Recent Advances in Nanomaterial-Based Nanoplatforms for Chemodynamic Cancer Therapy

Triggered by the endogenous chemical energy in the tumor microenvironment (TME), chemodynamic therapy (CDT) as an emerging non-exogenous stimulant therapeutic modality has received increasing attention in recent years. The chemodynamic agents can convert internal hydrogen peroxide (H₂O₂) into the lethal reactive oxygen species (ROS) hydroxyl radicals (^•OH) for oncotherapy. Compared with other therapeutic modalities, CDT possesses many notable advantages, such as tumor-specific, highly selective, fewer systemic side effects, and no need for external stimulation. Nevertheless, mild acid pH, low H₂O₂ content, and overexpressed reducing substance in TME severely suppressed the CDT efficiency. With the rapid development of nanotechnology, some kinds of nanomaterials have been utilized with improved CDT efficiency. In particular, the excellent photo-, ultrasound-, magnetic-, and other stimuli-response properties of nanomaterials make it possible for combination cancer therapy of CDT with other therapeutic modalities, and it has shown superior anti-cancer activity than monotherapies. Therefore, it is necessary to summarize the application of nanomaterial-based chemodynamic cancer therapy. In this review, the various nanomaterials-based nanoplatforms for CDT and its combinational therapies are summarized and discussed, aiming to provide inspiration for the design of better-quality agents to promote the CDT development and lay the foundation for its future conversion to clinical applications.     

Dual Targeted Immunotherapy via In Vivo Delivery of Biohybrid RNAi‐Peptide Nanoparticles to Tumor‐Associated Macrophages and Cancer Cells

Lung cancer is associated with very poor prognosis and considered one of the leading causes of death worldwide. Here, highly potent and selective biohybrid RNA interference (RNAi)‐peptide nanoparticles (NPs) are presented that can induce specific and long‐lasting gene therapy in inflammatory tumor associated macrophages (TAMs), via an immune modulation of the tumor milieu combined with tumor suppressor effects. The data here prove that passive gene silencing can be achieved in cancer cells using regular RNAi NPs. When combined with M2 peptide–based targeted immunotherapy that immuno‐modulates TAMs cell population, a synergistic effect and long‐lived tumor eradication can be observed along with increased mice survival. Treatment with low doses of siRNA (ED₅₀ 0.0025–0.01 mg kg^?1) in a multi and long‐term dosing system substantially reduces the recruitment of inflammatory TAMs in lung tumor tissue, reduces tumor size (≈95%), and increases animal survival (≈75%) in mice. The results here suggest that it is likely that the combination of silencing important genes in tumor cells and in their supporting immune cells in the tumor microenvironment, such as TAMs, will greatly improve cancer clinical outcomes.     

Engineered Oxygen Factories Synergize with STING Agonist to Remodel Tumor Microenvironment for Cancer Immunotherapy

Immunotherapy is a revolutionary achievement in cancer treatment. However, inadequate immune cells infiltration in tumor microenvironment (TME) always leads to treatment failure. Moreover, hypoxic TME hampers normal functions of immune cells. Here, it is found that hypoxia suppresses the STING signaling and immune cells activation in the work. Remodeling tumor immune microenvironment and relieving hypoxia are thus essential for enhancing immunotherapy efficiency. Herein, a spirulina platensis (SP)-based magnetic biohybrid system is constructed as an oxygen factory and loaded with stimulator of interferon genes (STING) agonist ADU-S100 (ADU@Fe-SP) for tumor immunotherapy. Magnet-guided biohybrid SP can actively target tumor tissues and produce oxygen in situ through photosynthesis, which reverses the hypoxic TME and facilitates the function of immune cells. Besides, the targeted delivery of ADU-S100 can activate the STING/TBK1/IRF3 signaling and boost cytokines production in tumor and innate immune cells. The ADU@Fe-SP system thus induces efficient immune cells infiltration in TME, which efficiently inhibits tumor progression and significantly enhances anti-PD-1 therapy efficiency in SCC VII-bearing tumor xenograft. ADU@Fe-SP exerts antitumor effect in a STING-dependent manner by in vivo STING-knockout mice model. The efficiency of this immunotherapy strategy is also demonstrated in patient-derived xenograft model originating from oral cancer, showing great clinical potential.     

