JAQUELINE JAMARA SOUZA SOARES
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
Resumo IPEN-doc 24852 Antimicrobial activity of Graphene Oxide/Silver nanocomposite obtained by Electron Beam2017 - SOUSA, THAINA S.; JACOVONE, RAYNARA M.S.; SOARES, JAQUELINE J.S.; RODRIGUES, DEBORA F.; SILVA, FLAVIA R. de O.; GARCIA, RAFAEL H.L.; ZAIM, MARCIO H.; SAKATA, SOLANGE K.Graphene oxide is a carbon-based nano material that has a high specific surface area, high chemical stability, excellent electrical and thermal conductivities, high mechanical resistance, the oxygen groups facilitate dispersion in polar solvents and its functionalization. In the literature, is described several methods of metal incorporation on graphene oxide surface using toxic reagents or with long periods of reaction. The objective of this work is to develop an innovative and sustainable method of incorporating silver into graphene oxide that does not involve toxic reagents or generated residues. in a short reaction time at room temperature beyond the use of the as an alternative process to the chemical processes traditional.A silver solution in the complex form was added to a dispersed graphene oxide in water/isopropanol solution. The mixture wassubmitted to a dose of radiation ranged from 150 to 400 KGy using a electron beam acelerator. The nanocomposite GO/Ag characterization was performed by thermogravimetry analysis (TGA), X-ray diffraction (XDR), scanning transmission electron microscope coupled to the energy dispersive X-ray spectrometry (TEM/EDS). The antimicrobial activity of GO/Ag was observed by Escherichia coli, a Gram negative bacterium and Bacillus subtilis a Gram positive bacterium in solid culture medium. The minimum inhibitory concentration of GO/Ag was 50 mg/L. .It is noteworthy that the incorporation of silver occurred at the same time the reduction of graphene oxide without the generation of toxic chemical residues.Resumo IPEN-doc 24850 The effect of GO-PEG-NH2 on the mechanical resistance of bovine pericardium used in cardiovascular device2017 - SOARES, JAQUELINE J.S.; JACOVONE, RAYNARA M.S.; MATHOR, MONICA B.; ZAIM, MARCIO H.; MAIZATO, MARINA J.S.; CESTARI, IDAGENE A.; JATENE, FABIO B.; SAKATA, SOLANGE K.Valvular heart disease (VHD) is a clinical condition where one of the four-heart valves is damage or has a defect. It was estimated that approximately 300,000 to 400,000 heart valve replacement surgeries were performed in 2014. There are two types of prostheses, the bioprothesis and the mechanical prosthesis. Even though the first one presents a smaller rejection, its durability is reduced due to calcification followed by deterioration. The objective of this work was to increase the durability of prostheses made from bovine pericardium (BP) by incorporating GO functionalized with amino-PEG (GO-PEG-NH2). Briefly, GO functionalized was firstly sterilized with gamma radiation and then incorporated to BP in two different ways: chemical and physical. Mechanical characterization assays of BP treated with GO-PEG-NH2 and untreated (control) were performed in an INSTRON model 3365 universal test equipment using the BioPlus accessory, which allows the assays to be carried out immersed in a physiological solution of 0,9% NaCl at 36 °C, simulating the environment of material’s application. The static deformation in the uniaxial direction of the test specimens was verified using the ASTM D638-10 standard test method for tensile properties of plastics, 2010 from the American Society for Testing and Materials (ASTM Standards). The results indicated that GO-PEG-NH2 improved the mechanical strength of the biomaterial, increasing the resistance to permanent plastic deformation, maximum supported load, flow limit, maximum traction tension, rupture tenacity and rupture traction tension no matter of GO-PEG-NH2 incorporation methods and it is possible to improve the performance of bioprothesis by coating them with GO-PEG-NH2 and consequently increasing their durability.Resumo IPEN-doc 24849 Characterization by atomic force microscope (AFM) of graphene oxide and graphene oxide-PEG-NH2 incorporated in bovine pericardium2017 - SOARES, JAQUELINE J.S.; COSTA, CARLOS A.R.; JACOVONE, RAYNARA M.S.; ZAIM, MARCIO H.; SAKATA, SOLANGE K.Atomic force microscopy (AFM) is a technique that allows images from the surface topography with high spatial resolution at Nano metric scales. AFM has being used in several fields in science such as Biology, Medicine, Chemistry and Pharmaceuticals. In this study, the tecnhique was used to characterize graphene oxide and graphene oxide functionalized with amino-PEG (GO-PEG-NH2) in the bovine pericardium (BP) surface. The treatment of BP with GO and (GO-PEG-NH2) improved the mechanical properties of the biomaterial that will be used in the manufacture of cardiovascular device that is used to replace heart valves. For the BP coating, two different pathways were tested: 1) chemical pathway using solution containing 1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and GO; and 2) in physical adsorption the incorporation were performed by ultrassom. The same procedure was performed to incorporate GO-PEG-NH2. The images of the BP with its modified surface were obtained by AFM and proof the efficiency in the two incorporation processes. The study also demonstrated the applicability of AFM to characterize incorporated nanomaterial in the biological samples.