Littérature scientifique sur le sujet « Biocomptability »

Background: periodontal disease is commonly caused by bacteria, especially actinomyces actinomycetemcomitans and porphyromonas gingivalis have an abilty enter epithelial cells objectives: to investigate systemic azithromycin as the antibiotic of choice for periodontal disease based on biocomptability test in connective tissue. Material and Methods: BHK 21 cell lines were exposed to 0.025%, 0.050%, 0.075%, and 0.1% azithromycin solution for seven times. Samples were put in incubator for 24 hours. Result: Azitrromycin 0.050%-0.1% showed significant difference between life cells percentage and control, however, azithromycin 0.025% revealed insignificant difference with control. Conclusion: 0.025% azithromycin was considered biocompatible with connective tissue and 0.050% was not.

Background: Owing to the importance of metallic nanoparticles, different researches and studies have been induced to synthesize them in many ways. One of the ways that paid attention last years is the green synthesis methods of nanoparticles or the so-called ''eco-friendly methods''. The most common sources that has been used for green synthesis of nanoparticles are plants, leaves, fungi and microorganisms. The green synthesis methods are widely used because they are inexpensive, usable, and nontoxic. Moreover, plant extracts are rich in reducing and capping agents. Methods: In the present review, green synthesis methods of gold nanoparticles (AuNps) using Chitosan, Klebsiella pneumoniae, Magnolia Kobus, Elettaria cardamomum (Elaichi) aqueous extract and other agents as a reducing/capping agents will be discussed in details. Moreover, we will make a comparison between different green routes of synthesis and the characterization of the obtained nanoparticles from each route. Results: The characterization and applications of the prepared GNPs from different routes are reviewed. Conclusion: The utilization of gold nanoparticles has been advocated because of their high biocomptability, administration in clinical applicability and in diverse aspects of life. It seems that plants are good candidates for nanoparticles production because they are inexpensive, available and renewable sources in addition, it is too simple to prepare extracts from them. Moreover, the great diversity in the types and amounts of reducing agents from plant extracts is responsible for the effortless generation of metallic nanoparticles of various shapes and morphologies.

The synthesis of β-type phase NbxTi (x= 50 at%) / SWCNTs (Single Walled Carbon Nanotubes) intermetallic matrix nanocomposite by mechanical alloying to ensure the effective distribution of (SWCNTs) within the matrix. It has been stated by several researchers that during ball-milling of NbxTi (x =50 at%) powder mixtures, Nb-Ti intermetallic compound formation occurs either gradually along milling time of mechanical allowing (MA), or suddenly through amechanically self-propagating reaction (MSPR), which occurs after a ignition time of MA. For this purpose, 0.4and 0.8 at% of SWNTs was added to the powder mixture after the completion of reactionbetween Nb and Ti. The obtained powders Nb50Ti intermetallic compound mixed with SWCNTs powder and then was also ball-milled. Bulk samples were compacted and then sintered by (FAST-SPS-FCT) method (Field Assisted Sintering Technics-Sparck Plasma Sintering- Furnace, Advanced Ceramics for High-Temperature) at the temperature range (1273-1473 °K) with some time that retained the integrity of SWNTs in the intermetallic matrix.Structural and mechanical and vibronic changes of the nanocomposites were investigated by X-ray diffractometery (XRD). Field emission scanning electron microscopy (FESEM) micrographs showed that the offered MA approach caused the SWNTs to be uniformly embedded in the in situ synthesized NbTi intermetallic matrix. Meanwhile better distribution of SWCNTs resulted in higher density of FAST-SPS-FCT bulk nanocomposite as well higher hardness up to 2.75GPa compared to 2.4 of Nb50Ti intermetallic alloy obtained after MA time. The total porosity, compressive strength, and compressive elastic modulus of the FAST-SPS-FCT manufactured material were determined as 7%, 600 MPa, and 120 MPa, respectively. The alloy’s and its intermetallic nanocomposite have Young’s elastic modulus is comparable to that of healthy cancellous bone which makes it applicable in the biomedical field. The in vitro biocomptability will be performed in the near future. The comparable results for the FAST-SPS-FCT nanocomposites were 3%, 650 MPa, and 130 MPa. The alloy’s elastic modulus is comparable to that of healthy cancellous bone. This difference in mechanical properties results from different porosity and phase composition of the bot β-phase NbxTi (x= 50 at%) and NbxTi (x= 50 at%)/SWCNTs intermetallic matrix nanocomposite. More other nanotechnologies applications of the nanocomposite will be focused in the study of the superconducting type I for the ITER Poloidal Field Coils by measuring of Jc (T, B) characteristics.

