The fast-growing field of photo-driven theranostics based on aggregation-induced emission

An AIE-active Janus filter membrane for highly efficient detection and elimination of bioaerosols

Highly efficient detection and sterilization techniques for bioaerosol prevention and control are urgently needed. Herein, we present an AIE-active Janus air filter membrane (AIE-HAFM) that features water-dissolvable micro-nano porous network architecture and aggregation-induced emission (AIE) activity constructed by the asymmetrical surface modification with an amphiphilic AIE photosensitizer (MeOTTVP). The all-round AIE-HAFM can not only provide low pressure drop and high interception efficiency for bioaerosol sampling but also perfectly inherit the AIE functions of MeOTTVP, which allows for intensive near-infrared (NIR) emission and efficient production of reactive oxygen species. The airborne pathogens can be effectively captured, collected, transferred, and released by AIE-HAFM for subsequent quantitative detection with colony counting and ATP bioluminescence, as well as stained by the incorporated MeOTTVP for NIR fluorescence imaging-guided visual detection. Meanwhile, AIE-HAFM enables on-demand and surface-dependent photodynamic effects for reliable bacterial eradication under white light irradiation due to the surface-concentrated MeOTTVP, consequently achieving the smart prevention and control of bioaerosols both in the simulated and real-world bioaerosol environment. The versatility of AIE-HAFM in handling diverse airborne pathogens may bring about a transformative solution to address the bioaerosol contamination problems.

Recent advances in developing bioorthogonally activatable photosensitizers for photodynamic therapy

Photodynamic therapy (PDT) is a promising and powerful cancer therapeutic modality, which can generate cytotoxic reactive oxygen species (ROS) from light-irradiated photosensitizers (PSs) to eradicate tumors. To overcome the drawbacks of currently used PSs, researchers have leveraged the advantages of bioorthogonal reactions to design diverse bioorthogonally activatable photosensitizers with excellent tumor selectivity, high ROS generation controllability, and low adverse effect for effective antitumor photodynamic therapy. In this review, we comprehensively summarize and highlight the recent advances in the development of bioorthogonally activatable photosensitizers, including the structure types, designing strategies, activation patterns, photophysical properties, ROS generation efficiency, in vitro and in vivo activities, biological applications, and limitations. We also provide directions and perspectives to address the therapeutic challenges of bioorthogonally activatable photosensitizers for promoting clinical applications. We believe that the principles summarized here will offer useful references for further development of next-generation advanced intelligent photosensitizers and related strategies to realize precise and efficient tumor treatment in the future.

Regulated cell death mechanisms in mitochondria-targeted phototherapy

Phototherapy, comprising photodynamic therapy (PDT) and photothermal therapy (PTT), was first introduced over a century ago and has since evolved into a versatile cancer treatment modality. While numerous studies have explored regulated cell death (RCD) mechanisms induced by phototherapy, a comprehensive synthesis centered on mitochondria-targeted phototherapeutic strategies and agents as mediators of RCD is still lacking. This review provides a systematic and in-depth analysis of recent advances in mitochondria-centered mechanisms driving phototherapy-induced death pathways, including apoptosis, autophagy, pyroptosis, immunogenic cell death, ferroptosis, and cuproptosis. We highlight the critical role of mitochondria as central regulators of these death pathways in response to phototherapeutic interventions. Moreover, we discuss fundamental design strategies for developing precision-targeted phototherapeutic materials to enhance efficacy and minimize off-target effects. Finally, we identify prevailing challenges and propose future research directions to address these hurdles, paving the way for next-generation mitochondria-targeted phototherapy as a highly effective strategy for cancer management.

Cationic AIEgens with large rigid π-planes: Specific bacterial imaging and treatment of drug-resistant bacterial infections

In this study, four D-π-A type cationic photosensitisers with aggregation-induced emission (AIE) properties were developed based on the electron-donating group triphenylamine and pyrene molecules acting as auxiliary electron donors and main π-bridges, as well as pyridinium salts of different charge numbers acting as electron acceptors: TPP1, MeOTPP1, TPP2 and MeOTPP2. The introduction of pyrene endowed the AIE photosensitizers with a high solid fluorescence quantum yield and long fluorescence lifetime. All four photosensitizer molecules were able to efficiently generate type I (·OH) and type II (1O2) under white light irradiation, achieving efficient inactivation of methicillin-resistant Staphylococcus aureus (MRSA) at low concentrations, and TPP1 and TPP2 successfully promoted wound healing in MRSA-infected mice. The introduction of a methoxy group effectively enhanced the intramolecular charge transfer effect, achieved longer wavelength absorption and fluorescence emission redshift, and effectively reduced ΔEst thereby promoting ROS (Reactive Oxygen Species) generation. However, after the introduction of the methoxy group, the CAC (Critical Aggregate Concentration) of MeOTPP1 and MeOTPP2 became smaller and the hydrophobicity was enhanced, which affected the interaction with bacteria. In fact, the photodynamic antimicrobial activity and imaging ability against bacteria were reduced. TPP2 achieves efficient killing of MRSA and MDR E.coli (Multidrug-resistant Escherichia coli) by disrupting the bacterial cell membrane due to its high photosensitization efficiency, two positive charges and very high CAC value. Under light (40 mW·cm-2), only 1 μM of TPP2 inactivated 87 % of MRSA, followed by TPP1, which inactivated 59 %, while MeOTPP1 and MeOTPP2 showed no significant antibacterial activity at this concentration. At a concentration of 10 μM, TPP2 deactivated more than 95 % of MDR E.coli, TPP1 deactivated about 41 %, and MeOTPP1 and MeOTPP2 had no antimicrobial activity against MDR E.coli at this concentration. In addition, TPP1, MeOTPP1 and TPP2 were able to rapidly identify MRSA and MDR E.coli under the irradiation of 365 nm UV light, which provides a visual method for the rapid identification of MRSA and MDR E.coli.

Molecularly manipulating pyrazinoquinoxaline derivatives to construct NIR-II AIEgens for multimodal phototheranostics of breast cancer bone metastases

Multimodal phototheranostics on the basis of single molecular species shows inexhaustible and vigorous vitality, particularly those emit fluorescence in the second near-infrared window (NIR-II), the construction of such exceptional molecules nonetheless retains formidably challenging. In view of the undiversified molecular skeletons and insufficient phototheranostic outputs of previously reported NIR-II fluorophores, herein, electron acceptor engineering based on heteroatom-inserted rigid-planar pyrazinoquinoxaline was manipulated to fabricate aggregation-induced emission (AIE)-featured NIR-II counterparts with donor-acceptor-donor (D-A-D) architecture. Systematical investigations substantiated that one of those synthesized AIE molecules, namely 4TPQ, incorporating a fused thiophene acceptor, synchronously exhibited high molar absorptivity (ε), NIR-II emission, typical AIE tendency, significant reactive oxygen species (ROS) generation, and high photothermal conversion efficiency. These extraordinary behaviors endowed 4TPQ nanoparticles with unprecedented performance on NIR-II fluorescence/photothermal imaging-navigated synergistic photodynamic/photothermal inhibition of tumors, as confirmed by the mice model of breast cancer bone metastases. This study thus brings significant insights into developing phototheranostic systems for clinical trials.

