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We report the synthesis and characterization of the macrocyclic ligand 2,2'-((2-(3,9-bis(carboxymethyl)-3,6,9-triaza-1(2,6)-pyridinacyclodecaphane-6-yl)ethyl)azanediyl)diacetic acid (H

Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190540 También participan en la elaboración de este artículo científico: Aracely Calatayud-Pascual, Alicia López-Castellano, Elena P. Albelda, Enrique García-España, Luis Martí-Bonmatí, Juan C. Frias y M. Teresa Albelda. Fumagillin-loaded liposomes were injected into ApoE-KO mice. The animals were divided into several groups to test the efficacy of this anti-angiogenic drug for early treatment of atherosclerotic lesions. Statistical analysis of the lesions revealed a decrease in the lesion size after 5 weeks of treatment.

The interaction of a polyazacyclophane ligand having an ethylamine pendant arm functionalized with an anthryl group (L), with the single-stranded polynucleotides polyA, polyG, polyU, and polyC as well as with the double-stranded polynucleotides polyA-polyU, poly(dAT)(2), and poly(dGC)(2) has been followed by UV/Vis titration, steady state fluorescence spectroscopy, and thermal denaturation measurements. In the case of the single-stranded polynucleotides, the UV/Vis and fluorescence titrations permit to distinguish between sequences containing purine and pyrimidine bases. For the double-stranded polynucleotides the UV/Vis measurements show for all of them hypochromicity and bathochromic shifts. However, the fluorescence studies reveal that both polyA-polyU and poly(dAT)(2) induce a twofold increase in the fluorescence, whereas interaction of poly(dGC)(2) with the ligand L induces a quenching of the fluorescence. Cu2+ modulates the interaction with the double-stranded polynucleotides due to the conformation changes that its coordination induces in compound L. In general, the spectroscopic studies show that intercalation seems to be blocked by the formation of the metal complex. All these features suggest the possibility of using compound L as a sequence-selective fluorescence probe.

ObjectivesWe sought to determine whether gadolinium (Gd)-containing lipid-based nanoparticles (NPs) targeting the macrophage scavenger receptor-B (CD36) improve cardiac magnetic resonance (CMR) detection and characterization of human atherosclerosis.BackgroundGd-containing lipid-based NPs targeting macrophages have improved MR detection of murine atherosclerosis.MethodsGadolinium-containing untargeted NPs, anti-CD36 NPs, and nonspecific Fc-NPs were created. Macrophages were incubated with fluorescent targeted and nontargeted NPs to determine uptake via confocal microscopy and inductively coupled plasma mass spectroscopy (ICP-MS) quantified Gd uptake. Human aortic specimens were harvested at autopsy. With a 1.5-T scanner, T1, T2, and PDW 3-dimensional scans were performed along with post-contrast scans after 24 h incubation. The T1 and cluster analyses were performed and compared with immunohistopathology.ResultsThe NPs had a mean diameter of 125 nm and 14,900 Gd-ions, and relaxivity was 37 mmol/l−1s−1 at 1.5-T and 37°C. Confocal microscopy and ICP-MS demonstrated significant in vitro macrophage uptake of targeted NPs, whereas non-targeted NPs had minimal uptake. On T1 imaging, targeted NPs increased contrast-to-noise ratio (CNR) by 52.5%, which was significantly greater than Fc-NPs (CNR increased 17.2%) and nontargeted NPs (CNR increased 18.7%) (p = 0.001). Confocal fluorescent microscopy showed that NPs target resident macrophages, whereas the untargeted NPs and Fc-NPs are found diffusely throughout the plaque. Targeted NPs had a greater signal intensity increase in the fibrous cap compared with non-targeted NPs.ConclusionsMacrophage-specific (CD36) NPs bind human macrophages and improve CMR detection and characterization of human aortic atherosclerosis. Thus, macrophage-specific NPs could help identify high-risk human plaque before the development of an atherothrombotic event.

