Latest ArticlesParticles administrated intravenously will pass through the pulmonary capillary network before being distributed to the body. Therefore, fabrication of vectors sensitive to blood shear and active with blood components should be a practical approach to develop lung-targeting gene carriers self-regulated by circulatory system. In this work, we designed a series of cationic peptides with the same charge density but varying hydrophobicity and capacity to form hydrogen bonds, and investigated their ability to form complexes with siRNA, the behaviours of peptide/siRNA complexes in the presence of serum under shear, and the lung-targeting efficacy of the complexes regulated by blood. The hydrophobic interaction controls the complexation between peptide and siRNA, while the hydrogen bonds are responsible for the binding of peptides to the serum components in blood. In vivo tests show that all the peptide/siRNA complexes can accumulate in lung. However, only the complexes that exhibit weak interaction with serum components and can be broken down by shear avoid the inflammation and death caused by pulmonary embolism. Moreover, the peptide with strong hydrophobicity can retain siRNA in lung without early release of the cargo. Our study provides a step toward the development of adaptive gene carriers under the regulation of circulatory system.
An unprecedented tunable hydrophobic effect in self-assembly of a small cationic organic fluorophore (NI-TPy+)-based with aggregation-induced emission (AIE) property was realized in aqueous solution. The amplification of hydrophobicity was found to be significantly dependent upon the increasing aggregates of NI-TPy+, which enabled the study of the hydrophobic binding of chaotropic anions with the Hofmeister series.
The recent electrocatalytic three-component annulation-halosulfonylation of 1, 6-enynes toward 1-indanones is highlighted.
Organosilicon compounds play an important role in the fields of materials science, pharmacy, and organic synthesis. The development of effective approaches for the preparation of these compounds have also become a research focus in organic synthesis. In recent years, free radical synthesis of organosilicons has been vigorously developed, which generally has the advantages of milder synthesis conditions, higher yields and selectivity, and free of precious metal catalysts compared with traditional strategies. This article reviews research progresses in the synthesis of organosilicon compounds by free radical pathways since 2016. In most cases, the radical silylation is achieved based on the reaction of silyl radicals, which are triggered by four routes including peroxide, transition-metal-induced peroxide decomposition, alkali, photocatalysis. The alkyl radicals can also initiate the radical silylation for the generation of C(sp3)Si bonds.
Pillar[n]arene-based amphiphiles, mainly including amphiphilic pillar[n]arenes and supra-amphiphilic pillar[n]arenes, have obtained considerable interests in recent years due to their fascinating chemical structures, various self-assembly behaviors, and widely applications. Thanks to the pillar-like frameworks and the rich host-guest recognitions of the cavities, these amphiphiles can be easily controlled to form dimensional and morphologic assemblies for multiple applications. Compared with traditional linear covalent amphiphiles, the introduction of host-guest recognitions facilitated the preparation and controllability of these supramolecular amphiphilic systems. Moreover, the host-guest recognitions endow the assemblies from pillar[n]arene-based amphiphiles with stimuli-responsive functions. In this mini-review, we summarized the chemical structures, self-assembly features, and the applications of pillar[n]arene-based amphiphiles. However, several research topics of pillar[n]arene-based amphiphiles can be further developed in the future, such as larger cavity amphiphilic pillar[n]arenes, co-assembly with 2D materials and utilization of the host-guest interactions.
Helix structures at atomic/molecular level have not been found in self-assembled peptide sequence with less than three residues. As β-sheet supramolecular secondary structures have been discovered in solid-state amino acids, we here report the conjugation of simple N-terminal aryl protecting group could give rise to helical supramolecular secondary structures in solid-state, which determines the optical activities of the adjacent aryl groups. The carboxylic acid-involved asymmetric H-bonds in N-terminal aryl amino acids induce the emergence of super-helical structures of amino acid residues and aryl groups. In most cases, supramolecular tilted chirality of aryl groups is opposite to that of amino acid sequences, of which handedness and helical pitch are determined by the H-bond modalities. Determining correlation between supramolecular tilted chirality of aryl segments and their chiroptical activities is firstly unveiled, which was verified by the computational results based on density functional theory. Most aryl amino acids self-assembled by nanoprecipitation method via crystallization induced self-assembly into rigid one-dimensional microstructures with ultra-high Young's modulus. This study reveals the generic existence of chiral supramolecular structures in aggregated amino acid derivatives and gives an in-depth investigation into the structural-property relationships, which could guide the rational design and screening of chiroptical supramolecular materials.
Surface-enhanced Raman scattering (SERS) is a powerful spectroscopic tool in quantitative analysis of molecules, where the substrate plays a critical role in determining the detection performance. Herein, a silver nanocubes/polyelectrolyte/gold film sandwich structure was prepared as a reproducible, high-performance SERS substrate by the water/oil interfacial assembly method. In addition to the hot spots on the nanocubes surface, the edge-to-edge interspace of the Ag nanocubes led to marked enhancement of the SERS intensity, with a limit of detection of 10-11 mol/L and limit of quantitation of 10-10 mol/L for crystal violet. When rhodamine 6G and crystal violet were co-adsorbed on the Ag nanocube surfaces, the characteristic SERS peaks of the two molecules remained well resolved and separated, and the peak intensities varied with the respective concentration, which could be exploited for concurrent detection of dual molecules. Results from this work indicate that organized ensembles of Ag nanocubes can serve as effective SERS substrate can for sensitive analysis for complex molecular systems.
Studies on the synthesis of antifungal and anticancer natural product, pseudolaric acid B, have led to the enantioselective synthesis of di-epi-trans-fused [5–7]-bicyclic core skeleton. The synthesis was achieved in 10 linear steps, which features the Sharpless asymmetric epoxidation, cyanide-opening reaction of epoxide, and intramolecular [5+2] cycloaddition reaction as the key transformations. The stereochemistry was determined by the X-ray crystallographic analysis.
Chemodivergent reactions of 2, 2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a CC bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2, 2-dimethoxyacetaldehyde reacted with aniline to form a new CN bond, in the presence of O2, via a CC bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new CO bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
Tumor penetration is important for effectively tumor targeting drug delivery. Recently, many researches are published to overcome the barriers that restrict tumor penetration and improve drug delivery efficiency. In the mini review, we first analyzed the barriers influence the tumor penetration, including tumor microenvironment barriers, nanoparticle properties, and interaction barriers between tumor and nanoparticles. To overcome the barrier, several strategies are developed, including modulating tumor microenvironment, changing particle size, transcytosis enabled tumor penetration, cell penetrating peptide modification and overcoming binding site barrier, which could effectively improve tumor penetration, and finally enhance tumor treatment outcome.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