Regioisomerism in NIR-II-emissive semiconducting biradicals for high-performance bioimaging and phototheranostics of tumors

Photothermal agents (PTAs) have received significant attention in medical therapeutic and diagnostic applications. Despite their tremendous development, developing PTAs is challenging when applied to a living body with deep tissue, as it usually leads to attenuated therapeutic efficiency and potential biosafety hazards. Here, we report a molecular isomerization strategy based on NIR-II semiconducting biradicals that boosts the performance of NIR-II phototheranostics. With a stereoisomeric design by precisely manipulating the substitution position of the alkyl side chain, the optimal isomer, α-TBTS, and its nanoparticles (NPs) provide enhanced NIR-II absorption and 63% photothermal conversion capabilities, resulting in efficient photoablation of tumor cells. Most importantly, the relationship between the molecular isomerism of these NIR-II theranostics enables enhanced NIR-II performance, which has been proven by theoretical and ultrafast spectroscopy studies. With all these advantages, the α-TBTS nanoplatform has simultaneously achieved high-resolution whole-body NIR-II angiography and trimodal tumor-targeted imaging in vivo. Moreover, α-TBTS NPs efficiently inhibited tumor growth without recurrence upon NIR-II light irradiation, providing good biosafety. This work demonstrates the feasibility of molecular isomerization in multimodal NIR-II biradical PTAs and thus provides a suitable theranostic agent for high-performance tumor phototheranostics.

Turning Lemons into Lemonade: One-Step Synthesized Dual-Acceptor Organic Photosensitizer to Boost the Photodynamic Therapy

Reactive oxygen species (ROS) are crucial in photodynamic therapy (PDT), but their generation is highly dependent on the S-T bandgap (ΔEST), spin-orbit coupling (SOC), intersystem crossing rate (kISC), and also excited triplet-states lifetime (τTriplet) in organic photosensitizers (PSs). In contrast to the widely reported donor-acceptor-donor (D-A-D) type PSs, D-A-A-D typed PSs are seldomly developed for the time-consuming and complicated synthesis, but show great potential in enhancing ROS generation in phototheranostics. This work here presents a one-step synthetic procedure of D-A-A-D type 2DMeTPA-2BT with a high yield of 47%, which is significantly different from the previously reported dual-acceptor cases. In contrast to 2DMeTPA-BT, the dual-acceptor PSs of 2DMeTPA-2BT display a much smaller ΔEST value but large SOC constants. Also, the intersystem crossing (ISC) dynamics indicate that fast kISC, long τTriplet, and large triplet population are observed in 2DMeTPA-2BT-based nanoparticles (NPs), contributing to a superior generation of ROS. 2DMeTPA-2BT NPs are then finally utilized for the imaging-guided PDT in vivo with a tumor inhibition rate of 90%. This method offers an efficient way to produce dual-acceptor typed PSs via a one-step reaction, providing new avenues in high-performance phototheranostics.

Theranostic advances and the role of molecular imprinting in disease management

Molecular imprinting has become an effective technology in the realm of diagnosing diseases, providing unparalleled specificity and sensitivity. This method is a promising trend in current medical research. This review examines the utilization of molecularly imprinted polymers (MIPs) in theranostic that integrates diagnostic functionalities for personalized medicine. The present work briefly discusses the fundamental concepts of molecular imprinting and how it has evolved into a versatile platform. Subsequently, the utilization of MIPs in the advancement of biosensors is focused, specifically emphasizing their contribution to the detection and diagnosis of diseases. The therapeutic potential of MIPs, focusing on targeted drug delivery and controlled release systems and the integration of MIPs into theranostic platforms is explored through case studies, showcasing the technology's ability to simultaneously diagnose and treat diseases. Finally, we address the current challenges facing MIPs and discuss future perspectives, emphasizing the potential of this technology to revolutionize the next generation.

Wireless charging LED mediated type I photodynamic therapy of breast cancer using NIR AIE photosensitizer

Due to limited light penetration and dependence on oxygen, photodynamic therapy (PDT) is typically restricted to treating shallow tissues. Developing strategies to overcome these limitations and effectively using PDT for tumor treatment is a significant yet unresolved challenge. In this study, we present a smart approach combining a wireless-charged LED (wLED) with a type I aggregation-induced emission photosensitizer, MeOTTMN, to address both light penetration and tumor hypoxia issues simultaneously. MeOTTMN, characterized by twisted molecular architecture and strong intramolecular electron donor-acceptor interaction, produces high levels of hydroxyl and superoxide radicals and emits near-infrared light in its aggregated state, thus facilitating fluorescence imaging-guided PDT once formulated into nanoparticles. The inhibition of breast cancer xenografts provides compelling evidence of the treatment efficacy of type I PDT irradiated through an implantable wLED. This strategy provides a conceptual and practical paradigm to overcome key clinical limitations of PDT, expanding possibilities for clinical translation.

Molecular Engineering of NIR-II Excitable Phototheranostic for Mitochondria-Targeted Cancer Photoimmunotherapy

The advancement of mitochondria-targeted near-infrared-II (NIR-II) excitable phototheranostics constitutes a promising strategy for improving fluorescence-image-guided cancer phototherapy. However, developing phototheranostic agents that simultaneously combine high-contrast NIR-II fluorescence imaging with effective multimodal therapeutic techniques remains a substantial challenge. Herein, we reported a shielding-donor-acceptor-donor-shielding structured NIR-II phototheranostic (FCD-T) by a molecular engineering strategy, followed by self-assembly with glutathione-responsive copolymer to form FCD-T nanoparticles. The introduction of functional bithiophene endows FCD-T with significant electron-donating properties and reduces intermolecular π-π stacking interactions. The robust π-conjugation of fluorene with good rigidity would enhance the intramolecular charge transfer capability. Therefore, FCD-T NPs exhibited an NIR-II absorption peak at 1075 nm and an emission peak at 1280 nm. Upon NIR-II light excitation, such nanoparticles could generate excellent photothermal and photodynamic performances with good biocompatibility. Moreover, the NIR-II mitochondria-targeted phototherapy further facilitated mitochondrial apoptosis-related pathways, activating antitumor immunity and inhibiting tumor growth with single irradiation at low doses.

NIR-II aggregation-induced emission nanoparticles camouflaged with preactivated macrophage membranes for phototheranostics of pulmonary tuberculosis

Phototheranostics, which allows simultaneous diagnosis and therapy, offers notable advantages in terms of noninvasiveness, controllability and negligible drug resistance, presenting a promising approach for disease treatment. By integrating second near-infrared (NIR-II, 1,000-1,700 nm) phototheranostic agents characterized by aggregation-induced emission (AIE) and cell membranes with specific targeting capacity, we have developed a versatile type of biomimetic nanoparticle (NP) for precise phototheranostics of pulmonary tuberculosis (TB). Coating the phototheranostic agents with preactivated macrophage membranes results in the formation of biomimetic NPs, which exhibit specific binding to TB through a lesion-pathogen dual-targeting strategy, allowing the accurate detection of Mycobacterium tuberculosis via NIR-II fluorescence imaging and precise photothermal therapy using the irradiation of a 1,064 nm laser. In comparison with traditional treatments, small individual granulomas (0.2 mm in diameter) in TB-infected mice are visualized, and improved antibacterial effects are achieved upon NP administration. Here we present a standardized workflow for the synthesis of the NIR-II AIE agents, their use for the fabrication of the biomimetic NPs and their in vitro and in vivo applications as phototheranostics against M. tuberculosis. The preparation and characterization of the NIR-II AIE agents requires ~8 d, the synthesis and characterization of the phototheranostic NPs requires ~8 d, the validation of in vitro targeting capacity and photothermal eradication requires ~26 d, and the in vivo NIR-II fluorescence imaging and imaging-guided photothermal therapy requires ~74 d. All procedures are straightforward and suitable for clinicians or researchers with prior training in organic synthesis and biomedical engineering.