Bioactive Bacteria/MOF Hybrids Can Achieve Targeted Synergistic Chemotherapy and Chemodynamic Therapy against Breast Tumors

The hypoxic tumor microenvironment (TME) significantly affects cancer treatment. Conventional chemotherapeutic agents cannot effectively target hypoxic tumor tissue, which decreases efficacy and results in severe toxic side effects. To alleviate this problem, a self-driving biomotor is developed by functionalizing MCDP nanoparticles containing calcium peroxide and doxorubicin (DOX) loaded onto polydopamine-coated metal–organic frameworks（MOF）, with the anaerobic Bifidobacterium infantis (Bif) for synergistic chemotherapy and chemodynamic therapy (CDT) against breast cancer. The materials of institute Lavoisier (MIL) frameworks + CaO₂ + DOX + polydopamine (MCDP)@Bif biohybrid actively targets hypoxic regions of solid tumors via the inherent targeting ability of Bif. Once it has accumulated in the tumor tissue, MCDP generates hydroxyl radicals through the enhanced Fenton-type reactions between Fe²⁺ and self-generated hydrogen peroxide in the acidic TME. The disruption of Ca²⁺ homeostasis and resulting mitochondrial Ca²⁺ overload triggers apoptosis and enhances oxidative stress, promoting tumor cell death. The results found that the DOX concentration in MCDP@Bif-treated tumors is 3.8 times higher than that in free-DOX-treated tumors, which significantly prolongs the median survival of the tumor-bearing mice to 69 days and reduces the toxic side effects of DOX. Therefore, the novel bacteria-driven drug delivery system is highly effective in achieving synergistic chemotherapy and CDT against solid tumors.     

Macrophage Hitchhiking Nanoparticles for the Treatment of Myocardial Infarction: An In Vitro and In Vivo Study

Myocardial infarction (MI) is the leading cause of death worldwide. However, current therapies are unable to restore the function of the injured myocardium. Advanced approaches, such as stimulation of cardiomyocyte (CM) proliferation are promising, but suffer from poor pharmacokinetics and possible systemic adverse effects. Nanomedicines can be a solution to the above-mentioned drawbacks. However, targeting the cardiac tissue still represents a challenge. Herein, a MI-selective precision nanosystem is developed, that relies on the heart targeting properties of atrial natriuretic peptide (ANP) and lin-TT1 peptide-mediated hitchhiking on M2-like macrophages. The system based on pH-responsive putrescine-modified acetalated dextran (Putre-AcDEX) nanoparticles, shows biocompatibility with cultured cardiac cells, and ANP receptor-dependent interaction with CMs. Moreover, treatment with nanoparticles (NPs) loaded with two pleiotropic cellular self-renewal promoting compounds, CHIR99021 and SB203580, induces a 4-fold increase in bromodeoxyuridine (BrdU) incorporation in primary cardiomyocytes compared to control. In vivo studies confirm that M2-like macrophages targeting by lin-TT1 peptide enhances the heart targeting of ANP. In addition, NP administration does not alter the immunological profile of blood and spleen, showing the short-term safety of the developed system in vivo. Overall, the study results in the development of a peptide-guided precision nanosystem for delivery of therapeutic compounds to the infarcted heart.     

Manganese‐Based Functional Nanoplatforms: Nanosynthetic Construction,Physiochemical Property,and Theranostic Applicability

Transition metal‐based nanoparticles have shown their broad applications in versatile biomedical applications. Although traditional iron‐based nanoparticles have been extensively explored in biomedicine, transition metal manganese (Mn)‐based nanoparticulate systems have emerged as a multifunctional nanoplatform with their intrinsic physiochemical property and biological effect for satisfying the strict biomedical requirements. This comprehensive review focuses on recent progress of Mn‐based functional nanoplatforms in biomedicine with the particular discussion on their elaborate construction, physiochemical property, and theranostic applicability. Several Mn‐based nanosystems are discussed in detail, including solid/hollow MnO_x nanoparticles, 2D MnO_x nanosheets, MnO_x‐silica/mesoporous silica nanoparticles, MnO_x‐Fe₃O₄ nanoparticles, MnO_x‐Au, MnO_x‐fluorescent nanoparticles, Mn‐based organic composite nanosystem, and some specific/unique Mn‐based nanocomposites. Their versatile biomedical applications include pH/reducing‐responsive T₁‐weighted positive magnetic resonance imaging, controlled drug loading/delivery/release, protection of neurological disorder, photothermal hyperthermia, photodynamic therapy, chemodynamic therapy, alleviation of tumor hypoxia, immunotherapy, and some specific synergistic therapies, which are based on their disintegration behavior under the mildly acidic/reducing condition, multiple enzyme‐mimicking activity, catalytic‐triggering Fenton reaction, etc. The biological effects and biocompatibility of these Mn‐based nanosystems are also discussed, accompanied with a discussion on challenges/critical issues and an outlook on the future developments and clinical‐translation potentials of these intriguing Mn‐based functional nanoplatforms.     

