PHOTOELECTRON SPECTROSCOPY

Dental implants are commonly used in daily practice; however, most surgeons do not really know the characteristics of these biomedical devices they are placing in their patients. The objective of this work is to describe the chemical and morphological characteristics of 14 implant surfaces available on the market and to establish a simple and clear identification (ID) card for all of them, following the classification procedure developed in the Dohan Ehrenfest et al (2010) Codification (DEC) system. Fourteen implant surfaces were characterized: TiUnite (Nobel Biocare), Ospol (Ospol), Kohno HRPS (Sweden & Martina), Osseospeed (AstraTech), Ankylos (Dentsply Friadent), MTX (Zimmer), Promote (Camlog), BTI Interna (Biotechnology Institute), EVL Plus (SERF), Twinkon Ref (Tekka), Ossean (Intra-Lock), NanoTite (Biomet 3I), SLActive (ITI Straumann), Integra-CP/NanoTite (Bicon). Three samples of each implant were analyzed. Superficial chemical composition was analyzed using X-ray photoelectro...

To ascertain the mode of action of a new Pro-Argin formula desensitizing dentifrice with a gentle whitening benefit containing 8.0% arginine, a high cleaning calcium carbonate system and sodium monofluorophosphate, utilizing a range of state-of-the-art surface techniques. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to assess tubule occlusion. Electron spectroscopy for chemical analysis (ESCA) was used to identify the composition of the occlusive material. CLSM was also used to identify the location of the arginine within the occluded dentin tubule and to demonstrate the resistance of the occlusion to an acid challenge. The CLSM and SEM studies demonstrated that the arginine-calcium carbonate technology in this new Pro-Argin formula sensitivity dentifrice was highly effective in occluding dentin tubules. ESCA showed that the dentin surface deposit contained high levels of calcium, phosphorous, oxygen and carbonate. CLSM also confirmed th...

In spite of the present advances in the scaffolds fabrication and bioreactor systems, the ability to create functional thick tissue masses in vitro is still a great tissue engineering challenge. To overcome this problem, the fabrication of a capillary bed, for nutrient supply to and waste product removal from the tissue engineering construct as it grows, is essential. However, the technical construction of a capillary-like architecture is complex and challenging. This study reports, for the very first time, a simple method to design and fabricate a porous hollow membrane sheet (PHMsh) to provide both a capillary bed and a scaffold to support tissue growth. The PHMsh composed of a flexible porous sheet involving parallel porous channels and can be used as flat-, rolled-, or sandwiched-shape scaffold. The PHMsh was fabricated from poly(ϵ-caprolactone) polymer solution using solvent casting methods (i.e., immersion precipitation and air casting). Optical microscopy and scanning electron microscopy were used for the morphological analyses. The PHMsh was surface treated using n-hepthylamine plasma polymer (HApp) and X-ray photoelectron spectroscopy confirmed successful surface coating. Human umbilical vein endothelial cells (HUVECs) and fibroblast cells were used to evaluate the capability of PHMsh toward cell adhesion. The HApp coating enhanced both HUVEC and fibroblast cells adhesion. The obtained preliminary results demonstrated the successful fabrication of the PHMsh, with potential application for tissue engineering scaffolds, particularly in large tissue mass generation under perfusion systems in vitro, which is our future research direction. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010

In the development of new antibacterial therapeutic approaches to fight multidrug-resistant bacteria, antimicrobial photodynamic therapy (aPDT) represents a well-known alternative to treat local infections caused by different microorganisms. Here we present a polypropylene (PP) fabric finished with citrate-hydroxypropyl-βCD polymer (PP-CD) entrapping the tetra-anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)-21H,23H-porphine (TPPS) as photosensitizer eluting scaffold (PP-CD/TPPS) for aPDT. The concept is based on host-guest complexation of porphyrin in the cavities of CDs immobilized on the PP fibers, followed by its sustained and controlled delivery in release medium and simultaneous photo-inactivation of microorganisms. Morphology of fabric was characterized by optical (OM) and scanning electron microscopies (SEM). Optical properties were investigated by UV-vis absorption, steady- and time-resolved fluorescence emission spectroscopy. X-ray Photoelectron Spectroscopy (XPS) and FT-IR ...

The atomic surface structure of SrTiO3(100) after annealing at 630 °C in vacuum is investigated by x-ray photoelectron diffraction (XPD) using the Sr 3d5/2 core level. The photoelectron diffraction peaks are successfully assigned by considering the forward scattering of photoelectrons by the atomic potential near the emitter atom in the lattice. The strongest diffraction peaks are aligned along the single crystal internuclear axes. We compare the results of photoelectron multiple scattering calculations (MSC) of SrO and TiO2 terminated SrTiO3(100) surfaces, including surface relaxation and rumpling, with the experimental data. For TiO2 and SrO terminated SrTiO3(100) surfaces, all top-layer cations relax inward, whereas second-layer atoms relax outward. The surface rumpling for SrO- and TiO2-terminated surfaces agrees well with low-energy electron diffraction results. Using a genetic algorithm the best agreement of MSC to the experimental XPD data is obtained for a SrO terminated surface with a 30% coverage of 3 ML SrO(100) islands.