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.

Bovine serum albumin framed activatable NIR AIE photosensitizer for targeted tumor therapy

Organic near-infrared (NIR) photosensitizers (PS) largely facilitate photodynamic therapy (PDT). To overcome aggregation induced quenching and diminishment of reactive oxygen species (ROS) generation capability of NIR-PS, aggregation-induced emission (AIE) effect groups have been introduced to generate NIR AIE photosensitizers. However, currently reported NIR AIE photosensitizers all take "always-on" activity that may cause systemic phototoxic side effects. Tumor microenvironment activatable NIR AIE photosensitizers have not been reported. Here we develop an activatable NIR AIE PSnanoparticle (a-NA-PSNP) for near-infrared-II (NIR-II) fluorescence (FL) imaging-guided PDT under 808 nm excitation. NIR AIE photosensitizer (N-PS) is designed and frames with cysteine (Cys)/glutathione (GSH) responsive charge transfer complex (CTC) in bovine serum albumin (BSA) to obtain a-NA-PSNP. With the aggregated state in BSA, N-PS shows high quantum yield with good photostability. As an energy acceptor, CTC quenchs NIR-II fluorescence and ROS production capability of a-NA-PSNP in normal cells and tissues. CTC is decomposed in response to tumor microenvironment Cys/GSH, therefore recovers NIR-II fluorescence of a-NA-PSNP and efficiently generates ROS under 808 nm light irradiation. The depletion of Cys/GSH also regulates tumor intracellular reductive environment to further facilitate PDT. Both in vitro and in vivo results confirmed the tumor microenvironment selective and efficient activation of a-NA-PSNP, indicating its potential in cancer therapy.

Enhanced delivery of azithromycin using asymmetric polyethersulfone membrane modified with KIT-6 mesoporous material: Optimization and mechanistic studies

This study presents the development of a novel drug delivery system designed for improving the release profile and sustained delivery of azithromycin (AZI), particularly aimed at applications requiring localized infection control and improved tissue compatibility. The system employs an asymmetric polyethersulfone (PES) membrane modified with KIT-6 mesoporous material, offering improved drug release performance and biocompatibility over conventional delivery platforms. Membrane optimization was achieved by systematically varying parameters such as thickness (150-600 µm), drug concentration (500-1500 mg/L), polymer content (13-21 % PES), pore maker percentage (0-4 % polyvinylpyrrolidone), and KIT-6 modifier percentage (0.5-2 %). Characterization included scanning electron microscopy, water contact angle measurements, porosity, tensile strength evaluation, and comprehensive bioactivity testing (cytotoxicity, antimicrobial efficacy, blood compatibility, and a novel tissue integrity assay). The optimized formulation (17 % PES, 2 % PVP, 1 % KIT-6) achieved a controlled and sustained release profile with improved drug availability (464 mg/L) compared to unmodified membranes (252 mg/L), with a sustained release profile governed by the Higuchi model. Additionally, the membrane demonstrated superior biocompatibility (-90 % cell viability, low hemolysis at 1.2 %) and preserved tissue integrity better than unmodified counterparts, as evidenced by in vitro and ex vivo studies. Notably, the system showed robust reusability over prolonged use, indicating its potential as an effective, sustainable, and biocompatible solution for localized AZI delivery. These advantages position this system as a promising alternative for medical applications requiring precise drug release and minimal tissue disruption.

A Universal Single-Activated-Dual-Release Vehicle: Enabling Synergistic Antitumor Therapy

Activatable combined therapeutic strategy exhibits significant potential for the management of malignant tumors. Ensuring the timely and spatially effective release of different therapeutic agents is a great challenge for maximizing the efficacy of combination therapy. Herein, based on the 1,4-and 1,6-elimination behaviors, the study proposes a novel universal single-activated-dual-release platform that can be triggered by various stimulants of interest. As a proof-of-concept, the study develops an example of a synergistic therapy called CyI-Cbl-NTR, which can be selectively activated by nitroreductase (NTR) to release the photosensitizer (CyI-OH) and DNA alkylating agent chlorambucil (Cbl), thereby enabling a combination of chemo- and photodynamic therapy. Both in vitro and in vivo experiments fully demonstrate the remarkable combined therapeutic effect of Cyl-Cbl-NTR and the feasibility of this strategy. This work provides a promising platform for the future development of activatable synergistic therapy.

Win-Win Integration of Genetically Engineered Cellular Nanovesicles with High-Absorbing Multimodal Phototheranostic Molecules for Boosted Cancer Photo-Immunotherapy

Photo-immunotherapy is one of the most promising cancer treatment strategies. As immunotherapeutic agents, immune checkpoint blockade antibodies against programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) exhibit substantial potential, but have to face non-specific distribution and the subsequent immune-related adverse events. Meanwhile, high-performance phototheranostic agents concurrently possessing multiple phototheranostic modalities and high light-harvesting capacity are really attractive and highly desired as touching phototheranostic modules. Herein, a win-win strategy that integrates phototheranostic molecule design and targeted immunotherapeutic module preparation is developed to construct high-powered photo-immunotherapy systems. Specifically, the phototheranostic agent (AOTTIT) displaying typical aggregation-induced fluorescence extending to the second near-infrared II window, as well as outstanding reactive oxygen species and heat production capacity is first obtained via ingenious design. Notably, AOTTIT exhibits a record high molar extinction coefficient among the reported organic multimodal phototheranostic molecules. Meanwhile, PD-1 genetically engineered cancer cell membrane-derived nanovesicles (PD-1/CMNVs) are prepared as both nanocarriers and immunotherapeutic agents to camouflage AOTTIT nanoparticles, yielding a multifunctional photo-immunotherapeutic agent (CMNPs/PD-1) with tumor-specific active and homologous targeting ability. The distinct suppression of primary and metastatic lung tumors after only once treatment to the primary tumor substantiated the synergistically strengthened photo-immunotherapeutic efficiency of this win-win strategy.

Aggregation-induced emission-based phototheranostics to combat bacterial infection at wound sites: A review

The healing of chronic wounds infected by bacteria has attracted increasing global concerns. In the past decades, antibiotics have certainly brought hope to cure bacteria-infected chronic wounds. However, the misuse of antibiotics leads to the emergence of numerous multidrug-resistant bacteria, which aggravate the health threat to clinical patients. To address these increasing challenges, scientists are committed to creating novel non-antibiotic strategies to kill bacteria and promote bacteria-infected chronic wound healing. Fortunately, with the quick development of nanotechnology, the representatives of phototherapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), exhibit promising possibilities in promoting bacteria-infected wound healing. Well-known, photothermal agents and photosensitizers largely determine the effects of PTT and PDT. A common problem for these molecules is the aggregation-induced quenching effect, which highly limits their further applicability in biomedical and clinical fields. Fortunately, the occurrence of aggregation-induced emission luminogens (AIEgens) efficiently overcomes the photobleaching and exhibit advantages, such as strongly aggregated emission, superior photostability, aggregation-enhanced reactive oxygen species (ROS), and heat generation, which makes great sense to the development of PTT and PDT. This article reviews various studies conducted on novel AIEgen-based materials that can mediate potent PDT, PTT, and a combination of PDT and PTT to promote bacteria-infected chronic wound healing.

