Navegando por Autor "Moura, Carlos Eduardo B."
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Artigo Effect of plasma‐nitrided titanium surfaces on the differentiation of pre‐osteoblastic cells(Wiley, 2019-03-18) Moura, Carlos Eduardo B.; Queiroz Neto, Moacir F.; Braz, Janine Karla França da Silva; Aires, Michelle de; Farias, Nainsandra B. Silva; Barboza, Carlos Augusto Galvão; Cavalcanti Júnior, Geraldo Barroso; Rocha, Hugo Alexandre de Oliveira; Alves Júnior, ClodomiroA titanium surface nitrided by plasma contains nitrogen ions that guarantee resistance to corrosion and biocompatibility. Despite this, no descriptions concerning the influence of the expression of cell adhesion proteins and their influence on osteogenic cell differentiation are available. Thus, the present study aimed to assess the response of murine pre‐osteoblastic cells (MC3T3‐E1) cultured on nitrided titanium surfaces. Pre‐osteoblastic cells were grown on polished titanium discs, used as controls, and on previously characterized plasma‐nitrided titanium discs. Cells from both groups were submitted to the MTT cell viability test. The expressions of α5, α2, and β1 integrin were assessed by flow cytometry and immunofluorescence, while osteocalcin expression was assessed by flow cytometry. The nitrided surface presented higher α2 and β1 integrin expressions, as well as osteocalcin expression, when compared to the polished surface, with no alterations in cell viability. These findings seem to suggest that the plasma nitriding treatment produces a titanium surface with the potential for effective in vitro osseointegration.Artigo Live endothelial cells on plasma-nitrided and oxidized titanium: an approach for evaluating biocompatibility(Elsevier, 2020-04-23) Braz, Janine Karla França da Silva; Martins, Gabriel Moura; Morales, Nicole; Naulin, Pamela; Fuentes, Christian; Barrera, Nelson P.; Vitoriano, Jussier de Oliveira; Rocha, Hugo Alexandre de Oliveira; Oliveira, Moacir F.; Alves Júnior, Clodomiro; Moura, Carlos Eduardo B.We evaluated the effects of titanium plasma nitriding and oxidation on live endothelial cell viscoelasticity. For this, mechanically polished titanium surfaces and two surfaces treated by planar cathode discharge in nitriding (36N2 and 24H2) and oxidant (36O2 and 24H2). Surfaces were characterized regarding wettability, roughness and chemical composition. Rabbit aortic endothelial cells (RAECs) were cultured on the titanium surfaces. Cell morphology, viability and viscoelasticity were evaluated by scanning electron microscopy (SEM), methyl thiazolyl tetrazolium (MTT) assay and atomic force microscopy (AFM), respectively. Grazing Incidence X-ray Diffraction confirmed the presence of TiN0,26 on the surface (grazing angle theta 1°) of the nitrided samples, decreasing with depth. On the oxidized surface had the formation of TiO3 on the material surface (Theta 1°) and in the deeper layers was noted, with a marked presence of Ti (Theta 3°). Both plasma treatments increased surface roughness and they are hydrophilic (angle < 90°). However, oxidation led to a more hydrophilic titanium surface (66.59° ± 3.65 vs. 76.88° ± 2.68; p = 0.001) due to titanium oxide films in their stoichiometric varieties (Ti3O, TiO2, Ti6O), especially Ti3O. Despite focal adhesion on the surfaces, viability was different after 24 h, as cell viability on the oxidized surface was higher than on the nitrided surface (9.1 × 103 vs. 4.5 × 103cells; p < 0.05). This can be explained by analyzing the viscoelastic property of the cellular cytoskeleton (nuclear and peripheral) by AFM. Surface oxidation significantly increased RAECs viscoelasticity at cell periphery, in comparison to the nucleus (2.36 ± 0.3 vs. 1.5 ± 0.4; p < 0.05), and to the RAECs periphery in contact with nitrided surfaces (1.36 ± 0.7; p < 0.05) and polished surfaces (1.55 ± 0.6; p < 0.05). Taken together, our results have shown that titanium plasma treatment directly increased cell viscoelasticity via surface oxidation, and this mechanobiological property subsequently increased biocompatibility.Artigo Plasma nitriding under low temperature improves the endothelial cell biocompatibility of 316L stainless steel(Springer, 2019-02-28) Braz, Janine Karla França da Silva; Martins, Gabriel M.; Sabino, Vladimir; Vitoriano, Jussier de Oliveira; Barboza, Carlos Augusto Galvão; Soares, Ana Katarina Menezes da Cruz; Rocha, Hugo Alexandre de Oliveira; Oliveira, Moacir. F.; Alves Júnior, Clodomiro; Moura, Carlos Eduardo B.Objectives To evaluate the effects of the surface modification of 316L stainless steel (SS) by lowtemperature plasma nitriding on endothelial cells for stent applications. Results X-ray diffraction (XRD) confirmed the incorporation of nitrogen into the treated steel. The surface treatment significantly increased SS roughness and hydrophilic characteristics. After 4 h the cells adhered to the nitride surfaces and formed clusters. During the 24 h incubation period, cell viability on the nitrided surface was higher compared to the polished surface. Nitriding reduced late apoptosis of rabbit aorta endothelial cell (RAEC) on the SS surface. Conclusion Low temperature plasma nitriding improved the biocompatible of stainless steel for use in stents.