Platinum(II)-Metallaclip-Based Theranostics for Cell Imaging and Synergetic Chemotherapy-Photodynamic Therapy.

Supramolecular coordination complexes formed by coordination-induced assembly not only avoid the loss of activity of precursors but also provide an efficient way for controlled release, which can be further used in various fields of biology such as drug delivery, cell imaging, and tumor treatment. In this work, a PtII metallaclip (4) was prepared from 4-[4-(1,2,2-triphenylvinyl)phenyl]pyridine (1), 5,10,15-triphenyl-20-(pyridin-4-yl)porphyrin (2), 90o Pt, and glycol-chain-modified isophthalic acid (3) in an acetone/water mixture through the "coordination-driven self-assembly" method. 31P and 1H NMR spectroscopy and high-resolution mass spectrometry were used to characterize the obtained metallaclip 4. 4 can self-assemble into fluorescent nanostructures in aqueous solution because of the tetraphenylethylene unit and its amphiphilic nature. Importantly, the fluorescent nanoparticles not only can be employed for cell imaging but also can generate singlet oxygen (1O2) under 660 nm laser irradiation and the release of Pt drug in the tumor issue for cancer therapy. The work may provide a new way for scientists to construct functional biomaterials with multiple applications via molecular self-assembly.

Emissive Nanoparticles from Co-assembly of Metallatetragon and Amphiphilic Tetraphenylethylene for Cancer Theranostics.

Platinum(II)-based metallacycles/cages have obtained tremendous attention due to their fascinating topology and wide range of applications, such as fluorescent materials, cell imaging, and tumor treatment. In this work, a metallatetragon (1) was constructed from 4-(4-(1,2,2-triphenylvinyl)phenyl)pyridine (2) and 90° cis-Pt(II) (Pt) in acetone through the strategy called "coordination driven self-assembly". Interestingly, through co-assembly of 1 and poly(ethylene glycol)-modified tetraphenylethylene (TPE-PEG22), fluorescent nanotheranostics, which could generate singlet oxygen (1O2) under the NIR irradiation and release Pt drugs under a low-pH microenvironment, were prepared successfully. The obtained theranostics could realize living cell imaging and synergistic chemo-photodynamic therapy in vitro and in vivo.

Pillar[5]arene-Derived Terpyridinepalladium(II) Complex: Synthesis, Characterization, and Application in Green Catalysis.

Metal nanoparticle catalysts have attracted great interest because they possess high surface-to-volume ratios and exhibit a very large number of catalytically active sites per unit area. However, high surface-to-volume ratios will induce nanoparticle aggregates during the catalytic reactions, making them lose their catalytic activity. In this work, a monoterpyridine-unit-functionalized pillar[5]arene (TP5) was synthesized successfully, which can be used as anchoring sites for the controllable preparation of well-dispersed palladium nanoparticles [TP5/Pd(0) NPs]. The as-prepared TP5/Pd(0) NPs were fully characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, and powder X-ray diffraction. Importantly, the ultrafine TP5/Pd(0) NPs are found to be excellent and reusable catalysts for the reduction of nitrophenols in aqueous solution.

Activation of Topological Defects Induces a Brittle-to-Ductile Transition in Epithelial Monolayers.

Epithelial monolayers are subjected to various mechanical forces, such as stretching, shearing, and compression. Thus, its mechanical response to external loadings is essential for its biological functions. However, the mechanism of the fracture failure of the epithelial monolayer remains poorly understood. Here, by introducing a new type of topological transition, i.e., detach transition or T4 transition, we develop a modified cellular vertex model to investigate the rupture of the cell monolayer. Interestingly, we find a brittle-to-ductile transition in epithelial monolayers, which is controlled by the mechanical properties of single cells and cell-cell contacts. We reveal that the external loadings can activate cell rearrangement in ductile cell monolayers. The plastic deformation results from the nucleation and propagation of "pentagon-heptagon defects" in analogy with the topological defects commonly seen in 2D materials. By using a simplified four-cell model, we further demonstrate that the brittle-to-ductile transition is induced by the competition between cell rearrangement and cell detachment. Our work provides a new theoretical framework to study the rupture of living tissues and may have important implications for many other biological processes, such as wound healing and tissue morphogenesis.

Polydopamine modified by pillar[5]arene in situ for targeted chemo-photothermal cancer therapy.

A pillar[5]arene-modified polydopamine (PDA-P[5]OH) displaying pH/NIR dual-responsive properties was constructed successfully in situ for targeted chemo-photothermal cancer therapy.

Fluorescence-enhanced supra-amphiphiles based on pillar[5]arene: construction, controllable self-assembly and application in cell imaging.

Fluorescence-enhanced supra-amphiphiles based on (WP5)2⊃ENDTn were constructed successfully. When n = 9, they can self-assemble into uniform micelles with an average diameter of about 90 nm and be further applied in cell imaging.

Pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper: synthesis, characterization and application in the fluorescence turn-on sensing of Zn2+ in water.

Two pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper were synthesized and characterized fully, and could be further applied in the fluorescence turn-on sensing of Zn2+ in water.