Search results for " biocompatible"

showing 10 items of 57 documents

Soft Tissue Healing at One-Piece Zirconia Implants Compared to Titanium and PEEK Implants of Identical Design: A Histomorphometric Study in the Dog

2013

This study aimed to histomorphometrically evaluate the soft tissue reactions of one-piece zirconia implants versus titanium implants in regard to their insertion depth. Four one-piece implants of identical geometry were inserted on each side of six mongrel dogs: an uncoated zirconia implant, a zirconia implant coated with a calcium liberating titanium oxide, a titanium implant, and an experimental implant made of a synthetic material. Using a split-mouth design, they were inserted in both submerged and nonsubmerged healing modes. After 4 months, dissected blocks were stained with toluidine blue to histologically assess the marginal portion of the implant mucosa, apical extension of the barr…

Materials sciencechemistry.chemical_elementDentistryConnective tissueOsseointegrationDogsCoated Materials BiocompatibleImplants ExperimentalOsseointegrationPeekmedicineAnimalsCubic zirconiaDental ImplantsTitaniumWound Healingbusiness.industryDental Implantation EndosseousSoft tissuemedicine.anatomical_structureDental Prosthesis DesignchemistryPeriodonticsZirconiumImplantOral SurgeryWound healingbusinessTitaniumInternational Journal of Periodontics and Restorative Dentistry
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Silica-coated calcium pectinate beads for colonic drug delivery

2013

The aim of this work is to develop novel organic-inorganic hybrid beads for colonic drug delivery. For this purpose, calcium pectinate beads with theophylline are prepared by a cross-linking reaction between amidated low-methoxyl pectin and calcium ions. The beads are then covered with silica, starting from tetraethyoxysilane (TEOS), by a sol-gel process. The influence of TEOS concentration (0.25, 0.50, 0.75 and 1.00 M) during the process is studied in order to modulate the thickness of the silica layer around the pectinate beads and thus to control the drug release. The interactions between the silica coating and the organic beads are weak according to the physicochemical characterizations…

Materials sciencefood.ingredientPectinColonPhosphodiesterase InhibitorsBiomedical Engineeringchemistry.chemical_elementCalciumBiochemistryCalcium pectinateDiffusionBiomaterialsfoodCoated Materials BiocompatibleNanocapsulesTheophyllineMaterials TestingmedicineAnimalsHumansTheophyllineMolecular BiologyDissolutionChromatographyGeneral MedicineSilicon DioxideControlled releaseGastrointestinal ContentsChemical engineeringchemistryDrug deliveryPectinsLayer (electronics)Biotechnologymedicine.drugActa Biomaterialia
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Xenotransplantation of parathyroids in rats using barium-alginate and polyacrylic acid multilayer microcapsules

2001

The integrity and function of encapsulated parathyroid tissue following xenotransplantation is limited by oxygen and nutrition supply and capsule fibrosis. Since some of these factors depend on stability and biocompatibility of the coating material, multilayer microcapsules have been developed. Parathyroid tissue pieces and digested single cells from pigs were encapsulated in barium-alginate and in polyacrylic acid (PAA) multilayer capsules. After 7 days of culture the function of the encapsulated cells were assessed. Subsequently, in a part of the cultured microcapsules the viability was directly assessed whereas the other part was transplanted in dark animal [DA] rats for 30 days. After e…

NecrosisBiocompatibilityAlginatesCell SurvivalSwineBarium CompoundsTransplantation HeterologousAcrylic ResinsConnective tissueParathyroid hormoneToxicologyPathology and Forensic MedicineParathyroid Glandschemistry.chemical_compoundDrug Delivery SystemsCoated Materials BiocompatibleGlucuronic AcidIn vivoFibrosismedicineAnimalsCells CulturedChemistryHexuronic AcidsGraft SurvivalCapsuleCell BiologyGeneral MedicineAnatomymedicine.diseaseGlucuronic acidMolecular biologyRatsmedicine.anatomical_structureParathyroid Hormonemedicine.symptomExperimental and Toxicologic Pathology
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Bioinspired catechol-terminated self-assembled monolayers with enhanced adhesion properties

2013

The role of the catechol moiety in the adhesive properties of mussel proteins and related synthetic materials has been extensively studied in the last years but still remains elusive. Here, a simplified model approach is presented based on a self-assembled monolayer (SAM) of upward-facing catechols thiol-bound to epitaxial gold substrates. The orientation of the catechol moieties is confirmed by spectroscopy, which also showed lack of significant amounts of interfering o-quinones. Local force-distance curves on the SAM measured by atomic force microscopy (AFM) shows an average adhesion force of 45 nN, stronger than that of a reference polydopamine coating, along with higher reproducibility …

