Activation of Pyroptosis by Membrane‐Anchoring AIE Photosensitizer Design: New Prospect for Photodynamic Cancer Cell Ablation

Anionic Surfactant-Triggered Excimer Emission from Dipyrene-Based Amphiphilic Dyes for Wash-Free Cell Membrane Imaging

Compared to monomer emission, excimer emission usually exhibits red-shifted, broadened, and large Stokes-shifted characteristics, which offer distinct advantages in biological imaging. In this work, we developed a rational design strategy for excimer-based cell membrane fluorescent probes, and on this basis, three fluorescent dyes (BPVP-C3, BPVP-C5 and BPVP-C8) exhibiting tunable excimer/monomer emission were obtained by covalent coupling of two pyrene units. In sodium dodecyl sulfate micelles, these fluorophores show bright excimer emission, whereas in dilute aqueous solutions, they emit monomer-dominated fluorescence. We proposed that the anionic micellar environment promotes intramolecular excimer formation between coupled pyrene units due to its balanced amphiphilicity, while these dye molecules can freely swing in dilute aqueous solution. Among them, BPVP-C8 exhibited optimal excimer-monomer switching property. Leveraging this environment-responsive dual-emission, it was explored as a wash-free cell membrane probe for simultaneous dual-channel (green and red) imaging.

Antimony Component Schottky Nanoheterojunctions as Ultrasound-Heightened Pyroptosis Initiators for Sonocatalytic Immunotherapy

Pyroptosis, an inflammatory modality of programmed cell death associated with the immune response, can be initiated by bioactive ions and reactive oxygen species (ROS). However, bioactive ion-induced pyroptosis lacks specificity, and further exploration of other ions that can induce pyroptosis in cancer cells is needed. Sonocatalytic therapy (SCT) holds promise due to its exceptional penetration depth; however, the rapid recombination of electron-hole (e--h+) pairs and the complex tumor microenvironment (TME) impede its broader application. Herein, we discovered that antimony (Sb)-based nanomaterials induced pyroptosis in cancer cells. Therefore, Schottky heterojunctions containing Sb component (Sb2Se3@Pt) were effectively designed and constructed via in situ growth of platinum (Pt) nanoparticles (NPs) on Sb2Se3 semiconductor with narrow band gaps, which were utilized as US-heightened pyroptosis initiators to induce highly effective pyroptosis in cancer cells to boost SCT-immunotherapy. Under US irradiation, excited electrons were transferred from Sb2Se3 nanorods (NRs) to the co-catalyst Pt via Schottky junctions, and band bending effectively prevented electron backflow and achieved efficient ROS generation. Moreover, the pores oxidized and depleted the overexpressed GSH in the TME, potentially amplifying ROS generation. The biological effects of the Sb2Se3@Pt nanoheterojunction itself combined with the sonocatalytic amplification of oxidative stress significantly induced Caspase-1/GSDMD-dependent pyroptosis in cancer cells. Therefore, SCT treatment with Sb2Se3@Pt not only effectively restrained tumor proliferation but also induced potent immune memory responses and suppressed tumor recurrence. Furthermore, the integration of this innovative strategy with immune checkpoint blockade (ICB) treatment elicited a systemic immune response, effectively augmenting therapeutic effects and impeding the growth of abscopal tumors. Overall, this study provides further opportunities to explore pyroptosis-mediated SCT-immunotherapy.

Two-Dimensional Atomically Thin Piezoelectric Nanosheets for Efficient Pyroptosis-Dominated Sonopiezoelectric Cancer Therapy

