Two series with three Pt(II) complexes each (PtLPh-n, PtLFpy-n) bearing asymmetric tetradentate ligands as dianionic luminophores with variable alkyl chain lengths were synthesized. Hence, each ligand series is distinguished by one of its cyclometallating rings (phenyl vs. 2,6-difluoropyrid-3-yl). Steady-state and time-resolved photoluminescence spectroscopic studies in diluted solutions at room temperature and in glassy matrices at 77 K show that the emissive state is mainly centered on the invariantly electron-rich cyclometalated side while the second ring regulates the admixture of ligand-centered and metal-to-ligand charge-transfer character. Hence, the radiative rates can be controlled, as indicated by quantum-mechanical calculations, which also explain the temperature-dependent trend in the phosphorescence rate constants. Studies in condensed phases (single-crystal X-ray diffractometry, polarized optical microscopy, differential scanning calorimetry, steady-state and time-resolved photoluminescence micro(spectro)scopy) showed the development of a smectic A mesophase for the fluorinated species bearing the two longest alkyl chains. Nuclear magnetic resonance-based studies on the thermodynamics of aggregation in solution confirm the marked enthalpic stabilization of aggregates mediated by the polar 2,6-difluoropyrid-3-yl moiety (and to a lesser extent by dispersive forces between the alkyl chains). On the other hand, the negative entropy of aggregation is dominated by the restriction of degrees of freedom involving the peripheral alkyl moieties upon stacking, which becomes increasingly relevant for longer chains. All these factors control Pt...Pt coupling, a crucial interaction for the design of photofunctional mesogens based on Pt(II) complexes.
Nanodrugs capable of aggregating in the tumor microenvironment (TME) have demonstrated great efficiency in improving the therapeutic outcome. Among various approaches, the strategy utilizing electrostatic interaction as a driving force to achieve intratumor aggregation of nanodrugs has attracted great attention. However, the great difference between the two nanodrugs with varied physicochemical properties makes their synchronous transport in blood circulation and equal-opportunity tumor uptake impossible, which significantly detracts from the beneficial effects of nanodrug aggregation inside tumors.We herein propose a new strategy to construct a pair of extremely similar nanodrugs, referred to as “twins-like nanodrugs (TLNs)”, which have identical physicochemical properties including the same morphology, size, and electroneutrality to render them the same blood circulation time and tumor entrance. The 1:1 mixture of TLNs (TLNs-Mix) intravenously injected into a mouse model efficiently accumulates in tumor sites and then transfers to oppositely charged nanodrugs for electrostatic interaction-driven coalescence via responding to matrix metalloproteinase-2 (MMP-2) enriched in tumor. In addition to enhanced tumor retention, the thus-formed micron-sized aggregates show high echo intensity essential for ultrasound imaging as well as ultrasound-triggered penetrative drug delivery. Owing to their distinctive features, the TLNs-Mix carrying sonosensitizer, immune adjuvant, and ultrasound contrast agent exert potent sonodynamic immunotherapy against hypovascular hepatoma, demonstrating their great potential in treating solid malignancies.
Despite recent advances in extrusion bioprinting of cell-laden hydrogels, using naturally derived bioinks to biofabricate complex elastic tissues with both satisfying biological functionalities and superior mechanical properties is hitherto an unmet challenge. Here, we address this challenge with precisely designed biological tough hydrogel bioinks featuring a double-network structure. The tough hydrogels consisted of energy-dissipative dynamically crosslinked glycosaminoglycan hyaluronic acid (o-nitrobenzyl-grafted hyaluronic acid) and elastin through Schiff’s base reaction, and free-radically polymerized gelatin methacryloyl. The incorporation of elastin further improved the elasticity, stretchability (∼170% strain), and toughness (∼45 kJ m−3) of the hydrogels due to the random coiling structure. We used this novel class of hydrogel bioinks to bioprint several complex elastic tissues with good shape retention. Furthermore, in vitro and in vivo experiments also demonstrated that the existence of elastin in the biocompatible bioinks facilitated improved cell behaviors and biological functions of bioprinted tissues, such as cell spreading and phenotype maintenance as well as tissue regeneration. The results confirmed the potential of the elastin-containing tough hydrogel bioinks for bioprinting of 3D complex elastic tissues with biological functionalities, which may find widespread applications in elastic tissue regeneration.
Cylinder-shaped macrocycles composed of π-panels have attracted special attention as one of the best platforms for the development of organic molecule-based chiroptical materials. Pillar[n]arenes are a class of macrocycles with the advantage of easy preparation but have not been extensively investigated from the perspective of luminescent molecules. However, common alkoxy pillar[n]arenes are fluorescent in non-haloalkane solvents, showing potential to be used for molecule-based chiroptical materials. In this work, circularly polarized luminescence (CPL) spectra are reported for a pillar[5]arene with stable planar chirality using tetrahydrofuran (THF) and cyclohexane as solvents, which has been missing for many years. The pillar[5]arene also forms co-aggregates with 1,4-bis(phenylethynyl)benzene and 1,4-bis[(pentafluorophenyl)ethynyl]benzene in THF/H2O mixtures, owing to a hydrophobic effect. The co-aggregates with the fluorinated π-rod display a new low-energy absorption peak and broad emission band as well as intense circular dichroism and CPL signals. Chiral information from the enantiopure pillar[5]arene core is efficiently transmitted to the co-aggregates with the π-conjugated rod, leading to the highest dissymmetry factor for CPL (2.9 × 10−2 at 472 nm) among pillar[n]arene-based CPL materials.
