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2001, Applied Surface Science
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8 pages
1 file
A study of the laser ablation and deposition, on Ti6Al4V substrates, of a biological active glass (Bioglass 1 45S5) is reported. The gaseous phase composition has been determined by laser ablation inductively coupled plasma mass spectrometry, optical imaging and emission spectroscopy. The deposited ®lms were studied by scanning electron microscopy coupled with energy and wavelength dispersive X-ray analysis and X-ray diffraction. The adhesion of ®lms to the substrates has been studied by scratch tests. Moreover, after exposing the coatings to a simulating body¯uid solution, their bioactivity has been monitored by X-ray diffraction analysis of the hydroxylapatite growth. This procedure has been followed for different time scales up to a maximum of 24 days. The deposition mechanism seems to be related mainly to the mechanical transport of the target material in form of droplets, while the gaseous phase, having a very different composition, plays a marginal role. The overall ®lm retains the target stoichiometry and bioactivity in a large range of experimental conditions.
Applied Surface Science, 1999
Ž w . A study of the laser ablation and deposition, on Ti-Al substrates, of a biologically active glass Bioglass suitable for bone implants is reported. The analysis of the gaseous phase by emission spectroscopy and the characterisation of the films from a compositional and morphological point of view have been carried out. The mean chemical composition of the deposits obtained from Bioglass ablation is very close to the target composition and the morphology indicates that different mechanisms of material ejection are present. q
Applied Surface Science, 2008
We report the synthesis by pulsed laser deposition of thin structures of two bioactive glasses belonging to the SiO2–Na2O–K2O–CaO–MgO–P2O5 system, on medical grade Ti substrates. We evaluated their biocompatibility after immersion in simulated body fluids and by performing cells adhesion tests. The films were characterized by confocal scanning laser microscopy and Fourier transform infrared spectrometry, before and after 30 and 46 days immersion in fluids. Our studies demonstrated that deposited coatings were degraded in simulated fluids. A new apatite layer was synthesized by ions changing with the fluid during the decomposition of bioglasses. We investigated after immersion in fluids cells adhesion and the cytoskelet organization of synthesized structures, by fluorescence microscopy. A good adhesion to bioglass coatings was evidenced.
Acta Biomaterialia, 2010
Laser cladding by powder injection has been used to produce bioactive glass coatings on titanium alloy (Ti6Al4V) substrates. Bioactive glass compositions alternative to 45S5 Bioglass Ò were demonstrated to exhibit a gradual wetting angle-temperature evolution and therefore a more homogeneous deposition of the coating over the substrate was achieved. Among the different compositions studied, the S520 bioactive glass showed smoother wetting angle-temperature behavior and was successfully used as precursor material to produce bioactive coatings. Coatings processed using a Nd:YAG laser presented calcium silicate crystallization at the surface, with a uniform composition along the coating cross-section, and no significant dilution of the titanium alloy was observed. These coatings maintain similar bioactivity to that of the precursor material as demonstrated by immersion in simulated body fluid.
Acta Physica Polonica A, 2012
Surface modification of medical implants is often required to improve their biocompatibility or, through bioactive properties of the surface material, facilitate its intergrowth with the living tissue. Bioactive-glass coatings can serve that purpose for the bone implants. We report a successful preparation of silicate-phosphate bioactive-glass coating on titanium substrate using the pulsed laser deposition method and present the coating characterization in terms of bonding configuration and chemical activity. The former was studied with high-resolution Raman microspectroscopy and revealed the presence of structural units responsible for the material's bioactivity. The bioactivity was also tested directly, in vitro, by soaking the samples in the simulated body fluid and examining the result with the Raman spectroscopy. The Raman spectrum, typical of hydroxyapatite was observed proving that the bone-like-material formed on the coating's surface.
Applied Surface Science, 2005
The effect of two reactive gases on the properties of bioactive glass thin films produced by pulsed laser deposition (PLD) was studied. The ablation of a bioactive silica-based glass was carried out by an ArF excimer laser (l = 193 nm, F = 4.2 J cm À2 , t = 25 ns, f = 10 Hz) at various pressures of Si 2 H 6 /Ar and NH 3 /Ar reactive mixtures. The bonding configuration and chemical environment of the resulting coatings were followed by Fourier transform infrared spectroscopy (FT-IR). The composition and bond arrangement of bioactive glass films were tuned by varying the chamber atmosphere. The results show how to adjust film characteristics for osteointegration of implants.
