Rational Design of NIR-II AIEgens with Ultrahigh Quantum Yields for Photo- and Chemiluminescence Imaging

NIR-II AIEgen nanocomplex with suppressed nonradiative decay and intersystem crossing for high-contrast mesenteric vascular imaging

The prompt assessment of the mesenteric vasculature is crucial for the diagnosis of lethal mesenteric ischemia, underscoring the need for real-time mesenteric vascular imaging using small organic molecules that radiate fluorescence within the second near-infrared spectrum (NIR-II) due to its deep penetration and elevated signal-to-background ratio (SBR), which have been rarely reported. Unfortunately, numerous NIR-II dyes exhibit low quantum yields (QYs) when employed in practical applications, highlighting the need for QY enhancement. For this research, a NIR-II fluorescent AIEgen, termed TPETPA-TQT, was rationally designed by incorporating tetraphenylethylene (TPE)-fused triphenylamine (TPA) into the robust, high QY core of 6,7-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline (TQT). We further encapsulated this dye within F127 to form the TPETPA-TQT F127 nanocomplex, which exhibits a 6.5-fold enhancement in fluorescence intensity over the TPA-TQT dye encapsulated with DSPE-PEG2000, attributed to the suppression of molecular nonradiative decay and intersystem crossing. The abdominal vasculature and microvessels on the intestinal wall surface, as narrow as 0.41 mm, can real-time visualization using TPETPA-TQT F127 nanocomplex, and exhibit a 94 % improvement of SBR versus ICG. Our findings will push forward the progress of high-brightness NIR-II contrast agents for enhanced mesenteric vasculature imaging and mesenteric ischemia diagnosis.

Multi-dimensional donor engineering of NIR-II AIEgens for multimodal phototheranostics of orthotopic breast cancer

"One-for-all" multimodal phototheranostic agents, which integrate multiple photodiagnostic and phototherapeutic functionalities into a single component, have emerged as promising platforms for advancing cancer treatment. Among these, agents featuring second near-infrared (NIR-II) emission are particularly appealing due to their superior tissue penetration depth and high signal-to-background ratio (SBR). However, most reported NIR-II fluorophores suffer from severely imbalanced radiative and non-radiative excited-state energy dissipation in biological environments, resulting in extremely low fluorescence quantum yields (QYs) and limited diagnostic efficacy. This highlights the urgent need for innovative molecular design strategies to develop high-performance NIR-II "one-for-all" multimodal phototheranostic agents. Herein, we present, for the first time, a multi-dimensional donor engineering protocol that optimizes donor design at the molecular, aggregated, and solvent-interaction levels. By introducing 2,4,4-trimethylpentan-2-yl groups into the diphenylamine indeno[1,2-b]thiophene donor unit, we developed a donor-acceptor-donor (D-A-D) type NIR-II aggregation-induced emission-active luminogen (AIEgen), i.e. OPITBT. When formulated into nanoparticles (NPs), OPITBT NPs exhibited a 16-fold enhancement in fluorescence QY compared to OPITBT in tetrahydrofuran, along with excellent photothermal conversion efficiency (PCE) and acceptable type-I reactive oxygen species (ROS) generation. When further fabricated into tumor-targeting NPs, the resulted OPITBT-R NPs effectively eliminated orthotopic breast cancer through fluorescence-photoacoustic-photothermal multimodal imaging-guided photodynamic-photothermal synergistic therapy under single 808 nm laser irradiation. Notably, the exceptional NIR-II fluorescence brightness of OPITBT-R NPs enables high-resolution NIR-IIb whole-body vascular imaging in living mice. This work provides a versatile strategy to enhance radiative dissipation of NIR-II fluorophores for balanced phototheranostic performance and advances the development of "one-for-all" phototheranostic systems.

An all-in-one PEGylated NIR-II conjugated polymer for high-resolution blood circulation imaging and photothermal immunotherapy

Fluorescence imaging in the second near-infrared window (NIR-II) has shown tremendous potential for in vivo monitoring of biological processes, offering high spatial resolution and real-time imaging capabilities. Conjugated polymers, commonly used as photothermal agents (PTAs) in photothermal therapy, have emerged as promising candidates for NIR-II imaging. However, their imaging efficiency is compromised by aggregation, which arises from strong π-π stacking interactions between their extended π-conjugated backbones. In this work, we designed a novel conjugated polymer (CP) and developed an integrated nanoplatform (CPN-PEGnk, n = 2 or 5) through PEGylation. Notably, CPN-PEG5k exhibited a red-shift in NIR absorption along with a marked increase in NIR-II fluorescence intensity (2.97 folds greater) compared to physically encapsulated nanoparticles (F127@CPN). Furthermore, CPN-PEG5k retained a remarkable photothermal conversion efficiency of up to 58.6%. The exceptional NIR-II imaging performance of CPN-PEG5k was validated in detailed blood circulation imaging in mice, with a signal-to-background ratio of 8.9. In addition, in a breast cancer mouse model, CPN-PEG5k successfully eradicated tumors and stimulated immune responses, effectively suppressing tumor progression and metastasis. These findings underscore the potential of CPN-PEG5k in advancing conjugated polymer applications for NIR-II imaging.

Self-Assembly versus Coassembly: An Amphiphilic NIR-II Aggregation-Induced Emission Luminogen for Phototheranostics of Orthotopic Glioblastoma

Glioblastoma (GBM) is the most lethal form of malignant brain tumor, known for its high infiltration, aggressiveness, and poor prognosis. Second near-infrared (NIR-II, 1000-1700 nm) phototheranostic agents bring intriguing opportunities for GBM management owing to their noninvasive nature, controllability, and deeper tissue penetration. Herein, an amphiphilic NIR-II luminogen (PEG-TD) with aggregation-induced emission (AIE) characteristics, along with its hydrophobic counterpart (C6-TD), was meticulously synthesized. Specifically, PEG-TD nanoparticles (NPs), formed through straightforward self-assembly, exhibited superior stability, simplicity, robust reactive oxygen species production efficiency, and excellent photothermal conversion compared to C6-TD NPs, which were fabricated via coassembly with DSPE-mPEG, primarily attributed to the distinct molecular arrangements within the forming aggregates. The inherent advantages of PEG-TD NPs led to significant therapeutic efficacy against GL261 cells under 808 nm laser irradiation. Eventually, NIR-II fluorescence/photothermal duplex imaging-guided combined photodynamic/photothermal therapy was successfully performed in an orthotopic glioblastoma mouse model with minimal adverse effects.

Rabies Virus Targeting NIR-II Phototheranostics

Rabies is a viral disease with an almost 100% fatality rate, primarily transmitted through bites from infected animals, with a long incubation period and no effective clinical treatments to date. Herein, we developed the first fluorescent nanotheranostic probe in the second near-infrared (NIR-II) window capable of efficiently crossing the blood-brain barrier (BBB), precisely targeting rabies virus (RABV), and enabling safe photodynamic therapy (PDT). This probe is based on a novel NIR-II organic polyacetylene fluorophore, DK, which self-assembles via a click reaction with a nanoparticle carrier, N3-PEG2000-R, that we synthesized with a high biocompatibility and BBB permeability. The probe surface is further modified with an aptamer that specifically binds to RABV glycoprotein (RVG), resulting in our final nanotheranostic probe, DK@RA-PEG. Upon intravenous injection into mice, it effectively crosses the BBB, localizes to the infection site, and binds to the RVG, allowing for real-time NIR-II fluorescence imaging. Additionally, it efficiently converts light energy into chemical energy without generating thermal effects, ensuring safe and effective PDT. This advanced nanotheranostic probe integrates precise targeting, deep-tissue imaging, and safe therapy, making it a promising candidate for future clinical applications in rabies treatment.

