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41.
Guillerm B Darcos V Lapinte V Monge S Coudane J Robin JJ 《Chemical communications (Cambridge, England)》2012,48(23):2879-2881
Well-defined graft copolymers were obtained using a copper-catalysed azide-alkyne Huisgen's cycloaddition click reaction from both biocompatible and non-toxic poly(ε-caprolactone) and poly(2-methyl-2-oxazoline) homopolymers. Resulting amphiphilic copolymers proved to form micelles that could be used as potential drug carriers. 相似文献
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Tiffany G. Chan Carmen L. Ruehl Sophie V. Morse Michelle Simon Viktoria Rakers Helena Watts Francesco A. Aprile James J. Choi Ramon Vilar 《Chemical science》2021,12(27):9485
One of the key hallmarks of Alzheimer''s disease is the aggregation of the amyloid-β peptide to form fibrils. Consequently, there has been great interest in studying molecules that can disrupt amyloid-β aggregation. While a handful of molecules have been shown to inhibit amyloid-β aggregation in vitro, there remains a lack of in vivo data reported due to their inability to cross the blood–brain barrier. Here, we investigate a series of new metal complexes for their ability to inhibit amyloid-β aggregation in vitro. We demonstrate that octahedral cobalt complexes with polyaromatic ligands have high inhibitory activity thanks to their dual binding mode involving π–π stacking and metal coordination to amyloid-β (confirmed via a range of spectroscopic and biophysical techniques). In addition to their high activity, these complexes are not cytotoxic to human neuroblastoma cells. Finally, we report for the first time that these metal complexes can be safely delivered across the blood–brain barrier to specific locations in the brains of mice using focused ultrasound.We report a series of non-toxic cobalt(iii) complexes which inhibit Aβ peptide aggregation in vitro; these complexes can be safely delivered across the blood–brain barrier in mice using focused ultrasound. 相似文献
44.
Giant unilamellar vesicles (diameter of a few tens of micrometers) are commonly produced by hydration of a dried lipidic film. After addition of the aqueous solution, two major protocols are used: (i) the gentle hydration method where the vesicles spontaneously form and (ii) the electroformation method where an ac electric field is applied. Electroformation is known to improve the rate of unilamellarity of the vesicles though it imposes more restricting conditions for the lipidic composition of the vesicles. Here we further characterize these methods by using fluorescence microscopy. It enables not only a sensitive detection of the defects but also an evaluation of the quantity of lipids in these defects. A classification of the defects is proposed and statistics of their relative importance in regard to both methods and lipid composition are presented: it shows for example that 80% of the vesicles obtained by electroformation from 98% 1,2-dioleoyl-sn-glycero-3-phosphocholine are devoid of significant defects against only 40% of the vesicles with the gentle hydration method. It is also shown that the presence of too many negatively charged lipids does not favor the formation of unilamellar vesicles with both methods. For the gentle hydration, we checked if the negatively charged lipids were inserted in the vesicles membrane in the same proportion as that of the lipid mixture from which they are formed. The constant incorporation of a negatively charged labeled lipid despite an increasing presence of negatively charged 1,2-dioleoyl-sn-glycero-3-[phospho-l-serine] tends to confirm that the composition of vesicles is indeed close to that of the initial mixture. 相似文献
45.
Luce VanderElst Audrey Sessoye Sophie Laurent RobertN. Muller 《Helvetica chimica acta》2005,88(3):574-587
The self‐diffusion (Dc) coefficients of various lanthanum(III) diamagnetic analogues of open‐chain and macrocyclic complexes of gadolinium used as MRI contrast agents were determined in dilute aqueous solutions (3–31 mM ) by pulsed‐field‐gradient (PFG) high‐resolution 1H‐NMR spectroscopy. The self‐diffusion coefficient of H2O (Dw) was obtained for the same samples to derive the relative diffusion constant, a parameter involved in the outersphere paramagnetic‐relaxation mechanism. The results agree with an averaged relative diffusion constant of 2.5 (±0.1)×10?9 and of 3.3 (±0.1)×10?9 m2 s?1 at 25 and 37°, respectively, for 'small' contrast agents (Mr 500–750 g/mol), and with the value of bulk H2O (2.2×10?9 and 2.9×10?9 m2 s?1 at 25° and at 37°, respectively) for larger complexes. The use of the measured values of Dc for the theoretical fitting of proton NMRD curves of gadolinium complexes shows that the rotational correlation times (τR) are very close to those already reported. However, differences in the electronic relaxation time (τSO) at very low field and in the correlation time (τV) related to electronic relaxation were found. 相似文献
46.