PolydopamineIndolesPolymersCatecholsBiocompatible MaterialsNanotechnologyMolecular Dynamics Simulationengineering.materialBiomimèticaMicroscopy Atomic ForceBiomaterialsMolecular dynamicschemistry.chemical_compound:Enginyeria química [Àrees temàtiques de la UPC]Coated Materials BiocompatibleCoatingMonolayerMoietyGeneral Materials ScienceMagnetite NanoparticlesAdhesive surfaceCatecholChemistrySAMsAdhesivenessSelf-assembled monolayerGeneral ChemistryAdhesionBiomimetic polymersChemical engineeringCatecholengineeringPrintingMagnetic nanoparticlesBiomimeticGoldBiotechnology
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Amphiphilic Copolymers Based on Poly[(hydroxyethyl)-d,l-aspartamide]: A Suitable Functional Coating for Biocompatible Gold Nanostars

2013

Novel amphiphilic copolymers have been synthesized based on a biocompatible poly(hydroxyethylaspartamide) (PHEA) backbone, bearing both anchoring groups for gold nanoparticles, such as thiols and disulfide, and conjugable moieties, such as amino groups, the latter as points suitable for appending further functional agents. The strategy was to functionalize α,β-poly[(N-2- hydroxyethyl)-d,l-aspartamide] (PHEA) with PEG2000-NH2 and with ethylenediamine (EDA) obtaining a partially pegylated copolymer with a large number of pendant primary amino groups. A fraction of the latter was conjugated with molecules bearing terminal thiol moieties such as 12-mercaptododecanoic acid (MDA) and disulfide gr…

Polymers and PlasticsCell SurvivalMetal NanoparticlesBioengineeringEthylenediamineengineering.materialConjugated systemPolyethylene GlycolsBiomaterialsSurface-Active Agentschemistry.chemical_compoundCoated Materials BiocompatibleCoatingCell Line TumorMaterials TestingAmphiphilePolymer chemistryMaterials ChemistryCopolymerHumansMoleculePoly(hydroxyethyl)-DL-aspartamideParticle Sizechemistry.chemical_classificationAmphiphilic copolymersgold nanostarlipoic acidEthylenediamineschemistrySettore CHIM/09 - Farmaceutico Tecnologico ApplicativoColloidal goldThiolengineeringGoldPeptidesgold nanoparticleBiomacromolecules
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External reinforcement of varicose veins with PTFE prosthesis in infrainguinal bypass surgery -- clinical results.

2003

OBJECTIVE Segmental varicose degeneration of the autogenous greater saphenous vein may limit its use in infrainguinal bypass surgery. Wrapping a PTFE prosthesis around dilated veins has emerged as an option to create externally reinforced vein bypasses. Results regarding graft patency and limb salvage were analyzed. METHODS Between September 1995 and January 2001, 35 infrainguinal bypass operations in 33 patients were performed with greater saphenous veins exhibiting segmental varicose dilatation. Grafts were followed by duplex scan and retrospective analysis of graft patency and limb salvage was performed. RESULTS One bypass prompted successful revision for early occlusion. Four bypasses r…

Pulmonary and Respiratory MedicineMaleReoperationmedicine.medical_specialtyTime FactorsPopliteal VeinLimb salvagemedicine.medical_treatmentInfrainguinal bypassGreater saphenous veinInguinal CanalProsthesisSeverity of Illness IndexTimeVaricose VeinsBlood Vessel Prosthesis ImplantationCoated Materials BiocompatibleOcclusionVaricose veinsMedicineHumansSaphenous VeinVeinPolytetrafluoroethyleneVascular PatencyAgedRetrospective StudiesAged 80 and overbusiness.industryGraft Occlusion VascularMiddle Agedmedicine.diseaseCombined Modality TherapySurvival AnalysisSurgeryRadiographyStenosismedicine.anatomical_structureTreatment OutcomeSurgeryFemalemedicine.symptomCardiology and Cardiovascular MedicinebusinessFollow-Up StudiesThe Thoracic and cardiovascular surgeon
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Biologic response of inguinal hernia prosthetics: a comparative study of conventional static meshes versus 3D dynamic implants.