Near-Infrared Chemiluminescent Theranostics

Molecular chemiluminescence probes with near-infrared (NIR) emission offer promising benefits in deciphering complex pathological processes in a living system, as NIR chemiluminescence minimizes autofluorescence, enhances deep-tissue penetration, and improves signal-to-noise ratio. Molecular engineering using single-luminophore design and dual-luminophore design with intramolecular energy transfer provides ways to develop conventional chemiluminophore scaffolds into NIR chemiluminescence probes with ideal chemiluminescence quantum yield and half-life. By virtue of the structural diversity, 1,2-dioxetane-based NIR chemiluminophores with biomarker activity have been developed. This review summarizes the molecular design strategies of NIR chemiluminescence theranostic probes (NCTPs), followed by introducing activatable NCTPs with their biomedical applications for disease theranostics. Lastly, future perspectives and potential challenges of NIR chemiluminescence imaging in preclinical research and clinical translational potential are discussed.

Red Fluorescent Molecule with Aggregation-Induced Emission Based on Dehydroabietic Acid Diarylamine for Bioimaging

In this paper, molecules with AIE red light properties were designed by coupling dehydroabietic acid diarylamine and 2,3-diphenylfumaronitrile, which were designated 2DTPA-CN and 2TPA-CN. The emission wavelengths were 683 nm and 701 nm, respectively. The 2DTPA-CN and 2TPA-CN showed typical AIE characteristics with large Stokes shifts of 7.4 × 104 cm-1 and 6.7 × 104 cm-1, respectively. The obvious solvatochromism and electron cloud distributions of HOMO/LUMO in the ground and excited states both reveal the intramolecular charge transfer (ICT) effect. The 2DTPA-CN, boasting exceptional biocompatibility, was successfully prepared into nanoparticles (NPs), which were applied to tumor cell imaging, showing good bioimaging effects both in vitro imaging in live cells and in vivo imaging in live mice. The results demonstrated that it possesses significant potential as an effective bioimaging reagent for the detection of tumor cells. Furthermore, the incorporation of 2,3-diphenylfumaronitrile moieties to dehydroabietic acid diarylamine emerged as a proficient approach to broaden the emission wavelengths of rosin-based fluorescent materials.

Cyclometalated Iridium(III) Schiff Base Complexes for Chemiluminogenic Bioprobes

Chemiluminogenic bioimaging has emerged as a promising paradigm due to its independence from light excitation, thereby circumventing challenges related to light penetration depth and background autofluorescence. However, the availability of effective chemiluminophores remains limited, which substantially impedes their bio-applications. Herein, we discovered for the first time that cyclometalated iridium(III) Schiff base complexes can unexpectedly generate chemiluminescence. Notably, the chemiluminescence reaction was rapid, with a half-life of only 0.86 s, significantly faster than previously reported examples. Unlike conventional chemiluminescent scaffolds, the distinguishing feature of the chemiluminogenic iridium(III) complex is its unique intramolecular imine-to-amide conversion upon reaction with reactive oxygen species (ROS). Intriguingly, the chemiluminogenicity of these complexes is not influenced by the cyclometalating ligands but is closely associated with the Schiff base ligand, allowing for tuning of the emission colors via altering the cyclometalating ligands. Additionally, we formulated one of the Schiff base complexes (1) as water-soluble chemiluminogenic nanoparticles (CLNPs) and successfully employed them as activatable chemiluminescence bioprobes for precise and rapid imaging of hypochlorite-related biological events both in vitro and in vivo. We believe that this significant finding of the development of chemiluminogenic Schiff base complexes will greatly facilitate the designing of innovative chemiluminophores for theranostic applications.

Highly Emissive Platinum(II) Metallacage in the Near-Infrared Region for Synergistic Chemo-Photodynamic Therapy

Highly emissive metallacages that generate reactive oxygen species (ROS) are important to synergistic cancer therapy, but it is still challenging to balance the emission and phototheranostic properties. Herein, a metallacage of DTPABT-Mc is prepared. It is observed that emission in the near-infrared region from 600 to 1000 nm with a high photoluminescence quantum yield value of 7.92% in solids is recorded for DTPABT-Mc. In addition, the ability to produce both type I and type II ROS under light irradiation is also observed, leading to potential application in photodynamic therapy (PDT) and chemotherapy. After that, 4T1@DTPABT-Mc-NPs, covering DTPABT-Mc nanoparticles with 4T1 cell membranes, are prepared to enhance their tumor-targeting ability. This finally results in effective therapeutic performance in vivo, effectively inhibiting tumor growth. These results suggest that DTPABT-Mc-NPs exhibit excellent synergistic therapeutic effects by combining PDT and chemotherapy, providing new ideas to design agents for diagnosis and therapy in the future.

A Bright Organic Fluorophore for Accurate Measurement of the Relative Quantum Yield in the NIR-II Window

Organic dyes with photoluminescence in the second near-infrared window (NIR-II, 1000-1700 nm) are promising for bioimaging and optoelectronic devices. Photoluminescence quantum yield (PLQY) is a direct measure of their performance. Integrating sphere technology is effective in determining the absolute PLQY. However, the low PLQY values of most NIR-II organic fluorophores lead to significant measurement errors. Therefore, the most common method for PLQY determination is a relative approach using a photoluminescence spectrometer and a standard reference like IR-26. Although the relative method enables precise calculation of the PLQY ratio between the sample and the reference, the specific PLQY value of IR-26 is not clearly defined and is reported to range from 0.05% to 0.50%. Such a deviation can cause significant errors in relative PLQY measurements. In this study, it is reported that a bright organic fluorophore called TPE-BBT exhibits a high PLQY of 3.94% in THF, which can be accurately measured using a commercially available integrating sphere. Using TPE-BBT as a standard, the PLQY values of IR-26 in 1,2-dichloroethane and IR-1061 in dichloromethane are accurately determined to be 0.0284% and 0.182%, respectively. It is hoped that using this reliable standard will unify the evaluation criteria for NIR-II organic fluorophores.

Asymmetric D-A-D' Ratiometric Molecule for Highly Specific Hypochlorous Acid Detection

Hypochlorous acid exists as HClO in acidic conditions and as ClO- in alkaline conditions, posing a significant challenge for differentiation due to their strong and closely similar oxidative reaction activities. Addressing this challenge, our study presents an asymmetric donor-acceptor-donor' (D-A-D') molecular architecture for the design of a fluorescent probe (PMT NPs) that demonstrates exceptionally high specificity toward HClO alongside an optimized ratiometric response. The incorporation of the strong electron acceptor 2-(diphenylmethylene)malononitrile (A) modulates the reducing ability of the phenothiazine recognition site, adjusting the probe's oxidation potential to an intermediate level between HClO and ClO-. This adjustment directly dictates the probe's selectivity, enabling it to respond exclusively to HClO. By incorporating D', the probe's response to HClO shifts the intramolecular charge transfer (ICT) from the original D-A to D'-A, instead of the usual Dox-A as presented in previous works. This adjustment controls the blue shift in fluorescence wavelength upon recognition, thereby improving the accuracy of ratiometric signals in vivo. The ability of PMT NPs to precisely recognize HClO in acidic environments was validated through live cell imaging and in vivo experiments using zebrafish and mouse models, enabling real-time monitoring of HClO surges. This dual-pronged molecular design strategy, which combines D-A interaction modulation with a D-A-D' molecular architecture, promises to revolutionize probe designs for various biomolecules and is anticipated to advance the understanding of diseases linked to these analytes.

Alleviating NIR-II emission quenching in ring-fused fluorophore via manipulating dimer populations for superior fluorescence imaging

Emission quenching resulting from fluorophore aggregation has long been a significant challenge in optimizing emission-based technologies, such as fluorescence imaging and optoelectronic devices. Alleviating this quenching in aggregates is crucial, yet progress is impeded by the limited understanding of the nature and impact of aggregates on emission. Here, we elucidate the critical role of dimeric aggregate (dimer) in alleviating second near-infrared (NIR-II, 900-1700 nm) emission quenching from ring-fused fluorophore 4F for superior fluorescence imaging. Spectral decomposition and molecular dynamics simulations demonstrate the predominance of dimer populations in 4F aggregates. Notably, dimers exhibit significantly weaker emission but intense intermolecular nonradiative (interNR) decay compared to monomers, as demonstrated by ultrafast spectra and quantum calculation. Therefore, the predominant population of dimers with weak emission and pronounced interNR feature underlies the emission quenching in 4F aggregates. This discovery guides the preparation of ultrabright NIR-II 4F nanofluorophore (4F NP3s) by decreasing dimer populations, which show 5-fold greater NIR-II brightness than indocyanine green, enabling superior resolution in visualizing blood vessels. This work offers valuable insights into aggregation-caused quenching, with broad implications extending far beyond NIR-II fluorescence imaging.

