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https://www.readbyqxmd.com/read/28230222/conceptual-density-functional-theory-for-electron-transfer-and-transport-in-mesoscopic-systems
#1
Paulo R Bueno, David A Miranda
Molecular and supramolecular systems are essentially mesoscopic in character. The electron self-exchange, in the case of energy fluctuations, or electron transfer/transport, in the case of the presence of an externally driven electrochemical potential, between mesoscopic sites is energetically driven in such a manner where the electrochemical capacitance (C[small mu, Greek, macron]) is fundamental. Thus, the electron transfer/transport through channels connecting two distinct energetic (ΔE[small mu, Greek, macron]) and spatially separated mesoscopic sites is capacitively modulated...
February 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28230203/water-insoluble-photosensitizer-nanocolloids-stabilized-by-supramolecular-interfacial-assembly-towards-photodynamic-therapy
#2
Yamei Liu, Kai Ma, Tifeng Jiao, Ruirui Xing, Guizhi Shen, Xuehai Yan
Nanoengineering of hydrophobic photosensitizers (PSs) is a promising approach for improved tumor delivery and enhanced photodynamic therapy (PDT) efficiency. A variety of delivery carriers have been developed for tumor delivery of PSs through the enhanced permeation and retention (EPR) effect. However, a high-performance PS delivery system with minimum use of carrier materials with excellent biocompatibility is highly appreciated. In this work, we utilized the spatiotemporal interfacial adhesion and assembly of supramolecular coordination to achieve the nanoengineering of water-insoluble photosensitizer Chlorin e6 (Ce6)...
February 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28230060/flower-like-superstructures-of-aie-active-tetraphenylethylene-through-solvophobic-controlled-self-assembly
#3
Mina Salimimarand, Duong Duc La, Mohammad Al Kobaisi, Sheshanath V Bhosale
The development of well-organized structures with high luminescent properties in the solid and aggregated states is of both scientific and technological interest due to their applications in nanotechnology. In this paper we described the synthesis of amphiphilic and dumbbell shaped AIE-active tetraphenylethylene (TPE) derivatives and studied their self-assembly with solvophobic control. Interestingly, both TPE derivatives form a 3D flower-shape supramolecular structure from THF/water solutions at varying water fractions...
February 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28228859/dynamics-and-interactions-of-ibuprofen-in-cyclodextrin-nanosponges-by-solid-state-nmr-spectroscopy
#4
Monica Ferro, Franca Castiglione, Nadia Pastori, Carlo Punta, Lucio Melone, Walter Panzeri, Barbara Rossi, Francesco Trotta, Andrea Mele
Two different formulations of cyclodextrin nanosponges (CDNS), obtained by polycondensation of β-cyclodextrin with ethylenediaminetetraacetic acid dianhydride (EDTAn), were treated with aqueous solutions of ibuprofen sodium salt (IbuNa) affording hydrogels that, after lyophilisation, gave two solid CDNS-drug formulations. (1)H fast MAS NMR and (13)C CP-MAS NMR spectra showed that IbuNa was converted in situ into its acidic and dimeric form (IbuH) after freeze-drying. (13)C CP-MAS NMR spectra also indicated that the structure of the nanosponge did not undergo changes upon drug loading compared to the unloaded system...
2017: Beilstein Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28225257/exploiting-noncovalently-conformational-locking-as-a-design-strategy-for-high-performance-fused-ring-electron-acceptor-used-in-polymer-solar-cells
#5
Yahui Liu, Zhe Zhang, Shiyu Feng, Miao Li, Liangliang Wu, Ran Hou, Xinjun Xu, Xuebo Chen, Zhishan Bo
We have developed a kind of novel fused-ring small molecular acceptor, whose planar conformation can be locked by intramolecular noncovalent interaction. The formation of planar supramolecular fused-ring structure by conformation locking can effectively broaden its absorption spectrum, enhance the electron mobility, and reduce the nonradiative energy loss. Polymer solar cells (PSCs) based on this acceptor afforded a power conversion efficiency (PCE) of 9.6%. In contrast, PSCs based on similar acceptor, which can't form a flat conformation, only gave a PCE of 2...
