Search

A novel family of precision-engineered gene vectors with well-defined structures built on trehalose and trehalose-based macrocycles (cyclotrehalans) comprising linear or cyclic polyamine heads have been synthesized through procedures that exploit click chemistry reactions. The strategy was conceived to enable systematic structural variations and, at the same time, ensuring that enantiomerically pure vectors are obtained. Notably, changes in the molecular architecture translated into topological differences at the nanoscale upon co-assembly with plasmid DNA, especially regarding the presence of regions with short- or long-range internal order as observed by TEM. In vitro and in vivo experiments further evidenced a significant impact on cell and organ transfection selectivity. Altogether, the results highlight the potential of trehalose-polyamine/pDNA nanocomplex monoformulations to achieve targeting transfection without the need for any additional cell- or organ-sorting component.

The removal of the two dams on the Sélune River since 2019 has led to profound changes in the aquatic ecosystem. Lentic habitats bordered by forest had shifted to new conditions (running water and sparsely vegetated riverbanks) therefore shaping organisms’ assemblies. We studied how the reestablishment of aquatic lotic habitats in interaction with riparian vegetation could mediate the restoration of important ecological functions in the new river. Six stations located along the river continuum were surveyed for 3 years after dam removal: two control stations upstream the former reservoir, three restored stations within the former reservoir, and one control station downstream. We monitored physico-chemical characteristics, phytobenthos biomass and the river’s benthic metabolism, and assessed the functional composition of macroinvertebrate communities. We compared the recorded variables among upstream, downstream and restored sampling stations. We observed a rapid recolonization by invertebrates, but a still low phytobenthic primary production in restored stations. Such a low primary productivity was also reflected in the functional composition of invertebrate communities. Three years after dam removal, there was still a significant time lag between communities recovery and expected ecosystem functioning restoration. We observed a quick colonization by aquatic running-water invertebrate communities of new lotic reaches, but a slower recovery of important ecological functions rates such as those observed in control stations.

A novel family of precision-engineered gene vectors with well-defined structures built on trehalose and trehalose-based macrocycles (cyclotrehalans) comprising linear or cyclic polyamine heads have been synthesized through procedures that exploit click chemistry reactions. The strategy was conceived to enable systematic structural variations and, at the same time, ensuring that enantiomerically pure vectors are obtained. Notably, changes in the molecular architecture translated into topological differences at the nanoscale upon co-assembly with plasmid DNA, especially regarding the presence of regions with short- or long-range internal order as observed by TEM. In vitro and in vivo experiments further evidenced a significant impact on cell and organ transfection selectivity. Altogether, the results highlight the potential of trehalose-polyamine/pDNA nanocomplex monoformulations to achieve targeting transfection without the need for any additional cell- or organ-sorting component.

[Abstract] The limited use of palladium-103 and -109 radionuclides for molecular radiotherapy is surely due to the lack of appropriate ligands capable of fulfilling all criteria required for application in nuclear medicine. Furthermore, the thermodynamic properties of these complexes in solution remain difficult to establish. The challenge is compounded when considering that radiolabeling of compounds for translation to clinical trials requires fast complexation. Thus, the coordination of Pd(II) and 103/109Pd-nuclides is a huge challenge in terms of molecular design and physicochemical characterization. Herein, we report a comprehensive study highlighting TE1PA, a monopicolinate cyclam – already established in nuclear imaging with 64Cu-PET (positron emission tomography) imaging tracers – as a highly relevant chelator for natural Pd and subsequently 109Pd-nuclide. The structural, thermodynamic, kinetic and radiolabeling studies of Pd(II) with TE1PA, as well as the comparison of this complex with three structurally related derivatives, support palladium-TE1PA radiopharmaceuticals as leading candidates for targeted nuclear medicine.

We investigated whether perennial soil organic amendments of pig slurry (PS) and methanized pig slurry (MPS) affect active bacterial communities and change the diversity and the C-flux of Volatile Organic Compounds (VOCs) emitted by soils compared to control plots without any fertilization (C). The long term effects of the fertilization history of the amendments and the short term impact of the organic inputs were both investigated by measuring VOCs emissions using a Proton Transfer Reaction-Mass Spectrometer (PTR-MS) and by analyzing active bacterial diversity by MiSeq Illumina sequencing just before and up to 64 days following the inputs. Soil VOCs emissions (diversity and fluxes) naturally varied with temperature and rainfall variations, irrespective of manure inputs. No effect of the 5-yr fertilization history was observed on bacterial communities' composition and on soil VOCs emissions. However, both manure inputs (PS and MPS) were associated with an inoculation of gamma-Proteobacteria (Pseudomonas sp. and/or Marinospirinum sp.) to the soil on top of which PS inputs activated native soil Bacillus sp. (Firmicutes). VOCs spectra was mainly dominated by methanol and acetonitrile, the acetonitrile emissions not depending on the organic practices. C-VOCs fluxes from the soil to the atmosphere varied from 12 to 76 mu g of C-VOCs h(-1) m(-2) in the control plots. Pig slurry and methanized pig slurry differentially impacted soil VOCs emissions: PS inputs doubled the C-VOC fluxes due to high emission of methanol while MPS inputs reduced VOCs fluxes even less than the control unamended plots, which is of great interest in the context of mitigating greenhouse gases in agriculture. Our results suggest that soil fluxes could, under certain conditions, not be marginal compared to plant fluxes and be potentially driven by new land-uses in agriculture.

[Abstract] The acid–base and copper(II) coordination properties of three previously described cyclam derivatives are reported. Potentiometry, mass spectrometry, UV-vis absorption spectroscopy, electrochemistry and theoretical calculations were combined to investigate the protonation and binding properties of Bn-cyclam-EtOH (L1), oxo-cyclam-EtOH (L2) and oxo-Bn-cyclam-EtOH (L3). These three cyclams are C-functionalized by a hydroxyethyl pendant arm and display either one N-benzyl group and/or an amide replacing one macrocyclic secondary amine. The N-benzylic substitution has a significant effect of lowering the basicity of the corresponding protonation sites, while the presence of the amide function lowers the first protonation constants of the ligands. Regardless of the system considered, ESI mass spectrometry showed that only monocupric chelates are formed. Compared to the literature data, the stability constants measured by potentiometry (pCu L1 = 14.67; pCu L2 = 16.95; pCu L3 = 15.28) showed that: (i) the C-appended group has a negligible influence on Cu2+ complexation, (ii) N-benzylation decreases the cupric complex stability, and (iii) the “oxo” function significantly increases the stability of the Cu2+ complex. Furthermore, UV-vis absorption versus pH measurements are in excellent agreement with the potentiometric titrations and show an equal involvement of the four nitrogen atoms in L1 and the strong binding properties of L2 and L3 related to the deprotonation of the carboxamide. The electrochemistry parameters determined by cyclic voltammetry showed the predominance of the [CuL1]2+, [CuL2-H]+and [CuL3-H]+ species but also the irreversibility of the three Cu2+/Cu+ systems. Finally, density functional theory (DFT) and multiconfigurational CASSCF/NEVPT2 calculations confirmed that the protonation of the cupric complexes occurs at the oxygen atom of the amide group of the “oxo” ligands, which is in agreement with the experimental data.