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Mireia Campos-Martorell,1 Mary Cano-Sarabia,2 Alba Simats,1 Mar Hernández-Guillamon,1 Anna Rosell,1 Daniel Maspoch,2,3 Joan Montaner1,4 1Neurovascular Research Laboratory, Institut de Recerca Vall d’Hebron, Universitat Autònoma de Barcelona, Barcelona, 2Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Universitat Autònoma de Barcelona, Barcelona, 3Institució Catalana de Recerca i Estudis Avançats (ICREA), 4Neurovascular Unit, Department of Neurology, Universitat Autònoma de Barcelona, Hospital Vall d’Hebron, Barcelona, Spain Background and aims: Although the beneficial effects of statins on stroke have been widely demonstrated both in experimental studies and in clinical trials, the aim of this study is to prepare and characterize a new liposomal delivery system that encapsulates simvastatin to improve its delivery into the brain. Materials and methods: In order to select the optimal liposome lipid composition with the highest capacity to reach the brain, male Wistar rats were submitted to sham or transitory middle cerebral arterial occlusion (MCAOt) surgery and treated (intravenous [IV]) with fluorescent-labeled liposomes with different net surface charges. Ninety minutes after the administration of liposomes, the brain, blood, liver, lungs, spleen, and kidneys were evaluated ex vivo using the Xenogen IVIS® Spectrum imaging system to detect the load of fluorescent liposomes. In a second substudy, simvastatin was assessed upon reaching the brain, comparing free and encapsulated simvastatin (IV) administration. For this purpose, simvastatin levels in brain homogenates from sham or MCAOt rats at 2 hours or 4 hours after receiving the treatment were detected through ultra-high-protein liquid chromatography. Results: Whereas positively charged liposomes were not detected in brain or plasma 90 minutes after their administration, neutral and negatively charged liposomes were able to reach the brain and accumulate specifically in the infarcted area. Moreover, neutral liposomes exhibited higher bioavailability in plasma 4 hours after being administered. The detection of simvastatin by ultra-high-protein liquid chromatography confirmed its ability to cross the blood–brain barrier, when administered either as a free drug or encapsulated into liposomes. Conclusion: This study confirms that liposome charge is critical to promote its accumulation in the brain infarct after MCAOt. Furthermore, simvastatin can be delivered after being encapsulated. Thus, simvastatin encapsulation might be a promising strategy to ensure that the drug reaches the brain, while increasing its bioavailability and reducing possible side effects. Keywords: simvastatin, liposomes, delivery, brain, stroke, rat

Four different metal–organic framework powders (UiO-66, UiO-66-NH2, UiO-67, and HKUST-1) were shaped into tablets. The effect of the applied pressure on porous properties, mechanical resistance and tablet bulk density is reported. We observe a linear relationship between densification and tensile strength for all four studied MOFs, with the slope being MOF-dependent. We also report conditions for improving significantly the volumetric uptake. Finally, we evaluated our tablets' stability over time in the presence of moisture. [ABSTRACT FROM AUTHOR]

Hybrid core–shell Au/CeO2 nanoparticles (NPs) dispersed in UiO-66 shaped into microspherical beads are created using the spray-drying continuous-flow method. The combined catalytic properties of nanocrystalline CeO2 and Au in a single particle and the support and protective function of porous UiO-66 beads make the resulting composites show good performances as catalysts for CO oxidation (T50 = 72 °C; T100 = 100 °C) and recyclability. [ABSTRACT FROM AUTHOR]

A new macrocyclic linker 1,4,7,10-tetraazacyclododecane-1,7-bis(4-acetamidobenzoic)-4,10-diacetic acid (H4L1) was synthesized and characterized. This linker was used to create two heterometallic coordination polymers following a two-step synthesis. This synthesis consisted of first combining this polyazamacrocyclic linker with Ni(ii) or Mn(ii) ions to obtain the corresponding metallomacrocyclic complexes showing non-coordinated carboxylic groups. In a second step, these metallated macrocycles were used as building units to construct two heterometallic Ni(ii)–Zn(ii) and Mn(ii)–Zn(ii) coordination polymers when combined with Zn(ii) ions. In addition, a third Zn(ii)–Zn(ii) coordination polymer could also be synthesized by direct mixing of H4L1 with Zn(ii) ions. Interestingly, the Mn(ii)–Zn(ii) coordination polymer exhibits a reversible type-I “crystal-to-amorphous transformation” upon water sorption/desorption. [ABSTRACT FROM AUTHOR]

The exceptional porosity of Metal–Organic Frameworks (MOFs) could be harnessed for countless practical applications. However, one of the challenges currently precluding the industrial exploitation of these materials is a lack of green methods for their synthesis. Since green synthetic methods obviate the use of organic solvents, they are expected to reduce the production costs, safety hazards and environmental impact typically associated with MOF fabrication. Herein we describe the stepwise optimisation of reaction parameters (pH, reagent concentrations and reaction time) for the room temperature, water-based synthesis of several members of the CPO-27/MOF-74-M series of MOFs, including ones made from Mg(ii), Ni(ii), Co(ii) and Zn(ii) ions. Using this method, we built MOFs with excellent BET surface areas and unprecedented Space-Time Yields (STYs). Employing this approach, we have synthesised CPO-27-M MOFs with record BET surface areas, including 1279 m2 g−1 (CPO-27-Zn), 1351 m2 g−1 (CPO-27-Ni), 1572 m2 g−1 (CPO-27-Co), and 1603 m2 g−1 (CPO-27-Mg). We anticipate that our method could be applied to produce CPO-27-Ni, -Mg, -Co and -Zn with STYs of 44 kg m−3 per day, 191 kg m−3 per day, 1462 kg m−3 per day and a record 18 720 kg m−3 per day, respectively. [ABSTRACT FROM AUTHOR]

A new cobalt(II) complex with a polychlorotriphenylmethyl radical ligand properly functionalized with a carboxylate group (PTMMC−), [Co(PTMMC)2(py)2(H2O)2]·[Co(PTMMC) (py)3(H2O)(Cl)]2·2py·2THF (3), has been synthesized and characterized including single-crystal X-ray diffraction. The structure of 3 consists of two different Co(II) units, [Co(PTMMC)2(py)2(H2O)2] (3A) and [Co(PTMMC) (py)3(H2O)(Cl)] (3B), which cocrystallize together with two molecules of pyridine and two molecules of THF. Its magnetic behaviour shows the presence of antiferromagnetic interactions between the PTMMC radicals and the Co(II) ions. The experimental data was fitted to a magnetic model based on the sum of a linear trimer (SR1…SCo…SR2) and a dimer (SCo…SR3) to give a Co(II)-radical exchange coupling of J/KB=−16.0 K for both complexes. [Copyright &y& Elsevier]

Abstract: Sub-50nm spherical particles that exhibit single-molecule magnet (SMM) behaviour have been fabricated by direct precipitation of [Mn12O12(CH3COO)16(H2O)4] clusters in a mixture of acetonitrile and toluene. The magnetic properties clearly indicate that particle formation does not affect the molecular composition of Mn12O12 clusters, although some interesting differences appear when the magnetic behaviour exhibited by such nanoparticles is compared with a polycrystalline sample of [Mn12O12(CH3COO)16(H2O)4]. [Copyright &y& Elsevier]

We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn12 acetate have been fabricated and characterized by chemical, infrared, TEM, x-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn12 acetate crystal in the field parallel to the easy axis. Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for a single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by reanalyzing the old data on a powdered sample of nonoriented micron-size crystals of Mn12 acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets. [ABSTRACT FROM AUTHOR]