Polymer-coated nanoparticles are widely studied in the context of nanomedicine and it is therefore of utmost importance to understand not only how their structure but also how their colloidal dynamics are affected by physiologically relevant conditions. A characteristic feature of the cytosol of cells is the very high concentration of proteins among other matrix components, often termed macromolecular crowding. Here, the structure and colloidal dynamics of poly(ethylene glycol) (PEG)-coated gold nanoparticles in the presence of bovine serum albumin (BSA) concentrations ranging from 0 to 265 mg/mL are studied with X-ray photon correlation spectroscopy. For protein–nanoparticle mixtures with high BSA concentrations, comparable to intracellular levels, a significant deviation of the apparent viscosity from expectations for pure BSA solutions is found. The findings strongly indicate that the nanoscopic viscous properties of the dense protein solutions are significantly affected by the nanoparticles. At these high concentrations, the colloidal stability of the samples depends on the molecular weight of the coating PEG–ligand, whereas at lower concentrations no differences are observed.
The immunological implications of cuproptosis, a form of cell death highly sensitive to oxygen presence, remain largely unexplored in the context of tumor immunotherapy. Herein, we initially investigate the positive correlation between cuproptosis and tumor immunotherapy through bioinformatics analysis. Subsequently, an oxygen generator loaded with copper ions (Cu/APH-M) has been constructed, which serves as an effective carrier of copper ions and crucially enhances the oxygenation of the tumor microenvironment. Importantly, Cu/APH-M-mediated dual strengthening of cuproptosis and radiotherapy could not only trigger a powerful antitumor immunity related to immunogenic cell death by RNA-sequencing analysis, but also effectively inhibit the growth of both distal and in situ low rectal tumors after combined immunotherapy, creating a robust immune memory effect. Our work reveals the beneficial effects of enhanced cuproptosis in radio-immunotherapy and elucidates its underlying mechanisms, which provides a novel approach for the synergistic integration of cuproptosis with immunotherapy and radiotherapy, broadening the scope of cuproptosis-mediated tumor therapy.
Organic scintillators have recently gained considerable attentions in X-ray detection for their potential applications in biomedical radiograph and security inspection. However, the weak X-ray absorption and/or inefficient exciton utilization have limited the development and commercialization of organic scintillators. Currently, high-performance X-ray organic scintillators are scarce and organic scintillators with dual triplet-harvesting channels have not been explored before. Here, we develop several proof-of-concept sulfone-based organic molecules, C1–C7, using different alkoxy chains to manipulate molecular packing mode. These materials exhibit dual triplet-harvesting channels of thermally activated delayed fluorescence (TADF) and room-temperature phosphorescence (RTP) in aggregated state. Inspiringly, these molecules display distinct radioluminescence under the X-ray stimulation. Among them, C6 behaves the highest light yield of 16,558 photons MeV−1. Moreover, clear X-ray images are demonstrated in both aggregated state and single-molecule level. High spatial resolutions of 15.0 and 10.6 line pairs per millimeter (lp mm−1) are achieved for rigid and flexible scintillator screens, exceeding most reported organic and conventional inorganic scintillators. These results highlight the great potential of organic molecules with TADF and RTP nature for efficient X-ray scintillation and imaging.
The high curing temperatures required for traditional benzocyclobutene (BCB) materials have posed limitations on their applicability in high-temperature-sensitive fields. To address this challenge, our work focuses on the synthesis of a novel tetraphenylethylene (TPE)-functionalized BCB monomer, TPE–BCB, achieved through the introduction of an ether bond onto the BCB’s four-membered ring via Williamson reaction. TPE–BCB demonstrates remarkable low-temperature curing properties, characterized by a ring-opening peak temperature of 190°C, representing a reduction of 60°C compared to conventional BCBs. Fully cured TPE–BCB resins exhibit exceptional dielectric and mechanical properties, coupled with minimal water absorption. Additionally, the incorporation of TPE with aggregation-induced emission characteristics enhances the resins’ luminescence and photolithographic capabilities. Notably, our TPE–BCB resins achieve impressive photolithography performance with a resolution ratio of up to 10 µm. In contrast to conventional BCB-functionalized resins, TPE–BCB offers the dual advantage of low-temperature curing and luminescence. This development marks a significant step in the advancement of low-temperature curing BCB materials and serves as a pioneering example in the realm of multilayer wafer bonding materials.