Sonopiezocatalytic therapy is an emerging therapeutic strategy that utilizes ultrasound irradiation to activate piezoelectric materials, inducing polarization and energy band bending to facilitate the generation of reactive oxygen species (ROS). However, the efficient generation of ROS is hindered by the long distance of charge migration from the bulk to the material surface. Herein, atomically thin Bi2O2(OH)(NO3) (AT-BON) nanosheets are rationally engineered through disrupting the weaker hydrogen bonds within the [OH] and [NO3] layer in the bulk material. The ultrathin structure of AT-BON piezocatalytic nanosheets shortens the migration distance of carriers, expands the specific surface area, and accelerates the charge transfer efficiency, showcasing a natural advantage in ROS generation. Importantly, the non-centrosymmetric polar crystal structure grants the nanosheets the ability to separate electron-hole pairs. Under ultrasonic mechanical stress, Bi2O2(OH)(NO3) nanosheets with the remarkable piezoelectric feature exhibit the desirable in vivo antineoplastic outcomes in both breast cancer model and liver cancer model. Especially, the AT-BON-induced ROS bursts lead to the activation of the Caspase-1-driven pyroptosis pathway. This study highlights the beneficial impact of bulk material thinning on enhancing ROS generation efficiency and anti-cancer effects.

Bioinspired Nano-Photosensitizer-Activated Caspase-3/GSDME Pathway Induces Pyroptosis in Lung Cancer Cells

Noninflammatory apoptosis is transformed into inflammatory pyroptosis by activating caspase-3 to lyse gasdermin E (GSDME), and this process can be used as an effective therapeutic strategy. Thus, a selective and powerful inducer of activated caspase-3 plays a vital role in pyroptosis-based cancer therapy. Herein, a human cell membrane vesicle-based nanoplatform (HCNP) is designed for photodynamic therapy (PDT). HCNP is modified with vesicular stomatitis virus G-protein (VSVG) to anchor nano-photosensitizers on the tumor cell membrane. Photosensitizers are bonded to HCNP by clicking chemical reaction as pyroptosis inducers. The results show that HCNP effectively disrupts the mitochondrial function of cells by generating reactive oxygen species (ROS) upon laser irradiation; concomitantly, GSDME is cleaved by activated caspase-3 and promotes pyroptosis of lung cancer cells. Here an effective intervention strategy is proposed to induce pyroptosis based on light-activated PDT.

Photocatalytic Carbon Dots-Triggered Pyroptosis for Whole Cancer Cell Vaccines

Manufacturing whole cancer cell vaccines (WCCV) with both biosafety and efficacy is crucial for tumor immunotherapy. Pyroptotic cancer cells, due to their highly immunogenic properties, present a promising avenue for the development of WCCV. However, the successful development of WCCV based on pyroptotic cancer cells is yet to be accomplished. Here, a facile strategy that utilized photocatalytic carbon dots (CDs) to induce pyroptosis of cancer cells for fabricating WCCV is reported. Photocatalytic CDs are capable of generating substantial amounts of hydroxyl radicals and can effectively decrease cytoplasmic pH values under white light irradiation. This process efficiently triggers cancer cell pyroptosis through the reactive oxygen species (ROS)-mitochondria-caspase 3-gasdermin E pathway and the proton motive force-driven mitochondrial ATP synthesis pathway. Moreover, in vitro, these photocatalytic CDs-induced pyroptotic cancer cells (PCIP) can hyperactivate macrophage (M0-M1) with upregulation of major histocompatibility complex class II expression. In vivo, PCIP induced specific immune-preventive effects in melanoma and breast cancer mouse models through anticancer immune memory, demonstrating effective WCCV. This work provides novel insights for inducing cancer cell pyroptosis and bridges the gap in the fabrication of WCCV based on pyroptotic cancer cells.

Molecular engineering to elevate reactive oxygen species generation for synergetic damage on lipid droplets and mitochondria

