Massively Evoking Immunogenic Cell Death by Focused Mitochondrial Oxidative Stress using an AIE Luminogen with a Twisted Molecular Structure

CuPc-Fe@BSA nanocomposite: Intracellular acid-sensitive aggregation for enhanced sonodynamic and chemo-therapy

Due to their rigid π-conjugated macrocyclic structure, organic sonosensitizers face significant aggregation in physiological conditions, hindering the production of reactive oxygen species (ROS). An acid-sensitive nanoassembly was developed to address this issue and enhance sonodynamic therapy (SDT) and emission. Initially, copper phthalocyanine (CuPc) was activated using a H2SO4-assisted hydrothermal method to introduce multiple functional groups (-COOH, -OH, and -SO3H), disrupting strong π-π stacking and promoting ROS generation and emission. Subsequently, negatively charged CuPc-SO4 was incorporated into bovine serum albumin (BSA) to form CuPc-Fe@BSA nanoparticles (10 nm) with Fe3+ ions serving as linkers. In acidic conditions, protonation of CuPc-SO4 and BSA weakened the interactions, leading to Fe3+ release and nanostructure dissociation. Protonated CuPc-SO4 tended to self-aggregate into nanorods. This acidity-sensitive aggregation is vital for achieving specific accumulation within the tumor microenvironment (TME), thereby enhancing retention and SDT efficacy. Prior to this, the nanocomposites demonstrated cycling stability under neutral conditions. Additionally, the released Fe ions exhibited mimicry of glutathione peroxidase and peroxidase activity for chemotherapy (CDT). The synergistic effect of SDT and CDT increased intracellular oxidative stress, causing mitochondrial injury and ferroptosis. Furthermore, the combined therapy induced immunogenic cell death (ICD), effectively activating anticancer immune responses and suppressing metastasis and recurrence.

Exciting Bacteria to a Hypersensitive State for Enhanced Aminoglycoside Therapy by a Rationally Constructed AIE Luminogen

The diminishing effectiveness of existing aminoglycoside antibiotics (AGs) compels scientists to seek new approaches to enhance the sensitivity of current AGs. Despite ongoing efforts, currently available approaches remain restricted. Herein, a novel strategy involving the rational construction of an aggregation-induced-emission luminogen (AIEgen) is introduced to significantly enhance Gram-positive bacteria's susceptibility to AGs. The application of this approach involves the simple addition of AIEgens to bacteria followed by a 5 min light irradiation. Under light exposure, AIEgens efficiently generate reactive oxygen species (ROS), elevating intrabacterial ROS levels to a nonlethal threshold. Post treatment, the bacteria swiftly enter a hypersensitive state, resulting in a 21.9-fold, 15.5-fold, or 7.2-fold increase in susceptibility to three AGs: kanamycin, gentamycin, and neomycin, respectively. Remarkably, this approach is specific to AGs, and the induced hypersensitivity displays unparalleled longevity and heritability. Further in vivo studies confirm a 7.0-fold enhanced bactericidal ability of AGs against Gram-positive bacteria through this novel approach. This research not only broadens the potential applications of AIEgens but also introduces a novel avenue to bolster the effectiveness of AGs in combating bacterial infections.

Nanozymes in cancer immunotherapy: metabolic disruption and therapeutic synergy

Over the past decade, there has been a growing emphasis on investigating the role of immunotherapy in cancer treatment. However, it faces challenges such as limited efficacy, a diminished response rate, and serious adverse effects. Nanozymes, a subset of nanomaterials, demonstrate boundless potential in cancer catalytic therapy for their tunable activity, enhanced stability, and cost-effectiveness. By selectively targeting the metabolic vulnerabilities of tumors, they can effectively intensify the destruction of tumor cells and promote the release of antigenic substances, thereby eliciting immune clearance responses and impeding tumor progression. Combined with other therapies, they synergistically enhance the efficacy of immunotherapy. Hence, a large number of metabolism-regulating nanozymes with synergistic immunotherapeutic effects have been developed. This review summarizes recent advancements in cancer immunotherapy facilitated by nanozymes, focusing on engineering nanozymes to potentiate antitumor immune responses by disturbing tumor metabolism and performing synergistic treatment. The challenges and prospects in this field are outlined. We aim to provide guidance for nanozyme-mediated immunotherapy and pave the way for achieving durable tumor eradication.

Advanced Strategies for Strengthening the Immune Activation Effect of Traditional Antitumor Therapies

The utilization of traditional therapies (TTS), such as chemotherapy, reactive oxygen species-based therapy, and thermotherapy, to induce immunogenic cell death (ICD) in tumor cells has emerged as a promising strategy for the activation of the antitumor immune response. However, the limited effectiveness of most TTS in inducing the ICD effect of tumors hinders their applications in combination with immunotherapy. To address this challenge, various intelligent strategies have been proposed to strengthen the immune activation effect of these TTS, and then achieve synergistic antitumor efficacy with immunotherapy. These strategies primarily focus on augmenting the tumor ICD effect or facilitating the antigen (released by the ICD tumor cells) presentation process during TTS, and they are systematically summarized in this review. Finally, the existing bottlenecks and prospects of TTS in the application of tumor immune regulation are also discussed.

Organelle-based immunotherapy strategies for fighting against cancer

Destruction of subcellular organelles can cause dysfunction and even death of cells to elicit immune responses. In this review, the characteristics and functions of important organelles are mainly summarized. Then, the intelligent immunotherapeutic strategies and suggestions based on influencing the organelles are further highlighted. This review will provide ideas for developing novel and effective immunotherapy strategies and advance the development of cancer immunotherapy.

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

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

Donor-Acceptor Modulating of Ionic AIE Photosensitizers for Enhanced ROS Generation and NIR-II Emission

Photosensitizers (PSs) with aggregation-induced emission (AIE) characteristics are competitive candidates for bioimaging and therapeutic applications. However, their short emission wavelength and nonspecific organelle targeting hinder their therapeutic effectiveness. Herein, a donor-acceptor modulation approach is reported to construct a series of ionic AIE photosensitizers with enhanced photodynamic therapy (PDT) outcomes and fluorescent emission in the second near-infrared (NIR-II) window. By employing dithieno[3,2-b:2',3'-d]pyrrole (DTP) and indolium (In) as the strong donor and acceptor, respectively, the compound DTP-In exhibits a substantial redshift in absorption and fluorescent emission reach to NIR-II region. The reduced energy gap between singlet and triplet states in DTP-In also increases the reactive oxygen species (ROS) generation rate. Further, DTP-In can self-assemble in aqueous solutions, forming positively charged nanoaggregates, which are superior to conventional encapsulated nanoparticles in cellular uptake and mitochondrial targeting. Consequently, DTP-In aggregates show efficient photodynamic ablation of 4T1 cancer cells and outstanding tumor theranostic in vivo under 660 nm laser irradiation. This work highlights the potential of molecular engineering of donor-acceptor AIE PSs with multiple functionalities, thereby facilitating the development of more effective strategies for cancer therapy.

A Dual-Channel Ca2+ Nanomodulator Induces Intracellular Ca2+ Disorders via Endogenous Ca2+ Redistribution for Tumor Radiosensitization

Tumor cells harness Ca2+ to maintain cellular homeostasis and withstand external stresses from various treatments. Here, a dual-channel Ca2+ nanomodulator (CAP-P-NO) is constructed that can induce irreversible intracellular Ca2+ disorders via the redistribution of tumor-inherent Ca2+ for disrupting cellular homeostasis and thus improving tumor radiosensitivity. Stimulated by tumor-overexpressed acid and glutathione, capsaicin and nitric oxide are successively escaped from CAP-P-NO to activate the transient receptor potential cation channel subfamily V member 1 and the ryanodine receptor for the influx of extracellular Ca2+ and the release of Ca2+ in the endoplasmic reticulum, respectively. The overwhelming level of Ca2+ in tumor cells not only impairs the function of organelles but also induces widespread changes in the gene transcriptome, including the downregulation of a set of radioresistance-associated genes. Combining CAP-P-NO treatment with radiotherapy achieves a significant suppression against both pancreatic and patient-derived hepatic tumors with negligible side effects. Together, the study provides a feasible approach for inducing tumor-specific intracellular Ca2+ overload via endogenous Ca2+ redistribution and demonstrates the great potential of Ca2+ disorder therapy in enhancing the sensitivity for tumor radiotherapy.