Acute and infected wounds resulting from accidents, battlefield trauma, or surgical interventions have become a global healthcare burden due to the complex bacterial infection environment. However, conventional gauze dressings present insufficient contact with irregular wounds and lack antibacterial activity against multi-drugresistant bacteria. In this study, we develop in situ nanofibrous dressings tailored to fit wounds of various shapes and sizes while providing nanoscale comfort and excellent antibacterial properties. Our approach involves the fabrication of these dressings using a handheld electrospinning device that allows for the direct deposition of nanofiber dressings onto specific irregular wound sites, resulting in perfect conformal wound closure without any mismatch in 2 min. The nanofibrous dressings are loaded with multi-armed antibiotics that exhibit outstanding antibacterial activity against Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus. Compared to conventional vancomycin, this in situ nanofibrous dressing shows great antibacterial performance against up to 98% of multi-drug-resistant bacteria. In vitro and in vivo experiments demonstrate the ability of in situ nanofibrous dressings to prevent multi-drug-resistant bacterial infection, greatly alleviate inflammation, and promote wound healing. Our findings highlight the potential of these personalized nanofibrous dressings for clinical applications, including emergency, accident, and surgical healthcare treatment.
Melt electrowriting (MEW) is a solvent-free (i.e., no volatile chemicals), a high-resolution three-dimensional (3D) printing method that enables the fabrication of semi-flexible structures with rigid polymers. Despite its advantages, the MEW process is sensitive to changes in printing parameters (e.g., voltage, printing pressure, and temperature), which can cause fluid column breakage, jet lag, and/or fiber pulsing, ultimately deteriorating the resolution and printing quality. In spite of the commonly used error-and-trial method to determine the most suitable parameters, here, we present a machine learning (ML)-enabled image analysis-based method for determining the optimum MEW printing parameters through an easy-to-use graphical user interface (GUI). We trained five different ML algorithms using 168 MEW 3D print samples, among which the Gaussian process regression ML model yielded 93% accuracy of the variability in the dependent variable, 0.12329 on root mean square error for the validation set and 0.015201 mean square error in predicting line thickness. Integration of ML with a control feedback loop and MEW can reduce the error-and-trial steps prior to the 3D printing process, decreasing the printing time (i.e., increasing the overall throughput of MEW) and material waste (i.e., improving the cost-effectiveness of MEW). Moreover, embedding a trained ML model with the feedback control system in a GUI facilitates a more straightforward use of ML-based optimization techniques in the industrial section (i.e., for users with no ML skills).
Near-infrared (NIR) chiroptical response has been less explored because it is challenging to achieve both chirality and NIR absorption/emission. Herein, we describe the design of heterohelicene-type β-isoindigo-based boron-dipyrromethene (BODIPY) analogs (β-IBs), which shift the absorption peak to 800 nm and produce significant Cotton effects (127.8 M−1 cm−1) and absorbance dissymmetry factors (|gabs| = 3.5 × 10−3). The luminescence dissymmetry factor (glum) and circularly polarized luminescence (CPL) brightness (BCPL) of up to 1.24 × 10−3 and 1.78 M−1 cm−1 were realized beyond 800 nm. These β-IBs are the first examples of helicene-type compounds with the highest gabs in the NIR region and CPL beyond 800 nm. Theoretical calculations demonstrate that the strong chiroptical activities are triggered by their large transition magnetic dipole moments. This study not only provides a new approach to the synthesis of a larger variety of unprecedented helicene-type BODIPY analogs but also demonstrates excellent NIR chiroptical properties.
The emergence of flexible organic crystals changed the perception of molecular crystals that were regarded as brittle entities over a long period of time, and sparked a great interest in exploring mechanically compliant organic crystalline materials toward next-generation smart materials during the past decade. Schiff base compounds are considered to be one of the most promising candidates for flexible organic crystals owing to their easy synthesis, high yield, stimuli responsiveness and good mechanical properties. This paper gives an overview of the recent development of Schiff base flexible organic crystals (including elastic organic crystals, plastic organic crystals, and flexible organic crystals integrating elasticity and plasticity) from serendipitous discovery to design strategies and versatile applications such as stimuli responses, optical waveguides, optoelectronic devices, biomimetic soft robots, and organic photonic integrated circuits. Notably, atomic force microscopy-micromanipulation technique has been utilized to bring the multifunctional applications of flexible organic crystals from the macroscopic level to the microscopic world. Since understanding mechanical flexibility at the molecular level through crystal engineering can assist us to trace down the structural origin of mechanical properties, we focus on the packing structures of various Schiff base flexible organic crystals driven by non-covalent intermolecular interactions and their close correlation with mechanical behaviors. We hope that the information given here will help in the design of novel flexible organic crystals combined with other unique properties, and promote further research into the area of mechanically compliant organic crystalline materials toward multifunctional applications.