The innovations in science and technology have allowed researchers to look inside the human body. In some cases, like MRI, the protons present in the body generate enough signal for an image. However, the employ of certain atoms, metallic or non-metallic, enable detection through different imaging techniques (computed tomography, nuclear imaging, ultrasound or optical imaging), and improve the quality of the images. Here we discuss the different imaging atoms used depending on the imaging technique and the new possible imaging atoms for medical applications.

incubating for 45 minutes on a roller-bench at room temperature. The SATA-derivatized antibody was deacetylated by incubation with a hydroxylamine solution for 1 hour at room temperature. The activated antibody was added to the micelles. This preparation was stored at 4 °C under N2 overnight. Uncoupled antibody was separated from immunomicelles by washing twice. The size of this contrast agent was below 20 nm as determined with dynamic light scattering. Twelve thirteen-month-old apoE-KO mice were used for this study. The apoE-KO animals were fed a Western diet for 20 weeks. MSR-targeted micelles or untargeted micelles were administered at a dose of 0.075 mmol Gd/kg via intravenous injection into the tail vein. High resolution T1weighted images (pixel size: 0.109×0.109×0.5 mm 3 , TR: 800 ms and TE 9ms) of the abdominal aorta were acquired before, and 24 hours post injection at a Bruker 9.4 T, 89 mm-bore system. Images were analyzed using Mathematica (Wolfram Research, Inc.). The contrast to noise was defined as CNR = (I wall – I muscle)/I noise, which is a measure for how well the vessel wall can be discriminated from the surrounding tissue. Immediately after the imaging at 24 hours post micelle injection, the animals were sacrificed. The presence of MSR-targeted micelles containing rhodamine was compared to the location of macrophages studied by immunohistochemistry (anti-CD68 antibody) on fluorescence microscopy of aortic cross-sections corresponding to MRI slices.

With advances in imaging technology and our understanding of the role of inflammation in atherosclerosis, the macrophage appears to be an excellent target for imaging the progression of disease. In addition to imaging the macrophage with only 1 modality, contrast agents can be created that can be imaged with multiple modalities. This seems extremely attractive, as lesion morphology and characteristics can be determined with modalities that provide high picture resolution, such as CT or MRI, whereas macrophage quantity can be accurately determined through the creation of a radiolabeled contrast agent such as FDG via PET. Although this combination of imaging technologies may yield clinically useful data, the associated cost would likely be quite high, and further studies are necessary to validate this approach before it achieves widespread use. The area in which macrophage detection may reach wide clinical utility first is likely the detection of high-risk carotid atherosclerotic plaque. If limitations in coronary image resolution are overcome in the setting of MRI and other imaging technologies, the ability to detect high-risk lesions in the coronary tree through molecular imaging may greatly change how we determine which lesions require therapy and how patients are managed. Therefore we believe that contrast agents that specifically target the macrophage may aid in the detection and risk stratification of atherosclerotic plaque and aid in determining which therapy will best reduce patient morbidity and mortality rates.

Background: Hypertension and type 2 diabetes mellitus are major modifiable risk factors for cardiac, cerebrovascular, and kidney diseases. Reasons for poor disease control include nonadherence, lack of patient engagement, and therapeutic inertia. Objective: The aim of this study was to assess the impact on clinic-measured blood pressure (BP) and glycated hemoglobin (HbA1c) using a digital medicine offering (DMO) that measures medication ingestion adherence, physical activity, and rest using digital medicines (medication taken with ingestible sensor), wearable sensor patches, and a mobile device app. Methods: Participants with elevated systolic BP (SBP ≥140 mm Hg) and HbA1c (≥7%) failing antihypertensive (≥2 medications) and oral diabetes therapy were enrolled in this three-arm, 12-week, cluster-randomized study. Participants used DMO (includes digital medicines, the wearable sensor patch, and the mobile device app) for 4 or 12 weeks or received usual care based on site randomization. Providers in the DMO arms could review the DMO data via a Web portal. In all three arms, providers were instructed to make medical decisions (medication titration, adherence counseling, education, and lifestyle coaching) on all available clinical information at each visit. Primary outcome was change in SBP at week 4. Other outcomes included change in SBP and HbA1c at week 12, and low-density lipoprotein cholesterol (LDL-C) and diastolic blood pressure (DBP) at weeks 4 and 12, as well as proportion of patients at BP goal (

Different approaches have been studied for the preparation of resins containing different polyazamacrocycles. Preparation of monolithic resins by polymerization of vinylic derivatives of the corresponding macrocycles is shown to be a more versatile strategy for this purpose. The use of energy-dispersive analysis by X-ray has revealed to be a very useful tool for the rapid evaluation of the interaction of those materials with both anions and cations and has allowed the corresponding selectivity trends to be obtained in a fast and simple way. Important effects of the polymeric matrix are observed in some cases.