Supramolecular dye nanoassemblies for advanced diagnostics and therapies

Dyes have conventionally been used in medicine for staining cells, tissues, and organelles. Since these compounds are also known as photosensitizers (PSs) which exhibit photoresponsivity upon photon illumination, there is a high desire towards formulating these molecules into nanoparticles (NPs) to achieve improved delivery efficiency and enhanced stability for novel imaging and therapeutic applications. Furthermore, it has been shown that some of the photophysical properties of these molecules can be altered upon NP formation thereby playing a major role in the outcome of their application. In this review, we primarily focus on introducing dye categories, their formulation strategies and how these strategies affect their photophysical properties in the context of photothermal and non-photothermal applications. More specifically, the most recent progress showing the potential of dye supramolecular assemblies in modalities such as photoacoustic and fluorescence imaging, photothermal and photodynamic therapies as well as their employment in photoablation as a novel modality will be outlined. Aside from their photophysical activity, we delve shortly into the emerging application of dyes as drug stabilizing agents where these molecules are used together with aggregator molecules to form stable nanoparticles.

Self-Adaptive Photodynamic-to-Photothermal Switch for Smart Antitumor Photoimmunotherapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) possess different merits in cancer phototherapy, but the tumor microenvironment becomes unfavorable during the phototheranostic progress. Herein, we report a self-adaptive cyanine derivative Cy5-TPA with the PDT-dominated state to PTT-dominated state autoswitch feature for enhanced photoimmunotherapy. The incorporation of rotatable triphenylamine (TPA) moiety renders Cy5-TPA with the temperature or intramolecular-motion regulated photoactivities, which shows preferable reactive oxygen species (ROS) generation at lower temperature while stronger photothermal conversion at higher ones. Such a promising feature permits the in situ switch from PDT-dominated state to PTT-dominated state along with intratumoral temperature increase during laser irradiation, which also works in line with the concurrently reduced intratumoral oxygen level, exhibiting a self-adaptive phototherapeutic behavior to maximize the phototherapeutic antitumor outcome. Most importantly, the self-adaptive PDT-dominated state to PTT-dominated state switch also facilitates the sequential generation and release of damage-associated molecular patterns during immunogenic cell death (ICD). Hence, Cy5-TPA demonstrates excellent photoimmunotherapy performance in ICD induction, dendritic cell maturation, and T cell activation for tumor eradication and metastasis inhibition.

Enhanced Osteosarcoma Immunotherapy via CaCO3 Nanoparticles: Remodeling Tumor Acidic and Immune Microenvironment for Photodynamic Therapy

Osteosarcoma (OS) is a "cold" tumor enriched in noninflammatory M2 phenotype tumor-associated macrophages (TAMs), which limits the efficacy of immunotherapy. The acidic tumor microenvironment (TME), generated by factors such as excess hydrogen (H+) ions and high lactate levels, activates immunosuppressive cells, further promoting a suppressive tumor immune microenvironment (TIME). Therefore, a multitarget synergistic combination strategy that neutralizes the acidic TME and reprograms TAMs can be beneficial for OS therapy. Here, a calcium carbonate (CaCO3)/polydopamine (PDA)-based nanosystem (A-NPs@(SHK+Ce6)) is developed. CaCO3 nanoparticles are used to neutralize H+ ions and alleviate the suppressive TIME, and the loaded SHK not only synergizes with photodynamic therapy (PDT) but also inhibits lactate production, further reversing the acidic TME and repolarizing TAMs to consequently lead to enhanced PDT-induced tumor suppression and comprehensive beneficial effects on antitumor immune responses. Importantly, A-NPs@(SHK+Ce6), in combination with programmed cell death protein 1 (PD-1) checkpoint blockade, shows a remarkable ability to eliminate distant tumors and promote long-term immune memory function to protect against rechallenged tumors. This work presents a novel multiple-component combination strategy that coregulates the acidic TME and TAM polarization to reprogram the TIME.

Boosted photo-immunotherapy via near-infrared light excited phototherapy in tumor sites and photo-activation in sentinel lymph nodes

Phototherapy is a promising modality that could eradicate tumor and trigger immune responses via immunogenic cell death (ICD) to enhance anti-tumor immunity. However, due to the lack of deep-tissue-excitable phototherapeutic agents and appropriate excitation strategies, the utility of phototherapy for efficient activation of the immune system is challenging. Herein, we report functionalized ICG nanoparticles (NPs) with the capture capability of tumor-associated antigens (TAAs). Under near-infrared (NIR) light excitation, the ICG NPs exhibited high-performance phototherapy, i.e., synergistic photothermal therapy and photodynamic therapy, thereby efficiently eradicating primary solid tumor and inducing ICD and subsequently releasing TAAs. The ICG NPs also captured TAAs and delivered them to sentinel lymph nodes, and then the sentinel lymph nodes were activated with NIR light to trigger efficient T-cell immune responses through activation of dendritic cells with the assistance of ICG NP generated reactive oxygen species, inhibiting residual primary tumor recurrence and controlling distant tumor growth. The strategy of NIR light excited phototherapy in tumor sites and photo-activation in sentinel lymph nodes provides a powerful platform for active immune systems for anti-tumor photo-immunotherapy.

Augmenting Cancer Therapy with a Supramolecular Immunogenic Cell Death Inducer: A Lysosome-Targeted NIR-Light-Activated Ruthenium(II) Metallacycle

Though immunogenic cell death (ICD) has garnered significant attention in the realm of anticancer therapies, effectively stimulating strong immune responses with minimal side effects in deep-seated tumors remains challenging. Herein, we introduce a novel self-assembled near-infrared-light-activated ruthenium(II) metallacycle, Ru1105 (λem = 1105 nm), as a first example of a Ru(II) supramolecular ICD inducer. Ru1105 synergistically potentiates immunomodulatory responses and reduces adverse effects in deep-seated tumors through multiple regulated approaches, including NIR-light excitation, increased reactive oxygen species (ROS) generation, selective targeting of tumor cells, precision organelle localization, and improved tumor penetration/retention capabilities. Specifically, Ru1105 demonstrates excellent depth-activated ROS production (∼1 cm), strong resistance to diffusion, and anti-ROS quenching. Moreover, Ru1105 exhibits promising results in cellular uptake and ROS generation in cancer cells and multicellular tumor spheroids. Importantly, Ru1105 induces more efficient ICD in an ultralow dose (10 μM) compared to the conventional anticancer agent, oxaliplatin (300 μM). In vivo experiments further confirm Ru1105's potency as an ICD inducer, eliciting CD8+ T cell responses and depleting Foxp3+ T cells with minimal adverse effects. Our research lays the foundation for the design of secure and exceptionally potent metal-based ICD agents in immunotherapy.