Donor–acceptor (D-A) conjugated polymers have demonstrated great potential in organic field-effect transistors application, and their aggregated structure is a crucial factor for high charge mobility. However, the aggregated structure of D-A conjugated polymer films is complex and the structure–property relationship is difficult to understand. This review provides an overview of recent progress in controlling the aggregated structure of D-A conjugated polymer films for higher mobility, including the mechanisms, methods, and properties. We first discuss the multilevel microstructures of D-A conjugated polymer films, and then summarize the current understanding of the relationship between film microstructures and charge transport properties. Subsequently, we review the theory of D-A conjugated polymer crystallization. After that, we summarize the common methods to control the aggregated structure of semi-crystalline and near-amorphous D-A conjugated polymer films, such as crystallites and aggregates, tie chains, film alignment, and attempt to understand them from the basic theory of polymer crystallization. Finally, we provide the current challenges in controlling the aggregated structure of D-A conjugated polymer films and in understanding the structure–property relationship.
The deposition of insoluble proteinaceous aggregates in the form of amyloid fibrils within the extracellular space of tissues is associated with numerous diseases. The development of molecular approaches to arrest amyloid formation and prevent cellular degeneration remains very challenging due to the complexity of the process of protein aggregation, which encompasses an infinite array of conformations and quaternary structures. Polyanionic biopolymers, such as glycosaminoglycans and RNAs, have been shown to modulate the self-assembly of amyloidogenic polypeptides and to reduce the toxicity induced by the formation of oligomeric and/or pre-fibrillar proteospecies. This study evaluates the effects of double-stranded DNA (dsDNA) nanostructures (1D, 2D, and 3D) on amyloid self-assembly, fibril disaggregation, and the cytotoxicity associated with amyloidogenesis. Using the islet amyloid polypeptide (IAPP) whose pancreatic accumulation is the hallmark of type 2 diabetes, it was observed that dsDNA nanostructures inhibit amyloid formation by inducing the formation of spherical complexes in which the peptide adopts a random coil conformation. Interestingly, the DNA nanostructures showed a persistent ability to disassemble enzymatically and thermodynamically stable amyloid fibrils into nanoscale DNA/IAPP entities that are fully compatible with β-pancreatic cells and are biodegradable by proteolysis. Notably, dsDNA nanostructures avidly trapped highly toxic soluble oligomeric species in complete cell culture media and converted them into non-toxic binary complexes. Overall, these results expose the potent modulatory effects of dsDNA on amyloidogenic pathways, and these DNA nanoscaffolds could be used as a source of inspiration for the design of molecules to fight amyloid-related disorders.
The induction of regulated cell death (RCD) through photo/ultrasound sensitization therapeutic agents has gained significant attention as a vital approach to combat drug resistance in tumors. Aggregation-induced emission (AIE) therapeutic agents generate reactive oxygen species through photo/ultrasound activation, which can synergize with RCD inducers or directly induce RCD, ultimately resulting in the death of tumor cells. The presented comprehensive review delves into recent advancements in AIE therapeutic agents designed to trigger RCD or synergize with RCD inducers, encompassing apoptosis, necroptosis, pyroptosis, immunogenic cell death, autophagy, ferroptosis, and cuproptosis. Additionally, the intricate regulatory mechanisms through which activatory-AIE therapeutics influence distinct RCD pathways are examined. A forward-looking perspective on future developments and pertinent challenges within this exciting realm is presented, anticipating the continued evolution of activatable AIE therapeutics as a transformative approach to enhance tumor therapy.
Ultrasound-generated antigens combined with TLR7/8 agonists as adjuvants have demonstrated significant anti-tumor efficacy as an in-situ vaccine. However, the use of TLR7/8 agonists can cause severe inflammatory responses. In this study, we present a novel tumor-targeting nano-adjuvant termed aPDL1-PLG/R848 NPs, which are composed of aPDL1 antibody, Fc-III-4C peptide linker (Fc-linker) and poly(L-glutamic acid)-grafted-R848. Under ultrasound irradiation, antigenpresenting cells activate immune mechanisms in vivo under dual stimulation of in situ antigens and immune adjuvants. The strategy inhibits primary tumor growth and induces a strong antigen-specific immune memory effect to prevent tumor recurrence in vivo. This work offers a safe and potent platform for an in situ cancer vaccine based on ultrasound therapy.
Aggregation-induced emission (AIE) is an intriguing photophysical phenomenon, where specific materials exhibit a remarkable surge in luminescence when brought together in non-ideal solvents or within a solid matrix. Since the concept of AIE was first introduced in 2001, numerous advanced applications have been gradually explored across various domains, including optics, electronics, energy, and the life sciences. Of particular note is the growing interest in the application of AIE systems with near-infrared (NIR) emissive feature in the field of biomedicine, encompassing detection, imaging, and therapeutic interventions. Notably, bibliometric analysis serves as a valuable tool to provide researchers with a comprehensive understanding of research achievements and developmental trends in specific fields, which is crucial for academic research. Herein, we present a general bibliometric overview spanning two decades of NIR-AIE development. With the assistance of core scientific databases and various bibliometric software tools, we conducted a systematic analysis of annual publications and citations, the most influential countries/regions, leading authors, journals, and institutions, as well as the hot topics related to NIR applications and forward-looking predictions. Furthermore, the application of AIE with NIR properties in the biomedical field is also systematically reviewed.