Biodegradable Calcium Phosphate Nanotheranostics with Tumor-Specific Activatable Cascade Catalytic Reactions-Augmented Photodynamic Therapy

Photodynamic therapy (PDT) is exploited as a promising strategy for cancer treatment. However, the hypoxic solid tumor and the lack of tumor-specific photosensitizer administration hinder the further application of oxygen (O₂)-dependent PDT. In this study, a biodegradable and O₂ self-supplying nanoplatform for tumor microenvironment (TME)-specific activatable cascade catalytic reactions-augmented PDT is reported. The nanoplatform (named GMCD) is constructed by coloading catalase (CAT) and sinoporphyrin sodium (DVDMS) in the manganese (Mn)-doped calcium phosphate mineralized glucose oxidase (GOx) nanoparticles. The GMCD can effectively accumulate in tumor sites to achieve an “off to on” fluorescence transduction and a TME-activatable magnetic resonance imaging. After internalization into cancer cells, the endogenous hydrogen peroxide (H₂O₂) can be catalyzed to generate O₂ by CAT, which not only promotes GOx catalytic reaction to consume more intratumoral glucose, but also alleviates tumor hypoxia and enhances the production of cytotoxic singlet oxygen from light-triggered DVDMS. Moreover, the H₂O₂ generated by GOx-catalysis can be converted into highly toxic hydroxyl radicals by Mn²⁺-mediated Fenton-like reaction, further amplifying the oxidative damage of cancer cells. As a result, GMCD displays superior therapeutic effects on 4T1-tumor bearing mice by a long term cascade catalytic reactions augmented PDT.     

Size/Charge Changeable Acidity‐Responsive Micelleplex for Photodynamic‐Improved PD‐L1 Immunotherapy with Enhanced Tumor Penetration

The checkpoint blockade‐based immunotherapy has recently emerged as a promising approach for tumor treatment, but its clinical implementation has been impeded by poor tumor penetration of the nanocarriers and activation of antitumor immune response. To overcome the obstacles, a tumor acidity‐responsive micellar nanocomplex co‐loaded with programmed death‐ligand 1 (PD‐L1)‐blockade siRNA and mitochondrion‐targeting photosensitizer for the synergistic integration of photodynamic therapy and immunotherapy is reported in the present study. The nanosystem is coated with long‐circulating polyethylene glycol (PEG) shells, which can be shed in response to the weakly acidic tumor microenvironment and lead to significant size reduction and increasing positive charge. These transitions facilitate penetration and uptake of nanocarriers against tumors. Subsequently, under the mild acidic endo/lysosome condition, the micellar nanocomplexes are rapidly protonated and disintegrated to release the PD‐L1‐blockade siRNA and photosensitizer through sponge effect. Results from in vitro and in vivo experiments collectively reveal that the nanosystem efficiently activates a photodynamic therapy‐induced immune response and silences immune resistance mediated by the checkpoint gene PD‐L1. In consequence, melanoma growth is inhibited and the recurrence rate is reduced via triggering systemic antitumor immune responses. This study offers an alternative strategy for the development of efficient antitumor immune therapy.     

