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Zinc (Zn)-derived foams have been prepared from an alkaline electrolyte solution by galvanostatic electrodeposition under different conditions. A detailed physico-chemical characterization was performed by Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). A pioneer application of these foams in medical implant-related applications was investigated. The in vitro behaviour of these Zn-derived foams in simulated physiological conditions was studied. The results revealed that the presence of zinc oxide was important enough to change the in vitro behaviour of these materials. The potential of these Zn-derived foams in inhibiting bone cancer cell proliferation - osteoscarcoma cells - and important pathogenic fungi responsible for implant-related infections -Candida albicans- was examined. Furthermore, the foams were evaluated for cytocompatibility with normal human osteoblasts. The results obtained allowed us to conclude that Zn-derived foams have an interesting potential for anti-cancer and anti-Candida activity, targeted for bone-related implant applications, suggesting that this novel material may have potential for further clinical studies.

This work reports the fabrication, by electrodeposition and post-thermal annealing, of hybrid electrodes for high rate electrochemical energy storage composed of nickel manganese oxide (Ni0.86Mn0.14O) nanosheets over 3D open porous dendritic NiCu foams. The hybrid electrodes are made of two different percolation networks of nanosheets and dendrites, and exhibit a specific capacitance value of 848 F g(-1) at 1 A g(-1). The electrochemical tests revealed that the electrodes display an excellent rate capability, characterized by capacitance retention of approximately 83% when the applied current density increases from 1 A g(-1) to 20 A g(-1). The electrodes also evidenced high charge-discharge cycling stability, which attained 103% after 1000 cycles.

Objective: The aim of this work was to evaluate the effect of KrF excimer laser treatment on the bond strength between dentin and an etch-and-rinse adhesive system., Materials and Methods: Polished dentin surfaces were subjected to the following treatments: (1) 35% phosphoric acid etching for 15 s; (2) laser surface treatment using KrF excimer laser radiation (1 J/cm(2)); and (3) laser treatment under the same conditions followed by acid etching. After treating the dentin, an etch-and-rinse adhesive (Adper Scotchbond 1 XT, 3M ESPE) was applied and composite (Esthet-X, Dentsply Caulk, Konstanz, Germany) build-ups were incrementally constructed. After 24 h of water storage at 37 degrees C, 1 mm(2) beams were longitudinally cut from the samples. Microtensile sticks were loaded in tension at a crosshead speed of 0.5 mm/min. Bond strength data were analyzed with one-way ANOVA and the Student-Newman-Keuls test (p < 0.05). The dentin surfaces resulting from each surface treatment and the fracture surfaces originated by the bond-strength tests were observed under a scanning electron microscope., Results: Laser-treated surfaces exhibited a cone-shaped topography with a frank occlusion of dentinal tubules, while acid etching produced a smoother surface with open tubules. Application of 35% phosphoric acid on laser-treated dentin surfaces resulted in the partial dissolution of the surface cones. Mean microtensile bond strengths for acid-etched dentin was significantly higher (33.7 +/- 8.7 MPa) than for laser-treated (13.8 +/- 5.1 MPa) and laser-treated and etched surfaces (19.7 +/- 6.9 MPa). A higher percentage of cohesive failures at the base of the cones occurred in the laser-treated group, whereas mixed failures were predominant on acid-etched samples., Conclusion: The cone-shaped texture produced by treating dentin with KrF laser radiation does not improve the bond strength of the tested etch-and rinse adhesive system when compared to the traditional acid-etching technique.

Biocompatibility has long been associated with surface microtopography, microtexture, and microchemistry. The surface topography eventually affects the nature and the intensity of the interactions that occur at biomaterial-biological interface (cell adhesion, mobility, spreading, and proliferation). Therefore, it is necessary to produce and work with controlled microtopographical surfaces that present reproducible microdomains of a dimension similar to that of the biological elements of interest (in this case, osteoblasts). There are a number of substrates that already have been studied in terms of surface topography; however, few studies are related to hydroxyapatite (HA) substrates. As it is well established, HA is a well-known ceramic that is extremely used in medical applications, namely implants and coatings. In this work, the surface topography of dense HA substrates was altered by using KFr excimer laser. The surface was characterized by atomic force microscopy and contact angle measurements, while the cell distribution and morphology was assessed by scanning electron microscopy and confocal laser scanning microscopy. Results revealed that the surface is characterized by a homogeneous columnar structure with high specific area. Moreover, cells were able to attach and spread on the surface of the samples, and gradually grow into nearly confluent monolayers., ((c) 2007 Wiley Periodicals, Inc.)

In the present work, the surface microtexture and chemical changes induced in human dentin by laser processing with KrF excimer laser radiation using fluences ranging from 0.5 to 20 J/cm2 were studied by SEM, XPS and FTIR. Two distinct behaviours were observed in the evolution of surface topography. In some samples, the laser-treated surface remained flat, independently of the fluence used. It was covered by a layer formed of redeposited ablation particles, which occluded the dentinal apertures. In other samples the surface topography depended on radiation fluence. When the fluence was lower than 1 J/cm2, preferential removal of intertubular dentin occurs, producing a columnar structure in which the columns are essentially formed of peritubular material. If the fluence exceeded 1 J/cm2 the processed surface was flat and covered with resolidified material. Despite these topographic changes, the dentin was not significantly affected by the laser treatment. The observed behaviour can be explained by differences in the constitution of dentin.

Surface treatment of materials with excimer laser radiation often results in the formation of a rough columnar or cone-shaped surface topography, which leads to a considerable increase in the surface area. As a result, the search for a non-porous bioactive material with adequate mechanical properties and a high surface to volume ratio, similar to porous materials, which could be used for drug delivery in the treatment of periodontitis, justified assessing excimer laser surface treatment to promote controlled roughning of hydroxyapatite (HA) and glass-reinforced hydroxyapatite (GR-HA). A KrF excimer laser with 248 nm radiation wavelength and 30 ns pulse duration was used for surface modification. The laser treatment was carried out in air, using wide ranges of radiation fluence and number of laser pulses. In order to identify the physico-chemical changes induced by the laser treatment and the column formation mechanisms in these materials, the treated surfaces were characterised by laser profilometry, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infra-red spectroscopy (FTIR). Laser processing induced the formation of a surface topography consisting of cone-shaped features. The constitution of the surface layer was also modified, as revealed by FTIR, XPS and XRD. This work has shown that laser surface modification increases the surface area of HA and GR-HA and is a promising technique to increase the reactivity and drug delivery capability of both materials.