Edge modification facilitated heterogenization and exfoliation of two-dimensional nanomaterials for cancer catalytic therapy

Near-infrared-II-driven Z-scheme heterojunction Polyglycolated MoS2/CoFe2O4 amplified edge potential for dual-mode imaging guided tumor synergistic therapy

Targeting the peculiarities of tumor tissue microenvironment different from normal tissue, such as lower pH and overexpression of hydrogen peroxide is the key to effective treatment. In this study, acid-responsive Z-scheme heterojunctions polyglycolated MoS2/CoFe2O4 (MoS2 = molybdenum disulfide, CoFe2O4 = cobalt ferrite) was synthesized using a two-step hydrothermal method, designated as MSCO-PEG, guided by dual modes of photoacoustic imagine (PAI) and nuclear magnetic imaging (MRI). MSCO-PEG (PEG = polyethylene glycol) responded to the acidic environment of tumor tissues and overexpression of hydrogen peroxide to turn on multimodal synergistic treatment of tumor cells under near-infrared-II (NIR-II) illumination. In particular, MSCO-PEG amplified the oxidizing ability of edge valence band holes (h+) and the reducing ability of conduction band electrons (e-) under NIR-II illumination through a "step-like" charge transfer mechanism, promoting the conversion of H2O to oxygen (O2) and the generation of superoxide radicals (O2-). In addition, the outstanding light absorption and photothermal conversion ability of MSCO made it have excellent photodynamic therapy (PDT) and photothermal therapy (PTT) effects. Meanwhile, the abundant multivalent metals endowed MSCO-PEG with the ability to generate chemodynamic therapy (CDT). MSCO-PEG's ability to clear glutathione (GSH) promotes tumor oxidative stress, increases reactive oxygen species (ROS) production, and enhances the synergistic therapeutic effect. This work provides a promising approach to advancing the clinical application of nanomaterials for anticancer therapy targeting the tumor microenvironment.

Charge regulated pH/NIR dual responsive nanoplatforms centered on cuproptosis for enhanced cancer theranostics

Multifunctional nanoplatforms capable of simultaneously executing multimodal therapy and imaging functions are of great potentials for cancer theranostics. We present an elegantly designed, easy-to-fabricate poly(acrylic acid)/mesoporous calcium phosphate/mesoporous copper phosphate nanosphere (PAA/mCaP/mCuP NS) with outstanding pH/NIR-sensitive multimodal-synergic anti-tumor effects. Optimal porous PAA NS scaffolds were prepared at room temperature by balancing the intra-PAA polymer and polymer-solvents Lennard-Jones potentials in a water:isopropyl alcohol (IPA) mix-solvent. Subsequent sponging of Ca2+ and Cu2+, and adsorption of PO43- to the PAA template were achieved through exquisite electrostatic interactions among ions and the ionizable PAA side-chain in an aqueous environment. This forms the basis for the tumor microenvironment pH-triggered release of Cu2+ to induce cuproptosis, as well as the photothermal effect originating from CuP, while Ca2+ can enhance the nanoplatform's biocompatibility and can damage mitochondria when overloaded. Lastly, PAA/mCaP/mCuP NSs still exhibit high drug loading efficiency for doxorubicin (DOX), enabling chemotherapy. Satisfactory anti-tumor effects of these modalities, along with their synergistic effects, were verified both in vitro and in vivo, with the NSs demonstrating good biodegradation in the latter. The fabricated NS itself holds great promise as an anti-tumor nanomedicine, and the thorough mechanical insights into NS formation may inspire the design of next-generation multifunctional nanoplatforms.