DNA interaction with scorpiand azamacrocycles has been achieved through modulation of their binding affinities. Studies performed with different experimental techniques provided evidence that pH or metal-driven molecular reorganizations of these ligands regulate their ability to interact with calf thymus DNA (ctDNA) through an intercalative mode. Interestingly enough, metal-driven molecular reorganizations serve to increase or decrease the biological activities of these compounds significantly.

International audience; The synthesis of boehmite nanoparticles modified with lanthanides (Eu, Tb and Gd) is described. Their synthesis, characterization and in vitro assays with HeLa cells were performed. The nuclear magnetic relaxation dispersion (NMRD) profiles of the two chelating moieties were studied. Imaging data from laser scanning confocal fluorescence microscopy and flow cytometry revealed that the nanoscaffolds were taken up by the cells, distributed throughout the cytoplasm and showed no toxicity. This platform could represent an alternative to silica-based inert matrices as imaging vehicles.

Contrast-enhanced MRI of atherosclerosis can provide valuable additional information on a patient’s disease state. As a result of the interactions of HDL with atherosclerotic plaque and the flexibility of its reconstitution, it is a versatile candidate for the delivery of contrast-generating materials to this pathogenic lesion. We herein discuss the reports of HDL modified with gadolinium to act as an MRI contrast agent for atherosclerosis. Furthermore, HDL has been modified with fluorophores and nanocrystals, allowing it to act as a contrast agent for fluorescent imaging techniques and for computed tomography. Such modified HDL has been found to be macrophage specific, and, therefore, can provide macrophage density information via noninvasive MRI. As such, modified HDL is currently a valuable contrast agent for probing preclinical atherosclerosis. Future developments may allow the application of this particle to further diseases and pathological or physiological processes in both preclinical models as well as in patients.

We report on the one-pot synthetic procedure of cyclen derivatives bearing three acetate groups attached on boehmite nanoparticles, the complexing capabilities of these inorganic–organic hybrid materials with rare earth cations, and the behaviour as contrast agents or fluorescence probes. Delgado Pinar, Estefania, Estefania.Delgado@uv.es ; Frias Martinez, Juan Carlos, Juan.Frias@uv.es ; Albelda Gimeno, Maria Teresa, Teresa.Albelda@uv.es ; Alarcon Navarro, Javier, Javier.Alarcon@uv.es ; Garcia-España Monsonis, Enrique, Enrique.Garcia-Es@uv.es

The ability to detect and characterize atherosclerosis with targeted contrast agents may enable initiation of therapy for atherosclerotic lesions prior to becoming symptomatic. Since lipoproteins such as high-density lipoprotein (HDL) and low-density lipoprotein (LDL) play a critical role in the regulation of plaque biology through the transport of lipids into and out of atherosclerotic lesions, modifying HDL and LDL with radioisotopes for nuclear imaging, chelates for magnetic resonance imaging (MRI) or other possible contrast agents for computed tomography imaging techniques may aid in the detection and characterization of atherosclerosis. This review focuses on the literature employing lipoproteins as contrast agents for imaging atherosclerosis and the feasibility of this approach. Copyright © 2007 John Wiley & Sons, Ltd.