2015

Despite improvements in prosthetics and surgical techniques, the rate of complications following inguinal hernia repair remains high. Among these, discomfort and chronic pain have become a source of increasing concern among surgeons. Poor quality of tissue ingrowth, such as thin scar plates or shrinking scars-typical results with conventional static implants and plugs-may contribute to these adverse events. Recently, a new type of 3D dynamically responsive implant was introduced to the market. This device, designed to be placed fixation-free, seems to induce ingrowth of viable and structured tissue instead of regressive fibrotic scarring. To elucidate the differences in biologic response be…

Sampling StudieTime FactorsTime FactorProstheses and ImplantBiomedical EngineeringMedicine (miscellaneous)BioengineeringBiocompatible MaterialsHernia InguinalPolypropylenesProsthesis DesignSampling StudiesStatistics NonparametricImaging Three-DimensionalProstheseTensile StrengthMaterials TestingHumansHerniorrhaphyBiocompatible MaterialMedicine (all)Inguinal herniaImplantTissue scaffoldProstheses and ImplantsSurgical MeshBiomaterialImmunohistochemistryProsthesis FailureSettore MED/18 - Chirurgia GeneraleTissue regenerationBiomaterials; Herniorrhaphy; Implants; Inguinal hernia; Prostheses; Tissue regeneration; Tissue scaffolds; Biocompatible Materials; Hernia Inguinal; Herniorrhaphy; Humans; Imaging Three-Dimensional; Immunohistochemistry; Materials Testing; Polypropylenes; Prosthesis Design; Prosthesis Failure; Sampling Studies; Statistics Nonparametric; Tensile Strength; Time Factors; Prostheses and Implants; Surgical Mesh; Biomaterials; Biomedical Engineering; Bioengineering; Medicine (miscellaneous); Medicine (all)PolypropyleneHumanArtificial organs
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Biomaterials coated by dental pulp cells as substrate for neural stem cell differentiation

2011

[EN] This study is focused on the development of an in vitro hybrid system, consisting in a polymeric biomaterial covered by a dental pulp cellular stroma that acts as a scaffold offering a neurotrophic support for the subsequent survival and differentiation of neural stem Cells. In the first place, the behavior of dental pulp stroma on the polymeric biomaterial based on ethyl acrylate and hydroxy ethyl acrylate copolymer was studied. For this purpose, cells from normal human third molars were grown onto 0.5-mm-diameter biomaterial discs. After cell culture, quantification of neurotrophic factors generated by the stromal cells was performed by means of an ELISA assay. In the second place, s…

Stromal cellMaterials scienceBiomedical EngineeringBiomaterialsCell therapyMiceNerve growth factorCoated Materials BiocompatibleNeural Stem Cellsstomatognathic systemNeurotrophic factorsAnimalsHumansNeural cellCells CulturedDental PulpCell ProliferationNeuronsStem cellBrain-Derived Neurotrophic FactorMetals and AlloysBiomaterialCell adhesionCell DifferentiationNeural stem cellRatsCell biologystomatognathic diseasesCell cultureMAQUINAS Y MOTORES TERMICOSCeramics and CompositesCell cultureStem cellNeural cellBiomedical engineering
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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Integrazione di celle fotovoltaiche ibride nel vetromattone

2012

L’invenzione riguarda l’integrazione del vetromattone con celle solari ibride (organiche/inorganiche), conosciute come Dye-sensitized Solar Cell (DSC). La combinazione del vetromattone con le DSC consente di migliorare le prestazioni del prodotto originario rendendolo in grado di produrre energia pulita. Le caratteristiche di trasparenza e isolamento termo-acustico del prodotto possono essere regolate agendo sulla configurazione delle DSC. Il prodotto può essere assemblato a formare pannelli fotovoltaici per la realizzazione di facciate traslucide energeticamente “attive” in varie condizioni luminose (condizioni di luce diffusa o artificiale) e indipendentemente dall’angolo di radiazione so…

The integration of Dye-sensitized Solar Cell (DSC) with the glassblock is disclosed. The combination of the two technological elements the glassblock and the DSC module enhance their own peculiarities. The final complete product is ready-made for installation owns the qualities of the glassblock and produces sustainable energy at the same time. The transparency and the thermo-acoustic insulation may be modulated according to the specific requirements of each case of installation. The product may be used for example to create PV panels for glazed and translucent façades that are able to perform efficiently in all light conditions (even in diffuse light also converting internal artificial light) that are not dependant on the angle of the solar radiation and do not suffer from the high operative temperatures of functioning due to the peculiarities of the DSCs. DSCs are made of economic and biocompatible materials and are produced with low-cost and highly productive printing methods on rigid or flexible substrates. With the integration of DSC modules with the glassblock PV panels coincide with the envelope itself so that they do not need any further structures to be installed on and allow the possibility of subtract from the price of the panel the price of the substituted building element allowing further economies. DSCs can be printed in different colours and with various patterns offering to designers and customers the possibility of intervening on the glassblock aesthetical aspect also taking advantage of the peculiar modularity of the glassblock for larger compositions of drawings on the building’s façade. Seven Hypotheses of integration are discussed in order to obtain DSC-integrated glassblock ready for the construction of a precast and dry-assembled PV panel which can use the horizontal and vertical cavities between the glassblocks to house plastic profiles where the electric interconnections and the steel bars -useful for improve the mechanical resistance of the panel- are integrated.Settore ICAR/10 - Architettura Tecnica
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