Browsing by Keyword "Cell proliferation"
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Item Biological response of laser macrostructured and oxidized titanium alloy: An in vitro and in vivo study(2011-09) Paz, María Dolores; Iñaki Álava, J.; Goikoetxea, Leire; Chiussi, Stefano; Díaz-Güemes, Idoia; Usón, Jesus; Sánchez, Francisco; León, Betty; BiomaterialesPurpose: To assess both the in vitro and in vivo biological response of a laser modified surface in an integrated manner. A combined innovative approach applies lasers to macrostructure as well as to oxidize the surface of titanium alloy implants. Materials and methods: A Nd:YAG marking and ArF excimer lasers were used for macrostructuring and UV-oxidizing the surface of Ti6Al4V discs, respectively. Human fetal osteoblastic cell culture and a sheep tibia model were used to assess the cell response and the osseogeneration capability of as-machined, laser macrostructured and laser macrostructured and oxidized surfaces. Results: In vitro: Laser macrostructuration alone did not promote cell response. Cellular proliferation was enhanced by the additional UV laser oxidation. In vivo: A greater significant percentage of bone-implant contact was obtained for both laser treated surfaces compared to machine-turned control samples, three months after implantation, in spite of the low cellular response for macrostructured samples. The use of sheep model for six months appears to be less adequate for a comparison because of the high level of bone integration in all samples. In spite of the often reported positive effect of titanium oxidation on the triggering of faster osseointegration, in this experiment the additional UV laser oxidation did not lead to a significant in vivo improvement. Conclusions: Laser macrostructuration of titanium alloy surfaces appears to promote bone apposition and may therefore constitute a promising surface modification strategy. In animal models, the natural process of titanium surface oxidation, because of physiologic fluids, alters properties observed in vitro with cells.Item Bone cell adhesion on ion implanted titanium alloys(2005-06-22) Braceras, I.; Onate, J.I.; Goikoetxea, L.; Viviente, J.L.; Alava, J.I.; de Maeztu, M.A.; Tecnalia Research & Innovation; Biomateriales; TECNOLOGÍA DE MEMBRANAS E INTENSIFICACIÓN DE PROCESOSThe authors have previously reported than ion implantation can have a significant effect on osseointegration of an implant, specially when the latter is introduced in areas of poorer bone density. These results indicate that this process is particularly suited for implant devices introduced in elderly patients or in those regions that have a poor quality of bone. The aim of this work is directed to study osteoblast adhesion on Ti alloy surfaces with different ion implantation treatments, so osseoconductive properties of several surfaces can be assessed. Polished discs of Ti–6Al–4V and Ti CP GR1 titanium alloy have been prepared and ion implanted with different species and parameters (dose and energy). Afterwards, the samples have been sterilized by UV light, inoculated with 1.5×105 human bone cells and incubated during 4 h at 37 C and 5% CO2 atmosphere. Then, once fixed and rinsed, image analysis has been used to quantify the number of cells attached to the Ti discs. On a second round of tests, cell proliferation tests have been conducted during 24, 48, 144 and 192 h, respectively. Furthermore, surface analysis techniques (e.g. AFM) have been applied to learn about the qualitative behavior, i.e. morphology, of the attached cells. Cell attachment has shown to be highly sensitive to ion implantation parameters. Although some quantitative differences have been observed, the more significant differences were qualitative. AFM analysis has shown that the star-shaped bone cells attached spread more and occupied larger surfaces like in osseointegration prone surfaces, most probably due to extracellular matrix synthesized around them, while other surfaces showed mainly large and narrow shaped or round shaped bone cells often with great cellular nucleus in the middle of the cells and little extracellular matrix around. So, ion implanted surfaces that facilitate osseointegration have been identified, in terms of initial bone cell attachment quality, where although the number of attached cells were not necessarily always larger, they tended to occupy wider areas with healthier cells.