLIVEIRA, MARIA J.A.; VASQUEZ, PABLO A.S.
Brazilian weather conditions affect directly tangible materials causing deterioration notably getting worse by insects and fungi attack. In this sense, gamma radiation provided from the cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because it has biocidal action. Radiation processing using gamma radiation for cultural heritage materials for disinfection has been widely used around the world in the last decades. Many cultural heritage objects especially made on paper and wood were studied in scientific publications aiming mechanical, physical and chemical properties changes. Over the last fifteen years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute located inside the Sao Paulo University campus has been irradiated many collections of archived materials, books, paintings and furniture. Adequate storage of photographic and cinematographic materials is a challenge for conservators from preservation institutions. Contamination by fungi is one of leading causes of problem in photographic and cinematographic collections. Several Sao Paulo University libraries have been affected by fungi in their photographic and cinematographic collections making it impossible to research on these materials either manipulate them for health and safety reasons. In this work are presented preliminary results of effects of the ionizing radiation in photographic and cinematographic films. Selected film samples made on cellulose acetate were prepared and characterized by FTIR-ATR spectroscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 50 kGy. Irradiated samples were analyzed by UV-VIS spectroscopy and electron microscopy techniques. Results shown that disinfection by gamma radiation can be achieved safely applying the disinfection dose between 6 kGy to 15 kGy with no significant change or modification of main properties of the constitutive materials.