Photodynamic therapy (PDT), characterized by high treatment efficiency, absence of drug resistance, minimal trauma, and few side effects, has gradually emerged as a novel and alternative clinical approach compared to traditional surgical resection, chemotherapy and radiation. Whereas, considering the limited diffusion distance and short lifespan of reactive oxygen species (ROS), as well as the hypoxic tumor microenvironment, it is crucial to design photosensitizers (PSs) with suborganelle specific targeting ability and low-oxygen dependence for accurate and highly efficient photodynamic therapy. In this study, we have meticulously designed three PSs, namely CIH, CIBr, and CIPh, based on molecular engineering. Theoretical calculation demonstrate that the three compounds possess good molecular planarity with calculated S1-T1 energy gaps (ΔES1-T1) of 1.04 eV for CIH, 0.92 eV for CIBr, and 0.84 eV for CIPh respectively. Notably, CIPh showcases remarkable dual subcellular targeting capability towards lipid droplets (LDs) and mitochondria owing to the synergistic effect of lipophilicity derived from coumarin's inherent properties combined with electropositivity conferred by indole salt cations. Furthermore, CIPh demonstrates exclusive release of singlet oxygen (1O2)and highly efficient superoxide anion free radicals(O2⦁-) upon light irradiation supported by its smallest S1-T1 energy gap (ΔES1-T1 = 0.84 eV). This leads to compromised integrity of LDs along with mitochondrial membrane potential, resulting in profound apoptosis induction in HepG2 cells. This successful example of molecular engineering guided by density functional theory (DFT) provides valuable experience for the development of more effective PSs with superior dual targeting specificity. It also provides a new idea for the development of advanced PSs with efficient and accurate ROS generation ability towards fluorescence imaging-guided hypoxic tumor therapy.

Cell Membrane as A Promising Therapeutic Target: From Materials Design to Biomedical Applications

The cell membrane is a crucial component of cells, protecting their integrity and stability while facilitating signal transduction and information exchange. Therefore, disrupting its structure or impairing its functions can potentially cause irreversible cell damage. Presently, the tumor cell membrane is recognized as a promising therapeutic target for various treatment methods. Given the extensive research focused on cell membranes, it is both necessary and timely to discuss these developments, from materials design to specific biomedical applications. This review covers treatments based on functional materials targeting the cell membrane, ranging from well-known membrane-anchoring photodynamic therapy to recent lysosome-targeting chimaeras for protein degradation. The diverse therapeutic mechanisms are introduced in the following sections: membrane-anchoring phototherapy, self-assembly on the membrane, in situ biosynthesis on the membrane, and degradation of cell membrane proteins by chimeras. In each section, we outline the conceptual design or general structure derived from numerous studies, emphasizing representative examples to understand advancements and draw inspiration. Finally, we discuss some challenges and future directions in membrane-targeted therapy from our perspective. This review aims to engage multidisciplinary readers and encourage researchers in related fields to advance the fundamental theories and practical applications of membrane-targeting therapeutic agents.

Nanomedicine Strategies in Conquering and Utilizing the Cancer Hypoxia Environment

Cancer with a complex pathological process is a major disease to human welfare. Due to the imbalance between oxygen (O2) supply and consumption, hypoxia is a natural characteristic of most solid tumors and an important obstacle for cancer therapy, which is closely related to tumor proliferation, metastasis, and invasion. Various strategies to exploit the feature of tumor hypoxia have been developed in the past decade, which can be used to alleviate tumor hypoxia, or utilize the hypoxia for targeted delivery and diagnostic imaging. The strategies to alleviate tumor hypoxia include delivering O2, in situ O2 generation, reprogramming the tumor vascular system, decreasing O2 consumption, and inhibiting HIF-1 related pathways. On the other side, hypoxia can also be utilized for hypoxia-responsive chemical construction and hypoxia-active prodrug-based strategies. Taking advantage of hypoxia in the tumor region, a number of methods have been applied to identify and keep track of changes in tumor hypoxia. Herein, we thoroughly review the recent progress of nanomedicine strategies in both conquering and utilizing hypoxia to combat cancer and put forward the prospect of emerging nanomaterials for future clinical transformation, which hopes to provide perspectives in nanomaterials design.