A Brain-Targeting NIR-II Polymeric Phototheranostic Nanoplatform toward Orthotopic Drug-Resistant Glioblastoma

Glioblastoma is the most common and devastating brain tumor owing to its high invasiveness and high-frequency drug resistance. Near infrared-II (NIR-II) imaging-guided phototherapy based on polymer luminogens provides a promising remedy against drug-resistant glioma, but it is difficult to maximize photoenergy utilization. Herein, we designed a series of semiconducting polymers to boost the visualization and ablation of glioblastoma. By subtly engineering the side chains or substituents on the phenothiazine and thiophene moieties, an NIR-II polymer luminogen with high-quality fluorescence performance, good solubility, superior photothermal conversion, and balanced reactive oxygen species generation is achieved. The optimal polymer possesses a branched alkyl chain and tetraphenylethylene pendant to manipulate the equilibrium between the radiative and nonradiative energy-dissipating channels. High-sensitivity NIR-II imaging was used to monitor the blood-brain barrier penetration and glioma cell targeting of apolipoprotein E-modified polymer nanoparticles. The NIR irradiation triggers and maximizes the photon utilization in prominent photodynamic/photothermal synergistic therapy in orthotopic drug-resistant glioblastoma.

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.

Photosensitizing Quantum Dot Killers Encoded by Bivalent DNA for Sequential Cell Penetration, Intracellular Bacterial Imaging, and Targeted Elimination

The precise identification and efficient in situ eradication of intracellular bacteria can not only prevent the bacteria from persisting and spreading within the host but also accelerate the healing of infected wounds and decrease the caused complications. In this study, we designed a multifunctional quantum dot (QD) killer equipped with aggregation-induced emission (AIE) photosensitizers and heterobivalent DNA sequences with the capability to specifically target, fluorescently image, and efficiently eliminate intracellular bacteria. These QD killers undergo cell penetration following lipopolysaccharide receptor-mediated endocytosis and then translocate to the cytosol for intracellular bacterial recognition and labeling. Additionally, by leveraging the robust photodynamic activity of sensitizing QD killers, the complete eradication of intracellular bacteria was realized by reducing the viability of the infected macrophages. The cytocompatibility of QD killers ensures safe treatment without harming normal host cells. Notably, bacterial-infected wounds in vivo showed accelerated healing rates following successful bacterial elimination with QD killer administration. This work highlights the potential of QD killers in eradicating intracellular bacteria hidden within immune cells, providing a promising strategy for addressing intracellular infection-relevant diseases.

From X- To J-Aggregation: Subtly Managing Intermolecular Interactions for Superior Phototheranostics with Precise 1064 nm Excitation

The stacking mode in aggregate state results from a delicate balance of supramolecular interactions, which closely affects the optoelectronic properties of organic π-conjugated systems. Then, managing these interactions is crucial for advancing phototheranostics, yet remains challenging. A subtle strategy involving peripheral phenyl groups is debuted herein to transform X-aggregated SQ-H into J-aggregated SQ-Ph, reorienting intermolecular dipole interactions while rationally modulating π-π interactions. Co-assembled with liposomes (DSPE-PEG2000), SQ-Ph nanoparticles (NPs) exhibit low toxicity, superior biocompatibility, and a bathochromic shift to the 1064 nm match-excited NIR-II region, with a fluorescence brightness (ε1064 nm ΦNIR-II) of 4129 M-1 cm-1 and a photothermal conversion efficiency (PCE) of 48.3%. Preliminary in vivo experiments demonstrate that SQ-Ph NPs achieve a signal-to-background ratio (SBR) of up to 14.29 in NIR-II fluorescence imaging (FLI), enabling highly efficient photothermal therapy (PTT) of tumors guided by combined photoacoustic imaging (PAI). This study not only enriches the J-aggregation library but also provides a paradigm for optimizing photosensitizers at the supramolecular level.

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.

Structure-Activity Relationship of Hemicyanine Molecules: Mitochondrion-Targeting Hemicyanine Fluorescent Molecular Probes for HSO3- Recognition and Near-Infrared Image-Guided Photothermal/Photodynamic Synergetic Therapy

Hemicyanine molecules have unparalleled potential in the fields of fluorescence sensing, bioimaging, and disease therapeutics due to their excellent optical properties, cell penetration, potential mitochondrial targeting, and photosensitivity. Herein, three dual-cation hemicyanine molecular probes named DCy, PDCy, and TDCy were developed. All of them could detect HSO3-, and PDCy could recognize HSO3- under 365 nm ultraviolet light or sunlight. In addition, TDCy is a multifunctional molecule, which has the following advantages: simple synthesis, red and near-infrared dual-channel mitochondrial imaging, and photothermal/photodynamic synergistic therapy capabilities. Upon analysis of the correlation between the structures of the three hemicyanine molecules and HSO3- recognition, photosensitivity, photothermal activity, cell imaging, and cytotoxicity, the structure-activity relationship of the hemicyanine molecules could be summarized, which could provide guidance for subsequent research and development.

Photoredox-Mediated Immunotherapy Utilizing Rhenium(I) Photocatalysts with Electron Donor-Acceptor-Donor Configuration

The hypoxic environment of solid tumors significantly diminishes the therapeutic efficacy of oxygen-dependent photodynamic therapy. Developing efficient photosensitizers that operate via photoredox catalysis presents a promising strategy to overcome this challenge. Herein, we report the rational design of two rhenium(I) tricarbonyl complexes (Re-TPO and Re-TP) with electron donor-acceptor-donor configuration. Notably, Re-TP exhibits aggregation-induced emission properties and enhanced spin-orbit coupling compared to Re-TPO, thus exhibiting promoted photosensitizing capability. In addition to generating type I and II reactive oxygen species, the excited Re-TP facilitates the photocatalytic oxidation of NADH to NAD+ and the photoreduction of pyruvic acid to lactic acid. This metabolic intervention triggers PD-L1-linked immune responses and disrupts tumor redox balance, leading to ferroptosis and immunogenic cell death. The combined ferroptosis and immunotherapy effects significantly suppress both primary and distant B16 tumors. This investigation provides a compelling model for designing efficient metal-based PSs for photoredox-mediated photoimmunotherapy against hypoxic tumors.

Twisted-Planar Molecular Engineering with Sonication-Induced J-Aggregation To Design Near-Infrared J-Aggregates for Enhanced Phototherapy

J-aggregates show great promise in phototherapy, but are limited to specific molecular skeletons and poor molecular self-assembly controllability. Herein, we report a twisted-planar molecular strategy with sonication-induced J-aggregation to develop donor-acceptor (D-A) type J-aggregates for phototherapy. With propeller aggregation-induced emission (AIE) moieties as the twisted subunits and thiophene as the planar π-bridge, the optimal twisted-planar π-interaction in MTSIC induces appropriate slip angle and J-aggregates formation, redshifting the absorption from 624 nm to 790 nm. In contrast, shorter π-planarity results in amorphous aggregates, and elongation promotes charge transfer (CT) coupled J-aggregates. Sonication was demonstrated to be effective in controlling self-assembly behaviors of MTSIC, which enables the transformation from amorphous aggregates to H-intermediates, and finally to stable J-aggregates. After encapsulation with lipid-PEG, the resultant J-dots show enhanced phototherapeutic effects over amorphous dots, including brightness, reactive oxygen species (ROS) generation, and photothermal conversion, delivering superior cancer phototherapy performance. This work not only advances D-A type J-aggregates design but also provides a promising strategy for supramolecular assembly development.

