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Monica Madalina Tucureanu,1,* Daniela Rebleanu,1,* Cristina Ana Constantinescu,1,2 Mariana Deleanu,3,4 Geanina Voicu,1 Elena Butoi,1 Manuela Calin,1 Ileana Manduteanu1 1Department of Biopathology and Therapy of Inflammation, Nicolae Simionescu Institute of Cellular Biology and Pathology, Bucharest, Romania; 2Faculty of Veterinary Medicine, University of Agronomic Sciences and Veterinary Medicine, Bucharest, Romania; 3Department of Lipidomics, Nicolae Simionescu Institute of Cellular Biology and Pathology, Bucharest, Romania; 4Faculty of Biotechnologies, University of Agronomic Sciences and Veterinary Medicine, Bucharest, Romania *These authors contributed equally to this work Background: Lipopolysaccharide (LPS) is widely recognized as a potent activator of monocytes/macrophages, and its effects include an altered production of key mediators, such as inflammatory cytokines and chemokines. The involvement of Gi protein in mediating LPS effects has been demonstrated in murine macrophages and various cell types of human origin. Purpose: The aim of the present work was to evaluate the potential of a Gi-protein inhibitor encapsulated in liposomes in reducing the inflammatory effects induced by LPS in monocytes/macrophages. Materials and methods: Guanosine 5´-O-(2-thiodiphosphate) (GOT), a guanosine diphosphate analog that completely inhibits G-protein activation by guanosine triphosphate and its analogs, was encapsulated into liposomes and tested for anti-inflammatory effects in LPS-activated THP1 monocytes or THP1-derived macrophages. The viability of monocytes/macrophages after incubation with different concentrations of free GOT or liposome-encapsulated GOT was assessed by MTT assay. MAPK activation and production of IL1β, TNFα, IL6, and MCP1 were assessed in LPS-activated monocytes/macrophages in the presence or absence of free or encapsulated GOT. In addition, the effect of free or liposome-encapsulated GOT on LPS-stimulated monocyte adhesion to activated endothelium and on monocyte chemotaxis was evaluated. Results: We report here that GOT-loaded liposomes inhibited activation of MAPK and blocked the production of the cytokines IL1β, TNFα, IL6, and MCP1 induced by LPS in monocytes and macrophages. Moreover, GOT encapsulated in liposomes reduced monocyte adhesion and chemotaxis. All demonstrated events were in contrast with free GOT, which showed reduced or no effect on monocyte/macrophage activation with LPS. Conclusion: This study demonstrates the potential of liposomal GOT in blocking LPS proinflammatory effects in monocytes/macrophages. Keywords: guanosine 5´-O-(2-thiodiphosphate) (GOT), MAPK activation, cytokine, monocyte adhesion, chemotaxis

The design of the equipment used in the processes of harvesting, transport, processing or storage, should take into account some important physical parameters and mechanics of cherry tomatoes (Solanum Lycopersicon). In this study, two varieties of the most popular cherry tomato, named Roma and Tomaccio, were studied to determine some of its physico-mechanical properties such as dimensions, geometric mean diameter, projection surface area, sphericity, true density, friction and rolling resistance coefficients. Moisture content and pH of the Roma variety samples were 91.01% (wb) and 5.704 respectively, and 88.28% (wb) and 5.870, respectively, for the Tomaccio. The fruit mass of Roma and Tomaccio were measured as 22.42 g and 26.55 g, respectively. The height, diameter, geometric mean diameter, sphericity and surface projected area were closely related to the mass of the tomato fruit. Friction and rolling resistance coefficients of tomato fruits on the plastic PVC and textolit material surfaces were measured. The mean of static friction coefficient for plastic PVC and textolit were found to be 0.32 and 0.29, respectively. The calculated sliding friction coefficients it was 0.23 for plastic PVC and 0.31 for textolit in sample fruits. The mean of rolling resistance coefficient for plastic PVC and textolit surface was 0.011 and 0.012, respectively. Frictional measurements performed perpendicular to the orientation of the microstructures of the material showed a wide variety of frictional responses probably due to environmental conditions in relation with the analytical methods used. Within broad limits, coefficients were not affected by the physical and material contact or varieties tested. [ABSTRACT FROM AUTHOR]

In this contribution we present the preparation and characterization of biocellulose nanowhiskers-MTA (mineral trioxide aggregates) cement composites for endodontic applications. Nanocrystalline biocellulose fibers were obtain by special procedure starting from bacterial cellulose grown and selected in special conditions. The prepared biocellulose nanowhiskers and commercial MTA cement were used for preparation of some composite: MTA-E (mineral trioxide aggregates-experimental), MTA-10% biocell and MTA-33% biocell cements. Considering one day hardened composites and taking into account XRD patterns and the thermal analysis data, we have concluded that the presence of biocellulose accelerates the hardening processes of MTA cement, decreasing in the same time the quantity of calcium hydroxide crystals. SEM images reveal, for the first time in the literature, crystalline hydrosilicates of high density grown around biocellulose nanowhiskers.The composite biocompatibility was good and was demonstrated by a test with HEp cells in ratio1 mg/ml MTA+33%biocel for 24h. Cells morphology and viability were identically with the ones of the untreated control. Investigations on composites morphology, weight losses, mineralogical composition and structure were performed by SEM, DTA, XRD and TEM respectively. [ABSTRACT FROM AUTHOR]

