Multivalent Aptamer-modified DNA Origami as Drug Delivery System for Targeted Cancer Therapy

In spite of great development in nanoparticle-based drug delivery systems(DDSs)for improved therapeutic efficacy,it remains challenging for effective delivery of chemotherapeutic drugs to targeted tumor cells.In this work,we report a triangle DNA origami as targeted DDS for cancer therapy.DNA origami shows excellent biocompatibility and stability in cell culture medium for 24 h.In addition,the DNA origami structures conjugated with multivalent aptamers enable for efficient delivery of anticancer drug doxorubicin(Dox)into targeted cancer cell due to their targeting function,reducing side effects associated with nonspecific distribution.Moreover,we also demonstrated that the multivalent aptamer-modified DNA origami loading Dox exhibits prominent therapeutic efficacy in vitro.Accordingly,this work provides a good paradigm for the development of DNA origami nanostructure-based targeted DDS for cancer therapy.     

Host-Guest Chemistry of Truncated Tetrahedral Imine Cages with Ammonium Ions

Three shape-persistent [4+4] imine cages with truncated tetrahedral geometry with different window sizes were studied as hosts for the encapsulation of tetra-n-alkylammonium salts of various bulkiness. In various solvents the cages behave differently. For instance, in dichloromethane the cage with smallest window size takes up NEt₄⁺ but not NMe₄ ^{+ ,} which is in contrast to the two cages with larger windows hosting both ions. To find out the reason for this, kinetic experiments were carried out to determine the velocity of uptake but also to deduce the activation barriers for these processes. To support the experimental results, calculations for the guest uptakes have been performed by molecular mechanics’ simulations. Finally, the complexation of pharmaceutical interested compounds, such as acetylcholine, muscarine or denatonium have been determined by NMR experiments.     

The Supramolecular Chemistry of Strained Carbon Nanohoops

Since 1996, a growing number of strained macrocycles, comprising only sp²‐ or sp‐hybridized carbon atoms within the ring, have become synthetically accessible, with the [n]cycloparaphenyleneacetylenes ( CPPAs ) and the [n]cycloparaphenylenes ( CPPs ) being the most prominent examples. Now that robust and relatively general synthetic routes toward a diverse range of nanohoop structures have become available, the research focus is beginning to shift towards the exploration of their properties and applications. From a supramolecular chemistry perspective, these macrocycles offer unique opportunities as a result of their near‐perfect circular shape, the unusually high degree of shape‐persistence, and the presence of both convex and concave π‐faces. In this Minireview, we give an overview on the use of strained carbon‐rich nanohoops in host–guest chemistry, the preparation of mechanically interlocked architectures, and crystal engineering.     

Direct Imaging of Atomically Dispersed Molybdenum that Enables Location of Aluminum in the Framework of Zeolite ZSM‐5

Integrated differential phase‐contrast scanning transmission electron microscopy (iDPC‐STEM) is capable of directly probing guest molecules in zeolites, owing to its sufficient and interpretable image contrast for both heavy and light elements under low‐dose conditions. This unique ability is demonstrated by imaging volatile organic compounds adsorbed in zeolite Silicalite‐1; iDPC‐STEM was then used to investigate molybdenum supported on various zeolites including Silicalite‐1, ZSM‐5, and mordenite. Isolated single‐Mo clusters were observed in the micropores of ZSM‐5, demonstrating the crucial role of framework Al in driving Mo atomically dispersed into the micropores. Importantly, the specific one‐to‐one Mo‐Al interaction makes it possible to locate Al atoms, that is, catalytic active sites, in the ZSM‐5 framework from the images, according to the positions of Mo atoms in the micropores.     

Nanoarchitectonics beyond Self‐Assembly: Challenges to Create Bio‐Like Hierarchic Organization

Incorporation of non‐equilibrium actions in the sequence of self‐assembly processes would be an effective means to establish bio‐like high functionality hierarchical 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 hierarchical 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 hierarchical structural organization.     

