Design, processing and characterization of titanium with radial graded porosity for bone implants

Titanium cylinders with radial graded porosity, which are potentially suitable for biomedical applications replacement of cortical and trabecular bones involved in different joint and dental restorations , have been developed by a novel uniaxial and sequential compaction device, based on powder metallurgy techniques. The macrostructural, microstructural and mechanical properties of the cylinders were characterized. The microstructure obtained is a new bio inspired bio mimetic approach to solving one of the most important drawbacks of titanium implants, i.e., bone resorption due to the stress shielding phenomenon. In addition, the developed device has proved to have unique advantages in customizing the structural integrity in conventional powder metallurgy manufacturing in a simple, economic and reproducible manne

Design, processing and characterization of titanium with radial graded porosity for bone implants porosity for bone implants

Titanium cylinders with radial graded porosity, which are potentially suitable for biomedical applications (replacement of cortical and trabecular bones involved in different joint and dental restorations), have been developed by a novel uniaxial and sequential compaction device, based on powder metallurgy techniques. The macrostructural, microstructural and mechanical properties of the cylinders were characterized. The microstructure obtained is a new bio-inspired/bio-mimetic approach to solving one of the most important drawbacks of titanium implants, i.e., bone resorption due to the stress-shielding phenomenon. In addition, the developed device has proved to have unique advantages in customizing the structural integrity in conventional powder metallurgy manufacturing in a simple, economic and reproducible manner.Ministerio de Economía y Competitividad MAT2015-71284-PComisión Nacional de Investigación Científica y Tecnológica de Chile Proyecto No. 3150060Junta de Andalucía P12-TEP-1401Unión Europea P12-TEP-140

Effect of food additives on key bacterial taxa and the mucosa-associated microbiota in Crohn’s disease. The ENIGMA study

ABSTRACTFood additives have been linked to the pro-inflammatory microbial dysbiosis associated with Crohn’s disease (CD) but the underlying ecological dynamics are unknown. Here, we examine how selection of food additives affects the growth of multiple strains of a key beneficial bacterium (Faecalibacterium prausnitzii), axenic clinical isolates of proinflammatory bacteria from CD patients (Proteus, Morganella, and Klebsiella spp.), and the consortia of mucosa-associated microbiota recovered from multiple Crohn’s disease patients. Bacterial growth of the axenic isolates was evaluated using a habitat-simulating medium supplemented with either sodium sulfite, aluminum silicate, carrageenan, carboxymethylcellulose, polysorbate 80, saccharin, sucralose, or aspartame, intended to approximate concentrations found in food. The microbial consortia recovered from post-operative CD patient mucosal biopsy samples were challenged with either carboxymethylcellulose and/or polysorbate 80, and the bacterial communities compared to unchallenged consortia by 16S rRNA gene amplicon profiling. Growth of all F. prausnitzii strains was arrested when either sodium sulfite or polysorbate 80 was added to cultures at baseline or mid-exponential phase of growth, and the inhibitory effects on the Gram-negative bacteria by sodium sulfite were conditional on oxygen availability. The effects from polysorbate 80, saccharin, carrageenan, and/or carboxymethylcellulose on these bacteria were strain-specific. In addition to their direct effects on bacterial growth, polysorbate 80 and/or carboxymethylcellulose can drive profound changes in the CD mucosa-associated microbiota via niche expansion of Proteus and/or Veillonellaceae – both implicated in early Crohn’s disease recurrence. These studies on the interaction of food additives with the enteric microbiota provide a basis for dietary management in Crohn’s disease