Multi-Responsive Biodegradable Cationic Nanogels for Highly Efficient Treatment of Tumors

The facile preparation, modular design, and multi-responsiveness are extremely critical for developing pervasive nanoplatforms to meet heterogeneous applications. Here, cationic nanogels (NGs) are modularly engineered with tunable responsiveness, versatility, and biodegradation. Cationic PVCL-based NGs with core/shell structure are fabricated by facile one-step synthesis. The formed PVCL-NH₂ NGs exhibit uniform size, thermal/pH dual-responsive behaviors, and redox-triggered degradation. Moreover, the NGs can be employed to modify or/and load with various functional agents to construct multipurpose nanoplatforms in a modular manner. Notably, the novel hybrid structure with copper sulfide (CuS) NPs loaded in the NGs shell is prepared, which leads to higher photothermal conversion efficiency (31.1%) than other CuS randomly loaded NGs reported. By personalized tailoring, these functionalized NGs display fluorescent property, r₁ relaxivity, strong near-infrared (NIR) absorption, good biocompatibility, and targeting specificity. The superior photothermal effect of hybrid NGs (CuS@NGs-LA) is presented under NIR II over NIR I. Importantly, hybrid NGs encapsulated doxorubicin (CuS@NGs-LA/DOX) show endogenous pH/redox and exogenous NIR multi-triggered drug release for efficient photothermal-chemotherapy, which can completely eliminate advanced tumors and effectively inhibit recurrence. Overall, the pervasive nanoplatforms based on intelligent cationic NGs with tunable responsiveness, versatility, and biodegradation are developed by engineered modular strategy for precision medicine applications.     

Copper(I) Phosphide Nanocrystals for In Situ Self‐Generation Magnetic Resonance Imaging‐Guided Photothermal‐Enhanced Chemodynamic Synergetic Therapy Resisting Deep‐Seated Tumor

Fe‐based Fenton agents can generate highly reactive and toxic hydroxyl radicals (·OH) in the tumor microenvironment (TME) for chemodynamic therapy (CDT) with high specificity. However, the strict condition (lower pH environment: 3–4) of the highly efficient Fenton reaction limits its practical application in the clinic. Development of new CDT agents more suitable for TME is significant and challenging. A highly efficient Cu(I)‐based CDT agent, copper(I) phosphide nanocrystals (CP NCs), which is more adaptable to the pH value of TME than Fe‐based agents, thereby producing more ·OH to trigger the apoptosis of cancer cells, is prepared. Moreover, the excess glutathione (GSH) in TME can reduce the Cu(II) produced by a Fenton‐like reaction to Cu(I), further increasing the generation rate of ·OH and relieving tumor antioxidant ability. Furthermore, owing to their strong absorption in the NIR II region, CP NCs exhibit an excellent photothermal conversion effect, which can further improve the Fenton reaction. What is more, CP NCs can act as in situ self‐generation magnetic resonance imaging (MRI) agents owing to the generation of paramagnetic Cu(II) in response to excess H₂O₂ in the TME. These properties may open up the exploration of copper‐based materials in clinical application of self‐generation imaging‐guided synergetic treatment.     

Metabolic Regulation of Tumor Microenvironment with Biohybrid Bacterial Bioreactor for Enhanced Cancer Chemo-Immunotherapy

Immunogenic cell death (ICD) induced by specific chemotherapeutic agents is often hampered by the immunosuppressive tumor microenvironment (TME). Here, a bacterial bioreactor E@Fe-DOX, is developed, to enhance ICD-mediated antitumor immunity by in situ manipulation of tumor metabolism-immune interactions. The E@Fe-DOX bioreactor is constructed by depositing doxorubicin-loaded iron-polyphenol nanoparticles on Eubacterium hallii, which can specifically target hypoxic tumor regions and release doxorubicin and Fe³⁺ to induce ICD. In addition, Eubacterium hallii can continuously convert intratumoral lactate to butyrate, which inhibits the polarization of pro-tumoral M2-like macrophages and improves the function of tumor-infiltrating cytotoxic T cells. Furthermore, E@Fe-DOX promotes the formation of immune cell-aggregated tertiary lymph structures (TLS) to augment ICD-induced antitumor immunity. In murine tumor models, E@Fe-DOX significantly inhibits tumor growth and enhances immune checkpoint blockade (ICB) therapy. Overall, the developed living biomaterial offers a promising strategy to potentiate cancer chemo-immunotherapy by continuously regulating the intratumoral immuno-metabolic microenvironment.     