Aggregation-Mediated Photoacoustic/NIR-II and Photodynamic Properties of pH-Reversible Thiopyrylium Agents: A Computational and Experimental Approach

Aggregation profoundly influences the photophysical properties of molecules. Here, a new series of thiopyrylium-based hemicyanine near-infrared II (NIR-II) fluorophores is developed by meticulously adjusting their aggregation states. Notably, the star molecule HTPA exhibits a remarkable pH-responsive behavior and a significant increase in photoacoustic (PA) intensity when aggregated. Additionally, their behavior and pH reversibility during aggregation formation are systematically investigated, including computational optimization, femtosecond transient absorption spectroscopy, NMR analysis, and single crystal analysis. Finally, an innovative "off " nanoparticle specifically is designed for effective tumor-targeted PA/NIR-II dual-modal imaging and photodynamic therapy by utilizing a pH-responsive polymer. The signal-to-background ratio (SBR) of PA signals significantly increased to 169 in the region of interest (ROI) in the mouse model when irradiated at 1064 nm. These findings not only provide a promising avenue for future studies of NIR-II small molecules but also pave the way for significant advances in the field of integrated cancer diagnosis and therapy.

Acid triggering highly-efficient release of reactive oxygen species to block mitochondrial-mediated homeostasis maintenance for accelerating cell death

A pivotal pathway of photodynamic therapy (PDT) is to prompt mitochondrial damage by reactive oxygen species (ROS) generation, thus leading to cancer cell apoptosis. However, mitochondrial autophagy is induced during such a PDT process, which is a protective mechanism for cancer cell homeostasis, resulting in undermined therapeutic efficacy. Herein, we report a series of meticulously designed donor (D)-π-acceptor (A) photosensitizers (PSs), characterized by the strategic modulation of thiophene π-bridges, which exhibit unparalleled mitochondrial targeting proficiency. Notably, TTBI within this series possesses remarkable ROS generation capability, which can directly trigger mitochondrial depolarization, thus effectively inducing apoptosis in cancer cells. Meanwhile, the damaged mitochondria activate the mitophagy process, which further boosts the ROS generation of the TTBI owing to the acidic environment in the lysosome, ultimately inducing lysosomal membrane permeability (LMP), thereby blocking the protective autophagy route and promoting extra apoptotic cell death. Accordingly, TTBI disrupts the integrity of mitochondrial and lysosome, leveraging a synergistic interplay between cellular compartments to achieve more potent apoptosis. This work provides new insights to overcome the limitation of PDT efficacy imposed by mitochondrial autophagy.

A galactose-tethered tetraphenylethene prodrug mediated apoptosis of senescent cells for osteoporosis treatment

Osteoporosis and bone injury healing in elderly patients are major medical challenges, often exacerbated by the accumulation of senescent cells. Herein, we show that TPE-Gal, which contains a tetraphenylethene unit and a galactose moiety, offers a promising molecular therapy designed to light up and eliminate senescent cells through a hydrolysis reaction catalyzed by β-galactosidase, an enzyme overexpressed in senescent cells. The reaction produces TPE-OH, which, in turn, increases reactive oxygen species levels within the senescent cells, leading to noninflammatory apoptosis of senescent cells. This targeted clearance mechanism helps to alleviate osteoporosis symptoms and promotes bone injury healing. Moreover, apoptotic vesicles, which are generated during the process, are partly phagocytosed by macrophages, mimicking physiological metabolic processes. This study opens new avenues for addressing bone health issues through the designed bioclearance of senescent cells, aligning with the body's natural pathways for maintaining homeostasis.

Sialic Acid-Modified NIR-II Fluorophore with Enhanced Brightness and Photoconversion Capability for Targeted Lymphoma Phototheranostics

Lymphoma is a malignant cancer characterized by a rapidly increasing incidence, complex etiology, and lack of obvious early symptoms. Efficient theranostics of lymphoma is of great significance in improving patient outcomes, empowering informed decision-making, and driving medical innovation. Herein, we developed a multifunctional nanoplatform for precise optical imaging and therapy of lymphoma based on a new photosensitizer (1-oxo-1H-benzoo[de]anthracene-2,3-dicarbonitrile-triphenylamine (OBADC-TPA)). OBADC-TPA is a donor-acceptor (D-A) molecule characterized by a novel small coplanar and strong electron-withdrawing acceptor skeleton, while the OBADC moiety facilitates strong intramolecular charge transfer. OBADC-TPA-based nanoparticles (NPs) were prepared through encapsulation with an amphiphilic polymer and subsequent modification with sialic acid (SA). Both in vitro and in vivo studies demonstrated that NPs-SA possessed good biocompatibility, effective tumor accumulation, high photoacoustic (PA) contrast, bright second near-infrared (NIR-II) fluorescence emission, and efficient photothermal/photodynamic conversion capabilities, which can serve as a multifunctional nanocomposite for targeted PA/NIR-II fluorescence imaging-guided synergistic type I/II photodynamic and photothermal therapy (PDT/PTT) of lymphoma. This work not only provides a new NIR-II fluorophore with a novel acceptor moiety but also offers a new, accurate, and effective approach for the targeted diagnosis and treatment of lymphoma, holding promising prospects for clinical application.

Recent advances and design strategies for organic afterglow agents to enhance autofluorescence-free imaging performance

Long-lasting afterglow luminescence imaging that detects photons slowly being released from chemical defects has emerged, eliminating the need for real-time photoexcitation and enabling autofluorescence-free in vivo imaging with high signal-to-background ratios (SBRs). Organic afterglow nano-systems are notable for their tunability and design versatility. However, challenges such as unsatisfactory afterglow intensity, short emission wavelengths, limited activatable strategies, and shallow tissue penetration depth hinder their widespread biomedical applications and clinical translation. Such contradiction between promising prospects and insufficient properties has spurred researchers' efforts to improve afterglow performance. In this review, we briefly outline the general composition and mechanisms of organic afterglow luminescence, with a focus on design strategies and an in-depth understanding of the structure-property relationship to advance afterglow luminescence imaging. Furthermore, pending issues and future perspectives are discussed.

Mechanistic Insights Into NIR-II AIEgens Boosted Multimodal Phototheranostics

Exploiting single molecular species synchronously affording powerful second near-infrared (NIR-II) fluorescence, superior photoacoustic output, prominent reactive oxygen species generation, and satisfactory photothermal conversion is supremely appealing for phototheranostics, yet remains formidably challenging. In this work, electron donor/π-bridge engineering is implemented on the basis of 6,7-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline moiety. The optimal molecule, namely TPATO-TTQ, is demonstrates to exhibit those notable features requested by exceptional phototheranostics, which are systematically elucidated through the depictions of excited-state energy dissipation pathways and the influence of intramolecular motion on the photophysical properties, with assistances of quantum chemical calculation and molecular dynamic simulation. By utilizing TPATO-TTQ nanoparticles, unprecedented performance on NIR-II fluorescence-photoacoustic-photothermal trimodal imaging-navigated type I photodynamic-photothermal synergistic therapy to orthotopic breast cancer is authenticates by the precise tumor diagnosis and complete tumor ablation.