We investigated the ability of targeted immunomicelles to detect and assess macrophages in atherosclerotic plaque using MRI in vivo . There is a large clinical need for a noninvasive tool to assess atherosclerosis from a molecular and cellular standpoint. Macrophages play a central role in atherosclerosis and are associated with plaques vulnerable to rupture. Therefore, macrophage scavenger receptor (MSR) was chosen as a target for molecular MRI. MSR-targeted immunomicelles, micelles, and gadolinium–diethyltriaminepentaacetic acid (DTPA) were tested in ApoE−/− and WT mice by using in vivo MRI. Confocal laser-scanning microscopy colocalization, macrophage immunostaining and MRI correlation, competitive inhibition, and various other analyses were performed. In vivo MRI revealed that at 24 h postinjection, immunomicelles provided a 79% increase in signal intensity of atherosclerotic aortas in ApoE−/− mice compared with only 34% using untargeted micelles and no enhancement using gadolinium–DTPA. Confocal laser-scanning microscopy revealed colocalization between fluorescent immunomicelles and macrophages in plaques. There was a strong correlation between macrophage content in atherosclerotic plaques and the matched in vivo MRI results as measured by the percent normalized enhancement ratio. Monoclonal antibodies to MSR were able to significantly hinder immunomicelles from providing contrast enhancement of atherosclerotic vessels in vivo . Immunomicelles provided excellent validated in vivo enhancement of atherosclerotic plaques. The enhancement seen is related to the macrophage content of the atherosclerotic vessel areas imaged. Immunomicelles may aid in the detection of high macrophage content associated with plaques vulnerable to rupture.

In the crystal structure of dichloro[3,6,9,12,15,18-hexaoxa-24,27-diazatricyclo[24.4.0.0 20,25 ]triaconta-1(26),20,22,24,27,29-hexaene-N,N']palladium(II), [PdCl 2 (C 22 H 30 N 2 O 6 )], the Pd atom is tetracoordinated by the two pyridyl N atoms and two Cl atoms. The planes formed by atoms Pd1, N21, N31 and atoms Pd1, Cl1, Cl2 make an angle of 12.12(9)° with one another. The twist of the two pyridyl rings of 31.59(9)° is associated with the ortho substitution, and the complexation of PdCl 2 seems to alter the shape of the crown ether cavity, so that it is less suitable for complexing metal cations.

The need for more specific and selective contrast agents for magnetic resonance imaging motivated us to prepare a new nanoparticle agent based on high-density lipoproteins (HDL). This second generation contrast agent can be prepared in three different ways. The HDL nanoparticles (rHDL) were fully characterized by FPLC and gel electrophoresis. The flexibility of the platform also allows us to incorporate optical probes into rHDL for localization ex vivo by confocal fluorescence microscopy. The contrast-agent-containing nanoparticles were injected into mice that develop atherosclerotic lesions. Magnetic resonance imaging of the animals showed clear enhancement of the atherosclerotic plaques.

The ability to specifically image macrophages may enable improved detection and characterization of atherosclerosis. In this study we evaluated the in vitro uptake of gadolinium (Gd)-containing immunomicelles (micelles linked to macrophage-specific antibody), micelles, and standard contrast agents by murine macrophages, and sought to determine whether immunomicelles and micelles improve ex vivo imaging of apolipoprotein E knockout (ApoE KO) murine atherosclerosis. Murine RAW 264.7 macrophages were incubated with Gd-DTPA, micelles, and immunomicelles. Cell pellets were prepared and imaged using a 1.5 T MR system with an inversion recovery spin-echo sequence to determine the in vitro T1 values. Ex vivo analysis of mouse aortas was performed using a 9.4T MR system with a high-spatial-resolution sequence (78x39x78 microm3). The T1 value was significantly decreased in cells treated with micelles compared to Gd-DTPA (P

A new contrast agent for MRI based on recombinant HDL-like nanoparticles has been prepared. It shows a great potential as a contrast agent for atherosclerotic plaques in a relative short time (24 h post-injection) as it is selective for the plaques and is an endogenous molecule. It also can distinguish between different types of plaques as the enhancement obtained is different, depending on plaque composition.

A synthetic procedure for the preparation of functional structured inorganic–organic hybrid materials consisting of boehmite-silica core–shell nanoparticles and anthracene-containing amines covalently attached to the nanoparticles surface is reported. The system functionalised with the monoamine chain shows a very high sensing performance for Hg2+ detection in pure water reaching a detection limit of 0.2 ppb. Two additional advantages of these systems are their stability over a wide pH window and the feasibility to be recovered by a simple procedure.

Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.