Compared with nanoparticle-aspect relatives titanium dioxide (TiO2), titanium-oxo clusters (TOCs) are atomically structural-determined and can be further precisely modified through coordination and supramolecular chemistry. Another parallel research direction is titanium-based metal-organic frameworks, and those based on TOC have attracted particular attention because of their high optical performances resulting from the cluster aggregation effect. Though challenging, assembling macro-materials from specific clusters helps establish the assembly chemistry of clusters and incorporates porous and flexible characteristics into a single bulk material. Although separate reviews are reported in these two branches, no comprehensive review is available to highlight the bridges between them. Herein, we review and summarize the development and progress of new aggregation of TOCs, from intramolecular unique cluster aggregation to hierarchical intermolecular aggregation via covalent forces, coordination bonds, and non-covalent forces using the specific clusters as precursors. We hope this review fills the gap in the methodology of assembling particular-aggregated TOCs and their derived frameworks, providing general guidance to researchers interested in this area.
Supramolecular liquid crystals (SLCs) are attractive materials for fabricating devices with new optoelectronic functions. Conventional SLCs are made from hydrogenbonded mesogens. However, these mesogens suffer from high melting points, and the types of formable aggregates are limited owing to the directionality of the hydrogen bonding. Therefore, to fabricate non-hydrogen-bonded SLCs, we hypothesized that the introduction of tertiary amide groups into calamitic molecules would be advantageous because they have an L-shaped structure with N- or C-alkyl side chains not aligned along the long axis and the flexibility to undergo cis–trans isomerization. In this study, we developed a novel non-hydrogen-bonded SLC by assembling an L-shaped dimer composed of calamitic molecules (phenyltolanes) with tertiary amides at their ends. These molecules exhibited a smectic B phase. The phase transition temperature of the SLCs from crystal to liquid crystal phase was low despite the long π-conjugated core. Wide-angle X-ray diffraction and variable-temperature Fourier-transform infrared measurements revealed dimer formation by weak intermolecular interactions, that is, the molecular recognition of L-shaped molecules, and mobility of the alkyl groups attached to amide driven by cis–trans isomerization in the liquid crystal phase. Thus, cis–trans isomerization of tertiary amides contributed enormously to the formation and lower clearing points of this SLC. The developed method can be used not only to develop non-hydrogen-bonded SLCs but also to develop novel soft matter with controlled properties by incorporating the SLCs, as the aggregates can be controlled to impart desired functionalities.
The development of stimuli-responsive circularly polarized luminescence (CPL) materials is quite attractive but challenging. Here, a pair of atomically precise enantiomers R/S-Ag20 nanoclusters has been synthesized using chiral acid ligands. And then, stimuli-responsive CPL materials were developed by assembling the chiral silver nanoclusters with an achiral bridging ligand. The atomically precise silver cluster-assembled materials produce CPL with a dissymmetry factor (|glum|) of 1 × 10−3, through the high-efficiency chiral induction process. More interestingly, the single CPL band at room temperature could quickly transform into highly separated dual CPL emissions at low temperature. This study provides a new strategy for the rational functionalization of chiral silver clusters in preparing cluster-based CPL emitters and enriches the types of stimuli-responsive CPL materials.
The management of infected wounds is always of great significance and urgency in clinical and biomedical fields. Recent efforts in this area are focusing on the development of functional wound patches with effective antibacterial, drug delivery, and sensor properties. Here, we present novel hyaluronic acid (HA) microneedle patches with these features by encapsulating aminobenzeneboronic acid-modified gold nanoclusters (A-GNCs) for infected wound management. The A-GNCs loaded microneedle patches were derived from negative-mold replication and showed high mechanical strength to penetrate the skin. The release of the A-GNCs was realized by the degradation of HA, and the self-monitor of the released actives was based on the dynamic bright orange fluorescence emitted from A-GNCs under ultraviolet radiation. As the A-GNCs could destroy bacteria membranes, the microneedle patches were with excellent in vitro antibiosis ability. Based on these features, we have demonstrated the bacteria inhibition, residual drug self-monitoring, and wound healing promotion abilities of the microneedle patches in Escherichia coli-or Staphylococcus aureus-infected wound management. These results indicated the great potential of such A-GNCs loaded microneedle patches for clinical applications.