Broadband Near-Infrared Fibers Derived from Nanocrystal-Glass Composites for Miniature Arrays Light Sources

Broadband near-infrared (NIR) fiber arrays are highly desirable for multiplexed fluorescence endoscopic, however, there is a challenge for the development of miniature light sources with highly efficient broadband NIR emissions. Here the synthesis of a MgAl2O4:Cr3+ nanocrystal-glass composite (NGC) with an Cr3+-clusters-induced broadband NIR emission possessing is presented and external quantum efficiency of 44% and a full width at half maximum of 297 nm, and the NGC fiber is further fabricated through a template solidification strategy, resulting in the construction of an all-fiber coupling system by fusing them with commercial quartz fiber that achieves an optical coupling efficiency of 95.2%. Furthermore, these NGC fibers are regularly arranged into fiber bundle as an array light source to enhance NIR luminescence and imaging ability, and the fluorescence imaging of 4 mm biological tissue penetration is realized, as well as the multiplexed fluorescence imaging, under the irradiation of the NIR fiber bundle. This study provides general and efficient fiber fabrication guidelines toward NIR array light sources, opening the new routes for fluorescence endoscopes.

Representation models and processing operators for quantum informational multi-media

To enhance the efficacy of multimedia quantum processing and diminish processing overhead, an advanced multimedia quantum representation model and quantum video display framework are devised. A range of framework processing operators are also developed, including an image color compensation operator, a bit plane inversion operator, and a frame displacement operator. In addition, to address image security issues, two quantum image operations have been proposed: color transformation operation and pixel blending operation. The research results indicated that the grayscale cost of the framework designed in this study was 33.8, the color cost was 40.5, and the total cost was 574 δ. In terms of color, the distribution of image elements in the red, green, and blue (RGB) channels was more balanced. In summary, the quantum video display framework has significant advantages in processing efficiency and image security. Compared to previous studies, the model proposed in this study exhibits higher processing speed and better processing quality in the face of complex image and video data. It effectively addresses the limitations of existing processing techniques while addressing emerging image security issues.

The Midas Touch by Iridium: A Second Near-Infrared Aggregation-Induced Emission-Active Metallo-Agent for Exceptional Phototheranostics of Breast Cancer

Developing small organic molecular phototheranostic agents with second near-infrared (NIR-II) aggregation-induced emission (AIE) is paramount for the phototriggered diagnostic imaging and synchronous in situ therapy of cancer via an excellent balance of the excited states energy dissipations. In this study, a multifunctional iridium(III) complex is exploited by the coordination of an AIE-active N^N ancillary ligand with a trivalent iridium ion. The resultant complex DPTPzIr significantly outperforms its parent ligand in terms of absorption/emission wavelengths, reactive oxygen species (ROS) production, and photothermal conversion, which simultaneously endow DPTPzIr nanoparticles with matched absorption peak to commercial 808 nm laser, the longest NIR-II emission peak (above 1100 nm) among those previously reported AIE iridium(III) complexes, potentiated type-I ROS generation, and as high as 60.5% of photothermal conversion efficiency. Consequently, DPTPzIr nanoparticles perform well in multimodal image-guided photodynamic therapy-photothermal therapy for breast cancer in tumor-bearing mice, enabling precise tumor diagnosis and complete ablation with high biocompatibility. Our present work provides a simple, feasible, and effective paradigm for the development of advanced phototheranostic agents.

Aggregation-Induced Emission Luminogens Realizing High-Contrast Bioimaging

A revolutionary transformation in biomedical imaging is unfolding with the advent of aggregation-induced emission luminogens (AIEgens). These cutting-edge molecules not only overcome the limitations of traditional fluorescent probes but also improve the boundaries of high-contrast imaging. Unlike conventional fluorophores suffering from aggregation-caused quenching, AIEgens exhibit enhanced luminescence when aggregated, enabling superior imaging performance. This review delves into the molecular mechanisms of aggregation-induced emission (AIE), demonstrating how strategic molecular design unlocks exceptional luminescence and superior imaging contrast, which is crucial for distinguishing healthy and diseased tissues. This review also highlights key applications of AIEgens, such as time-resolved imaging, second near-infrared window (NIR-II), and the advancement of AIEgens in sensitivity to physical and biochemical cue-responsive imaging. The development of AIE technology promises to transform healthcare from early disease detection to targeted therapies, potentially reshaping personalized medicine. This paradigm shift in biophotonics offers efficient tools to decode the complexities of biological systems at the molecular level, bringing us closer to a future where the invisible becomes visible and the incurable becomes treatable.

Intramolecular Repulsive Interactions Enable High Efficiency of NIR-II Aggregation-Induced Emission Luminogens for High-Contrast Glioblastoma Imaging

Strategies to acquire high-efficiency luminogens that emit in the second near-infrared (NIR-II, 1000-1700 nm) range are still rare due to the impediment of the energy gap law. Herein, a feasible strategy is pioneered by installing large-volume encumbrances in a confined space to intensify the repulsive interactions arising from overlapping electron densities. The experimental results, including smaller coordinate displacement, reduced reorganization energy, and suppressed internal conversion, demonstrate that the repulsive interactions assist in the inhibition of radiationless deactivation. Meanwhile, the configuration and hybridization form of the donor units are transformed along with the repulsive interactions, bringing about improved oscillator strength. A 3.8-fold higher luminescence efficiency is realized via the synergistic effect. Furthermore, the repulsive interactions endow the NIR-II fluorophores with a highly twisted conformation, superior AIE activity, and cascaded improvement of fluorescence emission from isolated molecules to aggregates. By utilizing a brain-targeting peptide to functionalize the NIR-II nanoparticles, accurate detection and high-contrast imaging of orthotopic glioblastoma are realized. This work not only explores a fundamental principle to handle the intractable energy gap law but also provides potential applications of NIR-II luminogens in high-contrast bioimaging and glioblastoma detection.

Time-Encoded Information Encryption with pH Clock Guided Broad-Spectrum Emission by Dynamic Assemblies

With growing threats from counterfeiting-based security breaches, multi-level and specific stimuli-responsive anti-counterfeiting devices and message encryption methods have attracted immense research interest. Fluorescence-based encryption from aggregation-induced emission (AIE)-based materials solves the problems to a considerable extent. However, the development of smarter patterns with hierarchical security levels alongside dynamic display is still challenging. To screen out this complication, we bring forward a pH-switchable fluorescent assembly of an AIEgen and an aliphatic acid. We later temporally direct the molecular assembly with the aid of a chemical trigger-regulated pH clock, generating a transitory multicolor emission, including transient white light generation. The pH-dependent emissions were further implemented in constructing smart multi-input fluorescent chemical AND gates. Subsequently, we integrate the time-gated emissive system to develop an advanced multi-dimensionally secure data encryption strategy. This novel approach enhances anti-counterfeiting measures by introducing an additional layer of security based on temporal characteristics.

As Aggregation-Induced Emission Meets with Noncovalent Conformational Locks: Subtly Regulating NIR-II Molecules for Multimodal Imaging-Navigated Synergistic Therapies

Phototheranostics is growing into a sparking frontier in disease treatment. Developing single molecular species synchronously featured by powerful absorption capacity, superior second near-infrared (NIR-II) fluorescence and prominent photothermal conversion ability is highly desirable for phototheranostics, yet remains formidably challenging. In this work, we propose a molecular design philosophy that the integration of noncovalent conformational locks (NoCLs) with aggregation-induced emission (AIE) in a single formulation is able to boost multiple photophysical properties for efficient phototheranostics. The introduction of NoCLs skeleton with conformation-locking feature in the center of molecular architecture indeed elevates the structural planarity and rigidity, which simultaneously promotes the absorption capacity and bathochromic-shifts the emission wavelength centered in NIR-II region. Meanwhile, the AIE tendency mainly originated from flexibly propeller-like geometry at the ends of molecular architecture eventually endows the molecule with satisfactory emission intensity and photothermal conversion in aggregates. Consequently, by utilizing the optimized molecule, unprecedented performance on NIR-II fluorescence-photoacoustic-photothermal trimodal imaging-guided photothermal-chemo synergistic therapy is demonstrated by the precise tumor diagnosis and complete tumor ablation.