February 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28225208/weak-supramolecular-interactions-governing-parallel-and-antiparallel-dna-quadruplexes-insights-from-large-scale-qm-analysis-of-experimentally-derived-models
#6
Yevgen P Yurenko, Jan Novotný, Radek Marek
The topology and energetics of guanine (G) quadruplexes is governed by supramolecular interactions within their strands. In this work, we performed an extensive QM study of supramolecular interactions shaping the stems of (4+0) parallel (P) and (2+2) antiparallel (AP) systems. The large-scale (~ 400 atoms) models of P and AP were constructed from high-quality experimental structures. The results evidence that each of the P and AP structures is shaped by a distinct network of supramolecular interactions. The analysis of electron topological characteristics of H-bonds in P and AP systems indicates that the P model benefits from the stronger intra-tetrad H-bonding...
February 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28225114/the-new-supramolecular-nano-aggregate-curcumin-cucurbit-7-uril-synthesis-photophysical-properties-and-biocompatibility-evaluation
#7
Leandro Araújo de Azevedo, Leonis Lourenço da Luz, Jamylle Nunes de Souza Ferro, Emiliano Barreto, Ricardo Oliveira Silva, Severino Alves, Iane Bezerra Vasconcelos Alves
The supramolecular nano-aggregate CUR-CB[7] (CUR = curcumin and CB[7] = cucurbit[7]uril) was efficiently prepared by mixing CUR and CB[7] at a molar ratio of 1 : 1 in ethanol at room temperature. The supramolecular aggregate formation was evidenced by mainly FTIR, (1)H NMR, DOSY and spectroscopy experiments. The supramolecular arrangement promotes the increase in the solubility and stability of CUR without affecting the biological properties of the A549 cells. The luminescence properties of CUR and CUR-CB[7] show anti-Kasha's rule fluorescence, and their remarkable NIR emission enables this material to be used as a luminescent probe and marker for in vivo tracking and structural integrity monitoring of the supramolecular complex...
February 22, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28225102/stability-of-reverse-micelles-in-rare-earth-separation-a-chemical-model-based-on-a-molecular-approach
#8
Yushu Chen, Magali Duvail, Philippe Guilbaud, Jean-François Dufrêche
Molecular complexes formed in the organic phase during solvent extraction may self-assemble as reverse micelles, and therefore induce a supramolecular organization of this phase. In most of the cases, water molecules play an essential role in the organization of this non polar medium. The aim of this work is to investigate the speciation of the aggregates formed in the organic phase during solvent extraction, and especially to assess their stability as a function of the number of water molecules included in their polar core...
February 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28225029/high-fidelity-self-assembly-pathways-for-hydrogen-bonding-molecular-semiconductors
#9
Xu Lin, Mika Suzuki, Marina Gushiken, Mitsuaki Yamauchi, Takashi Karatsu, Takahiro Kizaki, Yuki Tani, Ken-Ichi Nakayama, Mitsuharu Suzuki, Hiroko Yamada, Takashi Kajitani, Takanori Fukushima, Yoshihiro Kikkawa, Shiki Yagai
The design of molecular systems with high-fidelity self-assembly pathways that include several levels of hierarchy is of primary importance for the understanding of structure-function relationships, as well as for controlling the functionality of organic materials. Reported herein is a high-fidelity self-assembly system that comprises two hydrogen-bonding molecular semiconductors with regioisomerically attached short alkyl chains. Despite the availability of both discrete cyclic and polymeric linear hydrogen-bonding motifs, the two regioisomers select one of the two motifs in homogeneous solution as well as at the 2D-confined liquid-solid interface...
February 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28223805/harnessing-supramolecular-peptide-nanotechnology-in-biomedical-applications
#10
REVIEW
Kiat Hwa Chan, Wei Hao Lee, Shuangmu Zhuo, Ming Ni
The harnessing of peptides in biomedical applications is a recent hot topic. This arises mainly from the general biocompatibility of peptides, as well as from the ease of tunability of peptide structure to engineer desired properties. The ease of progression from laboratory testing to clinical trials is evident from the plethora of examples available. In this review, we compare and contrast how three distinct self-assembled peptide nanostructures possess different functions. We have 1) nanofibrils in biomaterials that can interact with cells, 2) nanoparticles that can traverse the bloodstream to deliver its payload and also be bioimaged, and 3) nanotubes that can serve as cross-membrane conduits and as a template for nanowire formation...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28223120/supramolecular-formulation-of-nitidine-chloride-can-alleviate-its-hepatotoxicity-and-improve-its-anticancer-activity
#11
Wanying Li, Hang Yin, David Bardelang, Jianbo Xiao, Ying Zheng, Ruibing Wang
Nitidine chloride (NC) has demonstrated promising anticancer activity. However, NC has also shown non-specific toxicity in various healthy organs such as the liver. In this study, we aimed to develop a supramolecular formulation for NC and investigate the associated benefits of such a supramolecular formulation on modulating its inherent hepatotoxicity and anticancer activity. The formation of NC-cucurbit[7]uil (NC@CB[7]) complexes was characterized by (1)H nuclear magnetic resonance and Fourier transform infrared spectroscopy, differential scanning calorimetry and powder X-ray diffraction analysis...
