Aggregate (Hoboken, N.J.)最新文献

The remarkable advantages and promising application potentials of aggregation-induced emission (AIE) materials have seen significant advancements in recent years. Notably, AIE materials incorporating dynamic covalent bonds (DCBs) have garnered escalating attention and demonstrated remarkable progress due to their reversible and self-adaptive properties, thus exhibiting immense potential across various domains including biomedicine, nanomaterials, sensing, and optical displays. This review aims to provide a comprehensive overview of the recent strides in DCBs-based AIE materials, organized by the types of dynamic covalent bonds utilized, such as Diels–Alder reaction, imine bond, transesterification, boronic ester bond, disulfide bond, [2+2] Cycloaddition Reaction and X-yne adducts exchange. Through exemplifying representative cases, we elucidate the design principles of chemical structures and the diverse dynamic behaviors exhibited by DCBs-based AIE materials. Leveraging the principles of dynamic covalent chemistry, these emissive materials can be facilely prepared, and they possess inherent self-adaptability and responsiveness to stimuli. Finally, we present succinct conclusions and discuss future trends in this burgeoning field, offering fresh insights into the design of novel luminescent materials based on dynamic covalent bonds for broader applications.

The elucidation of hierarchical assembly structure of metal nanoclusters is of fundamental importance in the context of bottom-up fabrication and functionalization. While recent studies have provided valuable insights into the multiscale assembly patterns of gold or silver-based nanoclusters, the success in achieving similar results for copper analogues has been notably limited. Herein, by virtue of a slow-ligand-release strategy, a copper nanocluster denoted as [Cu₆₆Cl₈(PPh₃)₈(SC₂H₅)₃₂H₂₄](SbF₆)₂ was synthesized, resulting in the formation of fresh hierarchical assembly structures in one-pot. The arrangement of the metal atoms within the cluster reveals an orderly of 16 Cu₄ squares, representing a rare copper nanocluster comprising square motifs. Additionally, the ligands (phosphine, thiolate, and halide) coordinate to the surface of the cluster in a regiospecific manner, displaying square patterns as well. The self-assembly facilitated by the C-H···F interaction between the cluster moieties and SbF₆⁻ anions further induces the formation of three-dimensional cubes and eventually large nanocrystals. Density functional theoretical (DFT) calculations reveal that hydride atoms with low chemical shifts typically exhibit short Cu-H distances. The cluster demonstrates moderate stability and high catalytic activity in the chemoselective hydrogenation of cyclohexanone under mild conditions.

Current radiotherapy (RT) lacks the ability to accurately discriminate between tumor and healthy tissues, resulting in significant radiation-induced damage for patients. Therefore, there is an urgent need for precise RT techniques that can optimize tumor control while minimizing adverse effects on surrounding healthy tissues. In this study, we developed a nanodrug (AuNR@Peptide) composed of furin-responsive RVRR peptide-conjugated AuNRs, which integrates an activatable probe and a radiosensitizer into a single system for accurate tumor localization, enabling image-guided precision RT. Upon reaching the tumor site after intravenous administration, proteolytic cleavage of RVRR substrates on AuNR@Peptide by biomarker triggers aggregation of gold nanorods (AuNRs) into larger aggregates, leading to activation of near-infrared (NIR)-II photoacoustic (PA) signals to precisely localize the tumor and enhance tumor retention by preventing migration and backflow of AuNRs. This significantly amplifies radiosensitivity efficiency. The peak time point at which the NIR-II PA signal was observed at the tumor site after injection serves as a reference for initiating RT, demonstrating substantial improvement in tumor RT through investigations related to radiosensitization mechanisms. The integration of imaging and therapy in this study offers a promising image-guided therapeutic modality for tumors.

Fluorescence signal “turn-on” lateral flow immunoassay (FONLFA) through nanomaterial labeled quenching fluorescent nanomaterial has shown significant potential for the detection of small molecules. However, the fluorescent nanomaterial immobilization on nitrocellulose (NC) membrane commonly requires tedious chemical modification and only a few combinations of fluorescence donor and quencher have been applied in FONLFA. In this work, bright fluorescent metal nanoclusters (Prot-AuNCs) were prepared and self-assembled into Prot-AuNCs/antigen aggregates with three typical small molecule antigens, respectively. The aggregates can be readily immobilized on the surface of the NC membrane, indicating that this strip fabrication strategy has good versatility. Moreover, we evaluated the performances of this FONLFA platform by using carbendazim as a model target and investigated four typical nanomaterials as colorimetric nanoprobes and fluorescence quenchers. We found that all the nanoprobes demonstrated significantly improved naked eye detection sensitivity (vLOD) and limits of detection (LODs) in quantitative analysis. Among them, combing the Fe-polydopamine nanoparticles as quencher with the above aggregates, the FONLFA in signal “turn-on” mode achieved 200-fold improved vLOD (0.05 ng mL⁻¹) compared with conventional colorimetric AuNPs-based lateral flow immunoassay (AuNPs-LFA) (10 ng mL⁻¹). In addition, the LOD in quantitative analysis also was improved by 22-fold and the whole test process was completed within 10 min. With the advantages of efficient fabrication, extraordinary sensitization, and good biocompatibility, our FONLFA platform is expected to have great potential in the rapid detection of various small molecules.