Fabricating Aptamer‐Conjugated PEGylated‐MoS2/Cu1.8S Theranostic Nanoplatform for Multiplexed Imaging Diagnosis and Chemo‐Photothermal Therapy of Cancer

Fabricating theranostic nanoparticles combining multimode disease diagnosis and therapeutic has become an emerging approach for personal nanomedicine. However, the diagnostic capability, biocompatibility, and therapeutic efficiency of theranostic nanoplatforms limit their clinic widespread applications. Targeting to the theme of accurate diagnosis and effective therapy of cancer cells, a multifunctional nanoplatform of aptamer and polyethylene glycol (PEG) conjugated MoS₂ nanosheets decorated with Cu_1.8S nanoparticles (ATPMC) is developed. The ATPMC nanoplatform accomplishes photoluminescence imaging, photoacoustic imaging, and photothermal imaging for in vitro and in vivo tumor cells imaging diagnosis. Meanwhile, the ATPMC nanoplatform facilitates selective delivery of gene probe to detect intracellular microRNA aberrantly expressed in cancer cells and anticancer drug doxorubicin (DOX) for chemotherapy. Moreover, the synergistic interaction of MoS₂ and Cu_1.8S renders the ATPMC nanoplatform with superb photothermal conversion efficiency. The ATPMC nanoplatform loaded with DOX displays near‐infrared laser‐induced programmed chemotherapy and advanced photothermal therapy, and the targeted chemo‐photothermal therapy presents excellent antitumor efficiency.     

Co–Ferrocene MOF/Glucose Oxidase as Cascade Nanozyme for Effective Tumor Therapy

Chemodynamic therapy (CDT), enabling selective therapeutic effects and low side effect, attracts increasing attention in recent years. However, limited intracellular content of H₂O₂ and acid at the tumor site restrains the lasting Fenton reaction and thus the anticancer efficacy of CDT. Herein, a nanoscale Co–ferrocene metal–organic framework (Co‐Fc NMOF) with high Fenton activity is synthesized and combined with glucose oxidase (GOx) to construct a cascade enzymatic/Fenton catalytic platform (Co‐Fc@GOx) for enhanced tumor treatment. In this system, Co‐Fc NMOF not only acts as a versatile and effective delivery cargo of GOx molecules to modulate the reaction conditions, but also possesses excellent Fenton effect for the generation of highly toxic ?OH. In the tumor microenvironment, GOx delivered by Co‐Fc NMOF catalyzes endogenous glucose to gluconic acid and H₂O₂. The intracellular acidity and the on‐site content of H₂O₂ are consequently promoted, which in turn favors the Fenton reaction of Co‐Fc NMOF and enhances the generation of reactive oxygen species (ROS). Both in vitro and in vivo results demonstrate that this cascade enzymatic/Fenton catalytic reaction triggered by Co‐Fc@GOx nanozyme enables remarkable anticancer properties.     

Synergy of Immunostimulatory Genetherapy with Immune Checkpoint Blockade Motivates Immune Response to Eliminate Cancer

Normalizing the tumor-induced immune deficiency in the immunosuppressive tumor microenvironment (TME) through increasing the efficient infiltration and activation of antitumoral immunity in TME is the core of promising immunotherapy. Herein, a Cyclo(Arg-Gly-Asp-d -Phe-Lys) (RGD) peptides-modified combinatorial immunotherapy system based on the self-assembly of the nanoparticles named RGD-DMA composed of RGD-PEG-PLA, methoxy poly(ethylene glycol)-poly(lactide) (MPEG-PLA) and 1,2-Dioleoyl-3-trimethylammonium-propane (DOTAP) is used to codeliver the immunostimulatory chemokine CCL19-encoding plasmid DNA (CCL19 pDNA) and immune checkpoint ligand PD-L1 inhibitor (BMS-1). The RGD-DMA/pCCL19-BMS-1 system not only exhibited significant inhibition of tumor progression but also induced locally high concentrations of immunostimulatory cytokines at tumor sites without causing an obviously systemic inflammatory response. The immunosuppressive TME is efficaciously reshaped by the coadministration of RGD-DMA/pCCL19 and BMS-1, as indicated by the activated T lymphocytes, increased intratumoral-infiltration of mature dendritic cells (DCs), and the repolarization of macrophages from pro-tumoral M2-phenotype toward tumoricidal M1-phenotype. The upregulated PD-L1 expression at tumor sites caused by the increased IFN-γ levels after immunostimulatory gene therapy further demonstrated the synergistic effects of BMS-1 in counteracting the inhibitory role of PD-L1 expression in antitumor immunity. Therefore, the combination of immunostimulating therapy and immune checkpoint inhibitor that synergistically target multiple immune regulatory pathways demonstrates significant potential as a novel immunotherapy approach.     