Phototherapeutic nanoplatforms that combine photodynamic therapy (PDT) and photothermal therapy (PTT) with the guidance of photoacoustic (PA) imaging are an effective strategy for the treatment of tumors, but establishing a universal method for this strategy has been challenging. In this study, we present a supramolecular assembly strategy based on Förster resonance energy transfer to construct a supramolecular nanostructured phototherapeutic agent (PcDA) via the anion and cation supramolecular interaction between two water-soluble phthalocyanine ramifications, PcD and PcA. This approach promotes the absorption of energy, thus enhancing the generation of reactive oxygen species (ROS) and heat by PcDA, improving its therapeutic efficacy, and overcoming the low photon utilization efficiency of conventional PSs. Notably, after the intravenous injection of PcDA, neoplastic sites could be clearly visualized using PA imaging, with a PA signal-to-liver ratio as high as 11.9. Due to these unique features, PcDA exhibits excellent antitumor efficacy in a preclinical model at a low dose of light irradiation. This study thus offers a general approach for the development of efficient phototherapeutic agents based on the simultaneous effect of PDT and PTT against tumors with the assistance of PA imaging.
Lipid droplets (LDs), which are the hubs of lipid metabolism, play a critical role in maintaining cellular energy homeostasis. The construction of advanced photosensitizers (PSs) capable of manipulating LD-mediated cell fate regulation is highly desirable though rarely reported. In this study, a near-infrared emissive PS (DPCMP) with LDs specificity was synthesized and successfully applied to induce ferroptosis and apoptosis. DPCMP exhibited typical aggregation-induced emission characteristics owing to its twisted molecular conformation. Excellent biocompatibility and suitable lipophilicity allowed DPCMP to specifically stain the LDs in living cells. Under white light illumination, the DPCMP displayed potent reactive oxygen species (ROS) generation capacity through both type I and II photochemistry. The massive accumulation of lethal ROS generated by DPCMP-mediated photosensitization initiated lipid peroxidation, impaired cellular redox homeostasis, and led to endoplasmic reticulum oxidative stress, ultimately inhibiting cellular proliferation via concurrent ferroptosis and apoptosis in both living cancer cells and multicellular tumor spheroids.
Photoluminescence (PL) mechanisms of nontraditional luminogens (NTLs) have attracted great interest, and they are generally explained with intra/intermolecular through-space conjugation (TSC) of nonconventional chromophores. Here a new concept of nonaromatic through-bond conjugation (TBC) is proposed and it is proved that it plays an important role in the PL of NTLs. The PL behaviors of the three respective isomers of cyclohexanedione and gemdimethyl-1,3- cyclohexanedione were studied and correlated with their chemical and aggregate structures. These compounds show different fluorescence emissions as well as different concentration, excitation and solvent-dependent emissions. The compounds which undergo keto-enol tautomerism and hence with a conjugated ketone-enol structure (i.e., nonaromatic TBC) show more red-shifted emissions. TBC effect reduces the energy gaps and facilitates the formation of stronger TSC in the aggregate state. The compounds in the ketone-enol form are also prone to occur excited state intra/intermolecular proton transfer (ESIPT). The cooperative effect of nonaromatic TBC and TSC determines the PL behaviors of NTLs. This work provides a novel understanding of the PL mechanisms of NTLs and is of great importance for directing the design and synthesis of novel NTLs.
Aggregation-induced emission (AIE) materials exhibit remarkable emission in the aggregated or solid state while demonstrating minimal emission in dilute solutions. In contrast to conventional luminescent materials, AIE luminogens (AIEgens) offer several advantages in the aggregate state, including high quantum yield, excellent photostability, and low background signals, making them highly promising for diverse applications. Integrating AIEgens into designable metal–organic frameworks (MOFs) enables tunable and well-ordered AIE materials, allowing for precise control over photophysical properties and deeper exploration of AIE mechanisms. Numerous AIE MOFs have been constructed and investigated, and several reviews focus on their structure design and applications in sensing and bioimaging. This review highlights the state-of-the-art advancements in AIE MOFs, including mechanisms, design strategies, and applications in chemical sensing, bioimaging, and disease therapy. The challenges associated with practical applications of AIE MOFs are also addressed, with an emphasis on their large-scale production involved interdisciplinary collaboration. This comprehensive review aims at guiding further development of AIE MOFs and promoting their practical applications in analysis, healthcare, and other luminescence related fields.
Fluorescent-patterned materials are widely used in information storage and encryption. However, preparing a patterned fluorescent display on a matrix currently requires a time-consuming (hours or even days) and complex multi-step process. Herein, a rapid and mild technique developed for the in-situ controllable synthesis of fluorescent nitrogen-doped carbon dots (NCDs) on eco-friendly transparent wood films (TEMPO-oxidized carboxyl wood film [TOWF]) within a few minutes was developed. A wood skeleton was employed as the carbon precursor for NCD synthesis as well as the matrix for the uniform and controlled distribution of NCDs. Moreover, the in-situ synthesis mechanism for preparing NCDs in TOWF was proposed. The resulting fluorescent wood films have excellent tensile strength (310.00 ± 15.57 MPa), high transmittance (76.2%), high haze (95.0%), UV-blocking properties in the full ultraviolet (UV) range, and fluorescent performance that can be modified by changing the heating parameters. Fluorescent patterning was simply achieved by regulating the in-situ NCD synthesis regions, and the fluorescent patterns were formed within 10 s. These fluorescent-patterned wood films can effectively store and encrypt information, and they can interact with external information through a transparent matrix. This work provides a green and efficient strategy for fabricating fluorescent information storage and encryption materials.