Tuning Zn-ion de-solvation chemistry with trace amount of additive towards stable Aqueous Zn anodes

Aqueous Zn-ion batteries (AZIBs) have attracted widespread attention due to their intrinsic safety, cost-effectiveness. However, active H2O in the solvated ions [Zn(H2O)6]2+ continuously migrate to the Zn surface to trigger hydrogen evolution reaction (HER) and accelerate Zn corrosion. Herein, Zn dendrites and the related by-products have been successfully inhibited by using trace amounts of Nitrilotriacetic acid (NTA). Theoretical research indicates that two carboxyl groups of NTA molecule strongly anchored on the Zn surface and exposed another carboxyl group outside. Due to the violent interaction of carboxyl groups of NTA with H2O, the de-solvation energy barrier of solvated Zn2+ ([Zn(H2O)6]2+) on the Zn surface was obviously decreased, inhibit the active water splitting. Meanwhile, the preferential adsorption of NTA on the Zn surface increases the thickness of electric double layer EDL and provides a buffer layer to hinder the dendrite growth. Using 0.04 M NTA as additives in 2.0 M ZnSO4 electrolyte, the cycling lifespan of both Zn||Zn symmetric and Zn||MnO2 full cells is markedly prolonged. This study provides certain perspectives for trace amounts of electrolyte additives to satisfy the demand of long-cycle life AZIBs.

Rational Design of NIR-II Ratiometric Fluorescence Probes for Accurate Bioimaging and Biosensing In Vivo

Intravital fluorescence imaging in the second near-infrared window (NIR-II, 900-1700 nm) has emerged as a promising method for non-invasive diagnostics in complex biological systems due to its advantages of less background interference, high tissue penetration depth, high imaging contrast, and sensitivity. However, traditional NIR-II fluorescence imaging, which is characterized by the "always on" or "turn on" mode, lacks the ability of quantitative detection, leading to low reproducibility and reliability during bio-detection. In contrast, NIR-II ratiometric fluorescence imaging can realize quantitative and reliable analysis and detection in vivo by providing reference signals for fluorescence correction, generating new opportunities and prospects during in vivo bioimaging and biosensing. In this review, the current design strategies and sensing mechanisms of NIR-II ratiometric fluorescence probes for bioimaging and biosensing applications are systematically summarized. Further, current challenges, future perspectives and opportunities for designing NIR-II ratiometric fluorescence probes are also discussed. It is hoped that this review can provide effective guidance for the design of NIR-II ratiometric fluorescence probes and promote its adoption in reliable biological imaging and sensing in vivo.

Ultrasensitive NIR-II Surface-Enhanced Resonance Raman Scattering Nanoprobes with Nonlinear Photothermal Effect for Optimized Phototheranostics

Surface-enhanced resonance Raman scattering (SERRS) in the second near-infrared (NIR-II) window has great potential for improved phototheranostics, but lacks nonfluorescent, resonant and high-affinity Raman dyes. Herein, it is designed and synthesize a multi-sulfur Raman reporter, NF1064, whose maximum absorption of 1064 nm rigidly resonates with NIR-II excitation laser while possessing absolutely nonfluorescent backgrounds. Ultrafast spectroscopy suggests that the fluorescence quenching mechanism of NF1064 originates from twisted intramolecular charge transfer (TICT) in the excited state. Gold nanorods (AuNRs) decorated with such nonfluorescent NF1064 (AuNR@NF1064) show remarkable SERRS performances, including zero-fluorescence background, femtomolar-level sensitivity as well as superb photostability without fluorescence photobleaching. More importantly, AuNR@NF1064 exhibits a nonlinear photothermal effect upon plasmonic fields of AuNRs by amplifying the non-radiative decay of nonfluorescent NF1064, thus achieving a high photothermal conversion of 68.5% in NIR-II window with potential for further augmentation. With remarkable SERRS and photothermal properties, the NIR-II nanoprobes allow for high-precision intraoperative guided tumor resection within 8 min, and high-efficient hyperthermia combating of drug-resistant bacterial infection within living mouse body. This work not only unlocks the potential of nonfluorescent resonant dyes for NIR-II Raman imaging, but also opens up a new method for boosting photothermal conversion efficiency of nanomaterials.

Brightness Strategies toward NIR-II Emissive Conjugated Materials: Molecular Design, Application, and Future Prospects

Recent advances have been made in second near-infrared (NIR-II) fluorescence bioimaging and many related applications because of its advantages of deep penetration, high resolution, minimal invasiveness, and good dynamic visualization. To achieve high-performance NIR-II fluorescence bioimaging, various materials and probes with bright NIR-II emission have been extensively explored in the past few years. Among these NIR-II emissive materials, conjugated polymers and conjugated small molecules have attracted wide interest due to their native biosafety and tunable optical performance. This review summarizes the brightness strategies available for NIR-II emissive conjugated materials and highlights the recent developments in NIR-II fluorescence bioimaging. A concise, detailed overview of the molecular design and regulatory approaches is provided in terms of their high brightness, long wavelengths, and superior imaging performance. Then, various typical cases in which bright conjugated materials are used as NIR-II probes are introduced by providing step-by-step examples. Finally, the current problems and challenges associated with accessing NIR-II emissive conjugated materials for bright NIR-II fluorescence bioimaging are briefly discussed, and the significance and future prospects of these materials are proposed to offer helpful guidance for the development of NIR-II emissive materials.

NIR-II AIEgens for Infectious Diseases Phototheranostics

Pathogenic infectious diseases have persistently posed significant threats to public health. Phototheranostics, which combines the functions of diagnostic imaging and therapy, presents an extremely promising solution to block the spread of pathogens as well as the outbreak of epidemics owing to its merits of a wide-spectrum of activity, high controllability, non-invasiveness, and difficult to acquire resistance. Among multifarious phototheranostic agents, second near-infrared (NIR-II, 1000-1700 nm) aggregation-induced emission luminogens (AIEgens) are notable by virtue of their deep penetration depth, excellent biocompatibility, balanced radiative and nonradiative decay and aggregation-enhanced theranostic performance, making them an ideal option for combating pathogens. This minireview provides a systematical summary of the latest advancements in NIR-II AIEgens with emphasis on the molecular design and nanoplatform formulation to fulfill high-efficiency in treating bacterial and viral pathogens, classified by disease models. Then, the current challenges, potential opportunities, and future research directions are presented to facilitate the further progress of this emerging field.

Multifunctional "Add-On" Module Enabled NIR-II Imaging-Guided Synergistic Photothermal and Chemotherapy of Drug-Resistant Lung Cancer

Imaging-guided chemo-photothermal combination therapy (chemo-PTT) is recognized for its synergistic therapeutic effects, reduced side effects, and minimal drug resistance, while the development of such theranostics has been hampered by poor imaging and therapy performance and tedious formulation. Herein, we introduce an all-in-one "add-on" module (BBT-C6) for the convenient construction of doxorubicin (DOX)-loaded nanoparticles (DOX@BBT) and efficient second near-infrared (NIR-II) fluorescence imaging (FLI)-guided synergistic chemo-PTT of drug-resistant lung cancer. The delicate Janus amphiphilic structure of BBT-C6 enables multifunctionality, including NIR-II FLI, aggregation-induced emission (AIE) characteristics, moderate photothermal conversion efficiency (PCE), excellent photostability, and polyethylene glycolation (PEGylation), which could improve the NIR-II FLI and PTT performance, relieve the complexity in theranostics, and enable high reproducibility of the multifunctional theranostics. Confocal microscopy revealed that BBT@DOX efficiently delivers DOX into cells, resulting in an increased accumulation of DOX that exceeds the efflux capacity of DOX-resistant cells. Both in vitro and in vivo studies demonstrate that BBT-C6 enhances the effectiveness of BBT@DOX, achieving highly effective photothermal-chemo synergistic therapy against DOX-resistant lung cancer. Beyond developing a versatile "add-on" module for conveniently constructing multifunctional nanosystems, this study provides new insights into the design of advanced theranostics for precise biomedical applications.