An Activatable Dual Polymer Nanosystem for Photoimmunotherapy and Metabolic Modulation of Deep-Seated Tumors

Nanomedicine in combination with immunotherapy has shown great potential in the cancer treatment, but phototherapeutic nanomaterials that specifically activate the immunopharmacological effects in deep tumors have rarely been developed due to limited laser penetration depth and tumor immune microenvironment. Herein, this work reports a newly synthesized semiconducting polymer (SP) grafted with imiquimod R837 and indoxmid encapsulated micelle (SPRIN-micelle) with strong absorption in the second near infrared window (NIR-II) that can relieve tumor immunosuppression and enhance the photothermal immunotherapy and catabolic modulation on tumors. Immune agonists (Imiquimod R837) and immunometabolic modulators (indoxmid) are covalently attached to NIR-II SP sensors via a glutathione (GSH) responsive self-immolation linker and then loaded into Pluronic F127 (F127) micelles by a temperature-sensitive critical micelle concentration (CMC)-switching method. Using this method, photothermal effect of SPRIN-micelles in deep-seated tumors can be activated, leading to effective tumor ablation and immunogenic cell death (ICD). Meanwhile, imiquimod and indoxmid are tracelessly released in response to the tumor microenvironment, resulting in dendritic cell (DC) maturation by imiquimod R837 and inhibition of both indoleamine 2,3-dioxygenase (IDO) activity and Treg cell expression by indoxmid. Ultimately, cytotoxic T-lymphocyte infiltration and tumor metastasis inhibition in deep solid tumors (9 mm) are achieved. In summary, this work demonstrates a new strategy for the combination of photothermal immunotherapy and metabolic modulation by developing a dual functional polymer system including activable SP and temperature-sensitive F127 for the treatment of deep solid tumors.

Nanocatalytic Anti-Tumor Immune Regulation

Immunotherapy has brought a new dawn for human being to defeat cancer. Although existing immunotherapy regimens (CAR-T, etc.) have made breakthroughs in the treatments of hematological cancer and few solid tumors such as melanoma, the therapeutic efficacy on most solid tumors is still far from being satisfactory. In recent years, the researches on tumor immunotherapy based on nanocatalytic materials are under rapid development, and significant progresses have been made. Nanocatalytic medicine has been demonstrated to be capable of overcoming the limitations of current clinicnal treatments by using toxic chemodrugs, and exhibits highly attractive advantages over traditional therapies, such as the enhanced and sustained therapeutic efficacy based on the durable catalytic activity, remarkably reduced harmful side-effects without using traditional toxic chemodrugs, and so on. Most recently, nanocatalytic medicine has been introduced in the immune-regulation for disease treatments, especially, in the immunoactivation for tumor therapies. This article presents the most recent progresses in immune-response activations by nanocatalytic medicine-initiated chemical reactions for tumor immunotherapy, and elucidates the mechanism of nanocatalytic medicines in regulating anti-tumor immunity. By reviewing the current research progress in the emerging field, this review will further highlight the great potential and broad prospects of nanocatalysis-based anti-tumor immune-therapeutics.

Molecular engineering of AIE-active boron clustoluminogens for enhanced boron neutron capture therapy

The development of boron delivery agents bearing an imaging capability is crucial for boron neutron capture therapy (BNCT), yet it has been rarely explored. Here we present a new type of boron delivery agent that integrates aggregation-induced emission (AIE)-active imaging and a carborane cluster for the first time. In doing so, the new boron delivery agents have been rationally designed by incorporating a high boron content unit of a carborane cluster, an erlotinib targeting unit towards lung cancer cells, and a donor-acceptor type AIE unit bearing naphthalimide. The new boron delivery agents demonstrate both excellent AIE properties for imaging purposes and highly selective accumulation in tumors. For example, at a boron delivery agent dose of 15 mg kg-1, the boron amount reaches over 20 μg g-1, and both tumor/blood (T/B) and tumor/normal cell (T/N) ratios reach 20-30 times higher than those required by BNCT. The neutron irradiation experiments demonstrate highly efficient tumor growth suppression without any observable physical tissue damage and abnormal behavior in vivo. This study not only expands the application scopes of both AIE-active molecules and boron clusters, but also provides a new molecular engineering strategy for a deep-penetrating cancer therapeutic protocol based on BNCT.

Intracellular Magnetic Hyperthermia Enables Concurrent Down-Regulation of CD47 and SIRPα To Potentiate Antitumor Immunity

Harnessing the potential of tumor-associated macrophages (TAMs) to engulf tumor cells offers promising avenues for cancer therapy. Targeting phagocytosis checkpoints, particularly the CD47-signal regulatory protein α (SIRPα) axis, is crucial for modulating TAM activity. However, single checkpoint inhibition has shown a limited efficacy. In this study, we demonstrate that ferrimagnetic vortex-domain iron oxide (FVIO) nanoring-mediated magnetic hyperthermia effectively suppresses the expression of CD47 protein on Hepa1-6 tumor cells and SIRPα receptor on macrophages, which disrupts CD47-SIRPα interaction. FVIO-mediated magnetic hyperthermia also induces immunogenic cell death and polarizes TAMs toward M1 phenotype. These changes collectively bolster the phagocytic ability of macrophages to eliminate tumor cells. Furthermore, FVIO-mediated magnetic hyperthermia concurrently escalates cytotoxic T lymphocyte levels and diminishes regulatory T cell levels. Our findings reveal that magnetic hyperthermia offers a novel approach for dual down-regulation of CD47 and SIRPα, reshaping the tumor microenvironment to stimulate immune responses, culminating in significant antitumor activity.

Toward Type I/II ROS Generation Photoimmunotherapy by Molecular Engineering of Semiconducting Perylene Diimide

As prospective phototheranostic agents for cancer imaging and therapy, semiconducting organic molecule-based nanomedicines are developed. However, near-infrared (NIR) emission, and tunable type I (O2 • -) and type II (1O2) photoinduced reactive oxygen species (ROS) generation to boost cancer photoimmunotherapy remains a big challenge. Herein, a series of D-π-A structures, NIR absorbing perylene diimides (PDIs) with heavy atom bromide modification at the bay position of PDIs are prepared for investigating the optimal photoinduced type I/II ROS generation. The heavy atom effect has demonstrated a reduction of molecular ∆EST and promotion of the intersystem crossing processes of PDIs, enhancing the photodynamic therapy (PDT) efficacy. The modification of three bromides and one pyrrolidine at the bay position of PDI (TBDT) has demonstrated the best type I/II PDT performance by batch experiments and theoretical calculations. TBDT based nanoplatforms (TBDT NPs) enable type I/II PDT in the hypoxic tumor microenvironment as a strong immunogenic cell death (ICD) inducer. Moreover, TBDT NPs showing NIR emission allow in vivo bioimaging guided phototherapy of tumor. This work uses novel PDIs with adjustable type I/II ROS production to promote antitumor immune response and accomplish effective tumor eradication, consequently offering molecular guidelines for building high-efficiency ICD inducers.

Photonic control of image-guided ferroptosis cancer nanomedicine

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

Nuclear-Targeted Nanostrategy Regulates Spatiotemporal Communication for Dual Antitumor Immunity

Intercellular communication between tumor cells and immune cells regulates tumor progression including positive communication with immune activation and negative communication with immune escape. An increasing number of methods are employed to suppress the dominant negative communication in tumors such as PD-L1/PD-1. However, how to effectively improve positive communication is still a challenge. In this study, a nuclear-targeted photodynamic nanostrategy is developed to establish positive spatiotemporal communication, further activating dual antitumor immunity, namely innate and adaptative immunity. The mSiO2 -Ion@Ce6-NLS nanoparticles (NPs) are designed, whose surface is modified by ionic liquid silicon (Ion) and nuclear localization signal peptide (NLS: PKKKRKV), and their pores are loaded with the photosensitizer hydrogen chloride e6 (Ce6). Ion-modified NPs enhance intratumoral enrichment, and NLS-modified NPs exhibit nuclear-targeted characteristics to achieve nuclear-targeted photodynamic therapy (nPDT). mSiO2 -Ion@Ce6-NLS with nPDT facilitate the release of damaged double-stranded DNA from tumor cells to activate macrophages via stimulator of interferon gene signaling and induce the immunogenic cell death of tumor cells to activate dendritic cells via "eat me" signals, ultimately leading to the recruitment of CD8+ T-cells. This therapy effectively strengthens positive communication to reshape the dual antitumor immune microenvironment, further inducing long-term immune memory, and eventually inhibiting tumor growth and recurrence.

