Cell adhesion evaluation of laser-sintered HAp and 45S5 bioactive glass coatings on micro-textured zirconia surfaces using MC3T3-E1 osteoblast-like cells

Laser texturing is a technique that has been increasingly explored for the surface modification of several materials on different applications. Laser texturing can be combined with conventional coating techniques to functionalize surfaces with bioactive properties, stimulating cell differentiation and adhesion. This study focuses on the cell adhesion of laser-sintered coatings of hydroxyapatite (HAp) and 45S5 bioactive glass (45S5 BG) on zirconia textured surfaces using MC3T3-E1 cells. For this purpose, zirconia surfaces were micro-textured via laser and then coated with HAp and 45S5 BG glass via dip coating. Afterwards, the bioactive coatings were laser sintered, and a reference group of samples was conventionally sintering. The cell adhesion characterisation was achieved by cell viability performing live/dead analysis using fluorescence stains and by SEM observations for a qualitative analysis of cell adhesion. The in vitro results showed that a squared textured pattern with 100μm width grooves functionalized with a bioactive coating presented an increase of 90% of cell viability compared to flat surfaces after 48h of incubation. The functionalized laser sintered coatings do not present significant differences in cell viability when compared to conventionally sintered coatings. Therefore, the results reveal that laser sintering of HAp and 45S5 BG coatings is a fast and attractive coating technique.publishe

Avaliação da qualidade de vida, da dor nas costas, da funcionalidade e de alterações da coluna vertebral de estudantes de fisioterapia

O objetivo deste estudo foi avaliar a qualidade de vida, dor nas costas, funcionalidade e as alterações da coluna vertebral de estudantes de fisioterapia. Participaram 42 universitários, sendo avaliada a coluna vertebral por meio do arcômetro, a dor nas costas por meio de um questionário multidimensional de dor, a qualidade de vida por meio do questionário SF-36 e funcionalidade a partir do Roland-Morris. Foi realizada estatística descritiva e teste qui-quadrado (α=0,05). Os resultados demonstraram: prevalência de alterações nas curvaturas da coluna vertebral de 38,1%; (n=16); alta prevalência de dor nas costas (69%; n=29); baixa prevalência de comprometimento da funcionalidade (3,4%; n=1); que não há associação entre as alterações nas curvaturas da coluna vertebral e funcionalidade e dor nas costas; e que os escores dos domínios do SF-36 foram maiores que 45, exceto o domínio "dor", cujo escore aproximado foi de 35. Conclui-se que quanto menor os níveis de intensidade da dor melhor o nível de qualidade de vida

FROM COVALENT TO IONIC BONDING - SPONTANEOUS BOND-DISSOCIATION IN OXY-SUBSTITUTED IMINOPHOSPHANES

NIECKE E, DETSCH R, NIEGER M, REICHERT F, Schoeller W. FROM COVALENT TO IONIC BONDING - SPONTANEOUS BOND-DISSOCIATION IN OXY-SUBSTITUTED IMINOPHOSPHANES. BULLETIN DE LA SOCIETE CHIMIQUE DE FRANCE. 1993;130(1):25-31.According to quantum chemical theory, structural changes in the PN double bond of iminophosphanes are strongly influenced by the electronic properties of sigma-push-pull substituents. This concept is strongly operative in oxy-substituted iminophosphanes, RO-P=N-Mes*, 2a-g, (R = silyl, organyl, and organosulfonyloxy; Mes* = 2,4,6-tBu3C6H2), which are synthesized by nucleophilic substitution of the chloro(aryl)iminophosphane 1 and structurally elucidated. The PO bond lengths vary from 1.585 (R = SiMe3) to 1.923 pm (R = CF3CSO2) indicating spontaneous PO bond dissociation in the latter

Static and dynamic cultivation of bone marrow stromal cells on biphasic calcium phosphate scaffolds derived from an indirect rapid prototyping technique

The adequate regeneration of large bone defects is still a major problem in orthopaedic surgery. Synthetic bone substitute materials have to be biocompatible, biodegradable, osteoconductive and processable into macroporous scaffolds tailored to the patient specific defect. Hydroxyapatite (HA) and tricalcium phosphate (TCP) as well as mixtures of both phases, biphasic calcium phosphate ceramics (BCP), meet all these requirements and are considered to be optimal synthetic bone substitute materials. Rapid prototyping (RP) can be applied to manufacture scaffolds, meeting the criteria required to ensure bone ingrowth such as high porosity and defined pore characteristics. Such scaffolds can be used for bone tissue engineering (BTE), a concept based on the cultivation of osteogenic cells on osteoconductive scaffolds. In this study, scaffolds with interconnecting macroporosity were manufactured from HA, TCP and BCP (60 wt% HA) using an indirect rapid prototyping technique involving wax ink-jet printing. ST-2 bone marrow stromal cells (BMSCs) were seeded onto the scaffolds and cultivated for 17 days under either static or dynamic culture conditions and osteogenic stimulation. While cell number within the scaffold pore system decreased in case of static conditions, dynamic cultivation allowed homogeneous cell growth even within deep pores of large (1,440 mm(3)) scaffolds. Osteogenic cell differentiation was most advanced on BCP scaffolds in both culture systems, while cells cultured under perfusion conditions were generally more differentiated after 17 days. Therefore, scaffolds manufactured from BCP ceramic and seeded with BMSCs using a dynamic culture system are the method of choice for bone tissue engineering

Modernisierung des Hochgeschwindigkeits-Windkanals fuer Kaltgastests an Raketenduesenmodellen mit Einfuehrungsmessungen

Moisture condensating from the expanding gas in the wind tunnel makes it impossible to compute the gas-dynamical processes by adiabatic equations. The condensation is avoided using a zeolite of the Fanjasite type as a drying agent. In addition, a new heater had to be installed to realize the temperature required for the regeneration of the drying agent. Pressure distribution measurements along a flat plug model proved the efficiency of the modernization measure. Condensation effects are subdued and the Mach number is increased. (WEN)SIGLEAvailable from TIB Hannover: F97B662+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany); Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA) GmbH, Bonn (Germany)DEGerman

Biological evaluations of silicate or carbonate-substituted hydroxyapatite ceramics with various microstructures for bone regeneration

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