Fibre-based wearables for embroidery, chemosensing, and biofluid’s unidirectional draining with good flexibility, tunability, and designability drive technological advance. However, synthetic polymer fibres are non-degradable, threatening the environment and human health. Herein, we have developed versatile microfibrebased wearables by combining many advantages in one platform of biodegradable polylactic acid (PLA) and melt electrowriting strategy. Diverse potential applications of PLA wearables are achieved by flexibly designing their printing files, components and structures. Three-dimensional printing files are generated from two-dimensional images to fabricate ‘embroidery-like’ patterns. PLA/aggregation-induced emission fluorogens (AIE) chemosensors exhibit colorimetric and fluorescent colour changes upon exposure to amine vapours. Janus PLA-cotton textiles with a hydrophobic/ hydrophilic structure could facilitate unidirectional draining of sweats which is favourable for the management of temperature and humidity on the surface of skin. The proposed platform can not only broaden the design possibilities in 3D/4D printing but also offer wide potential applications for functional wearables.
Flexible wearables have attracted extensive interests for personal human motion sensing, intelligent disease diagnosis, and multifunctional electronic skins. However, the reported flexible sensors, mostly exhibited narrow detection range, low sensitivity, limited degradability to aggravate environmental pollution from vast electronic wastes, and poor antibacterial performance to hardly improve skin discomfort and skin inflammation from bacterial growth under long-term wearing. Herein, bioinspired from human skin featuring highly sensitive tactile sensation with spinous microstructures for amplifying sensing sensitivity between epidermis and dermis, a wearable antibacterial degradable electronics is prepared from degradable elastomeric substrate with MXene-coated spinous microstructures templated from lotus leaf assembled with the interdigitated electrode. The degradable elastomer is facilely obtained with tunable modulus to match the modulus of human skin with improved hydrophilicity for rapid degradation. The as-obtained sensor displays ultra-low detection limit (0.2 Pa), higher sensitivity (up to 540.2 kPa-1), outstanding cycling stability (>23,000 cycles), a wide detection range, robust degradability, and excellent antibacterial capability. Facilitated by machine learning, the collected sensing signals from the integrated sensors on volunteer’s fingers to the related American Sign Language are effectively recognized with an accuracy up to 99%, showing excellent potential in wireless human movement sensing and smart machine learning-enabled human–machine interaction.
Bacterial infection is a major threat to public health. Nanotechnology offers a solution by combining nanomaterials with antibacterial agents. The development of an effective nanocomposite against drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is highly important yet challenging. Here, an anti- MRSA core-shell structure is designed, containing antibacterial zeolitic imidazolate framework-8 (ZIF-8) as the core and bactericidal benzalkonium chloride (BAC) templated rough-surface mesostructured silica nanocomposite (RMSN) as the shell. The resultant ZIF-8@RMSN nanocomposite exhibits sustained release of BAC and zinc ions, effective disruption of the bacterial membrane, generation of oxidative damage of bacterial DNA, leakage of intracellular components, and finally bacterial death. Furthermore, the synergistic antibacterial mechanisms lead to enhanced biofilm elimination performance. In addition, the ZIF-8@RMSN-modified band-aid effectively combats MRSA infection in vivo. This work has provided a promising nanocomposite against MRSA-related infections.
The silicon carbide (SiC) crystal growth is a multiple-phase aggregation process of Si and C atoms. With the development of the clean energy industry, the 4H-SiC has gained increasing attention as it is an ideal material for new energy automobiles and optoelectronic devices. The aggregation process is normally complex and dynamic due to its distinctive formation energy, and it is hard to study and trace back in a nondestructive and comprehensive way. Here, this work developed a non-destructive and deep learning-enhanced characterization method of 4H-SiC material, which was based on micro-CT scanning, the verification of various optical measurements, and the convolutional neural network (ResNet-50 architecture). Harmful defects at the micro-level, polytypes, micropipes, and carbon inclusions could be identified and orientated with more than 96% high performance on both accuracy and precision. The three-dimensional visual reconstruction with quantitative analyses provided a vivid tracing back of the SiC aggregation process. This work demonstrated a useful tool to understand and optimize the SiC growth technology and further enhance productivity.