Self-heating mitochondrion-induced free radical blast for immunogenic cell death stimulation and HCC immunotherapy

Hepatocellular carcinoma (HCC) is an immunosuppressive tumor associated with high mortality. Photothermal and photodynamic therapies have been applied to induce immunogenic cell death (ICD) in HCC, successfully eliciting immune responses but facing limitations in penetration depth in clinical trials. Here, intrinsic mitochondrial hyperthermia was used to trigger thermosensitive drug release. The mitochondria were further self-heated through 2,4-dinitrophenol uncoupling, dramatically promoting free radical initiation and inducing tumor ICD. The synthesized mitochondrial-targeting TPP-HA-TDV nanoparticles specifically generated free radicals in the mitochondria without external stimulation, and obviously enhanced the release of ICD markers, subsequently evoking immune responses. The results showed that mitochondrial hyperthermia could be an endogenous target for thermosensitive drug release. Furthermore, self-heating mitochondria-induced free radical blast could be an efficient therapeutic for deep-seated tumor therapy.

A mitochondria-targeting dihydroartemisinin derivative as a reactive oxygen species -based immunogenic cell death inducer

Immunogenic cell death (ICD) can activate the anticancer immune response and its occurrence requires high reliance on oxidative stress. Inducing mitochondrial reactive oxygen species (ROS) is a desirable capability for ICD inducers. However, in the category of ICD-associated drugs, numerous reported ICD inducers are a series of anthracyclines and weak in ICD induction. Herein, a mitochondria-targeting dihydroartemisinin derivative (T-D) was synthesized by conjugating triphenylphosphonium (TPP) to dihydroartemisinin (DHA). T-D can selectively accumulate in mitochondria to trigger ROS generation, leading to the loss of mitochondrial membrane potential (ΔΨm) and ER stress. Notably, T-D exhibits far more potent ICD-inducing properties than its parent compound. In vivo, T-D-treated breast cancer cell vaccine inhibits metastasis to the lungs and tumor growth. These results indicate that T-D is an excellent ROS-based ICD inducer with the specific function of trigging vigorous ROS in mitochondria and sets an example for incorporating artemisinin-based drugs into the ICD field.

Diverse drug delivery systems for the enhancement of cancer immunotherapy: an overview

Despite the clear benefits demonstrated by immunotherapy, there is still an inevitable off-target effect resulting in serious adverse immune reactions. In recent years, the research and development of Drug Delivery System (DDS) has received increased prominence. In decades of development, DDS has demonstrated the ability to deliver drugs in a precisely targeted manner to mitigate side effects and has the advantages of flexible control of drug release, improved pharmacokinetics, and drug distribution. Therefore, we consider that combining cancer immunotherapy with DDS can enhance the anti-tumor ability. In this paper, we provide an overview of the latest drug delivery strategies in cancer immunotherapy and briefly introduce the characteristics of DDS based on nano-carriers (liposomes, polymer nano-micelles, mesoporous silica, extracellular vesicles, etc.) and coupling technology (ADCs, PDCs and targeted protein degradation). Our aim is to show readers a variety of drug delivery platforms under different immune mechanisms, and analyze their advantages and limitations, to provide more superior and accurate targeting strategies for cancer immunotherapy.

Nanoscale Covalent Organic Framework with Staggered Stacking of Phthalocyanines for Mitochondria-Targeted Photodynamic Therapy

Phthalocyanine photosensitizers (PSs) have shown promise in fluorescence imaging and photodynamic therapy (PDT) of malignant tumors, but their practical application is limited by the aggregation-induced quenching (AIQ) and inherent photobleaching of PSs. Herein, we report the synthesis of a two-dimensional nanoscale covalent organic framework (nCOF) with staggered (AB) stacking of zinc-phthalocyanines (ZnPc), ZnPc-PI, for fluorescence imaging and mitochondria-targeted PDT. ZnPc-PI isolates and confines ZnPc PSs in the rigid nCOF to reduce AIQ, improve photostability, enhance cellular uptake, and increase the level of reactive oxygen species (ROS) generation via mitochondrial targeting. ZnPc-PI shows efficient tumor accumulation, which allowed precise tumor imaging and nanoparticle tracking. With high cellular uptake and tumor accumulation, intrinsic mitochondrial targeting, and enhanced ROS generation, ZnPc-PI exhibits potent PDT efficacy with >95% tumor growth inhibition on two murine colon cancer models without causing side effects.

Endoplasmic Reticulum-Targeting AIE Photosensitizers to Boost Immunogenic Cell Death for Immunotherapy of Bladder Carcinoma

Bladder cancer is characterized by high rates of recurrence and multifocality. Immunogenic cell death (ICD) of cancer cells has emerged as a promising strategy to improve the immunogenicity of tumor cells for enhanced cancer immunotherapy. Although photosensitizer-based photodynamic therapy (PDT) has been validated as capable of inducing ICD in cancer cells, the photosensitizers with a sufficient ICD induction ability are still rare, and there have been few reports on the development of advanced photosensitizers to strongly evoke the ICD of bladder cancer cells for eliciting potent antitumor immune responses and eradicating bladder carcinoma in situ. In this work, we have synthesized a new kind of endoplasmic reticulum (ER)-targeting aggregation-induced emission (AIE) photosensitizer (named DPASCP-Tos), which could effectively anchor to the cellular ER and trigger focused reactive oxygen species (ROS) production within the ER, thereby boosting ICD in bladder cancer cells. Furthermore, we have demonstrated that bladder cancer cells killed by ER-targeted PDT could serve as a therapeutic cancer vaccine to elicit a strong antitumor immunity. Prophylactic vaccination of the bladder cancer cells killed by DPASCP-Tos under light irradiation promoted the maturation of dendritic cells (DCs) and the expansion of tumor antigen-specific CD8+ T cells in vivo and protected mice from subsequent in situ bladder tumor rechallenge and extended animal survival. In summary, the ER-targeted AIEgens developed here significantly amplified the ICD of bladder cells through focused ROS-based ER oxidative stress and transformed bladder cancer cells into the therapeutic vaccine to enhance immunogenicity against orthotopic bladder cancer, providing valuable insights for bladder carcinoma treatment.

Photodynamic Modulation of Endoplasmic Reticulum and Mitochondria Network Boosted Cancer Immunotherapy

Immunogenic cell death (ICD) represents a promising approach for enhancing tumor therapy efficacy by inducing antitumor immune response. However, current ICD inducers often have insufficient endoplasmic reticulum (ER) enrichment and ineffectiveness in tumor immune escape caused by ER-mitochondria interaction. In this study, a kind of photoactivatable probe, THTTPy-PTSA, which enables sequential targeting of the ER and mitochondria is developed. THTTPy-PTSA incorporates p-Toluenesulfonamide (PTSA) for ER targeting, and upon light irradiation, the tetrahydropyridine group undergoes a photo oxidative dehydrogenation reaction, transforming into a pyridinium group that acts as a mitochondria-targeting moiety. The results demonstrate that THTTPy-PTSA exhibits exceptional subcellular translocation from the ER to mitochondria upon light irradiation treatment, subsequently triggers a stronger ER stress response through a cascade-amplification effect. Importantly, the augmented ER stress leads to substantial therapeutic efficacy in a 4T1 tumor model by eliciting the release of numerous damage-associated molecular patterns, thereby inducing evident and widespread ICD, consequently enhancing the antitumor immune efficacy. Collectively, the findings emphasize the pivotal role of photodynamic modulation of the ER-mitochondria network, facilitated by THTTPy-PTSA with precise spatial and temporal regulation, in effectively bolstering the antitumor immune response. This innovative approach presents a promising alternative for addressing the challenges associated with cancer immunotherapy.