NIR-II Fluorescent Nanotheranostics with a Switchable Irradiation Mode for Immunogenic Sonodynamic Therapy

Nanotheranostics, which integrate diagnostic and therapeutic functionalities, offer significant potential for tumor treatment. However, current nanotheranostic systems typically involve multiple molecules, each providing a singular diagnostic or therapeutic function, leading to challenges such as complex structural composition, poor targeting efficiency, lack of spatiotemporal control, and dependence on a single therapeutic modality. This study introduces NPRBOXA, a nanoparticle functionalized with surface-bound cRGD for targeted delivery to αvβ3/αvβ5 receptors on tumor cells, achieving theranostic integration by sequentially switching its irradiation modes. Under 808 nm laser irradiation, NPRBOXA emits NIR-II fluorescence, which aids in identifying the nanoparticle's location and fluorescence intensity, thereby determining the optimal treatment window. Following this, the irradiation mode switches to ultrasound irradiation at the optimal treatment window. Ultrasound irradiation induces NPRBOXA to generate reactive oxygen species, promoting the reduction of OXA-IV to OXA-II, which in turn triggers immunogenic cell death. This mechanism enables a combination of sonodynamic therapy, chemotherapy, and immunotherapy for tumor treatment. The versatile design of NPRBOXA holds promise for advancing precision oncology through enhanced therapeutic efficacy and real-time imaging guidance.

Synthesis of heavy-atom-free thienoisoindigo dye as near-infrared photosensitizer for type I photodynamic therapy and photoacoustic imaging

Thienoisoindigo (TIIG) has been extensively employed as promising building block of near-infrared (NIR) dyes and organic semiconductor materials. Herein, heavy-atom-free TIIG-based NIR dye TIIGTPA is reported as photosensitizer for combinational photodynamic and photothermal therapy and photoacoustic imaging (PAI). By introducing two methoxy-substituted triphenylamines as the rotors and electron donors at the periphery sites of the electron-deficient TIIG core, dye TIIGTPA featuring Donor-Acceptor-Donor (D-AD) structure is constructed with intensive NIR absorption. Through co-assembly with amphipathic F-127, water-soluble TIIGTPA NPs were prepared with good superoxide anion radical (O2-•) production and high photothermal conversion efficiency (PCE) of 59.0 % under 730 nm photoirradiation. Additionally, the excellent photothermal effect enabled a superior photoacoustic response for tumor blood vessel visualization through PAI. All results indicated the favorable potential of TIIGTPA NPs for PAI-mediated combinational phototherapy.

Conceptually innovative fluorophores for functional bioimaging

Fluorophore chemistry is at the forefront of bioimaging, revolutionizing the visualization of biological processes with unparalleled precision. From the serendipitous discovery of mauveine in 1856 to cutting-edge fluorophore engineering, this field has undergone transformative evolution. Today, the synergy of chemistry, biology, and imaging technologies has produced diverse, specialized fluorophores that enhance brightness, photostability, and targeting capabilities. This review delves into the history and innovation of fluorescent probes, showcasing their pivotal role in advancing our understanding of cellular dynamics and disease mechanisms. We highlight groundbreaking molecules and their applications, envisioning future breakthroughs that promise to redefine biomedical research and diagnostics.

Molecular Planar Rigidity Promoted Aggregation-Induced Delayed Electrochemiluminescence of Organic Dots for Nucleic Acid Assay

Developing organic aggregation-induced delayed electrochemiluminescence (AIDECL) active emitters is attractive due to their full utilization of excited species. However, current molecular designs primarily focus on the electron-deficient core benzophenone, resulting in relatively low ECL efficiency due to its flexible skeleton. Herein, we design a rigid electron acceptor, i.e., xanthenone, by inserting an oxygen bridge into the benzophenone moiety, and an AIDECL-active organic dot (OD) composed of a xanthenone-dimethylacridine compound is constructed. High ECL efficiency is achieved for the resultant ODs, with a 3-fold enhancement compared to control ODs. Oxygen bridge-induced planar moiety rigidifies the molecular configuration, further inhibiting intramolecular motions and thus suppressing nonradiative decay, supported by the single-crystal data together with theoretical calculations. Significantly, an ECL biosensor is constructed employing these ODs as emitters for the sensitive analysis of miR-21 associated with pancreatic cancer, which demonstrates a low detection limit of 2.8 fM. Our investigation provides a promising way to design efficient ECL emitters and deepens the understanding of structure-property relationships.

Instant in situ highlighting of latent fingerprints by a green fluorescent probe based on aggregation-induced emission

Fluorescence sensing of latent fingerprints (LFPs) has gained extensive attention due to its high sensitivity, non-destructive testing, low biotoxicity, ease of operation, and the potential for in situ visualization. However, the realization of in situ visualization of LFPs especially with green emission and rapid speed is still a challenge. Herein, we synthesized an amphibious green-emission AIE-gen TPE-NI-AOH (PLQY = 62%) for instant in situ LFP detecting, which integrates the excellent fluorescence properties of naphthalimide (NI) with a hydrophilic head and the AIE character as well as the donating property of tetraphenylethene (TPE). TPE-NI-AOH in ethanol/water binary solvent was used as an environmentally friendly LFP developer and achieved in situ green-fluorescence visualization of LFPs. The fluorescence signal achieves its 60% saturated intensity in 0.37 s and nearly 100% in 2.50 s, which is an instant process for the naked eye. Moreover, level 3 details and super-resolution images of LFPs could be observed clearly. Besides, the TPE-NI-AOH developer could be stored for at least 6 months, suitable for long-term storage. This instant in situ highlighting method does not require post-processing operations, providing a more convenient, rapid, and efficient detection method of LFPs. This work would inspire the further advancement of fluorescent sensors for fingerprint imaging.

From Simple Probe to Smart Composites: Water-Soluble Pincer Complex With Multi-Stimuli-Responsive Luminescent Behaviors

Water-soluble smart materials with multi-stimuli-responsiveness and ultra-long room-temperature phosphorescence (RTP) have garnered broad attention. Herein, a water-soluble terpyridine zinc complex (MeO-Tpy-Zn-OAc), featuring a simple donor-π-acceptor (D-π-A) structure is presented, which responds to a variety of stimuli, including changes in solvents, pH, temperature, and the addition of amino acids. Notably, MeO-Tpy-Zn-OAc functions as a fluorescence probe, capable of visually and selectively discriminating aspartate or histidine among other common amino acids in water. Additionally, when incorporated into polyvinyl alcohol (PVA) to form the composite MeO-Tpy-Zn-OAc@PVA, the material exhibits reversible writing, photochromism, and a prolonged RTP with a 14 s afterglow. These unique properties enable the composite to be utilized in potential applications such as secure data encryption and inkless printing.

An in situ-activated and chemi-excited photooxygenation system based on G-poly(thioacetal) for Aβ1-42 aggregates

The abnormal aggregation of Aβ proteins, inflammatory responses, and mitochondrial dysfunction have been reported as major targets in Alzheimer's disease (AD). Photooxygenation of the amyloid-β peptide (Aβ) is viewed as a promising therapeutic intervention for AD treatment. However, the limitations of the depth of the external light source passing through the brain and the toxic side effects on healthy tissues are two significant challenges in the photooxidation of Aβ aggregates. We proposed a method to initiate the chemical stimulation of Aβ1-42 aggregate oxidation through H2O2 and correct the abnormal microenvironment of the lesions by eliminating the cascading reactions of oxidative stress. The degradable G-poly(thioacetal) undergoes cascade release of cinnamaldehyde (CA) and thioacetal triggered by endogenous H2O2, with CA in turn amplifying degradation by generating more H2O2 through mitochondrial dysfunction. A series of novel photosensitizers have been prepared and synthesized for use in the photodynamic oxidation of Aβ1-42 aggregates under white light activation. The nanoparticles (BD-6-QM/NPs) self-assembled from BD-6-QM, bis[2,4,5-trichloro-6-(pentoxycarbonyl) phenyl] ester (CPPO), and G-poly(thioacetal) not only exhibit H2O2-stimulated controlled release but also can be chemically triggered by H2O2 to generate singlet oxygen to inhibit Aβ1-42 aggregates, reducing the Aβ1-42-induced neurotoxicity.

