Electrospun tubular vascular grafts to replace damaged peripheral arteries: A preliminary formulation study

Polymeric tubular vascular grafts represent a likely alternative to autologous vascular grafts for treating peripheral artery occlusive disease. This preliminary research study applied cutting-edge electrospinning technique for manufacturing prototypes with diameter ≤ 6 mm and based on biocompatible and biodegradable polymers such as polylactide-polycaprolactone, polylactide-co-glycolide and polyhydroxyethylmethacrylate combined in different design approaches (layering and blending). Samples were characterized about fiber morphology, diameter, size distribution, porosity, fluid uptake capability, and mechanical properties. Biocompatibility and cell interaction were evaluated by in vitro test. Goal of this preliminary study was to discriminate among the prototypes and select which composition and design approach could better suit tissue regeneration purposes. Results showed that electrospinning technique is suitable to obtain grafts with a diameter < 6 mm and thickness between 140 ± 7–175 ± 4 μm. Scanning electron microscopy analysis showed fibers with suitable micrometric diameters and pore size between 5 and 35 μm. polyhydroxyethylmethacrylate provided high hydrophilicity (≃ 100◦) and optimal cell short term proliferation (cell viability ≃ 160%) in accordance with maximum fluid uptake ability (300–350%). Moreover, addition of polyhydroxyethylmethacrylate lowered suture retention strength at value < 1 N. Prototypes obtaining combining polylactide-co-glycolide and polylactide-coglycolide/ polyhydroxyethylmethacrylate with polylactide-polycaprolactone in a bilayered structure showed optimal mechanical behavior resembling native bovine vessel

Combined Layer-by-Layer/Hydrothermal Synthesis of Fe3O4@MIL-100(Fe) for Ofloxacin Adsorption from Environmental Waters

: A simple not solvent and time consuming Fe3O4@MIL-100(Fe), synthesized in the presence of a small amount of magnetite (Fe3O4) nanoparticles (27.3 wt%), is here presented and discussed. Layer-by-layer alone (20 shell), and combined layer-by-layer (5 shell)/reflux or /hydrothermal synthetic procedures were compared. The last approach (Fe3O4@MIL-100_H sample) is suitable (i) to obtain rounded-shaped nanoparticles (200-400 nm diameter) of magnetite core and MIL-100(Fe) shell; (ii) to reduce the solvent and time consumption (the layer-by-layer procedure is applied only 5 times); (iii) to give the highest MIL-100(Fe) amount in the composite (72.7 vs. 18.5 wt% in the layer-by-layer alone); (iv) to obtain a high surface area of 3546 m2 g-1. The MIL-100(Fe) sample was also synthesized and both materials were tested for the absorption of Ofloxacin antibiotic (OFL). Langmuir model well describes OFL adsorption on Fe3O4@MIL-100_H, indicating an even higher adsorption capacity (218 ± 7 mg g-1) with respect to MIL-100 (123 ± 5 mg g-1). Chemisorption regulates the kinetic process on both the composite materials. Fe3O4@MIL-100_H performance was then verified for OFL removal at µg per liter in tap and river waters, and compared with MIL-100. Its relevant and higher adsorption efficiency and the magnetic behavior make it an excellent candidate for environmental depollution

Mechanothermal Solid-state Synthesis of Cobalt(II) Ferrite and Determination of its Heat Capacity by MTDSC

Cobalt ferrite (CoFe2O4) has been synthesized by a solid-state mechanothermal process, and its molar heat capacity has been determined. A stoichiometric mixture of CoC2O4 ・ 2H2O and FeC2O4 ・ 2H2O was subjected to a combination of mechanical activation (by high-energy milling) and thermal activation (by annealing at temperatures between 300 and 700 °C). The process was followed by thermogravimetric analysis and high-temperature X-ray powder diffraction. It has been shown that CoFe2O4 forms at all temperatures, though with different degrees of crystallization, while Co3O4 and Fe2O3 are the only products formed when starting from unmilled mixtures. The molar heat capacity of CoFe2O4 has been determined in the temperature range 60 - 400 °C by MTDSC. It has been shown that the molar CP values of CoFe2O4 samples produced at T ≥ 500 °C are close to each other while those of the samples produced at 300 and 400 °C are lower. Furthermore the CoFe2O4 samples prepared at T ≥ 500 °C show very similar microstructures