Dr. Sophie A.‐L. Thétiot‐Laurent Dr. Jérôme Boissier Dr. Anne Robert Prof. Dr. Bernard Meunier 《Angewandte Chemie (International ed. in English)》2013,52(31):7936-7956
After malaria, schistosomiasis (or bilharzia) is the second most prevalent disease in Africa, and is occurring in over 70 countries in tropical and subtropical regions. It is estimated that 600 million people are at risk of infection, 200 million people are infected, and at least 200 000 deaths per year are associated with the disease. All schistosome species are transmitted through contact with fresh water that is infested with free‐swimming forms of the parasite, which is known as cercariae and produced by snails. When located in the blood vessels of the host, larval and adult schistosomes digest red cells to acquire amino acids for growth and development. Vaccine candidates have been unsuccessful up to now. Against such devastating parasitic disease, the antischistosomal arsenal is currently limited to a single drug, praziquantel, which has been used for more than 35 years. Because the question of the reduction of the activity of praziquantel was raised recently, it is thus urgent to create new and safe antischistosomal drugs that should be combined with praziquantel to develop efficient bitherapies. 相似文献
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Bastien Jallabert Guadalupe Vaca-Medina Sophie Cazalbou Antoine Rouilly 《Cellulose (London, England)》2013,20(5):2279-2289
Pressure–volume–temperature (PVT) measurements of α-cellulose with different water contents, were performed at temperatures from 25 to 180 °C and pressures from 19.6 to 196 MPa. PVT measurements allowed observation of the combined effects of pressure and temperature on the specific volume during cellulose thermo-compression. All isobars showed a decrease in cellulose specific volume with temperature. This densification is associated with a transition process of the cellulose, occurring at a temperature defined by the inflection point T t of the isobar curve. T t decreases from 110 to 40 °C with pressure and is lower as moisture content increases. For isobars obtained at high pressures and high moisture contents, after attaining a minimum, an increase in volume is observed with temperature that may be related to free water evaporation. PVT α-cellulose experimental data was compared with predicted values from a regression analysis of the Tait equations of state, usually applied to synthetic polymers. Good correlations were observed at low temperatures and low pressures. The densification observed from the PVT experimental data, at a temperature that decreases with pressure, could result from a sintering phenomenon, but more research is needed to actually understand the cohesion mechanism under these conditions. 相似文献
49.
Dr. Margot N. Wenzel Dr. Riccardo Bonsignore Sophie R. Thomas Dr. Didier Bourissou Prof. Giampaolo Barone Prof. Angela Casini 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(32):7628-7634
With the aim of exploiting the use of organometallic species for the efficient modification of proteins through C-atom transfer, the gold-mediated cysteine arylation through a reductive elimination process occurring from the reaction of cyclometalated AuIII C^N complexes with a zinc finger peptide (Cys2His2 type) is here reported. Among the four selected AuIII cyclometalated compounds, the [Au(CCON)Cl2] complex featuring the 2-benzoylpyridine (CCON) scaffold was identified as the most prone to reductive elimination and Cys arylation in buffered aqueous solution (pH 7.4) at 37 °C by high-resolution LC electrospray ionization mass spectrometry. DFT and quantum mechanics/molecular mechanics (QM/MM) studies permitted to propose a mechanism for the title reaction that is in line with the experimental results. Overall, the results provide new insights into the reactivity of cytotoxic organogold compounds with biologically important zinc finger domains and identify initial structure–activity relationships to enable AuIII-catalyzed reductive elimination in aqueous media. 相似文献
50.
Alberto Palazzolo Sophie Feuillastre Viktor Pfeifer Sbastien Garcia‐Argote Donia Bouzouita Simon Tricard Cline Chollet Elodie Marcon David‐Alexandre Buisson Sophie Cholet Franois Fenaille Guy Lippens Bruno Chaudret Grgory Pieters 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):4945-4949
A general approach for the efficient hydrogen‐isotope exchange of nucleobase derivatives is described. Catalyzed by ruthenium nanoparticles, using mild reaction conditions, and involving either D2 or T2 as isotopic sources, this reaction possesses a wide substrate scope and a high solvent tolerability. This novel method facilitates the access to essential diagnostic tools in drug discovery and development: tritiated pharmaceuticals with high specific activities and deuterated oligonucleotides suitable for use as internal standards during LC‐MS quantification. 相似文献