Abstract: Fibrous nanostructured polyurethane composite membranes were developed using electrospinning process. Membranes of polyurethane having silver and zinc oxide as additives were prepared by electrospinning of solutions having dimethylformamide (DMF) or its mixture with tetrahydrofuran (THF) (50:50 volume ratio) as solvent. Morphology of the fibers was characterized by using optical microscopy and scanning electron microscopy, showing fiber diameters from 200 to 800 nanometers. Antibacterial properties were tested by eluting solutions of E.coli at different concentrations through the membranes.
Abstract: Bone tissue in ideal conditions morphofunctional remodeling properly. The bone can be affected by fractures, tumors, hormonal dysfunction, senescence, genetic modifications, among others. In such circumstances, the proper diet, drug use, exercise and other factors are important to the prevention of bone mineral loss. The effect of kinesiotherapy obtained through the application of vibratory waves administered through the vibrating platform, Juvent1000 ® already been established in the prevention of bone mineral density, muscular trophism, among other systems in humans. The response by analyzing bone tissue of bone repair in critical defect is not known in experimental animals and in human clinical. This research evaluated the osteogenic potential critical defect in the calvaria of rats subjected to the application of vibratory waves obtained by vibrating platform and implant in the critical defect of rat calvaria. The bone tissue response was evaluated showed satisfactory results obtained in biological points 15, 45 and 120 days.
Abstract: Titanium is an attractive material for dental and biomedical applications, because of high corrosion resistance, excellent biocompatibility and high mechanical strength combined with low density. However, the high reactivity of titanium in the liquid phase make it difficult to produce it by fusion, so a alternative is powder metallurgy (P/M) method. Powder Metallurgy has been used to manufacture porous implants. The presence of a porous surface is desirable because it improves the osteointegration increases the adhesion between the bone tissue and the implant, being favorable for transporting body fluid. This paper proposes to characterize the commercial pure titanium powder obtained by process of hydride-dehydride, obtain samples with adequate porosity by uniaxial pressing and vacuum sintering and evaluate the corrosion behavior of sintered titanium in Hank ́s solution. The results showed that the titanium powder of angular shape after uniaxial pressing of 400 MPa and sintered in vacuum at 1150 ° C, allowed obtaining samples with adequate surface porosity of around 17%. In potentiodynamic polarization curves revealed no typical behavior of passive metals but show low current density, that increasing corrosion resistance.
Keywords: titanium implants, powder metallurgy, porosity and electrochemical behavior.
Abstract: Research on titanium and its alloys as biomaterials have been attracted the interest because of its clinical success, but they have been facing problems due to failures caused by tissue cohesion loss, fracture. Studies involving the influence of surface roughness of titanium implants on the osseointegration rate and biomechanical fixation have been develop. However, it is neessary to understand the effect of surface morphology on the osseointegration process. This paper aims to examine the effect of current density on the electropolishing process of Ti in order to obtain nanostructured surfaces. Ti samples were mechanically abraded and then subjected to electropolishing in acidic solution. After the electropolishing process, the samples were characterized by atomic force microscopy, profilometry and wettability tests. Preliminary results show that the increase on current density contributed to the decrease in nanoroughness of substrate yet it did not affect the surface wettability, which presented an hydrophilic behaviour.
Abstract: In this work, the effect of the PCL content and E-GMA compatibilizer on the mechanical properties and morphology of poly (lactic acid) - PLA/ poly (ε-caprolactone)-PCL blends was investigated. The results of the mechanical properties showed that there was a reduction in the elastic modulus and tensile strength when PCL was added to PLA. The decrease in the modulus was more pronounced when the PCL content was increased from 10 to 20% (wt). The PLA/PCL/E-GMA blend showed the lower modulus and tensile strength. This blend also presented the higher elongation at break and impact strength. The morphology analysis by SEM showed that the PLA/PCL blends where characterized by lack of adhesion between the PLA and PCL phases. The presence of E-GMA in the PLA/PCL/E-GMA blend improved the adhesion between the PLA and PCL phases.Keywords: poly (latic acid); poly (ε-caprolactone); polymer blends; compatibilizer
Abstract: Several cements are used as biomaterials. Biopolymers such as chitosan and collagen exhibit excellent biocompatibility and can be used in the remodeling of bone tissue. The cement must have high mechanical strength and compatibility with original tissue. In this context, the objective of this study was to extract, characterize and cross-link collagen from bovine tendon, forlater associate it with chitosan and calcium phosphate to obtain cements for bone regeneration. Glutaraldehyde was used as cross-linker in 0.1, 0.5, 1.0 and 10% concentration. Infrared analysis confirmed the presence of functional groups characteristic of collagen, whereas the capacity of water absorption decreased with the increasing of cross-linking degree. Denaturation temperatures of collagen samples were obtained by Differential Scanning Calorimetry and Scanning Electron Microscopy showed the fiber structure characteristics of collagen, which were more organized for high degree of cross-linking samples.
Abstract: Selective internal radiotherapy is used to treat hepatocellular carcinoma. Glass microspheres containing β- particle emitter radionuclides are introduced into the liver close to the tumor. The microspheres are trapped in the arterioles which feed the tumor. The irradiation with β- particles can cause the death of cancer cells. In this work the development of phosphate glass microspheres containing holmium is proposed. 165Ho has a high cross section for neutron absorption enabling the production of 166Ho which decays to 166Er by emitting a β- particle. The microspheres were produced using the flame method and characterized by different techniques to evaluate their potential use in radiotherapy. Microspheres with suitable morphology, size, density, and holmium concentration were obtained.
Abstract: The study of moisture expansion (ME) in ceramic products has been object of research in the past few years, especially in UFCG. The ME is the increase of the dimensions of the ceramic materials by adsorption of water, it occurs slowly and is relatively small, being able to compromise the adherence of the ceramic plates to the subfloor, lead to the cracking of the glaze and conduct to the appearance of cracks in bricks, if the tensions generated by the deformation contained in the pieces exceed the limit resistance of the materials. Aiming to contribute with this research, this study aimed to characterize the alternative ceramic masses from ceramic blocks, seeking to determinate their influence in the development of the moisture expansion phenomenon. Compositions were formulated through the design of simplexes network mixtures technique. The specimens were conformed by uniaxial pressing at 20 MPa, dried in an oven at 110 °C and fired at temperatures of 800°, 900° and 1000 °C. After firing the MEs were determined by boiling and immersion. The results showed that the higher the percentage of granite waste in the formulation, lower the ME.
Abstract: The palygorskite or attapulgite is a mineral clay that has a fibrous morphology with porous crystalline structure, hydrated of type 2:1, which is constituted by layer-shaped strips with two tetrahedral layers connected by a central octahedral layer through the sharing of common oxygens [. It presents in its structure low surface charge, high magnesium content and high specific surface area. This mineral clay together with the sepiolite belong to the class of fibrous clay minerals [.