MARIA JOSE ALVES DE OLIVEIRA

MARIA JOSE ALVES DE OLIVEIRA

Página do item completo

Resultados de Busca

Agora exibindo 1 - 10 de 40

Effect of gamma radiation cobalt-60 on caffeine
2019 - MAIA, TIAGO C. dos S.; LUGAO, ADEMAR B.; AZOUBEL, ROBERTA; RAPOSO, MARCOS T.; OLIVEIRA, MARIA J.A. de
Objective: The objective of the study was to evaluate the effects of the incidence of gamma radiation of Cobalt-60 on caffeine. Material and Methods: The samples were studied in aqueous solution and powdered form after irradiation at doses: 2, 4, 8, 16 and 32 kGy by ionizing radiation source of 60Co. After wards, they were analyzed by differential scanning calorimetry (DSC), thermogravimetry (TG), and high performance liquid chromatography (HPLC). Results and Discussion: For the DSC technique no changes were observed in the curves after irradiation, which could witness changes in physicochemical properties after irradiation. The TG corroborated with the expected mass loss of caffeine, independent of the action of ionizing radiation. Furthermore, the results obtained by the chromatographic analysis did not show a percentage of caffeine degradation in the dose of the applied radiation when compared to the nonirradiated caffeine. Conclusion: In view of the results obtained, it was possible to observe the stability of caffeine on the influence of gamma radiation on the Cobalt-60 source.
Efeito do CMC no intumescimento de curativos de hidrogel à base de PVP com nanoprata
2019 - ALCANTARA, M.T.S.; OLIVEIRA, M.J.A.; LIERMANN, G.M.; LUGAO, A.B.
Hidrogéis de PVP são redes poliméricas tridimensionais, hidrofílicas, que apresentam propriedades de intumescimento e biocompatibilidade o que favorece seu uso como curativos. Por propiciar umidade no leito da ferida mantém o ambiente ideal para cicatrização, além de não aderir a ela. Por outro lado as nanopartículas de prata apresentam propriedades antimicrobianas e antiinflamatórias e o uso de radiação ionizante permite a reticulação e esterilização simultânea do curativo. O objetivo deste estudo foi avaliar o efeito do CMC no intumescimento de curativos de hidrogel com 22 e 80 ppm de nanopartículas de prata, reticulado por radiação ionizante, assim como avaliar a resistência mecânica dos curativos estudados. Os curativos foram avaliadas a partir de ensaios de fração gel, intumescimento e resistência mecânica. Os resultados indicaram um aumento importante no intumescimento do curativo com a adição de CMC, principalmente para o curativo com maior concentração de nanoprata, porém um menor grau de reticulação e consequentemente redução da sua resistência mecânica.
Influence of different gamma radiation doses on PVA/gelatin based scaffolds
2017 - OLIVEIRA, JUSTINE P.R. de; OLIVEIRA, MARIA J.A. de; SILVA, ISABELA C. da; VARCA, GUSTAVO H.C.; LUGAO, ADEMAR B.
The present work aimed to study the influence of different radiation doses on a polymer blend at cryogenic and room temperature by means of crosslinking formation, pore size, morphology, topography and mechanical properties. The scaffold was prepared based on two formulations, one composed by gelatin (7%, w/w) and PVA (5%, w/w), and the second by gelatin (10%, w/w) and PVA (5%, w/w). The formulations were separately solubilized in distilled water and heated up to 80 ºC under constant stirring for 1 hour. Posteriorly, both blends were disposed in circular glass moulds. Half of samples was frozen for at least 24 h and then irradiated at 15, 25 and 50 kGy. The other half was cooled at 4 ºC for at least 24 h and then irradiated using the same doses. After irradiation both sample groups were frozen and freeze dried. The scaffold was characterized in terms of structure and morphology by mechanical assays, differential scanning calorimetry, scanning electron microscopy, optical coherence tomography and infrared spectroscopy. In addition, platelet adhesion and release, and cytotoxic assays were also performed. Samples irradiated at 15 kGy presented pore size diameter of around 1.4 μm and porosity of 54%, while samples irradiated at 25 kGy, presented pore size diameter of around 1.1 μm and porosity of 49%. Optical coherence tomography showed that gelatin control samples presented more superficial degradation as irradiation dose increased, while PVA control sample presented higher integrity, indicating that this polymer is less sensitive to gamma radiation. The system presented suitable mechanical properties and the platelet adhesion and release assays showed that the scaffold presented adequate pore size range to host and release the platelets, and non-cytotoxic to platelets, featuring adequate properties to be applied as dressing for wound treatments.
