Navegando por Autor "Oliveira, Paulo Tambasco de"

Agora exibindo 1 - 2 de 2
  • Imagem de Miniatura
    Item
    Calcium Aluminate Cement Blends Containing Bioactive Glass and Strontium for Biomaterial Applications
    (SciELO) Barbosa, Ana Margarida; Santos, Kennedy Wallace dos; Gonçalves, Irene S.; Leite, Priscila Maria Sarmeiro Corrêa Marciano; Martorano, Antonio Secco; Grisote, Gabriela; Raucci, Larissa Moreira Spinola de Castro; Oliveira, Paulo Tambasco de; Raniero, Leandro José; Oliveira, Ivone Regina de
    In this work blends based on calcium aluminate cement (CAC) containing bioactive glass (BG) (5, 7.5 and 10 wt%) and strontium oxide (1 wt%) were produced aiming improve their bioactivity and the capacity to stimulate the bone regeneration. In the first part, the blends containing only BG were characterized as theoretical density, microhardness, uniaxial cold crush strength after SBF and apparent porosity and pore size distribution before and after SBF treatment. In the second part, bioactivity and cell culture tests were also conducted in the blends containing BG and strontium oxide. The addition of 7.5 wt% of BG in homogeneous calcium aluminate cement (CH) improved its mechanical properties as microhardness and uniaxial cold crushing strength. The blends were more bioactive due to the presence of a highly soluble amorphous phase as confirmed by means of SEM/EDX mainly for 7.5 wt% BG without and with Sr from 1 day in SBF. FTIR analyses indicated the formation the apatite-like phase by means of increase of intensity of the PO43- peaks after SBF treatment. All blends allowed the development of the osteoblastic phenotype and the formation of mineralized matrix increased due to the inclusion of BG and Sr promoting the osteogenesis process.
  • Imagem de Miniatura
    Item
    Cyto-genotoxicity and immunomodulation in fibroblasts exposed to calcium-aluminate cement with different radiopacifiers
    (Fundação Odontológica de Ribeirão Preto) Martorano, Antônio Secco; Messias, Nadyne Saab; Bighetti-Trevisan, Rayana Longo; Teixeira, Lucas Novaes; Oliveira, Ivone Regina de; Raucci-Neto, Walter; Oliveira, Paulo Tambasco de; Castro-Raucci, Larissa Moreira Spinola de
    Calcium aluminate cement (CAC) has been proposed as an alternative to mineral trioxide aggregate (MTA), but its biological behavior remains underexplored. This study evaluated the cytotoxicity, genotoxicity, and proinflammatory gene expression of fibroblasts exposed to CAC formulations containing zinc oxide or bismuth oxide with different proportions of calcium chloride, in comparison with MTA. Fibroblasts were cultured with CACz (25% ZnO + 2.8% CaCl₂), CACb (25% Bi₂O₃ + 2.8% CaCl₂), CACb+ (25% Bi₂O₃ + 10% CaCl₂), or MTA; non-exposed cells served as controls. Cytotoxicity was assessed by fluorescence microscopy and MTT viability assays at 24 h and 72 h, while genotoxicity was evaluated by the comet assay at 24 h. Gene expression of COL-1, TNF-α, IL-1β, IL-6, and MMP-9 was examined by RT-qPCR at 72 h. Data were analyzed using the Kruskal-Wallis test and the Student-Newman-Keuls post hoc test (α = 0.05). Cell viability did not differ among groups at 24 h, but was higher for CACb+ at 72 h (p < 0.05). DNA damage levels were similar across groups (p > 0.05). For gene expression, no significant differences were observed for COL-1, IL-1β, or TNF-α. All cements upregulated IL-6 compared with control (p < 0.05), with the highest levels in MTA and the lowest in CACb+. CACb+ increased MMP-9 expression (p < 0.05), while CACz showed the lowest levels. Within the limits of this study, CAC formulations with additives were not genotoxic or cytotoxic, and their biological behavior was composition-dependent, with CACb+ demonstrating the most favorable profile by enhancing fibroblast viability and extracellular matrix remodeling potential.