Hypoxia-responsive AIEgens for precise disease theranostics

Specific biomarker-activatable probes have revolutionized theranostics, being beneficial for precision medicine. Hypoxia is a critical pathological characteristic prevalent in numerous major diseases such as cancers, cardiovascular disorders, inflammatory diseases, and acute ischemia. Aggregation-induced emission luminogens (AIEgens) have emerged as a promising tool to tackle the biomedical issues. Of particular significance are the hypoxia-responsive AIEgens, representing a kind of crucial probe capable of delicately sensing and responding to the hypoxic microenvironment, thereby enhancing the precision of disease diagnosis and treatment. In this review, we summarize the recent advances of hypoxia-responsive AIEgens for varied biomedical applications. The hypoxia-responsive structures based on AIEgens, such as azobenzene, nitrobenzene, and N-oxide are presented, which are in response to the reduction property to bring about significant alternations in response spectra and/or fluorescence intensity. The bioapplications including imaging and therapy of tumor and ischemia diseases are discussed. Moreover, the review sheds light on the future challenges and prospects in this field. This review aims to provide comprehensive guidance and understanding into the development of activatable bioprobes, especially the hypoxia-responsive AIEgens for improving the diagnosis and therapy outcome of related diseases.

Dynamic immuno-nanomedicines in oncology

Anti-cancer therapeutics have achieved significant advances due to the emergence of immunotherapies that rely on the identification of tumors by the patients' immune system and subsequent tumor eradication. However, tumor cells often escape immunity, leading to poor responsiveness and easy tolerance to immunotherapy. Thus, the potentiated anti-tumor immunity in patients resistant to immunotherapies remains a challenge. Reactive oxygen species-based dynamic nanotherapeutics are not new in the anti-tumor field, but their potential as immunomodulators has only been demonstrated in recent years. Dynamic nanotherapeutics can distinctly enhance anti-tumor immune response, which derives the concept of the dynamic immuno-nanomedicines (DINMs). This review describes the pivotal role of DINMs in cancer immunotherapy and provides an overview of the clinical realities of DINMs. The preclinical development of emerging DINMs is also outlined. Moreover, strategies to synergize the antitumor immunity by DINMs in combination with other immunologic agents are summarized. Last but not least, the challenges and opportunities related to DINMs-mediated immune responses are also discussed.

Precise ligand engineering of Ir(III)-based photosensitizer with aggregation-induced emission for image-guided photodynamic therapy

Photodynamic therapy (PDT), which relies on the production of reactive oxygen species (ROS) induced by a photosensitizer to kill cancer cells, has become a non-invasive approach to combat cancer. However, the conventional aggregation-caused quenching effect, as well as the low ROS generation ability of photosensitizers, restrict their biological applications. In this work, a new Ir(III) complex with a dendritic ligand has been strategically designed and synthesized by ingenious modification of the ancillary ligand of a reported Ir(III) complex (Ir-1). The extended π-conjugation and multiple aromatic donor moieties endow the resulting complex Ir-2 with obvious aggregation-induced emission (AIE) activity and bathochromic emission. In in vitro experiments, importantly, Ir-2 nanoparticles exhibit the excellent photoinduced ROS generation capabilities of O2 •- and 1 O2 , as well as excellent biocompatibility and the lipid droplets (LDs) targeting feature. This study would provide useful guidance to design efficient Ir(III)-based photosensitizers used in biological applications in the future.

Dual Role of Vitamin C-Encapsulated Liposomal Berberine in Effective Colon Anticancer Immunotherapy

The aim of the study was to achieve effective colon anticancer immunotherapy using the alkaloid berberine. In the presented paper we attempt to develop a formulation of berberine loaded into liposomal carriers using the vitamin C gradient method, characterized by efficient drug encapsulation, high stability during long-term storage, low drug release in human plasma with specific cytotoxicity towards colon cancer cells. Liposomal berberine was responsible for the induction of oxidative stress, the presence of Ca2+ ions in the cytosol, the reduction of Δψm, and ATP depletion with a simultaneous lack of caspase activity. Moreover, treatment with liposomal berberine led to CRT exposure on the surface of cancer cells, extracellular ATP, and HMGB1 release. The above-described mechanism of action was most likely associated with ICD induction, contributing to the increased number of phagocytic cancer cells. We have shown that cancer cells treated with liposomal berberine were phagocytosed more frequently by macrophages compared to the untreated cancer cells. What is more, we have shown that macrophage pre-treatment with liposomal berberine led to a 3-fold change in the number of phagocytosed SW620 cancer cells. The obtained results provide new insights into the role of berberine in maintaining the immune response against colorectal cancer.

Semiconducting Polymers for Cancer Immunotherapy

As a monumental breakthrough in cancer treatment, immunotherapy has attracted tremendous attention in recent years. However, one challenge faced by immunotherapy is the low response rate and the immune-related adverse events (irAEs). Therefore, it is important to explore new therapeutic strategies and platforms for boosting therapeutic benefits and decreasing the side effects of immunotherapy. In recent years, semiconducting polymer (SP), a category of organic materials with π-conjugated aromatic backbone, has been attracting considerable attention because of their outstanding characteristics such as excellent photophysical features, good biosafety, adjustable chemical flexibility, easy fabrication, and high stability. With these distinct advantages, SP is extensively explored for bioimaging and photo- or ultrasound-activated tumor therapy. Here, the recent advancements in SP-based nanomedicines are summarized for enhanced tumor immunotherapy. According to the photophysical properties of SPs, the cancer immunotherapies enabled by SPs with the photothermal, photodynamic, or sonodynamic functions are highlighted in detail, with a particular focus on the construction of combination immunotherapy and activatable nanoplatforms to maximize the benefits of cancer immunotherapy. Herein, new guidance and comprehensive insights are provided for the design of SPs with desired photophysical properties to realize maximized effectiveness of required biomedical applications.

Nanocarrier-Mediated Immunogenic Cell Death for Melanoma Treatment

Melanoma, a highly aggressive skin tumor, exhibits notable features including heterogeneity, a high mutational load, and innate immune escape. Despite advancements in melanoma treatment, current immunotherapies fail to fully exploit the immune system's maximum potential. Activating immunogenic cell death (ICD) holds promise in enhancing tumor cell immunogenicity, stimulating immune amplification response, improving drug sensitivity, and eliminating tumors. Nanotechnology-enabled ICD has emerged as a compelling therapeutic strategy for augmenting cancer immunotherapy. Nanoparticles possess versatile attributes, such as prolonged blood circulation, stability, and tumor-targeting capabilities, rendering them ideal for drug delivery. In this review, we elucidate the mechanisms underlying ICD induction and associated therapeutic strategies. Additionally, we provide a concise overview of the immune stress response associated with ICD and explore the potential synergistic benefits of combining ICD induction methods with the utilization of nanocarriers.

Immunomodulator-Mediated Suppressive Tumor Immune Microenvironment Remodeling Nanoplatform for Enhanced Immuno/Chemo/Photothermal Combination Therapy of Triple Negative Breast Cancer

Despite immunotherapy having revolutionized cancer therapy, the efficacy of immunotherapy in triple-negative breast cancer (TNBC) is seriously restricted due to the insufficient infiltration of mature dendritic cells (DCs) and the highly diffusion of immunosuppressive cells in the tumor microenvironment. Herein, an immunomodulatory nanoplatform (HA/Lipo@MTO@IMQ), in which the DCs could be maximally activated, was engineered to remarkably eradicate the tumor via the combination of suppressive tumor immune microenvironment reversal immunotherapy, chemotherapy, and photothermal therapy. It was noticed that the immunotherapy efficacy could be significantly facilitated by this triple-assistance therapy: First, a robust immunogenic cell death (ICD) effect was induced by mitoxantrone hydrochloride (MTO) to boost DCs maturation and cytotoxic T lymphocytes infiltration. Second, the powerful promaturation property of the toll-like receptor 7/8 (TLR7/8) agonist on DCs simultaneously strengthened the ICD effect and restricted antitumor immunity to the tumor bed and lymph nodes. On this basis, tumor-associated macrophages were also dramatically repolarized toward the antitumor M1 phenotype in response to TLR7/8 agonist to intensify the phagocytosis and reverse the immunosuppressive microenvironment. Furthermore, the recruitment of immunocompetent cells and tumor growth inhibition were further promoted by the photothermal characteristic. The nanoplatform with no conspicuous untoward effects exhibited a splendid ability to activate the systemic immune system so as to increase the immunogenicity of the tumor microenvironment, thus enhancing the tumor killing effect. Taken together, HA/Lipo@MTO@IMQ might highlight an efficient combination of therapeutic modality for TNBC.

