Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 339
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Phys Chem Chem Phys ; 22(15): 7942-7951, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32232288

RESUMO

A pharmacophoric motif decorated with supramolecular functionalities (TZT) was designed for potential interaction with biological targets. Main insights of this work include the correlation of supra functionalities of TZT with its binding ability to proteins leading to the modulation of their structure and bioactivity as a promising perspective in the field of cellular protection from oxidative stress. To investigate the role of TZT in obliterating oxidative stress at a molecular level, its binding propensity with bovine serum albumin (BSA) and bovine liver catalase (BLC) was characterized using various biophysical methods. The binding constants of TZT with BSA (Kb = 2.09 × 105 M-1) and BLC (Kb = 2.349 × 105 M-1) indicate its considerable interaction with these proteins. TZT efficiently triggers favourable structural changes in BLC, thereby enhancing its enzyme activity in a dose dependent manner. The enzyme kinetics parameters of TZT binding to BLC were quantified using the Michaelis-Menten model. Both in silico and experimental results suggest that an increased substrate availability could be the reason for enhanced BLC activity. Furthermore, physiological relevance of this interaction was demonstrated by investigating the ability of TZT to attenuate oxidative stress. Treatment with TZT was found to mitigate the inhibition of A549 cell proliferation in the presence of high concentrations of vitamin C. This finding was confirmed at a molecular level by PARP cleavage status, demonstrating that TZT inhibits apoptotic cell death induced by oxidative stress.


Assuntos
Catalase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Tiazolidinas/farmacologia , Células A549 , Animais , Antioxidantes/farmacologia , Bovinos , Proliferação de Células/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos
2.
Artigo em Inglês | MEDLINE | ID: mdl-32170796

RESUMO

Incorporation of non-equilibrium actions in the sequence of self-assembly processes would be an effective means to establish bio-like high functionality hierarchic assemblies. As a novel methodology beyond self-assembly, nanoarchitectonics, which has as its aim the fabrication of functional materials systems from nanoscopic units through the methodological fusion of nanotechnology with other scientific disciplines including organic synthesis, supramolecular chemistry, microfabrication, and bio-process, has been applied to this strategy. The application of non-equilibrium factors to conventional self-assembly processes is discussed on the basis of examples of directed assembly, Langmuir-Blodgett assembly, and layer-by-layer assembly. In particular, examples of the fabrication of hierarchic functional structures using bio-active components such as proteins or by the combination of bio-components and two-dimensional nanomaterials, are described. Methodologies described in this review article highlight possible approaches using the nanoarchitectonics concept beyond self-assembly for creation of bio-like higher functionalities and hierarchic structural organization.

3.
J Nanosci Nanotechnol ; 20(8): 5151-5152, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32126715
4.
Chem Commun (Camb) ; 56(27): 3855-3858, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32134092

RESUMO

A directly linked BODIPY-oxoporphyrinogen dyad has been newly synthesized and occurrence of sequential photoinduced energy and electron transfer upon fluoride anion binding to oxoporphyrinogen has been demonstrated by spectral, electrochemical and femtosecond transient absorption studies.

5.
Adv Mater ; : e1905657, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32191374

RESUMO

Exploration of molecular functions and material properties based on the control of chirality would be a scientifically elegant approach. Here, the fabrication and function of chiral-featured materials from both chiral and achiral components using a supramolecular nanoarchitectonics concept are discussed. The contents are classified in to three topics: i) chiral nanoarchitectonics of rather general molecular assemblies; ii) chiral nanoarchitectonics of metal-organic frameworks (MOFs); iii) chiral nanoarchitectonics in liquid crystals. MOF structures are based on nanoscopically well-defined coordinations, while mesoscopic orientations of liquid-crystalline phases are often flexibly altered. Discussion on the effects and features in these representative materials systems with totally different natures reveals the universal importance of supramolecular chiral nanoarchitectonics. Amplification of chiral molecular information from molecules to materials-level structures and the creation of chirality from achiral components upon temporal statistic fluctuations are universal, regardless of the nature of the assemblies. These features are thus surely advantageous characteristics for a wide range of applications.