Ferroptosis and Pyroptosis Co-Activated Nanomodulator for “Cold” Tumor Immunotherapy and Lung Metastasis Inhibition

Immune checkpoint blockade (ICB) therapy is an emerging strategy for cancer immunotherapy; however, the actual effects of ICB therapy are greatly limited by the immunosuppressive tumor microenvironment (TME, i.e., “cold” tumors). Although engineered nanomaterials display significant importance to regulate TME in cancer treatment, most of them focus on “immunosilent” apoptotic processes that cannot elicit sufficient immune responses for further immunotherapy. Herein, a GSH-responsive nanomodulator is reported that can reverse the immunosuppressive TME for “cold” tumor immunotherapy and lung metastasis inhibition through simultaneous ferroptosis and pyroptosis induction. The nanomodulator is constructed by loading FDA-approved sulfasalazine (SAS) and doxorubicin (DOX) on disulfide-doped organosilica hybrid micelles, where SAS and DOX are released through the GSH-stimulated rupture of micelles to induce ferroptosis and pyroptosis, respectively, promoting dendritic cells (DCs) maturation and cytotoxic T lymphocytes (CTLs) elevation through massive tumor-associated antigen release. In vivo experimental results verify that desirable tumor destruction of the nanomodulator at low concentrations is achieved. More importantly, combination of this nanomodulator and programed death ligand-1 antibodies significantly inhibits primary tumors and distant lung metastases as a result of elevated mature DCs and CTLs. This strategy to modulate immunosuppressive TME by nanomodulator-induced non-apoptotic death provides a new promising paradigm for ICB therapy.     

Stepwise Degradable Nanocarriers Enabled Cascade Delivery for Synergistic Cancer Therapy

Hypoxia‐activated prodrugs have brought new opportunities for safe and effective tumor ablation, but their therapeutic efficacy is limited by insufficient activation in tumor microenvironments. Herein, a novel cascade delivery system with tandem functions by integrating a hypoxia‐activated prodrug (AQ4N) and glucose oxidase (GOx) is designed to improve its efficacy. Innovative yolk–shell organosilica nanoparticles with a tetrasulfide bridged composition, a small‐pore yolk, and a large‐pore shell featuring a shell‐to‐yolk stepwise degradability are constructed as a carrier for AQ4N and GOx, one enzyme that catalyzes the oxidation of glucose to produce hydrogen peroxide. The glutathione (GSH) is depleted by tetrasulfide bond in the framework and induces shell degradation for fast release of GOx, which in turn induces starvation (glucose removal), oxidative cytotoxicity (H₂O₂ production and GSH depletion), and hypoxia (oxygen consumption). Finally, the hypoxia activates the liberated prodrug AQ4N for chemotherapy. The cascading and synergistic functions including GSH depletion, starvation, oxidative cytotoxicity, and chemotherapy lead to improved performance in tumor inhibition and antimetastasis.     

Light‐Activatable Assembled Nanoparticles to Improve Tumor Penetration and Eradicate Metastasis in Triple Negative Breast Cancer

Triple‐negative breast cancer (TNBC) is a kind of aggressive malignancy with fast metastatic behavior. Herein, a nanosystem loaded with a near‐infrared (NIR) agent is developed to achieve chemo‐photothermal combination therapy for inhibiting tumor growth and metastasis in TNBC. The NIR agent of ultrasmall sized copper sulfide nanodots with strong NIR light‐absorbing capability is entrapped into the doxorubicin‐contained temperature‐sensitive polymer‐based nanosystem by a self‐assembled method. The temperature sensitive nanoclusters (TSNCs) can significantly enhance the drug penetration depth and significantly kill the cancer cells under the near‐infrared laser irradiation. Importantly, it is plausible that the tumor penetrating nanosystem combined with NIR laser irradiation can prevent lung and liver metastasis via extermination of the cancer stem cells. The in vivo characteristics, evaluated by photoacoustic imaging, pharmacokinetics, and biodistribution, confirm their feasibility for tumor treatment owing to their long blood circulation time and high tumor uptake. Thanks to the high tumor uptake and highly potent antitumor efficacy, the doxorubicin‐induced cardiotoxicity can be avoided when the TSNC is used. Taken together, it is believed that the nanosystem has excellent potential for clinical translation.     