"Closed-Loop" O2-Economizer Induced In Situ Therapeutic Vaccine against Hypoxic Tumors

Therapeutic tumor vaccines, which use tumor antigens to stimulate a cancer patient's immune system to eventually kill the tumor tissues, have emerged as one of the most attractive strategies in anticancer research. Especially, exploring in situ vaccines has become a potential field in cancer immunotherapy. However, due to the hypoxic tumor microenvironment, the generation of tumor antigens is always mild and not sufficient. Hence, in this study, we designed a closed-loop mitochondrial oxygen-economizer (TPCA) to induce enhanced phototherapy-driven in situ vaccines. The O2-economizer was developed by the integration of the photosensitizer CyI and the mitochondrial inhibitor atovaquone into the PAMAM dendrimer. In vitro and in vivo studies showed that TPCA could enter the mitochondria through (3-propylcarboxyl) triphenylphosphine bromide (TPP) and effectively restrict the respiration of tumor cells to reduce tumor hypoxia, thus providing continuous oxygen for enhanced iodinated cyanine dye mediated photodynamic therapy, which could further induce in situ vaccines for ablating the primary tumor directly and inhibiting the tumor metastasis and recurrence. Furthermore, the antitumor mechanism revealed that O2-economizer-based oxygen-boosted PDT elicited immunogenic cancer cell death with enhanced exposure and release of DAMPs and altered the immunosuppressive tumor microenvironment with increased recruitment of T cells in tumors, thereby inducing in situ vaccines and provoking the systematic antitumor responses against CT26 tumors. This study will provide innovative approaches for local, abscopal, and metastatic tumor treatment.

Synergetic regulation of cancer cells and exhausted T cells to fight cold tumors with a fluorinated EGCG-based nanocomplex

Immune therapy that targets PD-L1 (programmed cell death-ligand 1) is attractive to augment immune response by breaking the programmed cell death-1 (PD-1)/PD-L1 axis. However, T cell exhaustion associated with insufficient T cells infiltration may diminish the efficacy of cancer therapy. Here, we report a novel delivery system of FEGCG/FPEI@siTOX composed of fluorinated EGCG (FEGCG) and fluorinated polyethyleneimine (FPEI) for delivery of small interfering RNA anti-TOX (thymus high mobility group box protein, TOX) to treat tumor and metastasis. In this way, the reduction in PD-L1 expression by FEGCG can promote T-cell function, while inhibition of TOX expression with siTOX can alleviate T-cell exhaustion. FPEI are designed to deliver siRNA with high efficiency and low toxicity compared to classical PEI. Integrating FEGCG, FPEI and siTOX into such a novel system resulted in excellent anti-tumor and antimetastatic effects. It is a promising delivery system and potential strategy for the treatment of "cold" tumors.

Photodynamic Therapy-Induced Anti-Tumor Immunity: Influence Factors and Synergistic Enhancement Strategies

Photodynamic therapy (PDT) is an approved therapeutic procedure that exerts cytotoxic activity towards tumor cells by activating photosensitizers (PSs) with light exposure to produce reactive oxygen species (ROS). Compared to traditional treatment strategies such as surgery, chemotherapy, and radiation therapy, PDT not only kills the primary tumors, but also effectively suppresses metastatic tumors by activating the immune response. However, the anti-tumor immune effects induced by PDT are influenced by several factors, including the localization of PSs in cells, PSs concentration, fluence rate of light, oxygen concentration, and the integrity of immune function. In this review, we systematically summarize the influence factors of anti-tumor immune effects mediated by PDT. Furthermore, an update on the combination of PDT and other immunotherapy strategies are provided. Finally, the future directions and challenges of anti-tumor immunity induced by PDT are discussed.

cGAS-STING Pathway Activation and Systemic Anti-Tumor Immunity Induction via Photodynamic Nanoparticles with Potent Toxic Platinum DNA Intercalator Against Uveal Melanoma

The cGAS-STING pathway, as a vital innate immune signaling pathway, has attracted considerable attention in tumor immunotherapy research. However, STING agonists are generally incapable of targeting tumors, thus limiting their clinical applications. Here, a photodynamic polymer (P1) is designed to electrostatically couple with 56MESS-a cationic platinum (II) agent-to form NPPDT -56MESS. The accumulation of NPPDT -56MESS in the tumors increases the efficacy and decreases the systemic toxicity of the drugs. Moreover, NPPDT -56MESS generates reactive oxygen species (ROS) under the excitation with an 808 nm laser, which then results in the disintegration of NPPDT -56MESS. Indeed, the ROS and 56MESS act synergistically to damage DNA and mitochondria, leading to a surge of cytoplasmic double-stranded DNA (dsDNA). This way, the cGAS-STING pathway is activated to induce anti-tumor immune responses and ultimately enhance anti-cancer activity. Additionally, the administration of NPPDT -56MESS to mice induces an immune memory effect, thus improving the survival rate of mice. Collectively, these findings indicate that NPPDT -56MESS functions as a chemotherapeutic agent and cGAS-STING pathway agonist, representing a combination chemotherapy and immunotherapy strategy that provides novel modalities for the treatment of uveal melanoma.

A Mitochondria-Targeted NIR-II AIEgen Induced Pyroptosis for Enhanced Tumor Immunotherapy

Cancer immunotherapy is a favorable strategy for facilitating anti-tumor immunity, but it shows limited benefits in clinical practice owing to the immunosuppressive tumor microenvironment. Pyroptosis shows great immunostimulatory effect on tumor, whereas the lack of pyroptotic inducer with imaging property has restricted its progress in tumor theranostics. Herein, a mitochondria-targeted aggregation-induced emission (AIE) luminogen (TPA-2TIN) with NIR-II emission is designed for highly efficient induction of tumor cell pyroptosis. The fabricated TPA-2TIN nanoparticles can be efficiently taken up by tumor cells and selectively accumulated in tumor for a long term observed by NIR-II fluorescence imaging. More importantly, the TPA-2TIN nanoparticles can effectively stimulate immune responses both in vitro and in vivo mediated by the mitochondrial dysfunctions and the subsequent activation of the pyroptotic pathway. Ultimately, the reversal of the immunosuppressive tumor microenvironment significantly enhances the immune checkpoint therapy. This study paves a new avenue for adjuvant immunotherapy of cancer.

Copper-Bacteriochlorin Nanosheet as a Specific Pyroptosis Inducer for Robust Tumor Immunotherapy

Pyroptosis is increasingly considered a new weathervane in cancer immune therapy. However, triggering specific pyroptotic tumor cell death while preserving normal cells still remains a major challenge. Herein, a brand-new pyroptosis inducer, copper-bacteriochlorin nanosheet (Cu-TBB), is designed. The synthesized Cu-TBB can be activated to an "on" state in the tumor microenvironment with glutathione (GSH) overexpression, leading to the release of Cu+ and TBB, respectively. Intriguingly, the released Cu+ can drive cascade reactions to produce O2 -• and highly toxic ·OH in cells. Additionally, the released TBB can also generate O2 -• and 1 O2 upon 750 nm laser irradiation. Encouragingly, both Cu+ -driven cascade reactions and photodynamic therapy pathways result in potent pyroptosis along with dendritic cell maturation and T cell priming, thus simultaneously eliminating the primary tumors and inhibiting the distant tumor growth and metastases. Conclusively, the well-designed Cu-TBB nanosheet is shown to trigger specific pyroptosis in vitro and in vivo, leading to enhanced tumor immunogenicity and antitumor efficacy while minimizing systemic side effects.