Recent advances in biomaterials based near-infrared mild photothermal therapy for biomedical application: A review

Mild photothermal therapy (MPTT) generates heat therapeutic effect at the temperature below 45 °C under near-infrared (NIR) irradiation, which has the advantages of controllable treatment efficacy, lower hyperthermia temperatures, reduced dosage, and minimized damage to surrounding tissues. Despite significant progress has been achieved in MPTT, it remains primarily in the stage of basic and clinical research and has not yet seen widespread clinical adoption. Herein, a comprehensive overview of the recent NIR MPTT development was provided, aiming to emphasize the mechanism and obstacles, summarize the used photothermal agents, and introduce various biomedical applications such as anti-tumor, wound healing, and vascular disease treatment. The challenges of MPTT were proposed with potential solutions, and the future development direction in MPTT was outlooked to enhance the prospects for clinical translation.

Structure Tailoring of Hemicyanine Dyes for In Vivo Shortwave Infrared Imaging

In vivo bioimaging using shortwave infrared (SWIR) (1000-2000 nm) molecular dyes enables deeper penetration and higher contrast compared to visible and near-infrared-I (NIR-I, 700-900 nm) dyes. Developing new SWIR molecules is still quite challenging. This study developed SRHCYs, a panel of fluorescent dyes based on hemicyanine, with adjustable absorbance (830-1144 nm) and emission (886-1217 nm) wavelength. The photophysical attributes of these dyes are precisely tailored by strengthening the donor parts and extending polymethine chains. SRHCY-3, with its clickable azido group, was chosen for high-performance imaging of blood vessels in living mice, enabling the precise detection of brain and lung cancer. The combination of these probes achieved in vivo multicolor imaging with negligible optical crosstalk. This report presents a series of SWIR hemicyanine dyes with promising spectroscopic properties for high-contrast bioimaging and multiplexing detection.

Persistent Luminescence-Based Nanoreservoir for Benign Photothermal-Reinforced Nanozymatic Therapy

Adjusting the catalytic activity of nanozymes for enhanced oncotherapy has attracted significant interest. However, it remains challenging to engineer regulatory tactics with a minimal impact on normal tissues. By exploiting the advantages of energy storage, photostimulated, and long afterglow luminescence of persistent nanoparticles (PLNPs), a persistent luminescence-based nanoreservoir was produced to improve its catalytic activity for benign oncotherapy. In the study, PLNPs in a nanoreservoir with the ability to store photons served as a self-illuminant to promote its peroxidase-like activity and therapeutic efficacy by persistently motivating its photothermal effect before and after external irradiation ceased. The photostimulated and persistent luminescence of PLNPs and spatiotemporal controllability of exogenous light jointly alleviated adverse effects induced by prolonged irradiation and elevated the catalytic capability of the nanoreservoir. Ultimately, the system fulfilled benign photothermal-intensive nanozymatic therapy. This work provides new insights into boosting the catalytic activity of nanozymes for secure disease treatment.

Light-Enhanced Tandem-Responsive Nano Delivery Platform for Amplified Anti-tumor Efficiency

Designing nanomedicines with low toxicity, high targeting, excellent therapeutic effects, and precise release is always the major challenges in clinical cancer treatment. Here, we report a light-enhanced tandem-responsive nano delivery platform COF-B@X-03 for amplified anti-tumor efficiency. Biotin-loaded COF-B@X-03 could precisely target tumor cells, and the azo and hydrazone bonds in it would be depolymerized by the overexpressed azoreductase and acidic microenvironment in hypoxic tumors. In vitro experimental results indicate mitochondrial and endoplasmic reticulum stress caused by COF-B@X-03 under light is the direct cause of tumor cell death. In vivo experimental data prove COF-B@X-03 achieves low oxygen dependent phototherapy, and the maintenance of intratumoral hypoxia provides the possibility for the continuous degradation of COF-B@X-03 to generate more reactive oxygen species for tumor photodynamic therapy by released X-03. In the end, COF-B@X-03 phototherapy group achieves higher tumor inhibition rate than X-03 phototherapy group, which is 81.37 %. Meanwhile, COF-B@X-03 significantly eliminates the risk of tumor metastasis. In summary, the construction of this tandem-responsive nano delivery platform provides a new direction for achieving efficient removal of solid tumors in clinical practice.

Efficient Near-Infrared Fluorophores Based on Cyanostyrene Derivatives for Two-Photon Fluorescence Bioimaging

Organic fluorescent materials with red/near-infrared (NIR) emission are highly promising for use in biotechnology due to their exceptional advantages. However, traditional red/NIR fluorophores often exhibit weak emission at high concentrations or in an aggregated state due to the aggregate-caused quenching effect, which severely limits their applicability in biological imaging. To address this challenge, we developed a series of cyanostyrene derivatives with aggregation-induced emission characteristics, including 2,3-Bis-(4-styryl-phenyl)-but-2-enedinitrile (DPB), 2,3-Bis-{4-[2-(4-methoxy- phenyl)-vinyl]-phenyl}-but-2-enedinitrile (DOB), 2,3-Bis-{4-[2-(4-diphenylamino- phenyl)-vinyl]-phenyl}-but-2-enedinitrile (DTB), and 2,3-Bis-[4-(2-{4-[phenyl- (4-triphenylvinyl-phenyl)-amino]-phenyl}-vinyl)- phenyl]-but-2-enedinitrile (DTTB). Notably, these compounds exhibited intense solid state fluorescence owing to AIE effect, especially DTTB shows NIR emission with high solid state quantum efficiency (712 nm, ΦF=14.2 %). Then we prepared DTTB@PS-PEG NPs nanoparticles by encapsulating DTTB with the amphiphilic polymer polystyrene-polyethylene glycol (PS-PEG). Importantly, DTTB@PS-PEG NPs exhibited highly efficient NIR luminescence (ΦF=28.7 %) and a large two-photon absorption cross-section (1900 GM) under 800 nm laser excitation. The bright two-photon fluorescence of DTTB@PS-PEG indicated that it can be a highly promising candidate for two-photon fluorescence probe. Therefore, this work provides valuable insights for the design of highly efficient and NIR-emitting two-photon fluorescent probes.

Chemiexcitation-Triggered Photosensitizer Activation for Photooxidation of Aβ1-42 Aggregates

Oxidative degradation of the pathogenic amyloid-β-peptide (Aβ) aggregation is an effective and promising method to treat Alzheimer's disease under light irradiation. However, the limited penetration of external light sources into deep tissues has hindered the development of this treatment. Therefore, we have designed an unprecedented chemiluminescence-initiated photodynamic therapy system to replace external laser irradiation, primarily composed of d-glucose-based polyoxalate (G-poly(oxalate)), the novel photosensitizer (BD-Se-QM), and bis [2,4,5-trichloro-6-(pentoxy-carbonyl) phenyl] ester. BD-Se-QM possesses excellent singlet oxygen (1O2) generation efficiency and the ability to photooxidize Aβ1-42 aggregates under white light. G-poly(oxalate) not only helps the nanosystem to cross the blood-brain barrier but also has sufficient oxalate ester groups to significantly enhance the efficiency of chemiluminescence resonance energy transfer. The oxalate ester groups in BD-Se-QM/NPs can chemically react with H2O2 to produce high-energy intermediates that activate BD-Se-QM, which can generate 1O2 to inhibit Aβ1-42 aggregates and also promote microglial uptake of Aβ1-42, reducing the Aβ1-42-induced neurotoxicity. The chemically stimulated nanoplatform not only solves the drug delivery problem but also eliminates the need for external light sources. We anticipate that this chemically excited nanosystem could also be used for targeted delivery of other small molecule drugs.