Photo-Amplified Plasma Membrane Rupture by Membrane-Anchoring NIR-II Small Molecule Design for Improved Cancer Photoimmunotherapy

Immunotherapy is a promising cancer treatment method for eradicating tumor cells by enhancing the immune response. However, there are several major obstacles to conventional phototherapy-mediated immune responses, including inadequate immunogenicity and immunosuppressive environment. Here, we present a novel photoimmunotherapy modality-the development of membrane-anchoring small molecule inducing plasma membrane rupture (PMR) by NIR-II photo-stimulation, thus evoking cell necrotic death and enhancing antitumor immunotherapy. Our top-performing membrane-anchoring small molecule (CBT-3) exhibits temperature-tunable PMR efficiency, allowing rapid necrotic death in cancer cells at 50 μM dose by using exogenous NIR-II light-mediated mild photothermal effect (1064 nm, 0.6 W cm-2). Further evidence indicated that this gentle therapeutic approach activated inflammatory signaling pathways in cells, enhanced immunogenic cell death, and reshaped the immunosuppressive tumor microenvironment, ultimately promoting systemic antitumor immune responses in vivo. This study represents the first instance of utilizing NIR-II photo-amplified PMR effect based on membrane-anchoring small molecule, providing a novel avenue for advancing cancer photoimmunotherapy.

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.

Nanomaterials evoke pyroptosis boosting cancer immunotherapy

Cancer immunotherapy is currently a very promising therapeutic strategy for treating tumors. However, its effectiveness is restricted by insufficient antigenicity and an immunosuppressive tumor microenvironment (ITME). Pyroptosis, a unique form of programmed cell death (PCD), causes cells to swell and rupture, releasing pro-inflammatory factors that can enhance immunogenicity and remodel the ITME. Nanomaterials, with their distinct advantages and different techniques, are increasingly popular, and nanomaterial-based delivery systems demonstrate significant potential to potentiate, enable, and augment pyroptosis. This review summarizes and discusses the emerging field of nanomaterials-induced pyroptosis, focusing on the mechanisms of nanomaterials-induced pyroptosis pathways and strategies to activate or enhance specific pyroptosis. Additionally, we provide perspectives on the development of this field, aiming to accelerate its further clinical transition.

Glutathione-Driven Disassembly of Planar Organic Phototherapeutic Agents to Enhance Photodynamic-Photothermal Therapy Performance for Nasopharyngeal Carcinoma

The self-assembly of hydrophobic organic phototherapeutic agents (OPTAs) with expansive planar structures into nanoparticles (NPs) represents a pivotal strategy to bolster their biocompatibility. However, the tight molecular packing within these NPs significantly influences the generation of reactive oxygen species (ROS) and the photothermal conversion efficiency (PCE), posing a substantial hurdle to elevating the efficacy of photodynamic therapy (PDT) and photothermal therapy (PTT) for such NPs. In this article, three OPTAs by donor engineering are synthesized. Notably, 4,8-Bis (5-phenylthiophen-2-yl)-6-(2-ethylhexyl)-[1,2,5] thiadiazole [3,4-F] benzotriazole (BTBT), which incorporates a benzene ring as the donor, exhibits the highest ROS generation and optimal photothermal conversion capability. To further augment the overall phototheranostic potential of BTBT NPs, a glutathione (GSH)-driven disassembly strategy is employed. This strategy not only alleviates the aggregation-caused quenching (ACQ) effect on ROS but also facilitates enhanced free molecular rotation. As a result, the ROS production sees a tenfold increase, and the photothermal conversion temperature rises by 8.3 °C, achieving a PCE of 77.03%. In summary, a versatile disassembly strategy is proposed that concurrently enhances the performance of both PDT and PTT in planar OPTAs, while also advancing the state-of-the-art in nasopharyngeal carcinoma (NPC) treatment.

Integration of Motion and Stillness: A Paradigm Shift in Constructing Nearly Planar NIR-II AIEgen with Ultrahigh Molar Absorptivity and Photothermal Effect for Multimodal Phototheranostics

The two contradictory entities in nature often follow the principle of unity of opposites, leading to optimal overall performance. Particularly, aggregation-induced emission luminogens (AIEgens) with donor-acceptor (D-A) structures exhibit tunable optical properties and versatile functionalities, offering significant potential to revolutionize cancer treatment. However, trapped by low molar absorptivity (ε) owing to the distorted configurations, the ceilings of their photon-harvesting capability and the corresponding phototheranostic performance still fall short. Therefore, a research paradigm from twisted configuration to near-planar structure featuring a high ε is urgently needed for AIEgens development. Herein, by introducing the strategy of "motion and stillness" into a highly planar A-D-A skeleton, we successfully developed a near-infrared (NIR)-II AIEgen of Y5-2BO-2BTF, which boasts an impressive ε of 1.06 × 105 M-1 cm-1 and a photothermal conversion efficiency (PCE) of 77.8%. The modification of steric hindrance on the benzene ring in the acceptor unit of the aggregation-caused quenching counterpart Y5-2BO, to a meta-CF3-substituted naphthyl, leads to reversely staggered packing and various intermolecular noncovalent conformational locks in Y5-2BO-2BTF ("stillness"). Furthermore, the -CF3 moiety acted as a flexible motion unit with an ultralow energy barrier, significantly facilitating the photothermal process in loose Y5-2BO-2BTF aggregates ("motion"). Accordingly, Y5-2BO-2BTF nanoparticles enabled tumor eradication and pulmonary metastasis inhibition through NIR-II fluorescence-photoacoustic-photothermal imaging-navigated type I photodynamic-photothermal therapy. This work provides the first evidence that the highly planar conformation with a reversely staggered stacking arrangement could serve as a novel molecular design direction for AIEgens, shedding new light on constructing superior phototheranostic agents for bioimaging and cancer therapy.

Chiral helix amplification and enhanced bioadhesion of two-component low molecular weight hydrogels regulated by OH to eradicate MRSA biofilms

The supramolecular chemistry of small chiral molecules has attracted widespread attention owing to their similarity to natural assembly codes. Two-component low-molecular-weight (LMW) hydrogels are crucial as they form helical structures via chirality transfer, enabling diverse functions. Herein, we report a pair of two-component chiral LMW hydrogels based on the small molecular drugs baicalin (BA), scutellarin (SCU) and berberine (BBR). The two hydrogels exhibited different helicities and abilities to adhere to methicillin-resistant staphylococcus aureus (MRSA) biofilms. The BA or SCU can each laterally interact with BBR in a tail-to-tail configuration, forming a stable hydrophobic structure, while hydrophilic glucuronide groups are exposed to a water solution to form a hydrogel. However, the tiny variant steric hindrance of the terminal OH moiety of SCU affects π-π stacking in the layered assembly, resulting in SCU-BBR having much stronger chirality deviation and supramolecular chirality amplification than BA-BBR. Thereafter, the OH group in SCU-BBR forms more intermolecular hydrogen bonds with MRSA biofilms, enhancing stronger adhesion and better scavenging effects than BA-BBR. This work provides a unique chiral supramolecular assembly pattern, expands the antibacterial application prospect of a two-component LMW hydrogel accompanying chirality amplification, and provides a new perspective and strategy for biofilm removal.