A New Strategy to Elevate Absorptivity of AIEgens for Intensified NIR-II Emission and Synergized Multimodality Therapy

High-efficiency absorptivity is crucial for the construction of high-performance luminescent materials, especially the long-wavelength near-infrared II (NIR-II) materials; thus seeking an efficient and universal strategy to elevate the absorptivity is extremely important but is still an intractable challenge. In this work, a simple but efficient design strategy is discovered, involving the introduction of gold(I) unit that could effectively elevate the absorptivity of aggregation-induced-emission luminogens (AIEgens). As a result of the efficient elevation of absorptivity, the representative AIE-active TBTP-Au shows more superior NIR-II (1220 nm) luminescence, much higher photothermal conversion efficiency, and unique intracellular reactive oxygen species (ROS) generating ability compared with that of the TBTP ligand. Taking advantage of these improvements, the fabricated tumor-targeting TBTP-Au-cRGD nanoparticles achieve specific NIR-II tumorous imaging in vivo and exert high-efficiency cancer therapy via the synergistic chemotherapy and photothermal therapy. Thus, this work provides a new and efficient strategy to construct high-absorption luminescent materials and demonstrates the great potential of gold(I)-based AIEgens as multifunctional theranostic agents.

Acid-sensitive stable polymeric micelle-based oxidative stress nanoamplifier as immunostimulating anticancer nanomedicine

Oxidative stress amplifying compounds could elicit selective killing of cancer cells with minimal toxicity to normal cells and also induce immunogenic cell death (ICD). However, compared to conventional anticancer drugs, oxidative stress amplifying compounds have inferior therapeutic efficacy. It can be postulated that the anticancer therapeutic efficacy and immunostimulating activity of oxidative stress amplifying hybrid prodrug (OSamp) could be fully maximized by employing ultrastable polymeric micelles as drug carriers. In this work, we developed tumour-targeted oxidative stress nanoamplifiers, composed of OSamp, amphiphilic poly(ethylene glycol) methyl ether-block-poly(cyclohexyloxy ethyl glycidyl ether)s (mPEG-PCHGE) and a lipopeptide containing Arg-Gly-Asp (RGD). Tumour targeted OSamp-loaded mPEG-PCHGE (T-POS) micelles exhibited excellent colloidal stability and significant cytotoxicity to cancer cells with the expression of DAMPs (damage-associated molecular patterns). In the syngeneic mouse tumour model, T-POS micelles induced significant apoptotic cell death to inhibit tumour growth without noticeable body weight changes. T-POS micelles also induced ICD and activated adaptive immune responses by increasing the populations of cytotoxic CD4+ and CD8+ T cells. Therefore, these results suggest that T-POS micelles hold great translational potential as immunostimulating anticancer nanomedicine.

Glutathione-sensitive mesoporous nanoparticles loaded with cinnamaldehyde for chemodynamic and immunological therapy of cancer

Chemodynamic therapy as a novel type of chemotherapy can damage the DNA structures and induce cell apoptosis and immunogenic cell death (ICD) through generating reactive oxygen species (ROS) to aggravate oxidative stress. Nonetheless, as an intrinsic antioxidative response of tumor cells, the expression of glutathione (GSH) can be upregulated to maintain the cellular redox balance and protect the tumor cells from ROS-mediated damage. In this context, it is feasible to simultaneously boost ROS generation and GSH depletion in tumor cells; however, the precise delivery and release of GSH scavengers at specific subcellular sites is of great importance. Herein, we propose a GSH-responsive mesoporous organosilica nanoparticle (MON)-based nanomedicine MON-CA-TPP@HA through sequentially covalently attaching triphenylphosphine (TPP) and electrostatically coating hyaluronic acid (HA) onto the surface of cinnamaldehyde (CA)-loaded MONs, known as MON-CA-TPP@HA, which has been demonstrated to be an extremely effective therapeutic strategy for cancer treatment through inducing ICD and apoptosis of breast cancer cells. Systematic in vitro experimental results clearly revealed that the nanomedicine can actively target the tumor cells with the help of HA, subsequently enter the tumor cells, and precisely bind with the mitochondria through TPP residues. Upon cleavaging the disulfide bond in the MONs triggered by over-expressed GSH within tumors, the CA molecules can be released inducing the excessive ROS in situ surrounding the mitochondria to activate oxidative stress to induce apoptosis and ICD of breast cancer cells. The results of the in vivo experiments confirm that the MON-CA-TPP@HA nanomedicine can effectively promote dendritic cell (DC) maturation and CD 8+ T cell activation and regulate the ratio of M1/M2 macrophages, which improve tumor immunosuppressive microenvironment. It is thus believed that the current nanomedicine has paved a new way for future cancer therapy.

Tailoring the Amphiphilic Structure of Zwitterionic AIE Photosensitizers to Boost Antitumor Immunity

Although photodynamic therapy (PDT) for thorough cancer treatment is hindered by the limited generation of reactive oxygen species (ROS) with short lifetime from photosensitizers, PDT-induced antitumor immune response remedies the defects. Previous studies show that inducing immunogenic cell deaths is an attractive approach to activate antitumor immunity, which confers a robust adjuvanticity to dying cancer cells. In this work, amphiphilic luminogens with aggregation-induced emission characteristics (AIEgens) are rationally designed and synthesized. By modulating the hydrophobic π-bridge and zwitterionic functional groups, these AIEgens exhibit tunable organelle specificity to lysosome, endoplasmic reticulum, and plasma membrane and enhance ROS generation ability. Notably, the membrane-targeting AIEgen namely TPS-2 induces cell death and membrane rupture via PDT to facilitate the release of antigens and activation of immune cells. Furthermore, the size-controlled TPS-2 nanoaggregates are found to serve as an adjuvant, promoting antigen accumulation and delivery to sufficiently boost the in vivo antitumor immunity by only one dose injection in a prophylactic tumor vaccination model. This work thus provides new insights into optimizing AIE photosensitizers via a hydrophobicity-hydrophilicity balance strategy for evoking an antitumor immunity and directly suppressing the distanced tumor. A single small-molecular system for PDT-stimulated antitumor immunity is envisioned.

Promotion of ICD via Nanotechnology

Immunotherapy represents the most promising treatment strategy for cancer, but suffers from compromised therapeutic efficiency due to low immune activity of tumor cells and an immunosuppressive microenvironment, which significantly hampers the clinical translations of this treatment strategy. To promote immunotherapy with desired therapeutic efficiency, immunogenic cell death (ICD), a particular type of death capable of reshaping body's antitumor immune activity, has drawn considerable attention due to the potential to stimulate a potent immune response. Still, the potential of ICD effect remains unsatisfactory because of the intricate tumor microenvironment and multiple drawbacks of the used inducing agents. ICD has been thoroughly reviewed so far with a general classification of ICD as a kind of immunotherapy strategy and repeated discussion of the related mechanism. However, there are no published reviews, to the authors' knowledge, providing a systematic summarization on the enhancement of ICD via nanotechnology. For this purpose, this review first discusses the four stages of ICD according to the development mechanisms, followed by a comprehensive description on the use of nanotechnology to enhance ICD in the corresponding four stages. The challenges of ICD inducers and possible solutions are finally summarized for future ICD-based enhanced immunotherapy.

