Tumor Microenvironment-Activated NIR-II Nanotheranostic System for Precise Diagnosis and Treatment of Peritoneal Metastasis

Activatable theranostic systems show potential for improved tumor diagnosis and therapy owing to high detection specificities, effective ablation, and minimal side-effects. Herein, a tumor microenvironment (TME)-activated NIR-II nanotheranostic system (FEAD1) for precise diagnosis and treatment of peritoneal metastases is presented. FEAD1 was fabricated by self-assembling the peptide Fmoc-His, mercaptopropionic-functionalized Ag₂S quantum dots (MPA-Ag₂S QDs), the chemodrug doxorubicin (DOX), and NIR absorber A1094 into nanoparticles. We show that in healthy tissue, FEAD1 exists in an NIR-II fluorescence “off” state, because of Ag₂S QDs-A1094 interactions, while DOX remains in stealth mode. Upon delivery of FEAD1 to the tumor, the acidic TME triggers its disassembly through breakage of the Fmoc-His metal coordination and DOX hydrophobic interactions. Release of A1094 switches on Ag₂S fluorescence, illuminating the tumor, accompanied by burst release of DOX within the tumor tissue, thereby achieving precise tumor theranostics. This TME-activated theranostic strategy holds great promise for future clinical applications.     

Cations Controlling the Chiral Assembly of Luminescent Atomically Precise Copper(I) Clusters

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH₃OH)₂(18‐crown‐6)]⁺[Cu₅(S^tBu)₆]^? ( 1?CH₃OH ) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu₅(S^tBu)₆]^? cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH₃OH of the cationic units turned the chiral 1?CH₃OH crystal into a mesomeric crystal [K(18‐crown‐6)]⁺[Cu₅(S^tBu)₆]^? ( 1 ), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu₅(S^tBu)₆]^? units. The switchable chiral/achiral rearrangement of [Cu₅(S^tBu)₆]^? clusters along with the capture/release of CH₃OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d /l ‐valinol(18‐crown‐6)]⁺[Cu₅(S^tBu)₆]^? ( d /l ‐Cu_5V ), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1?CH₃OH and mesomeric 1 .     

Molecular Design Strategy for Ordered Mesoporous Stoichiometric Metal Oxide

A molecular design strategy is used to construct ordered mesoporous Ti³⁺‐doped Li₄Ti₅O₁₂ nanocrystal frameworks (OM‐Ti³⁺‐Li₄Ti₅O₁₂) by the stoichiometric cationic coordination assembly process. Ti⁴⁺/Li⁺‐citrate chelate is designed as a new molecular precursor, in which the citrate can not only stoichiometrically coordinate Ti⁴⁺ with Li⁺ homogeneously at the atomic scale, but also interact strongly with the PEO segments in the Pluronic F127. These features make the co‐assembly and crystallization process more controllable, thus benefiting for the formation of the ordered mesostructures. The resultant OM‐Ti³⁺‐Li₄Ti₅O₁₂ shows excellent rate (143 mAh g^?1 at 30 C) and cycling performances (<0.005 % fading per cycle). This work could open a facile avenue to constructing stoichiometric ordered mesoporous oxides or minerals with highly crystalline frameworks.     

Cuboid Vesicles Formed by Frame‐Guided Assembly on DNA Origami Scaffolds

We describe the use of a frame‐guided assembly (FGA) strategy to construct cuboid and dumbbell‐shaped hetero‐vesicles on DNA origami nanostructure scaffolds. These are achieved by varying the design of the DNA origami scaffolds that direct the distribution of the leading hydrophobic groups (LHG). By careful selection of LHGs, different types of amphiphiles (both polymer and small‐molecule surfactants) were guided to form hetero‐vesicles, demonstrating the versatility of the FGA strategy and its potential to construct asymmetric and dynamic hetero‐vesicle assemblies with complex DNA nano‐scaffolds.