Journal of the Mechanical Behavior of Biomedical Materials, 2021
Free from toxic elements biomaterial potentially applicable for load bearing biomedical implants was obtained for the first time by laser cladding of S520 bioactive glass onto ultrafinegrained commercially pure titanium. The cladding process affected the refined structure of the substrate inducing martensitic transformation near its surface. The α' acicular martensite gradually passes into relatively large grains with increasing distance from the substrate surface, which subsequently are transformed into smaller grains of about 2 μm in diameter. Both the melted zone, where the martensite crystalline structure was found, and the HAZ are characterized by relatively lower hardness in comparison with that of the substrate core indicating increased ductility. Such a combination of zones with different properties may have a synergistic effect and is beneficial for the obtained biomaterial. A characteristic region in the form of about 3 µm width band was formed in the melted zone at about 10 µm below the titanium surface. The results of EDS analysis indicate that several glass elements moved into the region while the titanium content in the same area was decreased. High bioactivity of the coated S520 glass was revealed by in vitro testing with SBF solution and almost complete reduction of P concentration occurred after 14 days.
Materials Science and Engineering: C, 2012
The surface of biomedical titanium implants has been covered with thin films of bioactive glass and bioactive glass + poly(methyl methacrylate nanocomposite) in order to increase the resistance to corrosion and improve the bioactivity of their area in contact with bone tissue. To this purpose Pulsed Laser Deposition and Matrix Assisted Pulsed Laser Evaporation with an excimer laser source have been applied. The layer assessments under conditions that simulate their biological interaction with the human body fluids and resistance to degradation have been studied by electrochemical polarization and electrochemical impedance spectroscopy. The poly(methyl methacrylate) addition to bioglass has reduced the bone ability to bond but resulted in a significant increase of the shielding efficiency against corrosion of the applied coatings. The obtained results support the application of bioactive glass and composite bioactive glass + poly(methyl methacrylate) coatings for the development of advanced highly stable implants and prostheses that cannot be affected by corrosion.
Journal of Materials Science: Materials in Medicine, 2011
The high-velocity suspension flame spraying technique (HVSFS) was employed in order to deposit 45S5 bioactive glass coatings onto titanium substrates, using a suspension of micron-sized glass powders dispersed in a water ? isopropanol mixture as feedstock. By modifying the process parameters, five coatings with different thickness and porosity were obtained. The coatings were entirely glassy but exhibited a through-thickness microstructural gradient, as the deposition mechanisms of the glass droplets changed at every torch cycle because of the increase in the system temperature during spraying. After soaking in simulated body fluid, all of the coatings were soon covered by a layer of hydroxyapatite; furthermore, the coatings exhibited no cytotoxicity and human osteosarcoma cells could adhere and proliferate well onto their surfaces. HVSFS-deposited 45S5 bioglass coatings are therefore highly bioactive and have potentials as replacement of conventional hydroxyapatite in order to favour osseointegration of dental and prosthetic implants.
Materials, 2020
The purpose of this work was to propose and evaluate a new composition for a bioactive glass-ceramic starting from the well-known 45S5 commercial product. Thus, we developed a modified version, including MgO, an oxide that turned out to induce superior mechanical properties and improved biological response. This had the following molar percentages: 46.1% SiO2, 2.6% P2O5, 16.9% CaO, 10.0% MgO, and 24.4% Na2O. The precursor alkoxides and nitrates were processed by a standard sol-gel technique, resulting in a glass-ceramic target, suitable for laser ablation experiments. Combeite (Na2Ca2Si3O9) was identified as a main crystalline phase within the calcined sol-gel powder, as well as in the case of the target sintered at 900 °C. The thin films were deposited on silicon substrates, at room temperature or 300 °C, being subsequently characterized from the material point of view, as well as in terms of bioactivity in simulated conditions and biocompatibility in relation to human fibroblast B...
Coatings, 2020
Silicate (13-93) and borate (13-93-B3) bioactive glass coatings were successfully deposited on titanium using the nanosecond Pulsed Laser Deposition technique. The coatings’ microstructural characteristics, compositions and morphologies were examined by a number of physico-chemical techniques. The deposited coatings retain the same functional groups of the targets, are a few microns thick, amorphous, compact and crack free. Their surface is characterized by the presence of micrometric and nanometric particles. The surface topography, investigated by Atomic Force Microscopy, is characterized by spherical or ellipsoidal particles of the 0.2–3 μm size range for the 13-93 silicate bioactive glass film and of the 0.1–1 µm range for the 13-93-B3 borate bioactive glass coating. Equine adipose tissue-derived mesenchymal stem cells (ADMSCs) were applied for biological tests and the osteogenic differentiation activity of cells on the deposited coatings was studied after ADMSCs growth in osteo...
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