Tyrosinase-activated Nanocomposites for Double-Modals Imaging Guided Photodynamic and Photothermal Synergistic Therapy

Tyrosinase (TYR) is an important biomarker of melanoma. The exploration of fluorescent pr-obes-based composites is beneficial to build an integrative platform for the diagnosis and treatment of melanoma. Herein, a multifunctional nanocomposite IOBOH@BSA activated by TYR is developed for selective imaging and ablation of melanoma. The chemical structure of IOBOH enables the fluorescence (FL) imaging activated by TYR, photoacoustic (PA) imaging, and photodynamic-photothermal activity by regulating the balance between radiative decay and non-radiative decay. IOBOH combined with bovine serum albumin (IOBOH@BSA) presents the response to TYR and realizes FL imaging with mitochondria-targeting in melanoma. Moreover, IOBOH@BSA shows excellent photothermal ability and is applied for PA imaging. After IOBOH@BSA is activated by TYR, the singlet oxygen generation increases obviously. IOBOH@BSA can realize TYR-activated imaging and photodynamic-photothermal therapy of melanoma. The development of TYR-activated multifunctional nanocomposites promotes the precise imaging and improves the therapeutic effect of melanoma.

AIE Bioconjugates for Accurate Identification and In Vivo Targeted Treatment of Bacterial Infection Based on Bioorthogonal Reaction

Targeted killing multidrug-resistant bacteria with high efficiency is urgently needed for the treatment of infection with minimal collateral damage. Herein, a new near-infrared (NIR) fluorescence nanoprobe is designed and synthesized with aggregation-induced emission (AIE) features, which also is excellent reactive oxygen species (ROS) generator. The as-prepared AIE nanoparticles (NPs) present outstanding sterilizing rate on methicillin-resistant Staphylococcus aureus (MRSA) and kanamycin-resistant Escherichia coli (KREC). Meanwhile, considering the differences in the surface structure of animal cells and bacteria, a non-invasive image-guided strategy for precise treatment of bacterial infection has been successfully implemented based on bioorthogonal reaction which can perform and control unnatural chemical reactions inside living organisms. The AIE NPs are thus specifically trapped on the bacterial surface while not on the normal cells, realizing real-time tracking of the infected site distribution in vivo and guiding photodynamic therapy (PDT) for eliminating bacteria in inflammation region. That significantly improves the accuracy and sterilization rate of bacterial-infected wounds with negligible side effects. The investigation developed a potential antibacterial agent and also provides an instructive way for targeting treatment based on bioorthogonal reaction.

Local Drug Delivery Techniques for Triggering Immunogenic Cell Death

Immunogenic cell death (ICD), a dying state of the cells, encompasses the changes in the conformations of cell surface and the release of damage-associated molecular patterns, which could initiate an adaptive immune response by stimulating the dendritic cells to present antigens to T cells. Advancements in biomaterials, nanomedicine, and micro- and nano-technologies have facilitated the development of effective ICD inducers, but the potential toxicity of these vesicles encountered in drug delivery via intravenous administration hampers their further application. As alternatives, the local drug delivery systems have gained emerging attention due to their ability to prolong the retention of high payloads at the lesions, sequester drugs from harsh environments, overcome biological barriers to exert optimal efficacy, and minimize potential side effects to guarantee bio-safety. Herein, a brief overview of the local drug delivery techniques used for ICD inducers is provided, explaining how these techniques broaden, alter, and enhance the therapeutic capability while circumventing systemic toxicity at the same time. The historical context and prominent examples of the local administration of ICD inducers are introduced. The complexities, potential pitfalls, and opportunities for local drug delivery techniques in cancer immunotherapy are also discussed.

Molecular engineering to enhance the reactive oxygen species generation of AIEgens and exploration of their versatile applications

Fluorescent dyes with aggregation-induced emission (AIE) characteristics have shown potential applications in the fields of biological imaging, photodynamic therapy and photothermal therapy, in which photosensitizers (PSs) play a crucial role. However, how to design high-quality PSs with high reactive oxygen species (ROS) generation efficiency remains unclear. In this contribution, an effective molecular design strategy to improve the ROS generation efficiency of AIE PSs was proposed. A series of tetraphenylethylene derivatives containing the pyridine ring or pyridinium with different substituents were designed and synthesized. All the molecules were weakly emissive when molecularly dissolved in solution but displayed intense emission upon aggregation, demonstrating a phenomenon of AIE characteristic. Pyridinium molecules could be used as visualization agents to specifically stain the mitochondria in living cells, while most of the molecules failed to generate ROS upon white light irradiation. In contrast, TPE-Pys-BP containing benzophenone produced ˙OH and 1O2 efficiently in the presence of light due to its large spin-orbit coupling constant to promote efficient intersystem crossing. Such a property allowed TPE-Pys-BP to serve as a PS to kill cancer cells using photodynamic therapy. TPE-Pys-BP also exhibited mechanochromic luminescence (ML), and its emission could be reversibly switched between two distinct colors through repeated grinding and fuming processes. A security paper was fabricated using the ML properties of TPE-Pys-BP.

AIE Nanozyme-Based Long Persistent Chemiluminescence and Fluorescence for POCT of Pathogenic Bacteria

Pathogenic bacteria are widely distributed in diverse environments and significantly threaten human health. Point-of-care testing (POCT) is a valuable way for early warnings of bacteria threat. Herein, a chemiluminescence (CL)-based ratiometric sensing platform was constructed for sensitive POCT of bacteria according to a newly designed aggregation-induced emission (AIE) molecule. The new AIE molecule presents oxidase-like properties (named as AIEzyme) and can trigger long persistent CL of luminol (LUM) with strong intensity in the absence of H2O2. The CL emission can be monitored with the naked eye for over 2 h. The emission mechanism is explored and may be attributed to the persistent reactive oxygen species generation of the AIEzyme according to the cyclic energy transfer between the AIEzyme and luminol, which catalyzes CL of luminol. Based on the CL resonance energy transfer mechanism, an afterglow luminescence system is further developed, which is used to construct a ratiometric biosensor for detection of pathogenic bacteria. With a homemade holder as a detection room and a smartphone as an analyzer, the portable biosensing platform is used for quantitative POCT of bacteria in real samples with good recovery. The detection is free of H2O2 and an external excitation source, which not only simplifies the operation but reduces interference. Specifically, the long persistent luminescence and the ratiometric strategy can significantly improve accuracy, providing an instructive way for point-of-need analysis, for example, SARS-CoV-2 detection and bioimaging analysis.

Multifunctional Calcium-Manganese Nanomodulator Provides Antitumor Treatment and Improved Immunotherapy via Reprogramming of the Tumor Microenvironment

Ions play a vital role in regulating various biological processes, including metabolic and immune homeostasis, which involves tumorigenesis and therapy. Thus, the perturbation of ion homeostasis can induce tumor cell death and evoke immune responses, providing specific antitumor effects. However, antitumor strategies that exploit the effects of multiion perturbation are rare. We herein prepared a pH-responsive nanomodulator by coloading curcumin (CU, a Ca2+ enhancer) with CaCO3 and MnO2 into nanoparticles coated with a cancer cell membrane. This nanoplatform was aimed at reprogramming the tumor microenvironment (TME) and providing an antitumor treatment through ion fluctuation. The obtained nanoplatform, called CM NPs, could neutralize protons by decomposing CaCO3 and attenuating cellular acidity, they could generate Ca2+ and release CU, elevating Ca2+ levels and promoting ROS generation in the mitochondria and endoplasmic reticulum, thus, inducing immunogenic cell death. Mn2+ could decompose the endogenous H2O2 into O2 to relieve hypoxia and enhance the sensitivity of cGAS, activating the cGAS-STING signaling pathway. In addition, this strategy allowed the reprogramming of the immune TME, inducing macrophage polarization and dendritic cell maturation via antigen cross-presentation, thereby increasing the immune system's ability to combat the tumor effectively. Moreover, the as-prepared nanoparticles enhanced the antitumor responses of the αPD1 treatment. This study proposes an effective strategy to combat tumors via the reprogramming of the tumor TME and the alteration of essential ions concentrations. Thus, it shows great potential for future clinical applications as a complementary approach along with other multimodal treatment strategies.