Light-responsive smart nanocarriers for wirelessly controlled photodynamic therapy for prostate cancers

Photodynamic therapy (PDT) is an effective non-invasive or minimally invasive treatment method against different tumors. Loading photosensitizers in nanocarriers can potentially increase their accumulation in tumor sites. However, the PDT efficacy may be hindered because of self-quenching of the encapsulated photosensitizer and the small diffusion radii of the generated reactive oxygen species (ROS). Herein, light responsive nano assemblies composed of (Polyethylene glycol)-block-poly(4,5-dimethoxy-2-nitrobenzylmethacrylate) (PEG-b-PNBMA) were designed and loaded with the photosensitizer, Rose Bengal lactone (RB), to act as a smart nanocarrier (RB-M) for the delivery of the photosensitizer. A wirelessly activated light-emitting diode (LED) implant was designed to programmatically induce the release of the loaded RB first, followed by activating PDT after diffusion of RB into the cytoplasm. The results showed that sequential '405-580 nm' irradiation of the RB-M treated 22RV1 cells resulted in the highest PDT outcome among different irradiation protocols. The combination of this smart nanocarrier and sequential '405-580 nm' irradiation strategy exhibited good PDT efficacy against 2D 22RV1 prostate cancer cells as well as 3D cancer cell spheroids. This platform overcomes the light penetration limitations in PDT, and can potentially be applied in cancer bearing patients who are unfit for chemotherapy. STATEMENT OF SIGNIFICANCE: Nanocarriers for the delivery of photosensitizer in photodynamic therapy may result in relatively low therapeutic efficacy because of self-quenching of the encapsulated photosensitizer and the small diffusion radii of the generated reactive oxygen species (ROS). Light responsive smart nanocarriers can potentially overcome this challenge. In this study, a light responsive polymer (Polyethylene glycol)-block-poly(4,5-dimethoxy-2-nitrobenzylmethacrylate) (PEG-b-PNBMA) was synthesized and utilized to fabricate the smart nanocarrier. A wirelessly activated light-emitting diode (LED) implant was designed for light delivery in deep tissue. This new approach permits wirelessly and programmatically control of photosensitizer release and PDT activation under deep tissue, thus significantly enhancing PDT efficacy against prostate cancer cells as well as 3D cancer cell spheroids. This design should have a significant impact on controllable PDT under deep tissue.

Rational Design of Self-Reporting Photosensitizers for Cell Membrane-Targeted Photodynamic Therapy

Organelle-targeted photosensitizers (PSs) have demonstrated enhanced phototherapeutic effect by specifically destroying subcellular organelle. As a critical cellular organelle, the cell membrane plays crucial roles in maintaining cell integrity and regulating cellular communications. To date, a variety of membrane-targeted PSs have been developed and shown exceptional therapeutic effects. However, functional PSs that can achieve membrane-targeted photodynamic therapy (PDT) and real-time monitor the therapeutic process have rarely been reported. In particular, the development of self-reporting PS with near-infrared (NIR) absorption is highly desirable but remains a challenge. Herein, we presented two molecular rotor-based self-reporting PSs. One of the PSs, MRMP-2, possesses NIR absorption property, making it a promising candidate for clinical applications. These PSs could not only enable membrane-targeted PDT but also demonstrate selective fluorescence response toward viscosity. In this regard, the fluorescence variation of these PSs could be utilized to indicate the disruption of membrane structure during PDT process. By leveraging the feedback of the fluorescence signal, we could make intuitive judgement about the phototherapeutic results. As a result, these two PSs possess significant potential in the field of imaging-guided PDT.

Enzyme-triggered deep tumor penetration of a dual-drug nanomedicine enables an enhanced cancer combination therapy

Cancer cells could be eradicated by promoting generation of excessive intracellular reactive oxygen species (ROS) via emerging nanomedicines. However, tumor heterogeneity and poor penetration of nanomedicines often lead to diverse levels of ROS production in the tumor site, and ROS at a low level promote tumor cell growth, thus diminishing the therapeutic effect of these nanomedicines. Herein, we construct an amphiphilic and block polymer-dendron conjugate-derived nanomedicine (Lap@pOEGMA-b-p(GFLG-Dendron-Ppa), GFLG-DP/Lap NPs) that incorporates a photosensitizer, Pyropheophorbide a (Ppa), for ROS therapy and Lapatinib (Lap) for molecular targeted therapy. Lap, an epidermal growth factor receptor (EGFR) inhibitor that plays a role in inhibiting cell growth and proliferation, is hypothesized to synergize with ROS therapy for effectively killing cancer cells. Our results suggest that the enzyme-sensitive polymeric conjugate, pOEGMA-b-p(GFLG-Dendron-Ppa) (GFLG-DP), releases in response to cathepsin B (CTSB) after entering the tumor tissue. Dendritic-Ppa has a strong adsorption capacity to tumor cell membranes, which promotes efficient penetration and long-term retention. Lap can also be efficiently delivered to internal tumor cells to play its role due to the increased vesicle activity. Laser irradiation of Ppa-containing tumor cells results in production of intracellular ROS that is sufficient for inducing cell apoptosis. Meanwhile, Lap efficiently inhibits proliferation of remaining viable cells even in deep tumor regions, thus generating a significant synergistic anti-tumor therapeutic effect. This novel strategy can be extended to the development of efficient membrane lipid-based therapies to effectively combat tumors.

