Fibroblasts and osteoblasts behavior after contact with different titanium surfaces used as implant abutment: An in vitro experimental study

Background: The goal of this in vitro study was to compare three different surfaces: two types of implant surfaces commercially available ([a] smooth/machined and [b] acid-treated surface) versus (c) anodized surface. Discs were manufactured with commercially pure titanium (CP) grade IV, which were subsequently analyzed by scanning microscopy and fibroblastic and osteoblastic cell cultures. Methods: Ninety-nine discs (5 ×2 mm) were manufactured in titanium grade IV and received different surface treatments: (i) Mach group: machined; (ii) AA group: double acid etch; and (iii) AN group: anodizing treatment. Three discs from each group were analyzed by Scanning Electron Microscopy (SEM) to obtain surface topography images and qualitatively analyzed by EDS. Balb/c 3T3 fibroblasts and pre-osteoblastic cells (MC3T3-E1 lineage) were used to investigate each group’s biological response (n =10/cellular type). The data were compared statistically using the ANOVA one-way test, considered as a statistically significant difference p Mach >AN). There was similar behavior for cell adhesion for the test groups (Mach and AN), with greater adhesion of Balb/c 3T3 fibroblast

Microesferas para absorção de metais pesados, processo para sua preparação, e processo de remoção de metais pesados de meios aquosos

Em 04/11/2016: Expedição de carta-patente ou certificado de adição de invenção no prazo ordinárioConcedidaRevela microesferas compostas de um polissacarídeo de origem biológica e um mineral pertencente ao grupo das apatitas, em especial o alginato e a hidroxiapatita, processos para sua preparação e seu uso na remoção de metais pesados como o chumbo em soluções aquosas em qualquer faixa de pH, como, por exemplo, em reservatórios contaminados e in vivo através de sua ação nos fluidos gástricos e/ou entéricos

Estudo do comportamento do chumbo em latossolos brasileiros tratados com fosfatos: contribuições para a remediação de sítios contaminados

Phosphates have been used for lead immobilization in soils but the influence of soil type is not fully understood. In this work, lead chemical behaviour in two Brazilian latosoils (LA and LV) was studied via treatment with phosphates. The Pb concentration in Toxicity Characteristic Leaching Procedure (TCLP) solutions was decreased in all treatments. After treatment with H3PO4 the Pb concentration in the LA remained within the regulatory limit established by EPA. The ecotoxicological results with Daphnia pulex showed that this treatment reduced the lead bioavailability. Sequential extraction analyses showed that the lead was transferred from the most available to the residual fraction. Relevant decrease of soluble lead was observed in all phosphate treatments

The durapatite as a metals absorver

Made available in DSpace on 2012-09-06T01:12:26Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 114.pdf: 2974812 bytes, checksum: f8ff05a4d6d47e944264989c2563d2b6 (MD5) Previous issue date: 1999Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, Brasil.A concentraçäo de metais poluentes, como o chumbo (Pb), tem aumentado em áreas populosas e desenvolvidas devido a poluiçäo atmosférica e outras atividades humanas. Conseqüentemente, o potencial para este elemento alcançar a cadeia alimentar aumentou. O chumbo é muito tóxico para o ser humano, especialmente para crianças, e a exposiçäo ao chumbo pode causar efeitos adversos à saúde humana. A hidroxiapatita (Hap), um composto de fosfato de cálcio, é o principal constituinte inorgânico dos ossos e dentes. Pesquisas concluiram que a hidroxiapatita sintética tem uma alta capacidade para remover metais pesados divalentes da água em condiçöes ambientais. Existem várias tecnologias empregadas para tratamento de água e solos contaminados. Estes tratamentos além de serem caros, muitas vezes säo destrutivos. Torna-se entäo necessário, desenvolver novos métodos para remover íons tóxicos de solos e esgotos pela reduçäo da solubilidade do Pb e conseqüentemente sua bio-disponibilidade. Visto ser a hidroxiapatita um regulador da concentraçäo de cálcio, fósforo e chumbo no meio ambiente, este material poderia ser usado com baixos custos, na remoçäo de chumbo em solos e águas contaminadas. O objetivo é elucidar os mecanismos envolvidos na remoçäo de chumbo de soluçöes aquosas, investigando-se a transformaçäo do Pb para uma forma mais estável: a piromorfita.The concentration of pollutant metals such as lead (Pb), has increased in populated and developed areas due to atmospheric pollution and other human activities. Consequently, the potential for these elements to enter the human food chain has increased. Lead is very toxic to humans especially to young children and the contamination by lead can cause adverse effects on human health. Hydroxyapatite (Hap), a calcium phosphate compound is the principal inorganic constituent of human bones and teeth. It has been found that synthetic hydroxyapatite has a high capacity for removing divalent heavy metals ions from water under ambient conditions. There are many technologies employed to clean up contaminated water and soils. These treatments are often costly and destructive. Thus, it is important to develop new methods to remove toxic ions from soils and wastewater by reducing Pb solubility and bioavailability. If hydroxyapatite can regulate the concentration of calcium, phosphate and lead in environments this material may provide a cost-effective technology for remediating lead contaminated soils and water. The aim of this work is to elucidate the mechanism involved in the removal of lead from aqueous solution through investigations of Pb and incorporation into a new stable phase: pyromorphite

Methodological implications on quantitative studies of cytocompatibility in direct contact with bioceramic surfaces

6 p. : il., tabCell adhesion, proliferation and differentiation are important specific parameters to be evaluated on biocompatibility studies of candidate biomaterials for clinical applications. Several different methodologies have been employed to study, both qualitative and quantitatively, the direct interactions of ceramic materials with cultured mammal and human cells. However, while quantitatively evaluating cell density, viability and metabolic responses to test materials, several methodological challenges may arise, either by impairing the use of some widely applied techniques, or by generating false or conflicting results. In this work, we tested the inherent interference of different representative calcium phosphate ceramic surfaces (stoichiometric dense and porous hydroxyapatite (HA) and cation-substituted apatite tablets) on different tests for quantitative evaluation of osteoblast adhesion and metabolism, either based on direct cell counting after trypsinization, colorimetric assays (XTT, Neutral Red and Crystal Violet) and fluorescence microscopy. Cell adhesion estimation after trypsinization was highly dependent on the time of treatment, and the group with the highest level of estimated adhesion was inverted from 5 to 20 minutes of exposition to trypsin. Both dense and porous HA samples presented high levels of background adsorption of the Crystal Violet dye, impairing cell detection. HA surfaces also were able to adsorb high levels of fluorescent dyes (DAPI and phalloidin-TRITC), generating backgrounds which, in the case of porous HA, impaired cell detection and counting by image processing software (Image Pro Plus 6.0). We conclude that the choice for the most suitable method for cell detection and estimation is highly dependent on very specific characteristics of the studied material, and methodological adaptations on well established protocols must always be carefully taken on consideration