Ionizing radiation for the preservation and conservation of photographic and cinematographic films
2019 - NAGAI, MARIA L.E.; SANTOS, PAULO S.; OTUBO, LARISSA; OLIVEIRA, MARIA J.A. de; VASQUEZ, PABLO A.S.
The Nuclear and Energy research Institute – IPEN-CNEN/SP through the Multipurpose Gamma Irradiation Facility has treated several bibliographical collections of Sao Paulo University-USP for disinfestation and disinfection of contaminated materials with insects and fungi. In this sense, gamma radiation from cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because the biocidal action. Disinfection using gamma radiation for cultural heritage materials has been widely applied around the world in the last decades. Adequate storage of photographic and cinematographic materials is a challenge for conservation experts from preservation institutions. Contamination by fungi is one of leading causes of problem in this kind of collections. In addition, another common physicochemical degradation affecting cellulose triacetate films causing deacetylation of polymer chain is called “vinegar syndrome”. In this work are presented results of effect of ionizing radiation on photographic and cinematographic films. Selected films were characterized by FTIR-ATR spectroscopy and FEGSEM-EDS microscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 200 kGy. Irradiated samples were analyzed by UV-vis spectrophotometry, FEGSEM, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Results showed that disinfection by gamma rays can be achieved safely applying radiation absorbed doses between 6 kGy and 10 kGy with no change or modification of main properties of the constitutive polymeric materials. Gamma rays due to the effect of crosslinking is presented as an alternative to treat films affected by “vinegar syndrome” applying absorbed dose of 50 kGy in order to increase shelf life of cultural heritage materials.
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).
Effectiveness of the hydrogel dressing crosslinked and sterilized by gamma radiation
2019 - GEMELLI, KARINE K.; SOUSA, GRAZIELLY M. de; GEMELLI, TIAGO F.; FERREIRA, OBEDE R.; OLIVEIRA, MARIA J.A. de; ALCANTARA, MARA T.S.; LUGAO, ADEMAR B.
Chronic wounds of difficult cicatrization are more incidents with an increased in life expectancy. The hydrogel with silver nanoparticles developed at the Nuclear Energetic Research Institute, crosslinked and sterilized by Gamma radiation, is inexpensive and has a simple manufacturing process that seems to be an alternative to the treatment of injuries. This experimental study compared the healing process of second intention of skin wounds of 4cm² on the back of 69 Wistar rats, considering the effectiveness of hydrogel dressings with silver nanoparticles. The animals were distributed in three groups that received treatment with hydrogel dressing, hydrogel with 22ppm of silver nanoparticles and hydrogel with 44ppm of silver nanoparticles, and the dressings were performed every 48 hours. The project was approved by the Animal Experiments Committee. Hydrogel dressings are transparent and allow accurate visualization of the center of the lesion. The part of the dressing in contact with the wound kept the medium moist, promoting interaction with the fluid of the lesion, besides adsorbing the moisture produced. The dressing replacement didn’t cause discomfort or pain, since the animals were manually contained during the procedure, and the cover is easy to remove without causing trauma to the healing tissue. Wounds remained free of fibrin formation and necrosis, and serous exudation of lesions was scarce. At 21 days all the lesions were healed showing that dressings weren’t negative to the second intention healing process.
Toxicity study using rat (WISTAR) model of a hydrogel dressing with silver nanoparticles crosslinked and sterilized by gamma radiation
2019 - SOUSA, GRAZIELLY M. de; GEMELLI, KARINE K.; MARTINS, OZENILDE A.R.; OLIVEIRA, MARIA J.A. de; ALCANTARA, MARA T.S.; LUGAO, ADEMAR B.; ROGERO, JOSE R.
Silver nanoparticles (NPAg) have a bactericidal and bacteriostatic action in combination with hydrogels to recover the damaged tissue, promoting healing of the wound. The objective of this study was to evaluate the toxicity of the hydrogel dressing with NPAg from the analysis of possible toxic effects on renal and hepatic functions. It is an experimental study with 85 male Wistar rats, young adults. Nanoprate hydrogel and bidrogel dressings were used at concentrations of 22 and 44 ppm, both crosslinked and sterilized by irradiation with gamma rays at the 25 kGy dose at the center of radiation technology (CTR). The animals were distributed according to the treatment received after surgical induction of the wound on the