In this work, we report on the preparation and characterization of collagen-glass ceramic composites. The materials used for obtaining collagen-glass ceramic composites were collagen type I (Coll) as bioresorbable polymer and glass ceramic (GC) from CaO-SiO2-P2O5 system as bioactive material. After incorporation of GC into Coll in different ratios (Coll/GC ratio was 25/75 wt% and 75/25 wt%) and freeze-drying of them, the obtained composite materials (Coll/GC) can be used, according to our results, as potential composite scaffold for bone tissue engineering. Coll/GC composite biocompatibility, assessed by an in-vitro test (SBF soaking for a period of 14 days, at a temperature of 37°C) and cytotoxicity of these on endothelial cells, was very good. The collagen-glass ceramic composites were characterized from the point of view of their mineralogical composition (by XRD) and morphology (by SEM). At the surface of the specimens soaked in simulated body fluid (SBF) for a period of 14 days, at a temperature of 37°C was observed the formation of mainly hydroxiapatite with a spherical morphology. Furthermore, the biocompatibility assays show that these collagen-glass ceramic composites are suitable for tissue engineering. Fluorescent microscopy of endothelial cells after 5 days in culture with this scaffolds revealed a great viability, also confirmed by the measurements of metabolic activity of endothelial cells. [ABSTRACT FROM AUTHOR]

Nanocrystalline ZnO particles were prepared from ethanolic solutions of zinc acetate by forced hydrolysis, at a low temperature. The fresh prepared ZnO nanoparticles were coated with gentamicin. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermal analysis (TG-DSC). The electronic (UV-Vis), infrared (FTIR) and photoluminescence (PL) spectra were also recorded. The biological activity tests such as minimum inhibitory concentration (MIC) and disk diffusion were performed in Mueller-Hinton broth using different concentrations of ZnO and ZnO-gentamicin hybrid nanoparticles, by a standard microbial method on Enterococcus faecalis, Salmonella, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. The bacteriological tests indicate a synergic activity of ZnO-gentamicin nanoparticles. The release rate of gentamicin was monitored photometrically with UV-Vis spectrometer. [ABSTRACT FROM AUTHOR]

Nanocrystalline ZnO particles doped with Mn(II) ions were prepared by a forced hydrolysis method of zinc acetate dihydrate and manganese acetate tetrahydrate, under reflux, in buthanol. The precipitate obtained was separated by centrifugation at 9.000 rpm and purified by refluxing in water. The dopant percentage was 1, 2.5 and 5%. The qualitative composition of the nanopowder has been evidenced in the elemental EDS maps. Optical investigation shows that the Mn doping in ZnO lattice leads to a decrease in the near band edge position due to the introduction of new unoccupied states by Mn 3d electrons. The luminescence of ZnO is quenched by increasing the dopant ions percentage. At doping rate of 1% Mn in the ZnO lattice a tenfold decrease in intensity of luminescence was observed, along with modification of the luminescence pattern. Further increases of dopant percent from 1% to 5% had as result a decrease of only 30% in the luminescence intensity. The photocatalytic activity was investigated against methylene blue. The increase of Mn percentage leads to a better photocatalytic activity. [ABSTRACT FROM AUTHOR]

White mineral trioxide aggregate (WMTA) for dental applications was synthesised by solgel route due to the advantages of this method as compared with the conventional one i.e. lower thermal treatment temperatures and higher purity of the product. Tetraethylorthosilicate (C6H16O3Si - TEOS) and soluble salts i.e. Ca(NO3)2.4H2O and Al(NO3)3.9H2O were used as precursors for WMTA synthesis. The material was obtained by a single step thermal treatment at 1200°C and 1350°C, for 30 minutes. Thermal analysis (DTA/TG/DTG), X-ray diffraction (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to investigate the WMTA synthesis. The biocompatibility was assessed in vitro, by soaking of WMTA powder in simulated body fluid (SBF) for 14 days. The XRD results indicated that one of the main mineralogical phases formed was hydroxyapatite, compound with good bioactivity [ABSTRACT FROM AUTHOR]

The Ba(Zn1/3Ta2/3)O3 (BZT) ceramic samples were prepared by solid-state reaction and sintered in the range 1550–1650°C for 2 h. Several methods—X-ray diffraction (XRD) and scanning electron microscopy (SEM)—were used for structural and morphological characterization. The unit cell distortion and the presence of the secondary phase content were studied by XRD. A long-range order with a 2:1 ratio of Ta and Zn cations on the octahedral positions of the perovskite structure was noticed with the increase of the sintering temperature. SEM investigations revealed polyhedral well-faceted grains and large grain size distribution. The dielectric properties in the microwave range were measured at room temperature and at 1 kHz on a large temperature interval (±150°C). The dielectric parameters were correlated with morphological and structural properties. Ceramic samples were annealed at 1410°C for 30 h to improve the microwave properties. The dielectric constant of BZT samples measured at 6 GHz and at 1 kHz was between 27 and 28 on the whole temperature range, that is, typical values for BZT material. The temperature coefficient of the resonance frequency at 6 GHz exhibits positive values less than 6 ppm/°C. [ABSTRACT FROM AUTHOR]

In order to obtain pure and fine BaTiO3 powders with controlled morphology, sol-precipitation methods involving the use of titanium iso-propoxide and of two different barium sources, i.e. barium nitrate and barium acetate, were proposed in this work. The thermal behaviour of the synthesized gels and the X-ray diffraction data obtained for the oxide powders pointed out that, by using Ba(NO3)2 as barium source, the decomposition process was completed at lower temperature (750°C) and was accompanied by a more pronounced tendency to obtain a single phase BaTiO3 composition, by comparison with the synthesis where barium acetate was used as raw material (1100°C). Scanning electron microscopy investigations emphasized the effect of the nature of barium source and synthesis conditions on the morphology of the oxide powders, as well as on the microstructure of the related ceramics. [ABSTRACT FROM AUTHOR]