Commercially pure titanium implants with surfaces modified by laser beam with and without chemical deposition of apatite. Biomechanical and topographical analysis in rabbits

Objectives: The purpose of this study was to evaluate the surfaces of commercially pure titanium (cp Ti) implants modified by laser beam (LS), without and with hydroxyapatite deposition by the biomimetic method (HAB), without (HAB) and with thermal treatment (HABT), and compare them with implants with surfaces modified by acid treatment (AS) and with machined surfaces (MS), employing topographical and biomechanics analysis. Methods: Forty-five rabbits received 75 implants. After 30, 60, and 90 days, the implants were removed by reverse torque and the surfaces were topographically analyzed. Results: At 30 days, statistically significant difference (P < 0.05) was observed among all the surfaces and the MS, between HAB/HABT and AS and between HAB and LS. At 60 days, the reverse torque of LS, HAB, HABT, and AS differed significantly from MS. At 90 days, difference was observed between HAB and MS. The microtopographic analysis revealed statistical difference between the roughness of LS, HAB, and HABT when compared with AS and MS. Conclusions: It was concluded that the implants LS, HAB, and HABT presented physicochemical and topographical properties superior to those of AS and MS and favored the osseointegration process in the shorter periods. In addition, HAB showed the best results when compared with other surfaces. © 2012 John Wiley & Sons A/S.

Interaction between mesenchymal stem cells and Ti-30Ta alloy after surface treatment

In this study, in vitro cytocompatibility was investigated in the Ti-30Ta alloy after two kinds of surfaces treatments: alkaline and biomimetic treatment. Each condition was evaluated by scanning electron microscopy/energy-dispersive X-ray spectroscopy. Cellular adhesion, viability, protein expression, morphology, and differentiation were evaluated with Bone marrow stromal cells (MSCs) to investigate the short and long-term cellular response by fluorescence microscope imaging and colorimetric assays techniques. Two treatments exhibited similar results with respect to total protein content and enzyme activity as compared with alloy without treatment. However, it was observed improved of the biomineralization, bone matrix formation, enzyme activity, and MSCs functionality after biomimetic treatment. These results indicate that the biomimetic surface treatment has a high potential for enhanced osseointegration. © 2013 Wiley Periodicals, Inc.

Structural and functional studies with mytoxin II from Bothrops moojeni reveal remarkable similarities and differences compared to other catalytically inactive phospholipases A2-like

Lys49-phospholipases A2 (Lys49-PLA2s) are proteins found in bothropic snake venoms (Viperidae family) and belong to a class of proteins which presents a phospholipase A2 scaffold but are catalytically inactive. These proteins (also known as PLA2s-like toxins) exert a pronounced local myotoxic effect and are not neutralized by antivenom, being their study relevant in terms of medical and scientific interest. Despite of the several studies reported in the literature for this class of proteins only a partial consensus has been achieved concerning their functional-structural relationships. In this work, we present a comprehensive structural and functional study with the MjTX-II, a dimeric Lys49-PLA2 from Bothrops moojeni venom which includes: (i) high-resolution crystal structure; (ii) dynamic light scattering and bioinformatics studies in order to confirm its biological assembly; (iii) myographic and electrophysiological studies and, (iv) comparative studies with other Lys49-PLA2s. These comparative analyses let us to get important insights into the role of Lys122 amino acid, previously indicated as responsible for Lys49-PLA2s catalytic inactivity and added important elements to establish the correct biological assembly for this class of proteins. Furthermore, we show two unique sequential features of MjTX-II (an amino acid insertion and a mutation) in comparison to all bothropic Lys49-PLA2s that lead to a distinct way of ligand binding at the toxin's hydrophobic channel and also, allowed the presence of an additional ligand molecule in this region. These facts suggest a possible particular mode of binding for long-chain ligands that interacts with MjTX-II hydrophobic channel, a feature that may directly affect the design of structure-based ligands for Lys49-PLA2s. © 2013 Elsevier Ltd.

Transcript finishing initiative: contribuição do laboratório IL2

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Desenvolvimento de métodos de cultivo de Gluconacetobacter xylinus para obtenção de compósitos à base de celulose bacteriana e colágeno tipo I adicionado in situ

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estruturação ex-vivo de vasos sanguíneos a partir da diferenciação de células tronco de coelhos

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Análise comparativa da distribuição de tensões em incisivo central superior, restaurado com diferentes sistemas de pinos intra-radiculares

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da viabilidade do selante de fibrina derivado de veneno de serpente como arcabouço biológico para células-tronco mesenquimais de medula óssea de ratos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de novas propostas em arcabouços tridimencionais (3D) para cultura de células-tronco mesenquinas e condogênese

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação de implantes dentários da liga experimental Ti-30Ta após tratamento de superfície biomimético e imobilização com bisfosfonato

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de superfícies ativas na ligaTi-15Mo para aplicação como biomaterial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do tratamento térmico em recobrimentos cerâmicos bioativos pelo método biomimético sobre titânio c.p. modificados pelo laser Nd:YAG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Recobrimento de apatitas empregando-se o método biomimético: estudo da influência dos íons K+, Mg2+, SO42- e HCO3- na formação de hidroxiapatita

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Crescimento da nanoapatita na liga Ti-30Ta, para aplicações odontológicas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Osseointegração de implantes porosos de titânio submetidos ao tratamento biomimético

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)