6.
J Phys Chem Lett ; 11(7): 2422-2429, 2020 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-32163290

RESUMO

We studied the supramolecular structure between barbituric acid (pyrimidine-2,4,6(1H,3H,5H)-trione, BA) and an amphiphilic melamine derivative at the air/water interface by heterodyne-detected vibrational sum frequency generation (HD-VSFG) spectroscopy. HD-VSFG measurements in situ showed a positive broad band from 2300 to 2950 cm-1. By comparing the experimental results with ab initio molecular dynamics (AIMD) simulations, we assigned the broad band to the NH stretching modes of BA strongly hydrogen-bonded to the melamine derivative. In addition, we report in situ HD-VSFG spectra of the interfacial supramolecular structure in the CO stretching region. Two CO stretching bands were identified. On the basis of the signs of the C=O bands, we uniquely determined the orientation of BA. The strong hydrogen bonds and the molecular orientations are direct evidence for the supramolecular structure based on complementary hydrogen bonds at the air/water interface.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32181636

RESUMO

The use of metallo-supramolecular polymer (MSP) as a thin-film-based redox supercapacitor electrode material is reported for the first time. Fe(II)- and Ru(II)-based MSPs (polyFe and polyRu, respectively) were synthesized by complexation of appropriate metal salts with 4',4″-(1,4-phenylene)bis-2,2':6',2″-terpyridine, and thin films of these polymers were prepared by spray coating onto an indium tin oxide glass substrate. A study of the energy storage performances of the polyFe and polyRu films in a nonaqueous electrolyte system revealed volumetric capacitances of ∼62.6 ± 3 F/cm3 for polyFe and 98.5 ± 7 F/cm3 for polyRu at a current density of 2 A/cm3. To improve the energy storage performance over a wider potential range, asymmetric supercapacitor (ASC) displays were fabricated with suitable combinations of the MSPs as cathodic materials and Prussian blue as the anodic counter material in a sandwich configuration with a transparent polymeric ion gel as the electrolyte. The fabricated ASCs showed a maximum volumetric energy density (∼10-18 mW h/cm3) that was higher than that of lithium thin-film batteries and a power density (7 W/cm3) comparable to that of conventional electrolyte capacitors, with superb cyclic stability for 10 000 cycles. To demonstrate the practical use of the MSP, the illumination of a light-emitting diode bulb was powered by a laboratory-made device. This work should inspire the development of high-performance thin-film flexible supercapacitors based on MSPs as active cathodic materials.

8.
Chemistry ; 26(29): 6461-6472, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32159246

RESUMO

Soft and flexible two-dimensional (2D) systems, such as liquid interfaces, would have much more potentials in dynamic regulation on nano-macro connected functions. In this Minireview article, we focus especially on dynamic motional functions at liquid dynamic interfaces as 2D material systems. Several recent examples are selected to be explained for overviewing features and importance of dynamic soft interfaces in a wide range of action systems. The exemplified research systems are mainly classified into three categories: (i) control of microobjects with motional regulations; (ii) control of molecular machines with functions of target discrimination and optical outputs; (iii) control of living cells including molecular machine functions at cell membranes and cell/biomolecular behaviors at liquid interface. Sciences on soft 2D media with motional freedom and their nanoarchitectonics constructions will have increased importance in future technology in addition to popular rigid solid 2D materials.

9.
Acc Chem Res ; 53(3): 644-653, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32073816

RESUMO

Chirality is a fundamental property of a molecule, and the significant progress in chirality detection and quantification of a molecule has inspired major advances in various fields ranging from chemistry, biology, to biotechnology and pharmacology. Chiral molecules have identical molecular formulas, atom-to-atom linkages, and bonding distances, and as such they are difficult to distinguish both sensitively and selectively. Today, most new drugs and those under development are chiral, which requires technological developments in the separation and detection of chiral molecules. Therefore, rapid and facile methods to detect and discriminate chiral compounds are necessary to accelerate advances in many research fields. The challenges in analysis stem from the obvious fact that chiral molecules have the same physical properties. Although significant progress on the detection of enantiomeric composition has been achieved in the past decade, in order to fully realize the capacity of chiral molecular interrogation, highly sensitive and selective, portable, and easy-to-use detection remains challenging because of the limitation of conventional techniques.Soft nanoarchitectonics is a new concept for the fabrication of functional soft material systems through harmonization of various actions including atomic/molecular-level manipulation, chemical reactions, self-assembly and self-organization, and their modulation by external fields/stimuli. Soft nanoarchitectonics has been widely used as a key enabling technology for integrating predefined molecular functionalities including electrochemical, optical, catalytic, or biological properties into biosensing devices, which provides exciting opportunities to design, assemble, and fabricate tailored nanosystems to enable new sensing strategies for chiral molecules.In this Account, we aim to concisely discuss how these molecule-inspired soft nanoarchitectonics work for enantioselective sensing. We will first outline the basic principle and mechanistic insights of the soft nanoarchitectonics approach for enantioselective sensing, and then we will describe the new breakthroughs and trends in the area that have been most recently reported by our groups and others. There will also be a discussion on the merits of soft nanoarchitectonics based sensing in comparison to conventional analytical methods. Finally, with this Account, we hope to spark new chiral molecule sensing strategies by fundamentally understanding chiral recognition and engineering soft nanoarchitectonics with programmable structures and predictable sensing properties.

