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Maria Lucia Curri
Ruolo
Professore Ordinario
Organizzazione
Università degli Studi di Bari Aldo Moro
Dipartimento
DIPARTIMENTO DI CHIMICA
Area Scientifica
AREA 03 - Scienze chimiche
Settore Scientifico Disciplinare
CHIM/02 - Chimica Fisica
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
Here a luminescent hybrid nanostructure based on functionalized quantum dots (QDs) is used as a fluorescent imaging agent able to target selectively mitochondria thanks to the molecular recognition of the translocator protein (TSPO). The selective targeting of such an 18 kDa protein mainly located in the outer mitochondrial membrane and overexpressed in several pathological states including neurodegenerative diseases and cancers may provide valuable information for the early diagnosis and therapy of human disorders. In particular, the rational design of amino functionalized luminescent silica coated QD nanoparticles (QD@SiO2 NPs) provides a versatile nanoplatform to anchor a potent and selective TSPO ligand, characterized by a 2-phenyl-imidazo[1,2-a] pyridine acetamide structure along with a derivatizable carboxylic end group, useful to conjugate the TSPO ligand and achieve TSPO-QD@SiO2 NPs by means of a covalent amide bond. The colloidal stability and optical properties of the proposed nanomaterials are comprehensively investigated and their potential as mitochondrial imaging agents is fully assessed. Subcellular fractionation, together with confocal laser scanning fluorescence microscopy and co-localization analysis of targeted TSPO-QD@SiO2 NPs in C6 glioma cells overexpressing the TSPO, proves the great potential of these multifunctional nanosystems as in vitro selective mitochondrial imaging agents.
Binary asymmetric nanocrystals (BNCs), composed of a photoactive TiO2 nanorod joined with a superparamagnetic gamma-Fe2O3 spherical domain, were embedded in polyethylene glycol modified phospholipid micelle and successfully bioconjugated to a suitably designed peptide containing an RGD motif. BNCs represent a relevant multifunctional nanomaterial, owing to the coexistence of two distinct domains in one particle, characterized by high photoactivity and magnetic properties, that is particularly suited for use as a phototherapy and hyperthermia agent as well as a magnetic probe in biological imaging. We selected the RGD motif in order to target integrin expressed on activated endothelial cells and several types of cancer cells. The prepared RGD-peptide/BNC conjugates, comprehensively monitored by using complementary optical and structural techniques, demonstrated a high stability and uniform dispersibility in biological media. The cytotoxicity of the RGD-peptide/BNC conjugates was studied in vitro. The cellular uptake of RGD-peptide conjugates in the cells, assessed by means of two distinct approaches, namely confocal microscopy analysis and emission spectroscopy determination in cell lysates, displayed selectivity of the RGD-peptide-BNC conjugate for the alpha v beta 3 integrin. These RGD-peptide-BNC conjugates have a high potential for theranostic treatment of cancer.
This paper reports a study on the photoelectrochemical processes occurring at the interface of ZnO nanocrystals/MEH-PPV composites. Colloidal chemical routes were used to obtain size controlled non-hydrolytic ZnO nanocrystals (NCs) dispersible in organic solvents, while a low molecular weight poly[2-methoxy-5-(2'-ethylhexyloxy)phenylene vinylene] (MEH-PPV), characterized by high degree of structural order, was synthesized via an organometallic method. The optical properties of the nanocomposite material were comprehensively investigated on solution and on films deposited by spin coating. Remarkably, a significant fluorescence quenching of the polymer at the MEH-PPV/ZnO junction was observed. Photoelectrochemical measurements demonstrated that the photoactivity of the composite material was significantly improved in the case of non-hydrolytic NCs with respect to hydrolytic route prepared ZnO. Moreover, the effective role of the organic/inorganic blend to improve the charge transfer with respect to the double layer hetero-junction was confirmed, thanks to the extended interfaces which enable an effective electron transfer between the hetero-junction components. The system was also studied at different film thicknesses and electrolyte compositions. The results indicated that film photoactivity increased with film thickness up to 300 nm due to the presence of a large number of interfaces, while the change of cation size influenced the ionic conductivity through the nanocomposite film. It was shown that efficient photoconductivity requires not only efficient charge separation, but also efficient transport of the carriers to the electrodes without recombination. (C) 2015 Elsevier B.V. All rights reserved.
The increasing importance of sigma-2 receptor as target for the diagnosis and therapy of tumors paves the way for the development of innovative optically traceable fluorescent probes as tumor cell contrast and therapeutic agents. Here, a novel hybrid organic-inorganic nanostructure is developed by combining the superior fluorescent properties of inorganic quantum dots (QDs), coated with a hydrophilic silica shell (QD@SiO2 NPs), the versatility of the silica shell, and the high selectivity for sigma-2 receptor of the two synthetic ligands, namely, the 6-[(6-aminohexyl)oxy]-2-(3-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)propyl)-3,4-dihydroisoquinolin-1(2H)-one (MLP66) and 6-[1-[3-(4-cyclohexylpiperazin-1-yl)propyl]-1,2,3,4-tetrahydronaphthalen-5-yloxy]hexylamine (TA6). The proposed nanostructures represent a challenging alternative to all previously studied organic small fluorescent molecules, based on the same sigma-2 receptor affinity moieties. Flow cytometry and confocal fluorescence microscopy experiments, respectively, on fixed and living cancerous MCF7 cells, which overexpress the sigma-2 receptor, prove the ability of functionalized (QD@SiO2-TA6 and QD@SiO2-MLP66) NPs to be internalized and demonstrate their affinity to the sigma-2 receptor, ultimately validating the targeting properties conveyed to the NPs by sigma-2 ligand conjugation. The presented QD-based nanoprobes possess a great potential as in vitro selective sigma-2 receptor imaging agent and, consequently, could provide a significant impact to future theranostic applications.
The present invention relates to a method for manufacturing electrode material particularly for lithium and lithium ion batteries comprising the following steps: a) providing nanoparticles of titanium dioxide, lithium titanate, silicon, silicon oxide or a transition metal oxide, coated with a monocarboxylic acid having a chain length of 7 to 26 carbon atoms; b) heat-treatment of the monocarboxylic acid coated nanoparticles of step a) for carbonization of the monocarboxylic acid coating.
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