Reaction of rat connective tissue to mineral trioxide aggregate and diaket

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to compare the reaction of rat connective tissue to two root-end filling materials: white Mineral Trioxide Aggregate (WMTA) and Diaket.</p> <p>Methods</p> <p>Each of the materials was placed in dentine tubes and implanted subcutaneously in the dorsal connective tissue of 21 Wistar albino rats. Tissue biopsies were collected 7, 30, and 60 days after the implantation procedure. The specimens were processed and stained with hematoxylin and eosin and examined microscopically. After determining inflammatory cell numbers in sections from each specimen, inflammatory reaction scores were defined as follows: 0; no or few inflammatory cells (no reaction), 1; less than 25 cells (mild reaction), 2; 25 to 125 cells, (moderate reaction), and 3; 125 or more cells (severe reaction). Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney tests.</p> <p>Results</p> <p>There were statistically significant differences in the median inflammatory cell numbers throughout the three test periods, with the most severe degree of inflammation observed at the one-week period. Few cases of necrosis were observed with WMTA. Diaket exhibited the most severe degree of inflammation and necrosis. After 30 days, both materials provoked moderate inflammatory reaction. The eight-week period showed the least severe degree of inflammation in all groups.</p> <p>Conclusions</p> <p>It was concluded that WMTA exhibits a more favourable tissue response compared with Diaket which induced more severe inflammatory reaction than WMTA and the control.</p

Effect of presence of gluten and spreads on the oral processing behavior of breads

Little is known about the oral processing behavior of gluten-free (GF) products. This study investigated the oral processing behavior of one commercial GF bread and one gluten-containing (GC) equivalent with and without spreads. Oral processing parameters were determined through video recording and the predominant texture attributes were accessed using a check-all-that-apply test. The GF bread was perceived crumbly, dry and sandy and had a longer eating duration than the GC bread, which was perceived soft, spongy, pasty and sticky. Results suggest that the structure of the GF bread was easily fragmented during mastication and a longer period in the mouth was required to prepare a cohesive bolus for swallowing. The addition of spreads increased softness perception but did not affect chewing behavior. Oral processing behavior of GF products should be further investigated to understand how eating rate, satiation responses and food intake can be modulated in GF products

Novel carvedilol paediatric nanomicelle formulation: in-vitro characterization and in-vivo evaluation

Objectives Carvedilol (CAR) is a poorly water-soluble beta-blocker. Its encapsu-lation within nanomicelles (NMs) could improve drug solubility and its oralbioavailability, allowing the development of a paediatric liquid CAR formulationwith commercially available copolymers: D-a-tocopheryl polyethylene glycol1000 succinate (TPGS) and poly(vinyl caprolactam)-poly(vinyl acetate)-poly(ethylene glycol) (Soluplusâ).Methods Drug-loaded NMs were prepared by copolymer and CAR dispersion indistilled water. Micellar size and morphology were characterized by dynamic lightscattering and transmission electron microscopy, respectively. In-vitro drug per-meation studies were evaluated by conventional gut sac method. In-vivo CARoral bioavailability from NMs dispersions and drug control solution was evalu-ated in Wistar rats.Key findings Carvedilol apparent aqueous solubility was increased (up to 60.4-folds) after its encapsulation within NMs. The micellar size was ranged between10.9 and 81.9 nm with a monomodal size distribution. There was a significantenhancement of CAR relative oral bioavailability for both copolymers vs amicelle-free drug solution (P < 0.05). This improvement was higher for TPGS-based micelles (4.95-fold) in accordance with the in-vitro CAR permeationresults.Conclusions The present investigation demonstrates the development of highlyconcentrated CAR liquid micellar formulation. The improvement on drug oralbioavailability contributes to the potential of this NMs formulation to enhanceCAR paediatric treatment.Fil: Wegmann, Marcel. Hochschule Furtwangen University; AlemaniaFil: Parola, Luciano. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Bertera, Facundo Martin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Taira, Carlos Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Cagel, Carlos Maximiliano. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Buontempo, Fabián. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Bernabeu, Ezequiel Adrian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Höcht, Christian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Chiappetta, Diego Andrés. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Moretton, Marcela Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Clickable Cisplatin Derivatives as Versatile Tools to Probe the DNA Damage Response to Chemotherapy

Cisplatin induces DNA crosslinks that are highly cytotoxic. Hence, platinum complexes are frequently used in the treatment of a broad range of cancers. Efficiency of cisplatin treatment is limited by the tumor-specific DNA damage response to the generated lesions. We reasoned that better tools to investigate the repair of DNA crosslinks induced by cisplatin would therefore be highly useful in addressing drug limitations. Here, we synthesized a series of cisplatin derivatives that are compatible with click chemistry, thus allowing visualization and isolation of DNA-platinum crosslinks from cells to study cellular responses. We prioritized one alkyne and one azide Pt(II) derivative, Pt-alkyne-53 and Pt-azide-64, for further biological characterization. We demonstrate that both compounds bind DNA and generate DNA lesions and that the viability of treated cells depends on the active DNA repair machinery. We also show that the compounds are clickable with both a fluorescent probe as well as biotin, thus they can be visualized in cells, and their ability to induce crosslinks in genomic DNA can be quantified. Finally, we show that Pt-alkyne-53 can be used to identify DNA repair proteins that bind within its proximity to facilitate its removal from DNA. The compounds we report here can be used as valuable experimental tools to investigate the DNA damage response to platinum complexes and hence might shed light on mechanisms of chemoresistance.publishe