Nanoparticle contrast agents for MRI may aid in identifying atherosclerotic lesions that give rise to ischemic events by means of penetration and retention in the plaque. These imaging agents may provide valuable information regarding plaque characteristics which can help determine the risk of plaque rupture. By increasing molecular flexibility or adding a means of specifically targeting ligands via antibody or peptide, nanoparticles can enhance certain regions of the atherosclerotic plaque. The development of single contrast agents detectable with multiple imaging modalities may further improve our ability to detect and characterize atherosclerosis in clinical and preclinical applications. These exciting developments may help in the realization of MRI as a powerful tool in the prevention of cardiovascular morbidity and mortality.

The synthesis of a polyazamacrocycle constituted by two diethylenetriamine bridges functionalized at their central nitrogen with naphth-2-ylmethyl units and interconnected through 2,6-dimethylpyridine spacers (L1) is reported. The protonation behaviour of the new macrocycle in water and in water-ethanol 70/30 v/v mixed solvent has been examined by means of pH-metric, UV-Vis and steady-state fluorescence techniques. The fluorescence emission is slightly quenched following the deprotonation of the central tertiary amines and more deeply quenched upon deprotonation of the secondary amino groups. pH-Metric titrations show that in water-ethanol 70/30 v/v L1 forms stable mononuclear complexes with the divalent transition and post-transition metal ions Mn2+, Fe2+, Co2+, Cu2+, Zn2+, Cd2+, Hg2+ and Pb2+. In the case of Cu2+, Zn2+, Hg2+ and Pb2+, formation of binuclear complexes has also been observed. Steady-state fluorescence emission studies show that while interaction with Cu2+ leads to quenching of the fluorescence emission above pH = 2, interaction with Zn2+, Cd2+, Hg2+ and Pb2+ give rise to enhancements of the fluorescence above pH ca. 5, which is particularly noticeable in the case of Zn2+.

A bibracchial lariat aza-crown ether (L) consisting of 2-aminoethylnaphthyl moieties appended to a 2 : 2 azapyridinophane structure displays significant activation of H–D exchange in malonic acid. The compound forms very stable adducts with malonate anions (MA) in the 2–10 pH range. Molecular dynamics studies performed for the species resulting from the interaction of the hexaprotonated macrocycle and the dianion show that malonate is encapsulated by L with distances between the CH2 group of malonate and the pyridine nitrogens of ca. 3.5 A. The pendant arms of L cap above and below the anion, defining a pseudo-cage structure. Quantum chemical calculations for α-proton abstraction from malonate by the protonated ligand L, at the B3LYP/6-31G** computational level using reduced models, have allowed transition states to be obtained that denote a concerted mechanism in which α-proton abstraction is accompanied by proton transfer from protonated amino groups of the receptor to the carboxylate groups. Kinetic measurements for ligand L, performed at pD = 6 following the variation of the 1H-NMR MA-CH2 and MA-CHD signals, allow the following rate constants to be calculated: kH1 = (60.2 ± 0.5) × 10−3 min−1 and kH2 = (75.3 ± 0.6) × 10−3 min−1, with values that equal the experimental values of the free substrate at pD = 0. The rate enhancement produced by the open-chain reference ligand (L1), containing the polyamine tren (tris(2-aminoethyl)amine) functionalized at one of its terminal amino groups with a naphthyl moiety, is much more moderate, with kH1 = (9.2 ± 0.2) × 10−3 min−1 and kH2 = (11.56 ± 0.03) × 10−3 min−1.

Interaction of cationic host species, in particular Zn 2+ salts, with polyaza[n]paracyclophanes (i.e. 2,6,9,13-Tetraaza[14]paracyclophane, B323 (1a) ) directs their selective N-functionalization. In this way compounds mono- or difunctionalized with ArCH 2− groups at the benzylic nitrogen atoms can be easily obtained. Direct reaction with the alkylating agent, in the absence of the Zn 2+ species, produces, in general, very complex mixtures of mono- and polyalkylated compounds except when 4-picolyl chloride is used. In this case, mono-, di-, tri- and tetra N-substituted derivatives of D323 can be isolated depending on the amount of the alkylating agent used. In this case, the mono- and dialkylated products obtained differ from the ones prepared using the metal assisted synthesis.