Host–Guest Complexation of Amphiphilic Molecules at the Air–Water Interface Prevents Oxidation by Hydroxyl Radicals and Singlet Oxygen

The oxidation of antioxidants by oxidizers imposes great challenges to both living organisms and the food industry. Here we show that the host–guest complexation of the carefully designed, positively charged, amphiphilic guanidinocalix[5]arene pentadodecyl ether (GC5A‐12C) and negatively charged oleic acid (OA), a well‐known cell membrane antioxidant, prevents the oxidation of the complex monolayers at the air–water interface from two potent oxidizers hydroxyl radicals (OH) and singlet delta oxygen (SDO). OH is generated from the gas phase and attacks from the top of the monolayer, while SDO is generated inside the monolayer and attacks amphiphiles from a lateral direction. Field‐induced droplet ionization mass spectrometry results have demonstrated that the host–guest complexation achieves steric shielding and prevents both types of oxidation as a result of the tight and “sleeved in” physical arrangement, rather than the chemical reactivity, of the complexes.     

Tiara[5]arenes: Synthesis,Solid‐State Conformational Studies,Host–Guest Properties,and Application as Nonporous Adaptive Crystals

Tiara[5]arenes (T[5]s), a new class of five‐fold symmetric oligophenolic macrocycles that are not accessible from the addition of formaldehyde to phenol, were synthesized for the first time. These pillar[5]arene‐derived structures display both unique conformational freedom, differing from that of pillararenes, with a rich blend of solid‐state conformations and excellent host–guest interactions in solution. Finally we show how this novel macrocyclic scaffold can be functionalized in a variety of ways and used as functional crystalline materials to distinguish uniquely between benzene and cyclohexane.     

Phytochemical and Biological Activity Studies on Nasturtium officinale (Watercress) Microshoot Cultures Grown in RITA® Temporary Immersion Systems

The main compounds in both extracts were gluconasturtiin, 4-methoxyglucobrassicin and rutoside, the amounts of which were, respectively, determined as 182.93, 58.86 and 23.24 mg/100 g dry weight (DW) in biomass extracts and 640.94, 23.47 and 7.20 mg/100 g DW in plant herb extracts. The antioxidant potential of all the studied extracts evaluated using CUPRAC (CUPric Reducing Antioxidant Activity), FRAP (Ferric Reducing Ability of Plasma), and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays was comparable. The anti-inflammatory activity of the extracts was tested based on the inhibition of 15-lipoxygenase, cyclooxygenase-1, cyclooxygenase-2 (COX-2), and phospholipase A₂. The results demonstrate significantly higher inhibition of COX-2 for in vitro cultured biomass compared with the herb extracts (75.4 and 41.1%, respectively). Moreover, all the studied extracts showed almost similar antibacterial and antifungal potential. Based on these findings, and due to the fact that the growth of in vitro microshoots is independent of environmental conditions and unaffected by environmental pollution, we propose that biomass that can be rapidly grown in RITA^® bioreactors can serve as an alternative source of bioactive compounds with valuable biological properties.     

Controlling Gas Selectivity in Molecular Porous Liquids by Tuning the Cage Window Size

Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe‐selective to CH₄‐selective, which is understood using ¹²⁹Xe, ¹H, and pulsed‐field gradient NMR spectroscopy.     

Benzidine/Quinoidal‐Benzidine‐Linked,Superbenzene‐Based π‐Conjugated Chiral Macrocycles and Cyclophanes

Synthesis of fully conjugated cyclophanes containing large‐size polycyclic aromatics is challenging. Now, three benzidine‐linked, hexa‐peri‐hexabenzocoronene (superbenzene)‐based ortho‐, para‐, and meta‐cyclophanes are synthesized through intermolecular Yamamoto coupling reaction of structurally pre‐organized precursors. Subsequent oxidative dehydrogenation gave the corresponding quinoidal benzidine‐linked cyclophanes. Their geometries were confirmed by X‐ray crystallographic analysis and their electronic properties were investigated by electronic absorption, cyclic voltammetry, and DFT calculations. The quinoidal benzidine‐linked cyclophanes show thermally populated paramagnetic activity with a relatively large singlet‐triplet energy gap. Two enantiomers for the ortho‐cyclophanes ( 1‐NH and 1‐N ) were isolated and their chiral figure‐of‐eight macrocyclic structures were identified. The cage‐like cyclophanes 2‐NH and 3‐NH with concave surface can selectively encapsulate fullerene C₇₀.