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.

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.

Biomimetic Metallacage Nanoparticles with Aggregation-Induced Emission for NIR-II Fluorescence Imaging-Guided Synergistic Immuno-Phototherapy of Tumors

The integration of theranostics, which combines diagnostics with therapeutics, has markedly improved the early detection of diseases, precise medication management, and assessment of treatment outcomes. In the realm of oncology, organoplatinum-based supramolecular coordination complexes (SCCs) that can coload therapeutic agents and imaging molecules have emerged as promising candidates for multimodal theranostics of tumors. To address the challenges of tumor-targeted delivery and multimodal theranostics for SCCs, this study employs a cell membrane cloaking strategy to fabricate biomimetic metallacage nanoparticles (MCNPs) with multimodal imaging capabilities and homologous targeting capabilities. Specifically, a photosensitizer molecule (BTTP) containing AIE-active groups was assembled into a metallacage of C-BTTP through Pt-N coordination. This process endows the metallacage with strong NIR-II fluorescence in the aggregated state and significantly superior ROS generation compared to that of the precursor ligand. After being encapsulated with F127, the MCNPs were further cloaked with U87 cancer cell membranes, creating biomimetic MCNPs that achieve tumor-targeting capabilities. Verified by in vitro and in vivo experiments, MCNPs enable multimodal imaging and initiate immunotherapy under photothermal and photodynamic stimulation, leading to synergistic antitumor effects. Furthermore, the evaluation of immunogenic cell death and dendritic cell maturation rate in U87 tumor-bearing mice confirmed the mechanism of photothermal and photodynamic synergistic immunotherapy. This study provides an innovative strategy for enhancing the tumor-targeting and therapeutic efficiency of SCCs, offering a versatile strategy for efficient and minimally invasive theranostics of tumors. The development of such biomimetic nanoparticles represents a significant advancement in the field of nanomedicine, potentially transforming cancer treatment through personalized and targeted therapies.

Molecular Engineering of AIE-Active Photosensitizers with High Biosafety for Effect Extracellular Antibacteria

Developing versatile photosensitizers to actualize selective antibacteria over normal cells presents an appealing yet significantly challenging task. In this study, a novel photosensitizer named DMMA-SCPI is rationally designed and facilely synthesized, which is demonstrated as a type-I photosensitizer featured by aggregation-induced emission tendency. DMMA-SCPI is capable of effectively eliminating both Galanz positive bacteria and Galanz negative bacteria in vitro and in vivo, and showed insignificant injury to normal cells and tissues, probably resulting from its pyridinium halide that has stronger adsorption property on negatively charged bacteria compared to normal cells, as well as its suitable antimicrobial activity. The antimicrobial activity of pyridinium salt type photosensitizer depends on the adsorptive activities on the surface of bacterial cells as well as the antimicrobial activity of the reactive oxygen species (ROS). Among three photosensitizers, DMMA-SCPI has better water solubility, which provides greater surface activity to adsorb bacteria. Moreover, DMMA-SCPI produces more superoxide anion radicals as ROS, which has proper antimicrobial activity with high biosafety for effect extracellular antibacteria.

A new era of cancer phototherapy: mechanisms and applications

The past decades have witnessed great strides in phototherapy as an experimental option or regulation-approved treatment in numerous cancer indications. Of particular interest is nanoscale photosensitizer-based phototherapy, which has been established as a prominent candidate for advanced tumor treatment by virtue of its high efficacy and safety. Despite considerable research progress on materials, methods and devices in nanoscale photosensitizing agent-based phototherapy, their mechanisms of action are not always clear, which impedes their practical application in cancer treatment. Hence, from a new perspective, this review elaborates the working mechanisms, involving impairment and moderation effects, of diverse phototherapies on cells, organelles, organs, and tissues. Furthermore, the most current available phototherapy modalities are categorized as photodynamic, photothermal, photo-immune, photo-gas, and radio therapies in this review. A comprehensive understanding of the inferiority and superiority of various phototherapies will facilitate the advent of a new era of cancer phototherapy.

Singlet oxygen storage and controlled release for improving photodynamic therapy against hypoxic tumor

Photodynamic therapy (PDT) is considered to be a promising tumor treatment method due to its non-invasiveness and low risk. However, there are two factors that affect the efficacy of this therapy. One is the light source and the other is the tumor hypoxia. An emerging PDT strategy has been developed to break these limits. This strategy is to adopt compounds, such as 2-pyridone, anthracene, and naphthalene derivatives, that have the ability to store and controlledly release the singlet oxygen (1O2) to achieve PDT in the dark. In this review, we focus on the construction strategies for integrated antitumor drugs containing these 1O2 storage/release units and photosensitizers and summarize their PDT performance in hypoxic tumors or in the dark. The methods to integrate these compounds with photosensitizers or nanocarriers are also discussed in detail to provide insightful design guidelines for the design of highly efficient antitumor systems based on 1O2 storage and controlled release.

Recent advances in nanoagents delivery system-based phototherapy for osteosarcoma treatment

Osteosarcoma (OS) is a prevalent and highly malignant bone tumor, characterized by its aggressive nature, invasiveness, and rapid progression, contributing to a high mortality rate, particularly among adolescents. Traditional treatment modalities, including surgical resection, radiotherapy, and chemotherapy, face significant challenges, especially in addressing chemotherapy resistance and managing postoperative recurrence and metastasis. Phototherapy (PT), encompassing photodynamic therapy (PDT) and photothermal therapy (PTT), offers unique advantages such as low toxicity, minimal drug resistance, selective destruction, and temporal control, making it a promising approach for the clinical treatment of various malignant tumors. Constructing multifunctional delivery systems presents an opportunity to effectively combine tumor PDT, PTT, and chemotherapy, creating a synergistic anti-tumor effect. This review aims to consolidate the progress in the application of novel delivery system-mediated phototherapy in osteosarcoma. By summarizing advancements in this field, the objective is to propose a rational combination therapy involving targeted delivery systems and phototherapy for tumors, thereby expanding treatment options and enhancing the prognosis for osteosarcoma patients. In conclusion, the integration of innovative delivery systems with phototherapy represents a promising avenue in osteosarcoma treatment, offering a comprehensive approach to overcome challenges associated with conventional treatments and improve patient outcomes.

The cyano positional isomerism strategy for constructing mitochondria-targeted AIEgens with type I reactive oxygen species generation capability

In this work, a series of cationic luminogens (designated as PSMP isomers) were developed based on the cyano positional isomerism strategy. The isomerism of the cyano substituent on the molecular skeleton can finely regulate the optical behaviour, the type of photoinduced reactive oxygen species (ROS), and mitochondria-targeted capability of isomers. Interestingly, PSMP-4, with the cyano group installed at an appropriate location, exhibits a special aggregation-induced emission effect and potent O2˙- generation efficacy through the type I photochemistry pathway. Notably, PSMP-4 can accumulate in mitochondria with high specificity. Taking advantage of its excellent photostability, PSMP-4 realizes in situ mitochondria imaging in a washing-free manner and sensitive response to the change of mitochondrial membrane potential. The integration of comprehensive photophysical properties and mitochondrial specificity enable PSMP-4 to successfully trigger the death of cancer cells through an efficient type I photodynamic therapy process both in vitro and in multicellular tumor spheroid models.