10.
ACS Nano ; 14(3): 3259-3271, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32049490

RESUMO

The cancer cell membrane contains an arsenal of highly specific homotypic moieties that can be used to recognize its own kind. These cell membranes are often used to coat spherical nanoparticles to enhance nanomedicines' targeting specificities and uptakes. A sphere, however, has only a point contact with a surface at any given time. It is shown here that, by retaining a flatter morphology of the cracked cell membrane through stiffening with in situ synthesized gold nanomaterials, an increased area of interaction could be maintained and hence improve upon the in vitro and in vivo homotypic targeting capabilities between cancer cell types. This enhancement is especially important in vivo as any nanomedicine with targeting moieties probably has a single pass at interacting with the target cell before subsequent system clearance. Possible future clinical applications may involve the usage of a patient's autologous tumor biopsy tissues, which are very limited in supply, and therefore ensuring that we capitalize on the entire collective surface area of the cancer cell membrane available becomes an important consideration in the design and delivery our cell membrane-derived nanomedicines.

11.
Chem Asian J ; 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32017354

RESUMO

Functional materials with rational organization cannot be directly created only by nanotechnology-related top-down approaches. For this purpose, a novel research paradigm next to nanotechnology has to be established to create functional materials on the basis of deep nanotechnology knowledge. This task can be assigned to an emerging concept, nanoarchitectonics. In the nanoarchitectonics approaches, functional materials were architected through combination of atom/molecular manipulation, organic chemical synthesis, self-assembly and related spontaneous processes, field-applied assembly, micro/nano fabrications, and bio-related processes. In this short review article, nanoarchitectonics-related approaches on materials fabrications and functions are exemplified from atom-scale to living creature level. Based on their features, unsolved problems for future developments of the nanoarchitectonics concept are finally discussed.

12.
Chem Asian J ; 15(3): 406-414, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31922659

RESUMO

Molecular functions depend on conformations and motions of the corresponding molecular species. An air-water interface is a suitable asymmetric field for the control of molecular conformations and motions under a small applied force. In this work, double-paddled binuclear PtII complexes containing pyrazole rings linked by alkyl spacers were synthesized and their orientations and emission properties dynamically manipulated at the air-water interface. The complexes emerge from water with concurrent variation of interface orientation of the planes of the PtII complexes from perpendicular to parallel during mechanical compression suggesting a unique 'submarine emission'. Phosphorescence of the complexes is quenched at the air-water interface prior to monolayer formation with intensities subsequently rapidly increasing during monolayer compression. These results indicate that asymmetric reactions and motions might be controlled by applying mechanical force at the air-water interface.

13.
Chem Phys Lipids ; 227: 104875, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31952936

RESUMO

Trastuzumab (Tmab), an antibody for breast cancer, was incorporated in Langmuir monolayers with different lipidic compositions to investigate the drug action in lipidic interfaces of pharmaceutical interest. Tmab caused all lipid films to expand as confirmed with by surface pressure-area isotherm, proving its incorporation. It also affected the compressional and structural properties as observed by in-plane elasticity curves and polarization modulation reflection-absorption infrared spectroscopy (PM-IRRAS), respectively. Although Tmab did not change significantly the compressional modulus for dipalmitoylphosphatidylcholine (DPPC) monolayers, it decreased it for the mixtures of DPPC with cholesterol. In contrast, for dipalmitoylphosphoethanolamine (DPPE), Tmab increased the compressional modulus for both monolayers, pure DPPE or mixed with cholesterol. While Brewster Angle Microscopy showed discrete distinctive morphological patterns for the monolayers investigated, PM-IRRAS showed that Tmab caused an increased number of gauche conformers related to the CH2 stretching mode for the lipid acyl chains, suggesting molecular disorder. Furthermore, the antibody kept the ß-sheet structure of the polypeptide backbone adsorbed at the lipid monolayers although the secondary conformation altered according to the film composition at the air-water interface. As a result, the results suggest that the membrane lipid profile affects the adsorption of Tmab at lipid monolayers, which can be important for the incorporation of this drug in lipidic supramolecular systems like in liposomes for drug delivery and in biomembranes.

14.
Adv Mater ; 32(4): e1905942, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31814174

RESUMO

There is a growing interest in the development of dynamic adaptive biomaterials for regulation of cellular functions. However, existing materials are limited to two-state switching of the presentation and removal of cell-adhesive bioactive motifs that cannot emulate the native extracellular matrix (ECM) in vivo with continuously adjustable characteristics. Here, tunable adaptive materials composed of a protein monolayer assembled at a liquid-liquid interface are demonstrated, which adapt dynamically to cell traction forces. An ultrastructure transition from protein monolayer to hierarchical fiber occurs through interfacial jamming. Elongated fibronectin fibers promote formation of elongated focal adhesion structures, increase focal adhesion kinase activation, and enhance neuronal differentiation of stem cells. Cell traction force results in spatial rearrangement of ECM proteins, which feeds back to alter stem cell fate. The reported biomimetic adaptive liquid interface enables dynamic control of stem cell behavior and has potential translational applications.