February 18, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28222609/bambusuril-as-a-one-electron-donor-for-photoinduced-electron-transfer-to-methyl-viologen-in-mixed-crystals
#12
Tomas Fiala, Lucie Ludvíková, Dominik Heger, Jan Švec, Tomáš Slanina, L'ubica Vetráková, Michal Babiak, Marek Nečas, Petr Kulhánek, Petr Klán, Vladimir Sindelar
Methyl viologen hexafluorophosphate (MV(2+)·2PF6(-)) and dodecamethylbambus[6]uril (BU6) form crystals in which the layers of viologen dications alternate with those of a 1:2 supramolecular complex of BU6 and PF6(-). This arrangement allows for a one-electron reduction of MV(2+) ions upon UV irradiation to form MV(+•) radical cations within the crystal structure with half-lives of several hours in air. The mechanism of this photoinduced electron transfer in the solid state and the origin of the long-lived charge-separated state were studied by steady-state and transient spectroscopies, cyclic voltammetry, and electron paramagnetic resonance spectroscopy...
February 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28221748/fe3-ph-thermo-responsive-supramolecular-hydrogel-with-multi-shape-memory-effect
#13
Xiaoxia Le, Wei Lu, He Xiao, Li Wang, Chunxin Ma, Jiawei Zhang, Youju Huang, Tao Chen
Poor, non-tunable mechanical properties as well as finite shape memory performance pose a barrier to shape memory hydrogels to realize practical applications. Here, a new shape memory hydrogel with tunable mechanical properties and multi-shape memory effect was presented. Three programmable reversible systems including PBA-diol ester bonds, AAc-Fe3+ and coil-helix transition of agar were applied to memorize temporary shapes and endow the hydrogel with outstanding multi-shape memory functionalities. Moreover, through changing the crosslinking densities, the mechanical properties of the as-prepared hydrogel can be adjusted...
February 21, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28221703/multiblock-copolymer-based-dual-dynamic-disulfide-and-supramolecular-crosslinked-self-healing-networks
#14
So Young An, Seung Man Noh, Jung Kwon Oh
A new multiblock copolymer self-healing strategy is reported that centers on the synthesis of block copolymers designed with different self-healing motifs incorporated into individual blocks. As a proof of concept, a novel pentablock copolymer (ABCBA) consisting of a poly(ethylene glycol) middle block and self-healable symmetric blocks of a polymethacrylate with pendant disulfide linkages and carboxylic acids is synthesized by a combination of consecutive controlled radical polymerization with hydrolytic cleavage...
February 21, 2017: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/28221380/spatial-mismatch-non-additive-binding-energies-and-selectivity-in-supramolecular-complexes
#15
REVIEW
Hans-Jörg Schneider
The consequences of spatial mismatch between a receptor and ligand on affinity and selectivity of supramolecular complexes are illustrated with several examples. Conformationally rigid complexes and shorter-range non-covalent forces are characterized by large affinity changes, in contrast to more flexible systems. In the most frequent complexes with several spaciously separated binding sites, the additivity of binding energies and the correlation between affinity and selectivity is often lost by partial mismatch...