De novo design of type-l photosensitizer agents based on structure-inherent low triplet energy for hypoxia photodynamic therapy

Photodynamic therapy (PDT), owing to its low invasiveness, high efficiency, fewer side effects, spatiotemporal controllability and good selectivity, has attracted increasing attention for its tremendous potential in revolutionizing conventional strategies of tumor treatment. However, hypoxia is a common feature of most malignancies and has become the Achilles' heel of PDT. Currently, Type II photosensitizers (PSs) have inadequate efficacy for PDT due to the inherent oxygen consumption of the anoxic tumor microenvironment. Moreover, due to the absence of a general molecular design strategy and the limitations imposed by the energy gap law, Type-I PSs are less reported. Therefore, the development of Type-I PSs with hypoxia resistant capabilities is urgently required. Herein, in this study, we have obtained pure Type-I materials for the first time by employing a strategy that decreases the triplet energy levels of the π-conjunction bridge. A sufficient donor-acceptor interaction reduces the lowest triplet energy level and aids in the transfer of excitons from singlet to triplet levels. With this strategy, dibenzofulvene derivatives (FEs) displayed purely Type-I ROS generation. Among them, FE-TMI exhibits superior Type-I reactive oxygen species-generation performance, showcasing the great potential of PDT in treating tumor cells under hypoxic conditions and several types of solid tumors in mouse in vivo experiments. This work provides a practical solution for the future design of Type-I PDT materials and is aimed at enhancing PDT efficiency.

Molecularly Imprinted Ratiometric Fluorescent Sensors for Analysis of Pharmaceuticals and Biomarkers

Currently, analyzing pharmaceuticals and biomarkers is crucial for ensuring medication safety and protecting life and health, and there is an urgent need to develop new and efficient analytical techniques in view of the limitations of traditional analytical methods. Molecularly imprinted ratiometric fluorescent (MI-RFL) sensors have received increasing attention in the field of analytical detection due to their high selectivity, sensitivity and anti-interference ability, short response time, and visualization. This review summarizes the recent advances of MI-RFL sensors in the field of pharmaceuticals and biomarkers detection. Firstly, the fluorescence sources and working mechanisms of MI-RFL sensors are briefly introduced. On this basis, new techniques and strategies for preparing molecularly imprinted polymers, such as dummy template imprinting, nanoimprinting, multi-template imprinting, and stimulus-responsive imprinting strategies, are presented. Then, dual- and triple-emission types of fluorescent sensors are introduced. Subsequently, specific applications of MI-RFL sensors in pharmaceutical analysis and biomarkers detection are highlighted. In addition, innovative applications of MI-RFL sensors in point-of-care testing are discussed in-depth. Finally, the challenges of MI-RFL sensors for analysis of pharmaceuticals and biomarkers are proposed, and the research outlook and development trends of MI-RFL sensors are prospected.

Harnessing Dual Phototherapy and Immune Activation for Cancer Treatment: The Development and Application of BODIPY@F127 Nanoparticles

Conventional phototherapeutic agents are typically used in either photodynamic therapy (PDT) or photothermal therapy (PTT). However, efficacy is often hindered by hypoxia and elevated levels of heat shock proteins in the tumor microenvironment (TME). To address these limitations, a formylated, near-infrared (NIR)-absorbing and heavy-atom-free Aza-BODIPY dye is presented that exhibits both type-I and type-II PDT actions with a high yield of reactive oxygen species (ROS) and manifests efficient photothermal conversion by precise adjustments to the conjugate structure and electron distribution, leading to a large amount of ROS production even under severe hypoxia. To improve biosafety and water solubility, the dye with an amphiphilic triblock copolymer (Pluronic F-127), yielding BDP-6@F127 nanoparticles (NPs) is coated. Furthermore, inspired by the fact that phototherapy triggers the release of tumor-associated antigens, a strategy that leverages potential immune activation by combining PDT/PTT with immune checkpoint blockade (ICB) therapy to amplify the systemic immune response and achieve the much-desired abscopal effect is developed. In conclusion, this study presents a promising molecular design strategy that integrates multimodal therapeutics for a precise and effective approach to cancer therapy.

Intermolecular Assembly of Dual Hydrogen Bonding Regio-Isomers Generates High-Performance AIE Probes

Regio-isomers are utilized to design innovative AIE luminogens (AIEgens) by regulating molecular aggregation behavior. However, relevant examples are limited, and the underlying mechanism is not fully understood. Herein, a regio-isomer strategy is used to develop AIEgens by precisely regulating the intermolecular interactions in the solid state. Among the regio-isomers it is investigated, ortho- isomer (DCM-O3-O7) exhibits enhanced AIE-activity than the para- isomer (DCM-P6), and the size of the ortho- substituents is crucial for the AIE performance. The underlying mechanism of the strategy is revealed using DFT calculations and single-crystal analysis. Dual hydrogen bonds (C─H∙∙∙π and C─H∙∙∙N) are generated between the molecules, which contributes to form dimers, tetramers, and 1D supramolecular structures in the crystal. By restricting intramolecular motion and attenuating π-π interactions, solid-state fluorescence is significantly enhanced. This strategy's effectiveness is validated using other donor-acceptor fluorophores, with DCM-O6 and its analogues serving as efficient probes for bioimaging applications. Notably, DCM-OM, which bears a morpholinyl instead of piperidinyl group, displayed strong lysosome-targeting ability and photostability; DCM-OP, incorporated by the hydrophilic quaternary ammonium group, exhibited wash-free imaging and cell membrane-targeting capabilities; and DCM-O6 nanoparticles enabled high-fidelity in vivo tumor imaging. Therefore, this strategy affords a general method for designing bright AIEgens.

Fiber Optic-Mediated Type I Photodynamic Therapy of Brain Glioblastoma Based on an Aggregation-Induced Emission Photosensitizer

Glioblastoma (GBM) is one of the most lethal human malignancies. The current standard-of-care is highly invasive with strong toxic side effects, leading to poor prognosis and high mortality. As a safe and effective clinical approach, photodynamic therapy (PDT) has emerged as a suitable option for GBM. Nevertheless, its implementation is significantly impeded by the limits of light penetration depth and the firm reliance on oxygen. To overcome these challenges, herein, a promising strategy that harnesses a modified optical fiber and less oxygen-dependent Type I aggregation-induced emission (AIE) photosensitizer (PS) is developed for the first time to realize in vivo GBM treatments. The proposed AIE PS, namely TTTMN, characterized by a highly twisted molecular architecture and a bulky spacer, exhibits enhanced near-infrared emission and strong production of hydroxyl and superoxide radicals at the aggregated state, thus affording efficient fluorescence imaging-guided PDT once formulated into nanoparticles. The inhibition of orthotopic and subcutaneous GBM xenografts provides compelling evidence of the treatment efficacy of Type I PDT irradiated through a tumor-inserted optical fiber. These findings highlight the substantially improved therapeutic outcomes achieved through fiber optic-mediated Type I PDT, positioning it as a promising therapeutic modality for GBM.