The conversion of the biomass into eco-friendly fuels and chemicals has been extensively recognized as the essential pathway to achieve the sustainable economy and carbon neutral society. Lignin, as a kind of promising biomass energy, has been certified to produce the high-valued chemicals and fuels. Numerous efforts have been made to develop various catalysts for lignin catalytic conversion. Both metalorganic frameworks (MOFs) and covalent organic frameworks (COFs) belong to very important heterogeneous porous catalysts due to their regular porous structures, high specific surface area, and precisely tailored diversities. In the review, the first part focused on the catalytic conversion of lignin, lignin model compounds, and lignin derivatives using the pristine MOFs, functional MOF composites, and MOF-derived materials. The second part summarized the catalytic conversion of lignin model compounds using pristine COFs and functional COF composites. The review here mainly concentrated on the design of the materials, screening of catalytic conditions, and explorations of the corresponded mechanisms. Specifically, (1) we summarized the MOF- and COF-based materials for the effects on the catalytic transformation of lignin-related substances; (2) we emphasized the catalytic mechanism of C–C and C–O bonds cleavage together with the structure–activity relationships; (3) we in-depth realized the relationship between the chemical/electronic/structural properties of the MOF- and COF-based catalysts and their catalytic performance for lignin-related substances. Finally, the challenges and future perspectives were also discussed on the catalytic conversion of lignin-related substances by MOF- and COF-based catalysts.
Urinary microalbumin (mALB) serves as an exceptionally sensitive indicator for the early detection of kidney damage, playing a pivotal role in identifying chronic renal failure and kidney lesions in individuals. Nevertheless, the current fluorescent methodologies for point-of-care (POC) diagnosis of mALB in real urine still exhibit suboptimal performance. Herein, the development and synthesis of QM-N2, an albumin-activated near-infrared (NIR) aggregation-induced emission (AIE) fluorescent probe, are presented. The strategic incorporation and positioning of quaternary ammonium salts within the quinoline-malononitrile (QM) scaffold significantly influence solubility and luminescence characteristics. Specifically, the quaternary ammonium salt-free variant, QM-OH, and the quaternary ammonium salt integrated at the donor function group (DFG) site, QM-N1, display limited solubility in aqueous solutions while demonstrating a distinct fluorescence signal. Conversely, the incorporation of quaternary ammonium salt at the conformational functional group (CFG) site in QM-N2 imparts superior dispersibility in water and reduces the initial fluorescence. Furthermore, the integration of a well-defined D-π-A structure within QM-N2 enables itself with near-infrared emission, which is crucial for mitigating interference from autofluorescence present in urine samples. Upon interaction with albumin, QM-N2 forms a tight bond with the IIA site of the subdomain of human serum albumin (HSA), inducing alterations in protein configuration and constraining the intrinsic motion of fluorescent molecules. This interaction induces fluorescence, facilitating the sensitive detection of trace albumin. Ultimately, QM-N2 is applied for POC testing of mALB using portable equipment, particularly in the diagnosis of mALB-related diseases, notably chronic renal failure. This positioning underscores its potential as an ideal candidate for self-health measurement at home or in community hospitals.
Near-infrared (NIR)-II fluorescence imaging-guided photothermal therapy (PTT) has attracted great research interest, and constructing donor-acceptor (D-A) electronic configurations has become an established approach to lower bandgap and realize NIR-II emission. However, very few π-conjugated phototheranostic agents can realize efficient NIR-II guided PTT using a clinically safe laser power density, implying that sufficient photothermal performance is still desired. In addition to the continuously refreshed photothermal conversion efficiency levels, the strategies that focus on enhancing light absorptivity have been rarely discussed and endow a new direction for enhancing PTT. Herein, a dimerization π-extension strategy is raised to synthesize π-conjugated dimers with A-D-A monomers. We observe that the light absorptivity (ϵ) of the dimers is strengthened three times owing to the enhanced electronic coupling effect as a result of the π-conjugation extension, thereby surpassing the 2-fold increase in chromophore numbers from the monomer to dimers. Thanks to the enhancement in light absorption, the dimers could generate much more photothermal heat than the monomer in in vivo PTT treatments. Therefore, an efficient anti-tumor outcome has been fulfilled by using dimers under a low laser power (0.3 W/cm2). Moreover, the dimers with extended π-conjugation structures become more favorable to the radiative excited state decay, thus exhibiting a distinguishing improvement in NIR-II imaging compared with monomer. Collectively, due to the improved light absorptivity, the dimers can gain superior NIR-II fluorescence brightness and photothermal performance over the recently reported material, which goes beyond the monomer in double doses for in vivo applications. All these results prove that dimerization is an effective strategy for designing high-performance phototheranostic materials.
Synergistic changes between tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) aggravated immune evasion of hepatocellular carcinoma (HCC), however, the underlying molecular mechanisms remain elusive. Their continuous and dynamic interactions are subject to bioactive molecule changes. A real-time and in situ monitoring method suitable for in vivo research of these processes would be indispensable but is scarce. In this study, a dual imaging strategy that tracing the TAMs and CAFs simultaneously was developed using a new arginase-specific probe and established CAFs-specific probe. The emerging roles of arginase in mediating CAFs activation in mice were explored. Results showed arginase up-regulation in TAMs, followed by proline increase. Subsequently, proline produced by TAMs initiated the activation of CAFs. Through the JAK-STAT signaling, CAFs up-regulated the PD-L1 and CTLA-4, ultimately promoting immune evasion of HCC. This study revealed a new mechanism by which TAMs and CAFs collaborate in immune evasion, providing new targets for HCC immunotherapy.