Xiujuan Shi

Due to the fast dynamics and re‐equilibration of supramolecular self‐assembly, bottom‐up molecular strategies to fabricate well‐defined and controllable multiblock structures are rare. Herein, we propose a new concept for fabrication of fluorescent multiblock microcolumns containing 1 to 7 blocks via hierarchical supramolecular self‐assembly based on cucurbit[8]uril (CB[8]), NaBr and an AIEgen guest. Through the complexation between CB[8] and different numbers of AIEgen guests (2, 1, 0), the competitive displacement caused by the binding of the sodium cation to the CB[8] portal, and the reversible assembly of positively charged guests in salt solutions, one‐pot hierarchical supramolecular self‐assembly is realized. The molecular structure of each block is analyzed by single‐crystal X‐ray diffraction. The AIEgen enables the self‐assembly of multiblocks to be visualized, understood, and regulated.

Due to the fast dynamics and re‐equilibration of supramolecular self‐assembly, bottom‐up molecular strategies to fabricate well‐defined and controllable multiblock structures are rare. Herein, we propose a new concept for fabrication of fluorescent multiblock microcolumns containing 1 to 7 blocks via hierarchical supramolecular self‐assembly based on cucurbit[8]uril (CB[8]), NaBr and an AIEgen guest. Through the complexation between CB[8] and different numbers of AIEgen guests (2, 1, 0), the competitive displacement caused by the binding of the sodium cation to the CB[8] portal, and the reversible assembly of positively charged guests in salt solutions, one‐pot hierarchical supramolecular self‐assembly is realized. The molecular structure of each block is analyzed by single‐crystal X‐ray diffraction. The AIEgen enables the self‐assembly of multiblocks to be visualized, understood, and regulated.

Nature possesses a powerful ability to assemble multiple complex structures to fabricate hierarchical biological structures in a living-assembled way. However, it is still a huge challenge for artificial systems to fabricate and characterize hierarchical living assemblies with well-defined and controllable but complex structures. In this work, we proposed a new concept for the fabrication of multiblock fluorescent microcolumns, which relies on the cooperation between the controllable host–guest complexation based on cucurbit[8]uril (CB[8]) and the living assembly of nanotubular supramolecular polymers composed of CB[8] and NaBr in aqueous solution. By using the complexation of CB[8] with different guest numbers of luminogens with aggregation-induced emission (AIEgens) characteristics, and the difference in affinity between CB[8] and different types of AIEgens, the concentration-controlled and self-sorting-controlled sequential living assembly are realized, respectively. Correspondingly, multiblock fluorescent microcolumns with different fluorescence emission are fabricated, and the molecular structure of each fluorescent block is analyzed by single crystal X-ray diffraction measurement. In addition, the living assembly of multiblock fluorescent microcolumns is visualized, understood, and regulated with the aid of AIEgens. The method developed here is expected to be extended to more guest molecules of CB[8] and also provides a referential crystallization method for CB[8]-based complexes.

Bacterial infections pose a serious threat to human health. Photodynamic therapy is an effective medical treatment to solve the problems raised by antibiotic resistant bacteria. But it is not easy to have photosensitizers (PSs) that can simultaneously produce efficient fluorescence and reactive oxygen species. Traditional PSs show compromised performances due to the aggregation‐caused quenching effect in aqueous media, however, luminogens with aggregation‐induced emission (AIE) can inherently achieve high fluorescence and efficient ROS generation. In addition, electrostatic interaction is generally accepted to be responsible for initial targeting of bacteria. But for AIE PSs, the roles of molecular charges on antibacterial efficiency are rarely considered. Herein, two red‐emissive AIE PSs with the same luminogenic core but carrying different number of positive charges are designed, and their antibacterial performance and the killing mechanism toward Gram‐positive (G(+)) and Gram‐negative (G(−)) bacteria are investigated. The AIE PSs with highly efficient singlet oxygen generation can clearly image and selectively kill bacteria over mammalian cells. With the increase in the positive charges of AIE PSs, the improvement in antibacterial efficiency is great against G(−) bacteria, but it is negligible against G(+) bacteria. This research will provide new insight into the rational design of new antibacterial materials.

Fast surface immobilization of native bioconjugates through a spontaneous amino-yne click reaction is realized.

Tissue regeneration is a crucial self-renewal capability involving many complex biological processes. Although transgenic techniques and fluorescence immunohistochemical staining have promoted our understanding of tissue regeneration, simultaneous quantification and visualization of tissue regeneration processes is not easy to achieve. Herein, we developed a simple and quantitative method for the real-time and non-invasive observation of the process of tissue regeneration. The synthesized ratiometric aggregation-induced-emission (AIE) probe exhibits high selectivity and reversibility for pH responses, good ability to map lysosomal pH both in vitro and in vivo, good biocompatibility and excellent photostability. The caudal fin regeneration of a fish model (medaka larvae) was monitored by tracking the lysosomal pH change. It was found that the mean lysosomal pH is reduced during 24–48 hpa to promote the autophagic activity for cell debris degradation. Our research can quantify the changes in mean lysosomal pH and also exhibit its distribution during the caudal fin regeneration. We believe that the AIE-active lysosomal pH probe can also be potentially used for long-term tracking of various lysosome-involved biological processes, such as tracking the stress responses of tissue, tracking the inflammatory responses, and so on.

A lipid-droplet-specific AIEgen was used to evaluate the inhibitory efficacy of HIF-1-targeting drugs by assessing lipid-droplet levels.

Acrylonitriles with aggregation-induced emission (AIE) characteristics have found to show promising applications in two-photon biomedical imaging. Generally, elaborate synthetic efforts are required to achieve different acrylonitriles with dis-tinct functionalities. In this work, we first reported the synthesis of two different group-functionalized AIE-active acrylo-nitriles (TPAT-AN-XF and 2TPAT-AN) obtained simply by mixing the same reactants at different temperature using a facile and transition metal-free synthetic method. These two AIE luminogens (AIEgens) exhibit unique properties such as bright red emission in the solid state, large Stokes shift and large two-photon absorption cross section. Water-soluble nanoparticles (NPs) of 2TPAT-CN were prepared by nanoprecipitation method. In vitro imaging data show that 2TPAT-CN NPs can selectively stain lysosome in live cells. Besides one-photon imaging, remarkable two-photon imaging of live tumor tissues can be achieved with high resolution and deep tissue penetration. 2TPAT-CN NPs show high biocompati-bility and are successfully utilized in in vivo long-term imaging of mouse tumor with high signal-to-noise ratio. Thus, the present work is anticipated to shed light on the preparation of a library of AIE-active functionalized acrylonitriles with intriguing properties for biomedical applications