A de novo zwitterionic strategy of ultra-stable chemiluminescent probes: highly selective sensing of singlet oxygen in FDA-approved phototherapy

Singlet oxygen (1O2), as a fundamental hallmark in photodynamic therapy (PDT), enables ground-breaking clinical treatment in ablating tumors and killing germs. However, accurate in vivo monitoring of 1O2 remains a significant challenge in probe design, with primary difficulties arising from inherent photo-induced side reactions with poor selectivity. Herein, we report a generalizable zwitterionic strategy for ultra-stable near-infrared (NIR) chemiluminescent probes that ensure a highly specific [2 + 2] cycloaddition between fragile electron-rich enolether units and 1O2 in both cellular and dynamic in vivo domains. Innovatively, zwitterionic chemiluminescence (CL) probes undergo a conversion into an inert ketone excited state with an extremely short lifetime through conical intersection (CI), thereby affording sufficient photostability and suppressing undesired photoreactions. Remarkably, compared with the well-known commercial 1O2 probe SOSG, the zwitterionic probe QMI exhibited an ultra-high signal-to-noise ratio (SNR, over 40-fold). Of particular significance is that the zwitterionic CL probes demonstrate excellent selectivity, high sensitivity, and outstanding photostability, thereby making a breakthrough in real-time tracking of the FDA-approved 5-ALA-mediated in vivo PDT process in living mice. This innovative zwitterionic strategy paves a new pathway for high-performance NIR chemiluminescent probes and high-fidelity feedback on 1O2 for future biological and medical applications.

Neutral Cyanine: Ultra-Stable NIR-II Merocyanines for Highly Efficient Bioimaging and Tumor-Targeted Phototheranostics

Fluorescence imaging (FLI)-guided phototheranostics using emission from the second near-infrared (NIR-II) window show significant potential for cancer diagnosis and treatment. Clinical imaging-used polymethine ionic indocyanine green (ICG) dye is widely adopted for NIR fluorescence imaging-guided photothermal therapy (PTT) research due to its exceptional photophysical properties. However, ICG has limitations such as poor photostability, low photothermal conversion efficiency (PCE), short-wavelength emission peak, and liver-targeting issues, which restrict its wider use. In this study, two ionic ICG derivatives are transformed into neutral merocyanines (mCy) to achieve much-enhanced performance for NIR-II cancer phototheranostics. Initial designs of two ionic dyes show similar drawbacks as ICG in terms of poor photostability and low photothermal performance. One of the modified neutral molecules, mCy890, shows significantly improved stability, an emission peak over 1000 nm, and a high photothermal PCE of 51%, all considerably outperform ICG. In vivo studies demonstrate that nanoparticles of the mCy890 can effectively accumulate at the tumor sites for cancer photothermal therapy guided by NIR-II fluorescence imaging. This research provides valuable insights into the development of neutral merocyanines for enhanced cancer phototheranostics.

Cationic conjugated polymer coupled non-conjugated segments for dually enhanced NIR-II fluorescence and lower-temperature photothermal-gas therapy

The lack of a simple design strategy to obtain ideal conjugated polymers (CPs) with high absorbance and fluorescence (FL) in the near-infrared-II (NIR-II; 1000-1700 nm) region still hampers the success of NIR-II light-triggered phototheranostics. Herein, novel phototheranostic nanoparticles (PPN-NO NPs) were successfully prepared by coloading a cationic NIR-II CPs (PBC-co-PBF-NMe3) and a NO donor (S-nitroso-N-acetylpenicillamine, SNAP) onto a 1:1 mixture of DSPE-PEG5000 and dimyristoylphosphatidylcholine (DMPC) for NIR-II FL and NIR-II photoacoustic (PA) imaging-guided low-temperature NIR-II photothermal therapy (PTT) and gas combination therapy for cancer treatment. A precise NIR-II FL dually enhanced design tactic was proposed herein by integrating flexible nonconjugated segments (C6) into the CPs backbone and incorporating quaternary ammonium salt cationic units into the CPs side chain, which considerably increased the radiative decay pathway, resulting in desirable NIR-II FL intensity and balanced NIR-II absorption and NIR PTT properties. The phototheranostic PPN-NO NPs exhibited distinguished NIR-II FL and PA imaging performance in tumor-bearing mice models. Furthermore, the low-temperature photothermal effect of PPN-NO NPs could initiate NO release upon 980 nm laser irradiation, efficiently suppressing tumor growth owing to the combination of low-temperature NIR-II PTT and NO gas therapy in vitro and in vivo.

Dual-modal imaging-guided agent based on NIR-II aggregation-induced emission luminogens with balanced phototheranostic performance

Phototherapy has garnered considerable interest for its potential to revolutionize conventional cancer treatment. Organic materials with near-infrared II (NIR-II, 1000-1700 nm) fluorescence and photothermal effects are key for precise tumor diagnosis and treatment, yet optimizing their output for higher resolution and reduced photodamage remains a challenge. Herein, a multifunctional NIR-II photosensitizer (LSC) has been developed using the aggregation-induced emission (AIE) technology. The utilization of thieno[3,2-b]thiophene as an electron-rich and bulky donor/acceptor bridge has allowed for the elongation of conjugation length and distortion of the AIE main chain. This strategic modification effectively enhances the electron push-pull effect, endowing the LSC with a Stokes shift of over 400 nm and AIE characteristics. We have successfully built-up stable nanoparticles called FA-LSC NPs using a nano-precipitation method. These nanoparticles exhibit high NIR-II fluorescent brightness (ε × QY = 1064 M-1 cm-1) and photothermal conversion efficiency (41%). Furthermore, the biocompatible FA-LSC NPs demonstrate effective tumor accumulation and exceptional photothermal therapeutic efficacy both in vitro and in vivo. These nanoparticles were applied to fluorescence-photothermal dual-mode imaging-guided photothermal ablation in a HeLa tumor xenograft mouse model, resulting in favorable photothermal clearance outcomes.

Nanoparticles destabilizing the cell membranes triggered by NIR light for cancer imaging and photo-immunotherapy

Cationic polymers have great potential for cancer therapy due to their unique interactions with cancer cells. However, their clinical application remains limited by their high toxicity. Here we show a cell membrane-targeting cationic polymer with antineoplastic activity (Pmt) and a second near-infrared (NIR-II) fluorescent biodegradable polymer with photosensitizer Bodipy units and reactive oxygen species (ROS) responsive thioketal bonds (PBodipy). Subsequently, these two polymers can self-assemble into antineoplastic nanoparticles (denoted mt-NPBodipy) which could further accumulate at the tumor and destroy cell membranes through electrostatic interactions, resulting in cell membrane destabilization. Meanwhile, the photosensitizer Bodipy produces ROS to induce damage to cell membranes, proteins, and DNAs to kill cancer cells concertedly, finally resulting in cell membrane lysis and cancer cell death. This work highlights the use of near-infrared light to spatially and temporarily control cationic polymers for photodynamic therapy, photo-immunotherapy, and NIR-II fluorescence for bio-imaging.

Unique Fluorescence of Aggregation-Induced Emission Luminogens on Solid Surfaces Modified by Silicone Nanofilaments

Aggregation-induced emission (AIE) has revolutionized solid-state fluorescence by overcoming the limitations of aggregation-caused quenching. While extensively studied in solutions, AIE's potential on solid surfaces remains largely unexplored, which can be fundamentally interesting and practically useful. In this work, we demonstrate the successful dispersion of tetraphenylethylene (TPE), one of the most classical AIE luminogens, on solid surfaces coated with silicone nanofilaments (SNF). The high surface area of SNF enables the uniform immobilization of TPE luminogens, replicating their dispersal behavior in solutions. Compared to unmodified surfaces, TPE dispersed on SNF-coated surfaces exhibits significantly enhanced fluorescence intensity. Moreover, a fascinating dynamic blue shift in TPE emission on SNF-coated surfaces is observed, with the velocity controllable by the surface group of SNF by up to 4 orders of magnitude, showing that TPE can be applied to the judgment of the nanoscale morphology and surface free energy of the solid surface. Owing to the superhydrophobicity and self-cleaning properties of SNF, the on-surface fluorescence can be sustained underwater and is resistant to dust contamination and rain erosion, with potential applications of information encryption presented. Our approach of uniformly dispersing AIE luminogens on nanomaterials with high surface areas provides a general methodology for creating on-surface fluorescence and saving the usage of expensive AIE luminogens in applications.