Bien que largement utilisé dans le domaine de la chirurgie et du médical plus généralement, le polytétrafluoroéthylène expansé (ePTFE) présente également des inconvénients importants, comme celui de la colonisation de bactéries multirésistantes et la formation de biofilms qui peuvent engendrer de graves conséquences sur la santé des patients. Il existe un besoin urgent d'empêcher ces colonisations bactériennes de survenir sans utilisation d'antibiotiques. C'est à cette fin que notre projet intervient. Ce manuscrit présente une nouvelle méthode de fonctionnalisation de surface du ePTFE consistant à mélanger des composés aliphatiques aminé ainsi qu'un métal alcalin, le lithium. Cette solution conduit à la défluoration et l'amination de surface du matériau, et caractérisé par spectroscopie XPS et IR-ATR. Ces traitements chimiques entrainent des modifications de propriétés physico-chimiques importantes comme la rigidification de la surface, ou son changement en surface hydrophile. Ces matériaux aminés sont ensuite fonctionnalisés par physi ou chimisorption de molécules antibactériennes. Par la suite, ces matériaux sont évalués par des tests de cytotoxicité indirecte. Six matériaux ont été sélectionnés par ce moyen comme potentiellement éligibles à une application médicale. Leur efficacité antibactérienne contre 6 souches à l'origine de maladies nosocomiales est enfin évaluée. Selon le composé aminé ou la molécule antibactérienne utilisés, des tendances se dessinent sur le nombre de bactéries affectées par les matériaux. Un des matériaux fonctionnalisés se démarque des autres, avec une probable activité antibactérienne sur toutes les souches testées
Although widely used in the field of surgery and, more generally, medicine, ePTFE also has significant drawbacks, such as the colonization of mÛiti-resistant bacteria which can have serious consequences on the health of patients. There is an urgent need to prevent these bacterial colonizations from occurring, without the use of antibiotics. It is to this end that our project intervenes. This manuscript presents a new surface functionalization method consisting in mixing aliphatic amino compounds and an alkali metal, lithium. This solution leads to defluorination and surface amination of the material, which have been proven by XPS and IR­ATR spectroscopy. These chemical treatments Jead to modifications of important physico-chemical properties such as the stiffening of the surface, or its change into a hydrophilic surface. These amino materials are then functionalized by immersion or grafting of antibacterial molecules. Subsequently, these materials are evaluated by indirect cytotoxicity assays. Six materials were selected by this mean as potentially eligible for medical application. Their antibacterial efficiency against 6 strains causing nosocomial diseases is then evaluated. Depending on the amino compound or the antibacterial molecule used, trends emerge in the number of bacteria affected by the materials. One of the functionalized materials stands out from the others, with probable antibacterial activity on ail the strains tested

Des films de TiO2 variant par le teneur relative en anatase et en rutile, par la rugosité, par la mouillabilité, par la morphologie de section transverse ont été déposés sur des plaquettes de titane par MOCVD à basse pression. Du titane oxydé par anodisation ou par explosion à l'air a aussi été préparé. La capacité des dépôts à protéger le titane contre la corrosion par un fluide biologique simulé s'est avérée supérieure à celle de l'oxyde naturel. Le comportement des fibroblastes et d'ostéoblastes (morphologie, adhérence, prolifération, rejet d'implant) cultivés sur différents dépôts a été évalué par une série de tests (libération du LDH, expression de fibronectine, d'intégrine, d'actine, de tubuline, détection de BrDU, Ki67, PCNA, activité des MMP). Les observations sont discutées en fonction des caractéristiques structurales et physico-chimiques des dépôts. Schématiquement, les meilleurs résultats sont obtenus sur des surfaces modérément rugueuses et modérément hydrophiles.