animal's back. They were euthanized with 24 hours, 3, 7, 14, 21 and 30 days and after collecting the blood to determine the biochemical parameters. The project was approved by CEUA FAPAC ITPAC PORTO. Data were analyzed using the Past, Shapiro-Wilk and Kruskal-Wallis programs. For distribution and comparison data ANOVA and Tukey test with a significance level of 95%. No changes were observed in relation to biochemical parameters (TGP, TGO, urea and creatinine), and there were no statistically significant differences between the three groups of animals, independent of time. It was possible to observe that the animals treated with 44 ppm had always lower mean values than the other two groups in all analyzes. The study showed that the dressings of NPAg tested may not induce toxicity, being necessary to complement with other tests, such as histopathological study and atomic absorption spectroscopy.
Synthesis and in vivo behavior of PVP/CMC/agar hydrogel membranes impregnated with silver nanoparticles for wound healing applications
2018 - LIMA, GABRIEL G. de; LIMA, DARLLA W.F. de; OLIVEIRA, MARIA J.A. de; LUGAO, ADEMAR B.; ALCANTARA, MARA T.S.; DEVINE, DECLAN M.; SA, MARCELO J.C. de
The field of wound healing has seen an increase in research activity in wound care and hydrogel-based dressings have been targeted as a solution for these applications. Hydrogels with silver nanoparticles can present many advantages for this field. However, if the aggregation and sterilization of this product have not been carefully considered, the effectiveness or use could be limited. Therefore, in the current study, a hydrogel-based wound dressing membrane was developed using polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), agar, and carboxymethyl cellulose (CMC). Silver ions (Ag+) were dispersed in the polymer matrix and its reduction with formation of a hydrogel and silver nanoparticles was performed using 60Co gamma irradiation to enhance the dressings antimicrobial properties. The resulting hydrogel presented a high degree of swelling and a good size control of silver nanoparticles. The incorporation of AgNPs was confirmed via Raman spectroscopy and the samples presented no signs of toxicity in vitro as assessed using an elution assay with neutral red uptake as the cytotoxic end point. Membranes were tested in vivo using a full thickness defeat model in rabbits. Postmortem histopathological analysis indicated that the use of the hydrogel membranes that incorporated AgNPs had a stimulatory action on wound healing as evidenced by a high intensity of fibroblasts and neovascularization in the tissue, which promoted a faster healing process when compared to the untreated wounds. We demonstrate the possibility of producing a hydrogel with good size control of AgNPs, which can also be directly sterilized within the formation of this material via gamma irradiation. Furthermore, the mechanism of hydrogel healing, in vivo, with silver nanoparticles was found to have a direct correlation of silver nanoparticles with in vitro cell results.
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.
Hydrogels with silver nanoparticles for wound treatment
2017 - OLIVEIRA, MARIA J.A.; SANTOS, JONNATAN J.; TOMA, SERGIO H.; ALCANTARA, MARA T.S.; VASQUEZ, PABLO A.V.; ARAKI, KOITI; LUGAO, ADEMAR B.
In recent years, the study and preparation of nanoparticles have attracted considerable interest for both fundamental and applied research. In biomedical area, silver nanoparticles have been a vast field of study, although antimicrobial properties have originated from their medical application since 19th century. Since silver has had several uses and its enormous potential for the treatment of injuries. Silver-containing topcoats are an excellent option for topical microbial combat on wounds that present infection, as well as being an essential tool for controlling bacterial load. Among these coatings are the hydrogel dressings with silver nanoparticles that have broad spectrum of antimicrobial action. In vitro studies have demonstrated bactericidal activity in strains of antibiotic resistant microorganisms. The objective of this work is characterize hydrogels with silver nanoparticles, prepared using polyvinylpyrrolidone (PVP), carboxymethylcellulose (CMC), used to treat wounds. A gamma radiation source cobalt-60 was used to crosslink the hydrogels, sterilize and form the silver nanoparticles simultaneously. Irradiation is recognized as a very viable tool because there is no need to add possibly harmful primers or crosslink that are difficult to remove. The results showed uniform distribution of the nanoparticles on the surface of the hydrogels, making it feasible for topical application.