Quercetin@Gd3+ doped Prussian blue nanocubes induce the pyroptotic death of MDA-MB-231 cells: combinational targeted multimodal therapy, dual modal MRI, intuitive modelling of r1-r2 relaxivities

Quercetin (Qu), a potential bioflavonoid has gained considerable interest as a promising chemotherapeutic drug which can inhibit the proliferation of triple-negative breast cancer (TNBC) cells due to its regulation of the expression of tumor-suppressor gene metastasis and antioxidant property. Notably, Qu exhibits a very negligible cytotoxic effect on normal cells, even with high-dose treatment, while it is shows high affinity to TNBC. However, the efficiency of Qu is limited clinically due to its poor bioavailability, caused by its low aqueous solubility (2.15 μg mL^-1 at 25 °C), rapid gastrointestinal digestion and chemical instability in alkaline and neutral media. Herein, polydopamine (PDA)-coated, NH₂-PEG-NH₂ and hyaluronic acid (HA)-functionalized Gd³⁺-doped Prussian blue nanocubes (GPBNC) are reported as a multifunctional platform for the codelivery of Qu as a chemotherapeutic agent and GPBNC as a photodynamic (PDT) and photothermal (PTT) agent with improved therapeutic efficiency to overcome theses barriers. PDA, NH₂-PEG-NH₂ and HA stabilize GPBNC@Qu and facilitate bioavailability and active-targeting, while absorption of near infrared (NIR) (808 nm; 1 W cm^-2) induces PDT and PTT activities and dual T₁-T₂-weighted magnetic resonance imaging (MRI) with high relaxometric parameters (r₁ 10.06 mM^-1 s^-1 and r₂ 24.96 mM^-1 s^-1 at a magnetic field of 3 T). The designed platform shows a pH-responsive Qu release profile and NIR-induced therapeutic efficiency of ∼79% in 20 minutes of irradiation, wherein N-terminal gardermin D (N-GSDMD) and a P2X7-receptor-mediated pyroptosis pathway induces cell death, corroborating the up-regulation of NLRP3, caspase-1, caspase-5, N-GSDMD, IL-1β, cleaved Pannexin-1 and P2X7 proteins. More interestingly, the increasing relaxivity values of Prussian blue nanocubes with Gd³⁺ doping have been explained on the basis of Solomon-Bloembergen-Morgan theory, considering inner- and outer-sphere relaxivity, wherein crystal defects, coordinated water molecules, tumbling rate, metal to water proton distance, correlation time, magnetisation value etc. play a significant role. In summary, our study suggests that GPBNC could be a beneficial nanocarrier for theranostic purposes against TNBC, while our conceptual study clearly demonstrates the role of various factors in increasing relaxometric parameters.

