Search

therosclerosis is a complex disease that can lead to life-threatening events, such as myocardial infarction and ischemic stroke. Despite the severity of this disease, diagnosing plaque vulnerability remains challenging due to the lack of effective diagnostic tools. Conventional diagnostic protocols lack specificity and fail to predict the type of atherosclerotic lesion and the risk of plaque rupture. To address this issue, technologies are emerging, such as noninvasive medical imaging of atherosclerotic plaque with customized nanotechnological solutions. Modulating the biological interactions and contrast of nanoparticles in various imaging techniques, including magnetic resonance imaging, is possible through the careful design of their physicochemical properties. However, few examples of comparative studies between nanoparticles targeting different hallmarks of atherosclerosis exist to provide information about the plaque development stage. Our work demonstrates that Gd (III)-doped amorphous calcium carbonate nanoparticles are an effective tool for these comparative studies due to their high magnetic resonance contrast and physicochemical properties. In an animal model of atherosclerosis, we compare the imaging performance of three types of nanoparticles: bare amorphous calcium carbonate and those functionalized with the ligands alendronate (for micro- calcification targeting) and trimannose (for inflammation targeting). Our study provides useful insights into ligand-mediated targeted imaging of atherosclerosis through a combination of in vivo imaging, ex vivo tissue analysis, and in vitro targeting experiments.

Manganese ferrite nanoparticles display interesting features in bioimaging and catalytic therapies. They have been recently used in theranostics as contrast agents in magnetic resonance imaging (MRI), and as catalase-mimicking nanozymes for hypoxia alleviation. These promising applications encourage the development of novel synthetic procedures to enhance the bioimaging and catalytic properties of these nanomaterials simultaneously. Herein, a cost-efficient synthetic microwave method is developed to manufacture ultrasmall manganese ferrite nanoparticles as advanced multimodal contrast agents in MRI and positron emission tomography (PET), and improved nanozymes. Such a synthetic method allows doping ferrites with Mn in a wide stoichiometric range (MnxFe3-xO4, 0.1 ≤ x ≤ 2.4), affording a library of nanoparticles with different magnetic relaxivities and catalytic properties. These tuned magnetic properties give rise to either positive or dual-mode MRI contrast agents. On the other hand, higher levels of Mn doping enhance the catalytic efficiency of the resulting nanozymes. Finally, through their intracellular catalase-mimicking activity, these ultrasmall manganese ferrite nanoparticles induce an unprecedented tumor growth inhibition in a breast cancer murine model. All of these results show the robust characteristics of these nanoparticles for nanobiotechnological applications.

Producción Científica, Two imidazolium salts containing one or two pentadodecyloxytriphenylene units linked through a hexyloxy chain and Br–, [AuBrmCl4–m]−, or [PtBrmCl4–m]2– (m = 0−3) as counterion have been prepared. Reaction of the imidazolium bromides with M2O (M = Cu, Ag), or carbene transmetalation from the silver product, leads to N-heterocyclic carbene complexes [MX(NHC)] (M = Cu, X = Br; M = Au, X = Cl, C≡CPh), [Ag(NHC)2][AgBr2], and [PtCl2(NHC)2], with NHC bearing one or two triphenylene fragments. Except for the gold derivatives and one Cu complex, the rest of them behave as liquid crystals organized in columnar mesophases (rectangular c2mm or p2mg or hexagonal p6mm symmetries) with melting points in the range 30 to 60 °C and clearing points in the range 57–112 °C. The mesophase structures were determined by small-angle X-ray scattering. Structural studies and models point to nanosegregation of triphenylene columns and imidazolium/metal carbene moieties, separated by alkoxy chains, leading to multicolumnar systems. The compounds display emission spectra related to the triphenylene core in solution, in the mesophase, in the isotropic liquid, and in the solid state., 2019-04-16, Ministerio de Ciencia e Innovación (Project CTQ2014-52796-P)

El estado de cristal líquido, también llamado cuarto estado de la materia, es una fase intermedia entre el sólido y el líquido y combina características propias de los dos estados, como la fluidez de los líquidos y la anisotropía de los sólidos. Los metalomesógenos son cristales líquidos con metales en la estructura. La presencia de un metal puede generar nuevas e interesantes propiedades. En la tesis doctoral se aborda la síntesis y el estudio de distintos complejos metálicos, principalmente de oro y plata, pero también de platino, cobre y cromo. Los ligandos 1,1'-biisoquinolina, ácidos 2- y 4-difenilfosfino benzoico, 4-isocianopiridina y NHC derivados de trifenileno fueron utilizados en la obtención de los complejos. Los complejos se utilizaron para preparar nuevos metalomesógenos, tanto calamíticos como discóticos. Se utilizaron interacciones supramoleculares de hidrógeno y de halógeno para generar nuevas arquitecturas moleculares con propiedades de cristal líquido. En el caso de los derivados de trifenileno, la introducción del metal en la estructura por medio de un ligando carbeno, generó nuevas características estructurales y térmicas en el cristal líquido. Se realizaron estudios estructurales y fotofísicos de los compuestos obtenidos., Departamento de Química Física y Química Inorgánica, Doctorado en Química: Química de Síntesis, Catálisis y Materiales Avanzados

Producción Científica, The reaction of AgCF3SO3 with diphenylphosphinobenzoic acids leads to a cyclic dinuclear or a polynuclear silver(I) compound, depending on the relative position of phosphine versus carboxylic functional group. The dimers [Ag2(OSO2CF3)2(μ-O,P-PPh2C6H4COOH-o)2] 1 or [{Ag(μ-O,P-PPh2C6H4COOH-o)(OH2)2}2](CF3SO3)2·2CH2Cl21a are 12-membered diargentacycles with a silver–silver distance of 3.982 or 3.754 Å, while the polymer [Agn(OSO2CF3)n(μ-O,P-PPh2C6H4COOH-p)n] 2 is a 1D type. The ligand is always acting as non-chelating bridge, being the silver center coordinated to the phosphine phosphorous, and one oxygen (carbonyl) of the carboxylic acid of next fragment. One oxygen of the triflate anion or two water molecules complete the coordination sphere. Besides, p-(diphenylphosphino)benzoic acid compound is emissive in solution and in the solid state at 298 and 77 K, while compound with the ortho ligand is not. At 298 K, the emissions are centered at 471 nm in the solid state and at 416 nm in solution., Ministerio de Economía, Industria y Competitividad (CTQ2011–25137), Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA302U13)