Flora vascolare spontanea della citt\ue0 di Modena: analisi del centro storico

Si presentano i risultati del primo studio sistematico sulla flora urbica di Modena. Il censimento qui illustrato \ue8 stato svolto fra il 2014 e il 2018, considerando ogni via e piazza del centro storico cittadino, quest\u2019ultimo inteso come area delimitata dai grandi viali che ricalcano il percorso dei bastioni cinquecenteschi. Sono state rinvenute 344 specie, delle quali 1 nuova per la flora d\u2019Italia, 10 per l\u2019Emilia-Romagna e altre 19 per la provincia di Modena; il 63% di queste nuove segnalazioni \ue8 esotico. Le specie non pi\uf9 ritrovate, segnalate almeno 20 anni fa o testimoniate solo da campioni d\u2019erbario del tardo Ottocento, sono 17. Lo spettro biologico \ue8 dominato dalle terofite (45%), seguite da emicriptofite (28%) e fanerofite (15%). Lo spettro corologico \ue8 dominato da eurasiatiche (28%), mediterranee (24%) e cosmopolite (24%). Le neofite sono il 18% del totale, valore piuttosto basso se rapportato a quanto riferito per altre citt\ue0 della Pianura Padana e dell\u2019Europa centrale: ci\uf2 \ue8 probabilmente dovuto alle ridotte dimensioni del centro storico cittadino, la cui compatta struttura urbanistica d\u2019impronta medievale pare opporre una certa resistenza all\u2019ingresso delle specie alloctone. Le specie invasive sono l\u201911% del totale. Interessante la presenza di 15 specie igrofile, talora indicatrici d\u2019irrigazione o iper-irrigazione di aiuole e tappeti erbosi. Le specie protette (solo a livello regionale) sono soltanto 4, di cui 2 presenti in quanto sfuggite a coltivazione. Considerando l\u2019affinit\ue0 delle specie censite all\u2019ecologia urbana, la lista \ue8 dominata dalle urbano-neutrali (45%) e dalle urbanofile (42%), il che pu\uf2 indicare sia una discreta variet\ue0 di ambienti di crescita, parecchi dei quali in una fase di evoluzione ecologica abbastanza avanzata per la citt\ue0, sia una discreta qualit\ue0 ambientale verosimilmente dovuta, almeno in parte, all\u2019abbondanza e ampiezza delle aree verdi. La ricchezza specifica in ogni via o piazza \ue8 fortemente correlata all\u2019eterogeneit\ue0 ambientale (\u3c1 = 0,794) e moderatamente correlata alla presenza limitrofa di aree verdi (\u3c1 = 0,544) e alla lunghezza della via o ampiezza della piazza (\u3c1 = 0,665 e 0,673, rispettivamente); esiste inoltre una debole correlazione fra presenza di specie orticole o alimentari e presenza, nella stessa via o piazza, di locali di ristorazione (\u3c1 = 0,212). La citt\ue0 si conferma dunque come un ecosistema assai dinamico e di grande ricchezza biologica, utile per capire le strategie ecologiche messe in atto dalle piante per adattarsi a condizioni anche proibitive. Le aree urbane, inoltre, spesso fungono da \uabsnodo\ubb per la diffusione delle specie lungo le infrastrutture viarie, durante il processo di colonizzazione del territorio. La comprensione e il rispetto dei ruoli ecologici delle specie spontanee sono concetti fondamentali per una moderna pianificazione urbanistica volta a migliorare la qualit\ue0 della vita nel suo complesso

The mitochondrial DNA control region shows genetically correlated levels of heteroplasmy in leukocytes of centenarians and their offspring

<p>Abstract</p> <p>Background</p> <p>Studies on heteroplasmy occurring in the mitochondrial DNA (mtDNA) control region (CR) in leukocytes of centenarians and younger subjects have shown that the C150T somatic transition is over-represented in centenarians. However, whether the occurrence/accumulation of heteroplasmy is a <it>phenotypic consequence </it>of extreme ageing or a <it>genetically controlled event </it>that may favor longevity is a question that deserves further attention. To clarify this point, we set up a Denaturing High Performance Liquid Chromatography (DHPLC) protocol to quantify mtDNA CR heteroplasmy. We then analyzed heteroplasmy in leukocytes of centenarians (100 subjects), their offspring and nieces/nephews (200 subjects, age-range 65–80 years, median age 70 years), and in leukocytes of 114 control subjects sex- and age-matched with the relatives of centenarians.</p> <p>Results</p> <p>The centenarians and their descendants, despite the different ages, showed similar levels of heteroplasmy which were significantly higher than levels in controls. In addition we found that heteroplasmy levels were significantly correlated in parent-offspring pairs (r = 0.263; p = 0.009), but were independent of mtDNA inherited variability (haplogroup and sequence analyses).</p> <p>Conclusion</p> <p>Our findings suggest that the high degree of heteroplasmy observed in centenarians is genetically controlled, and that such genetic control is independent of mtDNA variability and likely due to the nuclear genome.</p