ZIF-8 Nanoparticles Evoke Pyroptosis for High-Efficiency Cancer Immunotherapy

Although zeolitic imidazolate framework-8 (ZIF-8) has been applied in various tumor therapies, the intrinsic immunogenicity remains unclear. Here, we initiatively discover that ZIF-8 nanoparticles (NPs) can intrinsically induce pyroptosis by a caspase-1/gasdermin D (GSDMD)-dependent pathway. The pyroptotic cell death is accompanied by necrosis and immunogenic cell death (ICD) simultaneously for efficient in situ immunity initiation. Meanwhile, carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a mitochondrial depolarizing agent, is successfully loaded into ZIF-8 NPs and found to further enhance the pyroptosis process. Collectively, the obtained Pluronic F127-modified CCCP-incorporated ZIF-8 NPs (^F127 ZIF-8_CCCP NPs) activate antitumor immunity and reprogram immunosuppressive tumor microenvironment (TME), realizing high-efficiency tumor growth inhibition. This work will facilitate biomedicine applications of ZIF-8 and provide good inspiration for pyroptosis-induced cancer therapy.

Engineered Metallacycle-Based Supramolecular Photosensitizers for Effective Photodynamic Therapy

Although metallacycle-based supramolecular photosensitizers (PSs) have attracted increasing attention in biomedicine, their clinical translation is still hindered by their inherent dark toxicity. Herein, we report what to our knowledge is the first example of a molecular engineering approach to building blocks of metallacycles for constructing a series of supramolecular PSs (RuA-RuD), with the aim of simultaneously reducing dark toxicity and enhancing phototoxicity, and consequently obtaining high phototoxicity indexes (PI). Detailed in vitro investigations demonstrate that RuA-RuD display high cancer cellular uptake and remarkable antitumor activity even under hypoxic conditions. Notably, RuD exhibited no dark toxicity and displayed the highest PI value (≈406). Theoretical calculations verified that RuD has the largest steric hindrance and the lowest singlet-triplet energy gap (ΔE_ST , 0.61 eV). Further in vivo studies confirmed that RuD allows safe and effective phototherapy against A549 tumors.

Recent advances in lanthanide-doped up-conversion probes for theranostics

Up-conversion (or anti-Stokes) luminescence refers to the phenomenon whereby materials emit high energy, short-wavelength light upon excitation at longer wavelengths. Lanthanide-doped up-conversion nanoparticles (Ln-UCNPs) are widely used in biomedicine due to their excellent physical and chemical properties such as high penetration depth, low damage threshold and light conversion ability. Here, the latest developments in the synthesis and application of Ln-UCNPs are reviewed. First, methods used to synthesize Ln-UCNPs are introduced, and four strategies for enhancing up-conversion luminescence are analyzed, followed by an overview of the applications in phototherapy, bioimaging and biosensing. Finally, the challenges and future prospects of Ln-UCNPs are summarized.

Ultrasound-Amplified Enzyodynamic Tumor Therapy by Perovskite Nanoenzyme-Enabled Cell Pyroptosis and Cascade Catalysis

Overcoming apoptosis resistance to achieve efficient breast cancer treatment remains a challenge. The precise induction of another form of programmed cell death, pyroptosis, is an excellent alternative for treating cancer. Ultrasound (US)-enhanced enzyme dynamic (enzyodynamic) therapy is developed by employing LaFeO₃ (LFO) perovskite nanocrystals as a substrate to increase the rate of deleterious reactive oxygen species (ROS) generation for intensive cell pyroptosis. LFO nanocrystals possess quadruple enzyme-mimicking activities, including oxidase-, peroxidase-, glutathione peroxidase-, and catalase-mimicking activities, which undertake the dominant therapeutic task through cascade catalytic reactions, including the reversal of hypoxic microenvironment, depletion of endogenous glutathione, and continuous output of ROS. US exogenous stimulation increases the transition rate of the intermediate complex to Fe (II) and favors incremental ROS production, by which the ROS burst-induced pyroptosis process is accomplished through the ROS-TXNIP-NLRP3-GSDMD pathway. Both in vitro and in vivo antineoplastic outcomes affirm the ascendancy of LFO nanozyme-induced pyroptosis. This work highlights the critical role of US coupled with nanocatalytic reactors in pyroptosis-dominant breast cancer treatment with the apoptosis resistance circumvention feature.