February 21, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28221046/supramolecular-anion-recognition-mediates-one-pot-synthesis-of-3-amino-1-2-4-triazolo-pyridines-from-thiosemicarbazides
#16
Komala Pandurangan, Anna B Aletti, Devis Montroni, Jonathan A Kitchen, Miguel Martínez-Calvo, Salvador Blasco, Thorfinnur Gunnlaugsson, Eoin M Scanlan
A facile one-pot synthesis of 3-amino-[1,2,4]-triazolo[4,3-a]pyridines from thiosemicarbazides through anion mediated synthesis is reported. Thiosemicarbazides derived from 2-hydrazino pyridine, 5-chloro 2-hydrazino pyridine, and 2-hydrazine quinoline were formed in situ as anion receptors in the presence of TBAF. Under microwave heating, thiosemicarbazides furnished the triazolo pyridines in good to moderate yields. The formation of the thiosemicarbazides hydrogen bonding anion receptors was critical in cascading the reaction toward the formation of the triazolo pyridines...
February 21, 2017: Organic Letters
https://www.readbyqxmd.com/read/28220973/enzyme-controlled-nanodevice-for-acetylcholine-triggered-cargo-delivery-based-on-janus-au-mesoporous-silica-nanoparticles
#17
Antoni Llopis-Lorente, Paula Diez, Cristina de la Torre, Alfredo Sanchez, Felix Sancenon, Elena Aznar, Maria D Marcos, Paloma Martínez-Ruíz, Ramón Martínez-Máñez, Reynaldo Villalonga
This work reports a new gated nanodevice for acetylcholine-triggered cargo delivery. We prepared and characterized Janus Au-mesoporous silica nanoparticles functionalized with acetylcholinesterase on the Au face and with supramolecular β-cyclodextrin:benzimidazole inclusion complexes as caps on the mesoporous silica face. The nanodevice is able to selectively deliver the cargo in the presence of acetylcholine via enzyme-mediated acetylcholine hydrolysis, locally lowering the pH and opening the supramolecular gate...
February 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28220178/a-photo-degradable-supramolecular-hydrogel-for-selective-delivery-of-microrna-into-3d-cultured-cells
#18
Zhengquan Zhou, Qikun Yi, Tingting Xia, Wencui Yin, Adnan A Kadi, Jinbo Li, Yan Zhang
Multi-functional supramolecular hydrogels have emerged as smart biomaterials for diverse biomedical applications. Here we report a multi-functional supramolecular hydrogel formed by the conjugate of the bioactive GRGDS peptide with biaryltetrazole that is the substrate of photo-click reaction. The hydrogel was used as a biocompatible matrix to encapsulate live cells for 3D culture. The presence of the RGD epitope in the hydrogelator enhanced the interaction of the nanofiber with integrin over-expressing cells, which resulted in the selective enhancement in the miRNA delivery into the encapsulated U87 cells...
February 21, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28219033/using-a-facile-experimental-manipulation-to-fabricate-and-tune-a-polyoxometalate-cholesterol-hybrid-material
#19
Hai-Kuan Yang, Ling-Ling Liu, Xin Yuan, Shi-Mei Wu
In this work, we describe how the toluene and DMF addition order influences the gelation behaviors and supramolecular structures of a self-assembled polyoxometalate-cholesterol hybrid. Morphological studies of the dried xerogel samples were performed with transmission electron microscopy and atomic force microscopy, revealing that the order of solvent addition directed the self-assembly of polyoxometalate-cholesterol hybrids toward the formation of organogels with different supramolecular structures. In the case of organogel 1, which was formed by adding DMF dropwise into a hybrid-containing toluene solution, the characteristic organogel morphology contained a three-dimensional fibrous network structure...
February 14, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28219008/nanoroughness-strongly-impacts-lipid-mobility-in-supported-membranes
#20
Florence Sarah Blachon, Frederic F Harb, Bogdan Munteanu, Agnès Piednoir, Remy Fulcrand, Thierry Charitat, Giovanna Fragneto, Olivier Pierre-Louis, Bernard Tinland, Jean-Paul Rieu
In vivo lipid membranes interact with rough supramolecular structures such as protein clusters and fibrils. How these features whose size ranges from a few nanometers to a few tens of nanometers impact lipid and protein mobility is still investigated. Here, we study supported phospholipid bilayers, a unique biomimetic model, deposited on etched surfaces bearing nanometric corrugations. Surface roughness and mean curvature are carefully characterized by AFM imaging using ultrasharp tips. Neutron specular reflectivity supplements this surface characterization, and indicates that the bilayers follow the large scale corrugations of the substrate...
February 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
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