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Carbon dots are emerging in the nanotechnology field as the newest class of fluorescent probes, owing to their high water-solubility, good chemical and photo-stability and tunable photoluminescence. The ability of metal cations to quench carbon dots fluorescence is already well known. Anyway, a dedicated study directed to the rational design of the optimal carbon dot probe is still missing. Herein we present a novel synthetic method for the production of carbon nanodots from an economic and environmental polluting starting material: olive solid wastes. The obtained carbon dots are efficiently quenched in presence of Fe3+, allowing the cation detection. Starting from a comprehensive study on their quenching mechanism, we have been able to develop effective strategies to modulate the sensing properties of these carbon dots. The sensitivity and linear range of the probe have been tuned by modulating the surface functionalization of the nanoparticles. The selectivity toward Fe3+ has been improved by growing around the dots a porous microsphere of ion imprinted polymer. The results highlighted in this work demonstrate that the carbon dots sensing properties can be modulated to meet the requirement of the users, allowing the design of tailored probes for a wide range of applications.

Type I collagen is the most abundant protein of the human body. Due to its favourable properties, collagen extracted from animal tissues is adopted to manufacture a wide range of devices for biomedical applications. Compared to bovine and porcine collagens, which are the most largely used, equine collagen is free from the risk of zoonosis, has no reported immune reactions, and has not religious constraints. In this work, a recently available type I collagen extracted from horse tendon was evaluated and compared with a commercially available collagen isoform derived from the same species and tissue. Detailed physical, chemical and biological investigations were performed, in agreement with the requirements of the current standard for the characterization of type I collagen to be used for the manufacture of Tissue Engineering Medical Products. To the best of our knowledge, this is the first report on the complete primary structure of the investigated collagen.

A nanocomposite adsorbent material was synthetized in order to obtain an efficient system able to remove, by means of chemical adsorption, mainly aromatic analytes dissolved in aqueous phase. The adsorbing substrate is composed by a magnetic responsive iron oxide (γ-Fe2O3) core coated by a shell of SiO2. The adsorption process is mediated by the chemical interaction among amine and silanol groups on the surface of the nanocomposite adsorbent and the analyte π cloud. The paramagnetic core allows to remove the formed nanosystem-analyte adduct quickly and completely, representing a huge improvement in comparison of the most used gravimetric separation. The removal efficiency obtained using the proposed nanocomposite reaches about 93% for the dangerous pollutant 1,2-phenylenediamine in water solution, 70% for dinitrophenol, 60% for aniline. Further, the nano-adsorbent was decorated with plasmonic Ag nanoparticles without significantly affecting the ability to adsorb the aromatic compounds. The presence of the plasmonic nanoparticles on the SiO2 surface allows to obtain surface enhanced Raman scattering (SERS) of the signals of the adsorbed aniline and 1,2-phenylenediamine proposing this approach to remove and, concomitantly, discriminate the retrieved pollutants from water.

Background Kanamycin, mainly used in the treatment of drug-resistant-tuberculosis, is known to cause irreversible hearing loss. Using the xeno-transplant model, we compared both in vitro and in vivo characteristics of human mesenchymal stromal cells (MSCs) derived from adult tissues, bone marrow (BM-MSCs) and adipose tissue (ADSCs). These tissues were selected for their availability, in vitro multipotency and regenerative potential in vivo in kanamycin-deafened nod-scid mice. Methods MSCs were isolated from informed donors and expanded ex vivo. We evaluated their proliferation capacity in vitro using the hexosaminidase assay, the phenotypic profile using flow-cytometry of a panel of surface antigens, the osteogenic potential using alkaline phosphatase activity and the adipogenic potential using oil-red-O staining. MSCs were intravenously injected in deafened mice and cochleae, liver, spleen and kidney were sampled 7 and 30 days after transplantation. The dissected organs were analyzed using lectin histochemistry, immunohistochemistry, polymerase chain reaction (PCR) and dual color fluorescence in situ hybridization (DC-FISH). Results MSCs showed similar in vitro characteristics, but ADSCs appeared to be more efficient after prolonged expansion. Both cell types engrafted in the cochlea of damaged mice, inducing regeneration of the damaged sensory structures. Several hybrid cells were detected in engrafted tissues. Discussion BM-MSCs and ADSCs showed in vitro characteristics suitable for tissue regeneration and fused with resident cells in engrafted tissues. The data suggest that paracrine effect is the prevalent mechanism inducing tissue recovery. Overall, BM-MSCs and ADSCs appear to be valuable tools in regenerative medicine for hearing loss recovery.

For the first time, highly porous ZnO-based biomorphic materials were synthesised using cork as a natural sustainable template. In the first step, waste cork powder was pyrolysed and converted into inorganic carbon. This template was then infiltrated using a novel approach employing an aerosol of zinc-containing solutions. The infiltrated powders were calcined to convert the precursors into zinc oxide. Depending on temperature, these could form either a ZnO-graphite composite material, or pure ZnO. Their morphology, porosity, microstructure and composition were characterised; their optical band gap energies, ability to adsorb and photodegrade organic pollutants and UV absorption were also assessed. When heated to 350 degrees C they maintained the 3D porous cork structure, producing a graphite-containing composite material, with both physical adsorption and photocatalytic activity (E-g = 3.19 eV), suitable for environmental remediation. When heated to 700 degrees C, the powders were pure ZnO (no graphite), and they absorbed in the UV region, hence suitable for use as sunscreen. Doped ZnO ecoceramics were also produced, using silver and aluminium. An addition of 1 mol% Ag improved photocatalysis under solar light. Conversely, adding 2 mol% Al and calcining at 700 degrees C deactivated photocatalysis, but maintained strong UV absorption, producing a safer sunscreen material (no generation of free radicals). This is the first time that photocatalytic or UV absorption properties of any wood-derived biomorphic material or ecoceramic have been reported.