Polymersomes with Red/Near-Infrared Emission and Reactive Oxygen Species Generation

In photodynamic therapy (PDT), the uses of nanoparticles bearing photosensitizers (PSs) can overcome some of the drawbacks of using a PS alone (e.g., poor water solubility and low tumor selectivity). However, numerous nano-formulations are developed by physical encapsulation of PSs through Van der Waals interactions, which have not only a limited load efficiency but also some in vivo biodistribution problems caused by leakage or burst release. Herein, polymersomes made from an amphiphilic block copolymer, in which a PS with aggregation-induced emission (AIE-PS) is covalently attached to its hydrophobic poly(amino acid) block, are reported. These AIE-PS polymersomes dispersed in aqueous solution have a high AIE-PS load efficiency (up to 46% as a mass fraction), a hydrodynamic diameter of 86 nm that is suitable for in vivo applications, and an excellent colloidal stability for at least 1 month. They exhibit a red/near-infrared photoluminescence and ability to generate reactive oxygen species (ROS) under visible light. They are non-cytotoxic in the dark as tested on Hela cells up to concentration of 100 µm. Benefiting from colloidal stability, AIE property and ROS generation capability, such a family of polymersomes can be great candidates for image-guided PDT.

Design of a Metallacycle-Based Supramolecular Photosensitizer for In Vivo Image-Guided Photodynamic Inactivation of Bacteria

Bacterial infection is one of the greatest threats to public health. In vivo real-time monitoring and effective treatment of infected sites through non-invasive techniques, remain a challenge. Herein, we designed a PtII metallacycle-based supramolecular photosensitizer through the host-guest interaction between a pillar[5]arene-modified metallacycle and 1-butyl-4-[4-(diphenylamino)styryl]pyridinium. Leveraging the aggregation-induced emission supramolecular photosensitizer, we improved fluorescence performance and antimicrobial photodynamic inactivation. In vivo studies revealed that it displayed precise fluorescence tracking of S. aureus-infected sites, and in situ performed image-guided efficient PDI of S. aureus without noticeable side effects. These results demonstrated that metallacycle combined with host-guest chemistry could provide a paradigm for the development of powerful photosensitizers for biomedicine.

A Carbonic Anhydrase IX (CAIX)-Anchored Rhenium(I) Photosensitizer Evokes Pyroptosis for Enhanced Anti-Tumor Immunity

An ideal cancer treatment should not only destroy primary tumors but also improve the immunogenicity of the tumor microenvironment to achieve a satisfactory anti-tumor immune effect. We designed a carbonic anhydrase IX (CAIX)-anchored rhenium(I) photosensitizer, named CA-Re, that not only performs type-I and type-II photodynamic therapy (PDT) with high efficiency under hypoxia (nanomolar-level phototoxicity), but also evokes gasdermin D (GSDMD) mediated pyroptotic cell death to effectively stimulate tumor immunogenicity. CA-Re could disrupt and self-report the loss of membrane integrity simultaneously. This promoted the maturation and antigen-presenting ability of dendritic cells (DCs), and fully activated T cells dependent adaptive immune response in vivo, eventually eliminating distant tumors at the same time as destroying primary tumors. To the best of our knowledge, CA-Re is the first metal complex-based pyroptosis inducer.

A New Kind of RIV-type AIEgens and Their Applications for the Construction of Multifunctional Luminescent MOFs

In this work, a new kind of butterfly-like molecules of oxacalix[2]arene[2]pyrazine (OAP) are reported, which exhibit typical characteristics of aggregation-induced emission (AIE) via the restriction of intramolecular vibration (RIV) mechanism. Unlike any of the reported RIV-type AIE molecules, the synthetic procedures of which are complicated and associated high costs, OAP AIEgens can be synthesized in a facile manner by a one-step catalyst-free reaction using commercially available materials. Notably, OAP AIEgens are ideal ligands for constructing metal-organic frameworks (MOFs) due to their built-in coordination sites of pyrazine groups. OAP-based MOFs exhibit multiple potential applications in reversible gas response, encrypted information storage, and construction of white light-emitting devices. This work enriches limited kinds of RIV-type AIEgens, offers additional selections of bridging ligands for constructing luminescent MOFs and provides a visualized prototype to understand the effect of RIV process on the luminescence property of MOFs.