Personne : Mantovani, D.
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Université Laval. Département de génie des mines, de la métallurgie et des matériaux
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- PublicationAccès libreDevelopment and characterization of silver containing calcium phosphate coatings on pure iron foam intended for bone scaffold applications(2018-03-28) Hermawan, Hendra; Su, Yingchao; Mantovani, D.; Tolouei, Ranna; Champagne, Sébastien; Trenggono, AdhityaDespite its high structural strength and degradability, the potentiality of pure iron foam for bone scaffolds is low due to its lack of surface bioactivity. This work aims to provide a surface bioactivity to the iron foam by developing a calcium phosphate (CaP) conversion coating. Silver (Ag), known for its antibacterial property, was then incorporated onto the CaP coating via co-deposition (Ag/CaP-c) and post-treatment (Ag/CaP-p). By tuning the Ca/P ion ratio and Ag concentration during the coating process, an optimum coating parameter was obtained. All coatings were found to enhance mineralization ability and mechanical integrity of the iron foam over time. Electrochemical and immersion tests indicated that the coatings regulated the degradation rate of the iron foam via a variation of coating resistance and capacitance. Silver ions were released slowly from the Ag/CaP coating during the immersion test indicating a potential long-term antibacterial property of the coating. Details on the coating design and process optimization, the effects of three different simulated physiological solutions, and the mechanical property of the coated iron foam are discussed in this report.
- PublicationAccès libreGene expression profile of mouse fibroblasts exposed to a biodegradable iron alloy for stents.(Elsevier, 2013-11-10) Couët, Jacques; Hermawan, Hendra; Mantovani, D.; Purnama, Agung; Champetier, Serge.Iron-based materials could constitute an interesting option for cardiovascular biodegradable stent applications due to their superior ductility compared to their counterparts - magnesium alloys. Since the predicted degradation rate of pure iron is considered slow, manganese (35% w/w), an alloying element for iron, was explored to counteract this problem through the powder metallurgy process (Fe-35 Mn). However, manganese presents a high cytotoxic potential; thus its effect on cells must first be established. Here, we established the gene expression profile of mouse 3T3 fibroblasts exposed to Fe-35 Mn degradation products in order to better understand cell response to potentially cytotoxic degradable metallic material (DMM). Mouse 3T3 cells were exposed to degradation products eluting through tissue culture insert filter (3 μm pore size) containing cytostatic amounts of 3.25 mg ml(-1) of Fe-35 Mn powder, 0.25 mg ml(-1) of pure Mn powder or 5 mg ml(-1) of pure iron powder for 24 h. We then conducted a gene expression profiling study from these cells. Exposure of 3T3 cells to Fe-35 Mn was associated with the up-regulation of 75 genes and down-regulation of 59 genes, while 126 were up-regulated and 76 down-regulated genes in the presence of manganese. No genes were found regulated for the iron powder. When comparing the GEP of 3T3 fibroblasts in the presence of Fe-35 Mn and Mn, 68 up-regulated and 54 down-regulated genes were common. These results were confirmed by quantitative RT-PCR for a subset of these genes. This GEP study could provide clues about the mechanism behind degradation products effects on cells of the Fe-35 Mn alloy and may help in the appraisal of its potential for DMM applications.