A Near-Infrared Light-Responsive ROS Cascade Nanoplatform for Synergistic Therapy Potentiating Antitumor Immune Responses

Tumor occurrence is closely related to the unlimited proliferation and the evasion of the immune surveillance. However, it remains a challenge to kill tumor cells and simultaneously activate antitumor immunity upon spatially localized external stimuli. Herein, a robust tumor synergistic therapeutic nanoplatform is designed in combination with dual photosensitizers-loaded upconversion nanoparticles (UCNPs) and ferric-tannic acid (FeTA) nanocomplex. Dual photosensitizers-loaded UCNPs can induce photodynamic therapy (PDT) effect by generation of cytotoxic reactive oxygen species (ROS) on demand under near-infrared (NIR) light irradiation. FeTA can robustly respond to acidic tumor microenvironment to produce Fe²⁺ and subsequently induce chemodynamic therapy (CDT) by reacting with H₂O₂ in the tumor microenvironment. More importantly, the CDT/PDT synergy can not only exhibit significant antitumor ability but also induce ROS cascade to evoke immunogenic cell death. It increases tumor immunogenicity and promotes immune cell infiltration at tumor sites allowing further introduction of systemic immunotherapy responsiveness to inhibit the primary and distant tumor growth. This study provides a potential tumor microenvironment-responsive nanoplatform for imaging-guided diagnosis and combined CDT/PDT with improved immunotherapy responses and an external NIR-light control of photoactivation.     

Sustained Antitumor Immunity Based on Persistent Luminescence Nanoparticles for Cancer Immunotherapy

Immunotherapy holds great promise for cancer treatment. The key to improving the therapeutic effect is to drive the patient's own immune system to produce a strong, effective, and enduring tumor-specific immune response. Engineered nanoplatforms show promising potential in strengthening antitumor immune responses. However, current nanotherapeutic platforms based on exogenous responses stimulate the immune system only in a transitory and limited manner, which translates into insufficient immune activation and a low therapeutic efficacy. A novel targeted nano-immunostimulant (ZGS-Si-Pc@HA) is fabricated by coupling persistent luminescence nanoparticles with a photosensitizer and hyaluronic acid for sustained immune stimulation upon irradiation with biological window (659 nm) light. ZGS-Si-Pc@HA persistently drives reactive oxygen species production to induce immunogenic cell death, causing a durable tumor-specific immune response. Upon intratumoral injection, ZGS-Si-Pc@HA effectively alleviates immune tolerance and promotes T lymphocyte tumor infiltration. Further, ZGS-Si-Pc@HA enhances the therapeutic effect of checkpoint blockade immunotherapy, effectively inhibiting bilateral tumor growth and triggering an immunological memory effect. Nano-immunostimulants not only provide a new way to boost cancer immunotherapy, but also offer a reliable strategy for fighting cancer metastasis and recurrence clinically.     

Mesoporous Polydopamine Carrying Manganese Carbonyl Responds to Tumor Microenvironment for Multimodal Imaging‐Guided Cancer Therapy

Multifunctional nanodrugs integrating multiple therapeutic and imaging functions may find tremendous biomedical applications. However, the development of a simple yet potent theranostic nanosystem with a high payload and microenvironment responsiveness enhancing imaging‐guided cancer therapy is still a great challenge. Herein, a kind of MnCO‐entrapped mesoporous polydopamine nanoparticles are developed, which reach a 1.5 mg payload per gram carrier and exhibit marked theranostic capability through effective CO/Mn²⁺ generation and photothermal conversion inside the H⁺ and H₂O₂‐enriched tumor microenvironment, for a magnetic resonance/photoacoustic bimodal imaging‐guided tumor therapy. The multifunctional nanosystem exhibits a biocompatibility highly desirable for in vivo application and superior performance in inhibiting tumor growth and recurrence via combination CO and photothermal therapy.