Non-functionalized multi-walled carbon nanotubes alter the paracellular permeability of human airway cells

Little information is available upon the effects of carbon nanotubes (CNT) on the airway barrier. Here we study the barrier function of Calu-3 human airway epithelial cells, grown on permeable filters, after the exposure to commercial single-walled or multi-walled CNT, produced through chemical vapour deposition. To assess changes in the paracellular permeability of CNT-treated Calu-3 monolayers, we have measured the trans-epithelial electrical resistance (TEER) and the permeability to mannitol. Multi-walled CNT caused a large decrease in TEER and an increase in mannitol permeability but no substantial alteration in monolayer viability. Single-walled CNT produced much smaller changes of TEER while CNT, synthesized through the arc discharge method, and Carbon Black nanoparticles had no effect. If commercial multi-walled CNT were added during the formation of the tight monolayer, no further increase in trans-epithelial resistance was observed. Moreover, the same nanomaterials, but neither single-walled counterparts nor Carbon Black, prevented the TEER recovery observed after the discontinuation of interleukin-4, a Th2 cytokine that causes a reversible barrier dysfunction in airway epithelia. These findings suggest that commercial multi-walled CNT interfere with the formation and the maintenance of tight junctional complexes in airway epithelial cells

Highly porous 45S5 bioglass-derived glass–ceramic scaffolds by gelcasting of foams

Several types of alloplastic (artificial) grafts, known as scaffolds, have been developed for the treatment of bone defects caused by trauma and/or infection. Among the materials used to manufacture scaffolds, 45S5 Bioglass is a bioceramic that arouses significant interest due to ease preparation and excellent bioactive response. Among the various processing methods cited in the literature for the production of bioactive glass scaffolds, gelcasting is a method that produces macroporous structures, with interconnected and spherical pores and high mechanical strength. However, in the literature there are few reports about bioactive glass scaffolds produced by gelcasting method. In this work, 45S5-BG scaffolds were produced by gelcasting of foams varying the amount of foaming agent in order to optimize the desirable characteristics of the scaffold. The scaffolds show porosity between 70 and 86% and compressive strength of 1.22 +/- 0.7 and 0.78 +/- 0.4 MPa. In the biological studies, all 45S5-BG scaffolds showed cytocompatibility towards human osteoblastic cells and bioactive properties using SBF assay.Sao Paulo Research Foundation-FAPESPNational Council for Scientific and Technological DevelopmentErasmus Mundus Program (Be Mundus Project)Univ Fed Sao Paulo UNIFESP, Inst Sci & Technol ICT, Bioceram Lab BIOCERAM, BR-12231280 Sao Jose Dos Campos, SP, BrazilCNPEM, Brazilian Nanotechnol Natl Lab LNNANO, POB 6192, BR-13083970 Campinas, SP, BrazilUniv Porto FMDUP, Fac Med Dent, Lab Bone MetaUniv Fed Sao Paulo UNIFESP, Inst Sci & Technol ICT, Bioceram Lab BIOCERAM, BR-12231280 Sao Jose Dos Campos, SP, BrazilFAPESP: 2015/246597CNPq: 456461/2014-0Web of Scienc

The Polyphenol Oleuropein Aglycone Protects TgCRND8 Mice against Aß Plaque Pathology

The claimed beneficial effects of the Mediterranean diet include prevention of several age-related dysfunctions including neurodegenerative diseases and Alzheimer-like pathology. These effects have been related to the protection against cognitive decline associated with aging and disease by a number of polyphenols found in red wine and extra virgin olive oil. The double transgenic TgCRND8 mice (overexpressing the Swedish and Indiana mutations in the human amyloid precursor protein), aged 1.5 and 4, and age-matched wild type control mice were used to examine in vivo the effects of 8 weeks dietary supplementation of oleuropein aglycone (50 mg/kg of diet), the main polyphenol found in extra virgin olive oil. We report here that dietary supplementation of oleuropein aglycone strongly improves the cognitive performance of young/middle-aged TgCRND8 mice, a model of amyloid-ß deposition, respect to age-matched littermates with un-supplemented diet. Immunofluorescence analysis of cerebral tissue in oleuropein aglycone-fed transgenic mice showed remarkably reduced ß-amyloid levels and plaque deposits, which appeared less compact and “fluffy”; moreover, microglia migration to the plaques for phagocytosis and a remarkable reduction of the astrocyte reaction were evident. Finally, oleuropein aglycone-fed mice brain displayed an astonishingly intense autophagic reaction, as shown by the increase of autophagic markers expression and of lysosomal activity. Data obtained with cultured cells confirmed the latter evidence, suggesting mTOR regulation by oleuropein aglycone. Our results support, and provide mechanistic insights into, the beneficial effects against Alzheimer-associated neurodegeneration of a polyphenol enriched in the extra virgin olive oil, a major component of the Mediterranean diet