This report describes the development of a new nanocarrier, named as polyarginine (PArg) nanocapsules, specifically designed for overcoming cellular barriers. These nanocapsules are composed of an oily core and a PArg corona. The attachment of the PArg corona was mediated by its interaction with the oily core, which was conveniently stabilized with phosphatidylcholine. Hybrid PArg/PEG nanocapsules could also be obtained by introducing PEG-stearate in the nanocapsules formation process. The nanocapsules had an average size in the range of 120–160 nm, and a positive surface charge, which varied between +56 and +28 mV for PArg and PArg/PEG nanocapsules, respectively. They could accommodate significant amounts of lipophilic drugs, i.e., docetaxel, in their core, and also polar negatively charged molecules, i.e., plasmid DNA, on their coating. As a preliminary proof-of-principle, we explored the ability of these nanocarriers to enter cancer cells and to inhibit proliferation in the non-small cell lung cancer NCI-H460 cell line, using flow cytometry and confocal microscopy analysis. The results indicated that PArg nanocapsules are rapidly and massively accumulated into the NCI-H460 cells and that the PArg shell plays a critical role in the internalization process. Moreover, the incubation with docetaxel-loaded nanocapsules with NCI-H460 cells led to an enhanced inhibition of their proliferation, as compared to the free drug. Overall, this is the first report of the potential of PArg nanocapsules as intracellular drug delivery vehicles.
Abstract The cathodic coupling of unsaturated sulfones (title compounds) performed in aprotic media in the presence of lithium salts as electrolyte affords d,l dimers almost exclusively. 相似文献
Highly hydrated bioactive hydrogels containing immobilized oxidoreductase enzymes and immobilized redox mediators were simulated as the biorecognition layer of amperometric biosensors. The linear dynamic range of the amperometric response of mediated biosensors increases and moves to higher concentration brackets with an increase in the concentration of mediator. This informs the design of biosensors that target the same analyte but possesses several independently addressable electrodes modified with hydrogels that contain different concentrations of mediator. Increases in enzyme concentration increase the linear dynamic range but does not alter the sensitivity of amperometric biosensors. Both sensitivity and linear dynamic range of mediated amperometric enzyme biosensors may be “tuned” by varying the concentrations of the enzyme and the mediator. Simulations effectively guide the initial domains of study of complex systems such as implantable biosensors. 相似文献
Poly(3,5‐dichloroaniline) was prepared by chemical oxidation in the presence of various sulfonic acids as doping agent, using potassium permanganate as oxidant. 1‐Naphtalene sulfonic acid, 2‐naphatalene sulphonic acid, 1,5‐naphtalene disulfonic acid, and p‐toluenesulfonic acid were the acids of choice. Infrared and UV‐Vis spectroscopy, utilized to characterize the polymers, revealed that the compounds exist in the emeraldine (conductive) oxidation state. The level of doping, conductivity, and morphology were determined as well. The presence of a sulfonic acid produces a morphological change, from granular to microtubule structures, which is responsible for the strong increase in the conductivity of the polymer. 相似文献
The X-ray structure and the solid-state NMR measurements, mainly 15N CPMAS of the labelled compound, allow to determine the static and dynamic properties of 3(5)-ethyl-5(3)-phenyl-1H-pyrazole. The compound is a tetramer formed by three 5-ethyl-3-phenyl-1H-pyrazole and one 3-ethyl-5-phenyl-1H-pyrazole tautomers in dynamic equilibrium with the complementary situation. 相似文献
Highlights? Catalytic domain of JMJD2A (cJMJD2A) removes methyl marks in a distributive manner ? Homogeneously methylated nucleosomes were used as substrates ? Quantitative assay for nucleosome demethylation has been developed 相似文献
Two novel monofunctionalized fulleropyrrolidine derivatives (Prato adducts) were prepared and characterized by matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI). MALDI experiments conducted in the positive-ion mode on pure and mixed samples of both monofunctionalized fullerene derivatives revealed the efficient formation of bisadducts (in the case of the pure samples) and mixed bisadducts (in the case of a mixed sample). Bisadducts were not observed in the ESI experiments and thus not present in the sample. A mechanism for the MALDI formation of these bisadduct ions is proposed in which an azomethine ylide fragment is formed in situ from the monofunctionalized fulleropyrrolidine species upon laser irradiation. This fragment, which can survive as an intact moiety in the gas phase in the special environment provided by the MALDI experiment, is then able to attach to a fulleropyrrolidine monoadduct which acts as a dipolarophile, thus leading to the formation of a bisadduct fullerene derivative. The unprecedented re-attachment of the azomethine ylide implies that the establishment of the ligand attainment of Prato adducts based on MALDI analysis alone can lead to wrong assignments.
In a novel electron‐donor–acceptor conjugate, phthalocyanine (Pc) and perylenediimide (PDI) are connected through a trans‐platinum(II) diacetylide linker to yield Pc‐Pt‐PDI 1 . In the ground state, the presence of PtII disrupts the electronic communication between the two electroactive components, as revealed by UV/Vis spectroscopy and electrochemical studies. The photophysical behavior of 1 is compared with that of the corresponding Pc‐PDI electron‐donor–acceptor conjugate 2 in terms of charge separation and charge recombination. The insertion of PtII between Pc and PDI impacts the results in a longer‐lived Pc .+/PDI .? radical ion‐pair state. In addition, the intermediately formed Pc triplet excited state is formed with higher quantum yields in 1 than in 2 . 相似文献