Robust Natural Light-Absorbable and -Degradable AIE Photosensitizers for Fluorescence Labeling and Efficient Photodynamic Eradication of Algal Pollutants

Current water pollution caused by the excessive proliferation of harmful algae urges green methods that can efficiently utilize natural light to treat algal pollution. Herein, a series of aggregation-induced emission (AIE) photosensitizers that can efficiently harness sunshine were synthesized for the environmentally friendly and biocompatible treatment of algal pollution. By tuning the number of thiophene units and the electron conjugation degree, the photosensitizers' absorptions were broadened to cover the whole visible light range. The positive charges guided photosensitizers to aggregate on algal cell surfaces, resulting in a turn-on fluorescence signal and robust reactive oxygen species generation under sunshine, thereby achieving fluorescence labeling and photodynamic eradication of algae. The eradication outcomes demonstrated that the AIE photosensitizers significantly outperformed the commercial algaecide ALG. At 20 ppm photosensitizers, 90.4% and 94.2% killing rates were achieved for C. reinhardtii and C. vulgaris, respectively, 2.8- and 3.6-fold higher than those from the same concentration of ALG. Excellent performances in inhibiting algae growth were also verified with efficiency superior to that of ALG. Importantly, the photosensitizers can self-degrade into biocompatible fragments under irradiation to avoid secondary pollution. The developed photosensitizers that possess sunshine convertibility and degradability provide an efficient tool for algal treatment, showing broad research and application prospects.

Tandem Targeting and Dual Aggregation of an AIEgen for Enhanced Near-Infrared Fluorescence Imaging of Tumors

Near-infrared (NIR) aggregation-induced emission luminogens (AIEgens) are excellent probes for tumor imaging, but there still is space to improve their imaging specificity and sensitivity. In this work, a strategy of tandem targeting and dual aggregation of an AIEgen is proposed to achieve these two purposes. An AIEgen, β-tBu-Ala-Cys(StBu)-Lys(Biotin)-Pra(QMT)-CBT (Ala-Biotin-QMT), is designed to tandem target the biotin receptor and leucine aminopeptidase of a cancer cell and thereafter undergo CBT-Cys click reaction-mediated dual aggregations in the cell. Experimental results show that Ala-Biotin-QMT renders 4.8-fold and 7.9-fold higher NIR fluorescence signals over those in the "biotin + LAP inhibitor"-treated control groups in living HepG2 cells and HepG2 tumor-bearing mice, respectively. We anticipate that Ala-Biotin-QMT, which has the tandem targeting and dual aggregation property to simultaneously achieve enhanced tumor enrichment and fluorescence onset, could be applied for accurate cancer diagnosis in the clinic in the future.

Interstitial Optical Fiber-Mediated Multimodal Phototheranostics Based on an Aggregation-Induced NIR-II Emission Luminogen for Orthotopic Breast Cancer Treatment

One-for-all phototheranostics based on a single molecule is recognized as a convenient approach for cancer treatment, whose efficacy relies on precise lesion localization through multimodal imaging, coupled with the efficient exertion of phototherapy. To unleash the full potential of phototheranostics, advancement in both phototheranostic agents and light delivery methods is essential. Herein, an integrated strategy combining a versatile molecule featuring aggregation-induced emission, namely tBuTTBD, with a modified optical fiber to realize comprehensive tumor diagnosis and "inside-out" irradiation in the orthotopic breast tumor, is proposed for the first time. Attributed to the intense donor-acceptor interaction, highly distorted conformation, abundant molecular rotors, and loose intermolecular packing upon aggregation, tBuTTBD can synchronously undergo second near-infrared (NIR-II) fluorescence emission, photothermal and photodynamic generation under laser irradiation, contributing to a trimodal NIR-II fluorescence-photoacoustic (PA)-photothermal imaging-guided phototherapy. The tumor treatment is further carried out following the insertion of a modified optical fiber, which is fabricated by splicing a flat-end fiber with an air-core fiber. This configuration aims to enable effective in situ phototherapy by maximizing energy utilization for therapeutic benefits. This work not only enriches the palette of NIR-II phototheranostic agents but also provides valuable insight for exploring an integrated phototheranostic protocol for practical cancer treatment.

Hypoxia-accelerating pyroptosis nanoinducers for promoting image-guided cancer immunotherapy

Precise image-guided cancer immunotherapy holds immense potential in revolutionizing cancer treatment. The strategies facilitating activatable imaging and controlled therapeutics are highly desired yet to be developed. Herein, we report a new pyroptosis nanoinducer that integrates aggregation-induced emission luminogen (AIEgen) and DNA methyltransferase inhibitor with hypoxia-responsive covalent organic frameworks (COFs) for advanced image-guided cancer immunotherapy. We first synthesize and compare three donor-acceptor type AIEgens featuring varying numbers of electron-withdrawing units, and find that the incorporation of two acceptors yields the longest response wavelength and most effective photodynamic therapy (PDT) property, surpassing the performance of analogs with one or three acceptor groups. A COF-based nanoplatform containing AIEgen and pyroptosis drug is successfully constructed via the one-pot method. The intra-COF energy transfer significantly quenches AIEgen, in which both fluorescence and PDT properties greatly enhance upon hypoxia-triggered COF degradation. Moreover, the photodynamic process exacerbates hypoxia, accelerating pyroptosis drug release. The nanoagent enables sensitive delineation of tumor site through in situ activatable fluorescence signature. Thanks to the exceptional ROS production capabilities and hypoxia-accelerating drug release, the nanoagent not only inhibits primary tumor growth but also impedes the progression of distant tumors in 4T1 tumor-bearing mice through potent pyroptosis-mediated immune response. This research introduces a novel strategy for achieving activatable phototheranostics and self-accelerating drug release for synergetic cancer immunotherapy.

Laponite-activated AIE supramolecular assembly with modulating multicolor luminescence for logic digital encryption and perfluorinated pollutant detection

Recently, the non-covalently activated supramolecular scaffold method has become a prominent research area in the field of intelligent materials. Here, the inorganic clay (LP) promoted the AIE properties of 4,4',4″,4‴-(ethene-1,1,2,2-tetrayltetrakis(benzene-4,1-diyl))tetrakis(1-ethylpyridin-1-ium) (P-TPE), showing an astonishing 42-fold enhancement of the emission intensity of the yellow-green luminescence and a 34-fold increase of the quantum yield via organic-inorganic supramolecular strategy as well as the efficient light-harvesting properties (energy transfer efficiency up to 33 %) after doping with the dye receptor Rhodamine B. Furthermore, the full-color spectral regulation, including white light, was achieved by adjusting the ratio of the donor to the acceptor component and co-assembling with the carbon dots (CD). Interestingly, this TPE-based non-covalently activated full-color supramolecular light-harvesting system (LHS) could be achieved not only in aqueous media but also in the hydrogel and the solid state. More importantly, this panchromatic tunable supramolecular LHS exhibited the multi-mode and quadruple digital logic encryption property as well as the specific detection ability towards the perfluorobutyric acid and the perfluorobutanesulfonic acid, which are harmful to human health in drinking water. This result develops a simple, convenient and effective approach for the intelligent anti-counterfeiting and the pollutant sensing.