Aggregation and aging of nanoparticle–protein complexes at interfaces are resolved via an evanescent-light scattering microscopy. Time- and space-resolved measurements by correlation functions show that aging of such soft materials is out-of-equilibrium, stretched and compressed exponential decays can coexist in one aging process. Corona formation, inner stress and inter-connection are key for the aggregation and aging dynamics (e538).

In the newly developed MSS-RCA technique, a circular template with minimal secondary structure was designed to achieve the higher amplification efficiency compared with conventional RCA technique. The linear structure of the MSS-RCA product provides the highest signal binding efficiency. Integration with a blood glucose meter, MSS-RCA technique was suitable for point-of-care detection of HPV mRNA for cervical cancer screening (e569).

This paper focuses on the aggregation effects on the reactive oxygen species generation, highlighting the significant variations among isolated and various nano-aggregated states. It provides a consolidated overview on the fundamental principles, discusses current research methodologies, and reviews present research status concerning the aggregation effects on ROS generation, aiming to drive continuous progress in aggregate-level phototheranostic platforms (e540).

This study identifies metabolic reprogramming and immunosuppression as key factors in transarterial chemoembolization (TACE) refractoriness. Rhein is optimized as a glycolytic inhibitor and immunoactivator to enhance tumor response to TACE. An oil-in-water lipiodol emulsion stabilized with Rhein nanogel holds enhanced mechanical stability, ensuring effective embolization, prolonged drug release, and potent anti-tumor immunity, presenting a new approach for TACE (e552).

Numerous reports have demonstrated the construction of supramolecular nanodrugs (SNDs) via the π–π stacking of drug molecules for antitumor applications because most drugs possess aromatic rings or other planar conjugate units. However, the destruction of π–π stacking and the subsequent disassembly of SNDs under tumor microenvironment (TME), which is the precondition for drug release, have not been clearly described. In this work, based on a disassembly model of π–π stacked naphthoquinone SNDs, the influence of co-assembled drugs on disassembly is delineated. Both the experimental observation and computational simulation indicate that the disassembly of SNDs under simulated TME highly depends on the disassembly activation energy (ΔE_dis) of neighboring π–π stacked molecules. Owing to the high ΔE_dis, the disassembly of self-assembled naphthoquinone SNDs is greatly restricted. Meaningfully, the ΔE_dis is the sum of a series of activation energy according to the specific stimuli of TME. Thus, a concept of stimuli-responsive drug-mates is proposed for boosting the disassembly of π–π stacked SNDs, namely the foremost co-assembly of π-conjugated drugs with additional drug molecules that possess relatively weak π–π interaction but high TME responsiveness. Further computational simulation reveals that the introduction of stimuli-responsive drug-mates significantly lowers the ΔE_dis, thus accelerating the disassembly of SNDs and the release of drug payloads. Holding the advantages of π-conjugated drug library, the concept of stimuli-responsive drug-mates gives an extensive design of π–π stacked SNDs toward heterogeneous nidus microenvironment responsiveness, which highlights the superiority of widely used drug co-assembly strategy in constructing multifunctional SNDs.

The multifaceted regulation of the chiroptical properties and self-assembly behaviors of chiral fluorescent polymers is of great significance yet remains challenging to achieve. Herein, a series of novel salen-based chiral fluorescent polymers with aggregation-induced emission and varied substitution manners were facilely and efficiently synthesized. Multiple factors were systematically investigated on the chiroptical properties and self-assembly performance of these polymers, which include molecular structures, solvent environments, metal coordination, and liquid crystal (LC) assemblies. Sutle change in the solvent composition can lead to diverse assembly morphologies of all these chiral polymers, from single-handed helical fibers, helical toroids or loops, to spherical structures, consequently leading to an aggregation-reduced circular dichroism (CD) phenomenon. The polymers bearing salen units show highly selective and reversible coordination with Zn²⁺ and can also induce multiple responses in the absorption, luminescence, CD, and circularly polarized luminescence (CPL) of these chiral fluorescent polymers via a coordination- and dissociation-initiated self-assembly tuning. Furthermore, a small amount of the chiral fluorescent polymer in can induce achiral nematic 4-cyano-4′-n-pentylbiphenyl (5CB) to form ordered chiral nematic LC phase with significant improvement in their CD and CPL signal. The absolute absorption and luminescent dissymmetry factors of the resulting supramolecular assemblies can reach the order of 10⁻¹.