Cytocompatibility of Medical Biomaterials Containing Nickel by Osteoblasts: a Systematic Literature Review

The present review is based on a survey of 21 studies on the cytocompatibility of medical biomaterials containing nickel, as assessed by cell culture of human and animal osteoblasts or osteoblast-like cells. Among the biomaterials evaluated were stainless steel, NiTi alloys, pure Ni, Ti, and other pure metals. The materials were either commercially available, prepared by the authors, or implanted by various techniques to generate a protective layer of oxides, nitrides, acetylides. The observation that the layers significantly reduced the initial release of metal ions and increased cytocompatibility was confirmed in cell culture experiments. Physical and chemical characterization of the materials was performed. This included, e.g., surface characterization (roughness, wettability, corrosion behavior, quantity of released ions, microhardness, and characterization of passivation layer). Cytocompatibility tests of the materials were conducted in the cultures of human or animal osteoblasts and osteoblast-like cells. The following assays were carried out: cell proliferation and viability test, adhesion test, morphology (by fluorescent microscopy or SEM). Also phenotypic and genotypic markers were investigated. In the majority of works, it was found that the most cytocompatible materials were stainless steel and NiTi alloy. Pure Ni was rendered and less cytocompatible. All the papers confirmed that the consequence of the formation of protective layers was in significant increase of cytocompatibility of the materials. This indicates the possible further modifications of the manufacturing process (formation of the passivation layer)

Analyse d'extraits naturels utilisés en parfumerie par GC/olfactométrie (application à des extraits de Brassicales et d'Astérales)

Les matrices naturelles sont une source inépuisable de nouvelles molécules d intérêt organoleptique. Les études classiques permettent d en connaître la composition chimique, mais ne donnent aucune information sur les composés à impact. Le couplage GC/Olfactométrie qui utilise le nez humain en tant que détecteur parallèlement à un détecteur physique, permet de cibler les recherches sur les composés les plus odorants. Des extraits de Brassicales (absolue de cresson d Inde et extraits volatils de choux sauvages) et d une Astérale (huile essentielle de Tagetes minuta L.), connus pour leur richesse en composés azotés et soufrés, ont été étudiés par GC/MS, GC-FID, GC/FPD, GC x GC/MS ainsi que par GC/O (AEDA et VIDEO-Sniff). Nous avons confirmé l importance des composés soufrés dans les odeurs des Brassicales et deux nouvelles familles de molécules à potentiel organoleptique ont été mises en évidence, les thiocarbamates et les thiocarconates. Ces molécules et leurs homologues synthétisés ont montré des odeurs intéressantes et variées. Notre étude de l huile essentielle de T. minuta a permis de mettre en évidence les composés responsables de l odeur de cette HE et de déterminer l influence importante des notes fruitées des esters minoritaires. Mais, comme de nombreuses huiles essentielles, elle se dégrade au cours du temps. Nous avons étudié cette dégradation polymérisation par RMN et par chromatographie d exclusion stérique (CES) pour finalement connaître une gamme de masse moléculaires des macromolécules formées ainsi que d obtenir des informations sur les molécules impliquées dans ce processus.Natural matrices are an inexhaustible source of new odorant molecules. Classical analytical studies elucidate their chemical composition, but do not reveal the odour impact compounds. GC-Olfactometry uses the human nose as a detector parallel to a physical detection system and hence permits to target the most odorant compounds. An Asterale (essential oil of Tagetes minuta L.) and three Brassicales extracts (Indian cress absolute and volatile extracts of cabbage) were studied by GC6MS, GC/FPD, GC x GC-MS, and GC-O (AEDA and VIDEO-Sniff). Brassicales are known for the presence of nitrogenand sulphur containing compounds, and our studies confirmed the odour impact of the latter in the extracts. Furthermore, two new families of odorant molecules were discovered : thiocarbamates and thiocarbonates. These molecules as well as their synthetised homologues showed interesting and various olfactive notes. The study of T. minuta L. essential oil allowed us to determine the molecules responsible for the oil s odour and accentuated the impact of minor esters (fruity notes). As numerous essential oils, tagetes oil is known to degrade in the course of time. We studied this degradation-polymerisation by NMR and gel permeation chromatography (GPC). A mass range for the macromolecules that are formed during the polymerisation process was found, and information on the molecules affected was obtained.NICE-BU Sciences (060882101) / SudocSudocFranceF