15.
J Nanosci Nanotechnol ; 20(5): 2651, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31635599
16.
J Nanosci Nanotechnol ; 20(5): 2971-2978, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31635635

RESUMO

Crystalline fullerene C70 microtubes (FMTs) were produced employing ultrasound-assisted liquid- liquid interfacial precipitation (ULLIP) technique at the interface between fullerene C70 solution in 1,2 dichlorobenzene (DCB) and isopropanol (IPA) at 15 °C. Using the vortex-flow motion of the subphase water (also called Vortex-Langmuir-Blodgett technique), the FMTs were aligned and homogeneous films were prepared at the air-water interface. The aligned FMTs film exhibited enhanced photoluminescence (PL) with PL intensity ~5 times higher than that of the pristine C70. Moreover, the aligned FMT film showed better photovoltaics properties compared with randomly oriented FMTs and pristine C70 film obtained from the spin coating. The compact, directional orientation and proper surface coverage of the FMT film enhanced the charge transport properties in the photovoltaic device.

17.
ACS Nano ; 13(12): 14005-14012, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31794176

RESUMO

We report the production of fullerene microtubes (FMTs), having solid cores bisecting their tubular cavities, from solutions of mixtures of fullerene C60 and C70 and have demonstrated the structural transformation of FMTs to fullerene microhorns (FMHs) upon their exposure to alcohol/mesitylene mixtures at 25 °C. The conically shaped microhorns have hollow interiors and exhibit preferential recognition of silica particles over fullerene C70, polystyrene (PS) latex, PS hydroxylate, or PS carboxylate particles of similar dimensions due to strong electrostatic interactions between negatively charged FMHs and positively charged silica particles.

18.
Beilstein J Nanotechnol ; 10: 2014-2030, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667049

RESUMO

Many recent advances in sensor technology have been possible due to nanotechnological advancements together with contributions from other research fields. Such interdisciplinary collaborations fit well with the emerging concept of nanoarchitectonics, which is a novel conceptual methodology to engineer functional materials and systems from nanoscale units through the fusion of nanotechnology with other research fields, including organic chemistry, supramolecular chemistry, materials science and biology. In this review article, we discuss recent advancements in sensor devices and sensor materials that take advantage of advanced nanoarchitectonics concepts for improved performance. In the first part, recent progress on sensor systems are roughly classified according to the sensor targets, such as chemical substances, physical conditions, and biological phenomena. In the following sections, advancements in various nanoarchitectonic motifs, including nanoporous structures, ultrathin films, and interfacial effects for improved sensor function are discussed to realize the importance of nanoarchitectonic structures. Many of these examples show that advancements in sensor technology are no longer limited by progress in microfabrication and nanofabrication of device structures - opening a new avenue for highly engineered, high performing sensor systems through the application of nanoarchitectonics concepts.

19.
J Am Chem Soc ; 141(50): 19570-19574, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31736293

RESUMO

Peripherally substituted tetradecaazaheptacene (N14Hp) compounds, exhibiting amphiprotism-coupled emission, have been synthesized. X-ray crystallography reveals a planar acene-like chromophore, and electronic absorption and emission occur in the near-infrared biological transparency window (650-900 nm). The compounds exhibit long-wavelength emission with photoluminescence quantum yields ΦPL up to ∼0.61 at 686 nm, with the monodeprotonated state ΦPL ≈ 0.58 at 712 nm. This unprecedented highly nitrogenous chromophore illustrates the stability and utility of the pyrazinacenes for different applications based on their photophysical properties and chemical structures.

20.
Bioconjug Chem ; 30(9): 2287-2299, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31381854

RESUMO

Two-dimensional layered materials (2D LMs) are taking the scientific world by storm. Graphene epitomizes 2D LMs with many interesting properties and corresponding applications. Following the footsteps of graphene, many other types of 2D LMs such as transition metal dichalcogenides, black phosphorus, and graphitic-phase C3N4 nanosheets are emerging to be equally interesting as graphene and its derivatives. Some of these applications such as nanomedicine do have a high probability of human exposure. This review focuses on the biological and toxicity effects of 2D LMs and their associated mechanisms linking their chemistries to their biological end points. This review aims to help researchers to predict and mitigate any toxic effects. With understanding, redesign of newer and safer 2D LMs becomes possible.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA