Biocompatibility evaluation of a novel hydroxyapatite-polymer coating for medical implants (in vitro tests)

Nanocomposites consisting of hydroxyapatite (HA) and a sodium maleate copolymer (maleic polyelectrolyte), synthesized by hydrothermal method and deposited on titanium substrates by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique were tested for the biological properties. Coating bioanalysis was carried out by triple staining of actin, microtubules and nuclei followed by immunofluorescence microscopy. Within 24 h cells that occupied the biomaterial surface displayed the morphology and cytoskeleton pattern similar to the controls. Cells grown on nanocomposite coated surfaces had a higher proliferation rate than their counterparts grown on Ti coated with HA alone, indicating that maleic polyelectrolyte improved surface bio-adhesive characteristics. The capacity to induce cell attachment, spreading and proliferation demonstrated the potential of Ti coated with HA-polymer nanocomposites to be used as scaffolds in dental or orthopedic implantology.     

Inhibition of P2X7 Purinergic Receptor Ameliorates Fibromyalgia Syndrome by Suppressing NLRP3 Pathway

Fibromyalgia is a chronic condition characterized by persistent widespread pain that significantly reduces quality of life in patients. The purinergic P2X7 receptor (P2X7R) seems to be involved in different pain states and neuroinflammation. The purpose of this study is to investigate the positive effects of P2X7R inhibition by the antagonist Brilliant Blue G (BBG) in a rat model of reserpine-induced fibromyalgia. Sprague–Dawley male rats were injected with 1 mg/kg of reserpine for three consecutive days. Later, animals were administered BBG (50 mg/kg) intraperitoneally for seven days. Reserpine injections induced a significant increase in pain pro-inflammatory mediators as well as a significant increase in neuroinflammation. Chronic pain, in turn, led to depressive-like symptoms and reduced neurogenesis. Blockage of P2X7R by BBG administrations is able to attenuate the behavioral deficits, pain mediators and microglial activation induced by reserpine injection. Additionally, BBG prevents NLRP3 inflammasome activation and consequently the release of active interleukin (IL)-1 and IL-18, involved in the activation of nociceptors. In conclusion, these results suggest that inhibition of P2X7R should be further investigated to develop a potential approach for the management of fibromyalgia.     

Assessment of wastewater reuse potential for irrigation in rural semi-arid areas: the case study of Punitaqui,Chile

Clean Technologies and Environmental Policy - Wastewater reuse in agriculture has been identified as an adaptive solution to climate change. This practice copes with two of the most limiting...     

Antimicrobial PLA/TPS/gelatin sheets with enzymatically crosslinked surface containing silver nanoparticles

In the present work, poly (lactic acid)/thermoplastic starch/gelatin sheets were produced by calendering–extrusion process and silver nanoparticles (AgNPs, synthesized by chemical reduction with d ‐glucose), were incorporated at sheet surfaces to promote antimicrobial activity. A gelatin solution containing AgNPs was enzymatically crosslinked as a layer at sheets surface using transglutaminase. AgNPs presented 63 nm (z average size) and spherical shape (scanning electron microscopy, SEM) while morphology analysis showed that sheets presented internal porosity. Mechanical properties (Young modulus, elongation at break, and tensile strength) and water vapor permeability presented significant difference in function of gelatin amount added to sheets formulation due to increased internal porosity. Antimicrobial activity was demonstrated against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa for the AGNPs solution as well as for the surface treated films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43039.     

Characterizations of consistent pairwise comparison matrices over abelian linearly ordered groups

We consider the framework of pairwise comparison matrices over abelian linearly ordered groups. We introduce the notion of ⊙‐proportionality that allows us to provide new characterizations of the consistency, efficient algorithms for checking the consistency and for building a consistent matrix. Moreover, we provide a new consistency index. © 2010 Wiley Periodicals, Inc.     

Sterilization treatments on polysaccharides: Effects and side effects on pectin

Thermal and irradiation treatments represent techniques used for a wide range of materials intended for different applications in the food and medical industry aimed to decontamination and sterilization of different technologic processes. Traditional treatments with vapor combined with pressure, reactive gases, and radiation can be used for sterilization of medical implants and to prevent food deterioration. On the other side, these treatments can be employed to obtain a controlled distribution of molecular weight of polymers, as reported by literature.     

Spectroscopic Evidences of Charge Transfer Phenomena and Stabilization of Unusual Phases at Iron Oxide Monolayers Grown on Pt(111)

Strong electrostatic coupling between the local structure of metal-supported oxide ultra-thin films and the charge state of adsorbed species (such as Au atoms and O₂ molecules) is at the origin of a co-existence of alternative adsorption configurations, with drastically different structural and electronic characteristics. This effect may contribute also to the stabilization of oxide phases of unusual stoichiometries, where the ion valences are compensated by an electron exchange with the metal substrate. We report an analysis of the spectroscopic signatures of such differently charged adsorbates and unusual oxide phases, including valence and core electrons spectroscopies and vibrational characteristics. We show that the adsorbate charge states can be identified by their signature in the electronic states around the Fermi level and by the modification of the vibrational frequencies of adsorbed probe molecules. Moreover, core level analysis may contribute to the identification of the oxygen-rich phase, formed at high oxygen exposure. The detailed theoretical investigation of the spectroscopic signatures of alternative adsorption configurations and adsorbate charge states supplies a set of data, which may help the experimental identification of such species.