Near-infrared light-activated nanosystem endows scaffold with controllable nitric oxide release for peripheral nerve regeneration

The photosensitive S-nitrosocysteine (CysNO) could respond to light irradiation to produce nitric oxide (NO), exhibiting tremendous potential in accelerating peripheral nerve regeneration. However, its further application was limited by the burst release of NO and the requirement for ultraviolet excitation with low tissue penetration. Herein, a near-infrared-triggered NO controlled release nanosystem UCNP@ZIF-8/CysNO consisting of an upconversion nanoparticle (UCNP) core and zeolitic imidazolate framework-8 (ZIF-8) shell loading with CysNO was constructed, and then blended with poly-l-lactic acid powder to fabricate nerve scaffold by laser additive manufacturing technique. Once irradiated by near-infrared light, UCNP emitted ultraviolet light, triggering the S-NO cleavage of CysNO to generate NO, thereby achieving deep penetration therapy. In addition, the spatial confinement effect of 2-methylimidazole skeleton structure in ZIF-8 could effectively ensure the controlled release of NO. The Griess method test demonstrated that the scaffold exhibited sustained and stable NO release kinetics, as well as excellent near-infrared controllability. Immunofluorescence staining showed that the released NO upregulated the expression of neuronal markers Nestin and GFAP, indicating that the stem cells differentiated into neurons. Further mechanism revealed that the upregulated marker expression might be attributed to the enhanced Ca2+ influx. Consequently, this work might provide a novel perspective for nerve repair.

A glutathione-activated bismuth-gallic acid metal-organic framework nano-prodrug for enhanced sonodynamic therapy of breast tumor

Sonodynamic therapy is a promising, noninvasive, and precise tumor treatment that leverages sonosensitizers to generate cytotoxic reactive oxygen species during ultrasound stimulation. Gallic acid (GA), a natural polyphenol, possesses certain anti-tumor properties, but exhibits significant toxicity toward normal cells, limiting its application in cancer treatment. To overcome this issue, we synthesized a bismuth-gallic acid (BGA), coordinated metal-organic framework (MOF) nano-prodrug. Upon encountering glutathione (GSH), BGA gradually dissociated and depleted GSH, releasing GA, which had anti-tumor effects. As an MOF with semiconductor properties, BGA primarily produced superoxide anion radical upon ultrasound excitation. After the release of GA, GA generated superoxide anion radical and further produced high toxic singlet oxygen under ultrasound stimulation, while further oxidizing and consuming GSH, enhancing sonocatalytic performance. Additionally, the released GA induced cell cycle arrest, ultimately leading to apoptosis. Our results revealed that BGA, as a GSH-activated, metal-polyphenol MOF nano-prodrug, showed potential for use in breast tumor sonodynamic therapy, providing a novel strategy for precise tumor treatment.

A high-valence bismuth(V) nanoplatform triggers cancer cell death and anti-tumor immune responses with exogenous excitation-free endogenous H2O2- and O2-independent ROS generation

Reactive oxygen species with evoked immunotherapy holds tremendous promise for cancer treatment but has limitations due to its dependence on exogenous excitation and/or endogenous H2O2 and O2. Here we report a versatile oxidizing pentavalent bismuth(V) nanoplatform (NaBiVO3-PEG) can generate reactive oxygen species in an excitation-free and H2O2- and O2-independent manner. Upon exposure to the tumor microenvironment, NaBiVO3-PEG undergoes continuous H+-accelerated hydrolysis with •OH and 1O2 generation through electron transfer-mediated BiV-to-BiIII conversion and lattice oxygen transformation. The simultaneous release of sodium counterions after endocytosis triggers caspase-1-mediated pyroptosis. NaBiVO3-PEG intratumorally administered initiates robust therapeutic efficacies against both primary and distant tumors and activates systemic immune responses to combat tumor metastasis. NaBiVO3-PEG intravenously administered can efficiently accumulate at the tumor site for further real-time computed tomography monitoring, immunotherapy, or alternative synergistic immune-radiotherapy. Overall, this work offers a nanomedicine based on high-valence bismuth(V) nanoplatform and underscores its great potential for cancer immunotherapy.

ROS-mediated Therapeutics Combined with Metal-based Porphyrin Nanoparticles and their Applications in Tumor Treatment

High concentrations of reactive oxygen species (ROS) can disrupt cell structure and induce apoptosis and necrosis of tumor cells. Photodynamic therapy (PDT) and chemodynamic therapy (CDT) are two cancer treatments mediated by reactive oxygen species. Oxygen molecules (O2) are one of the indispensable factors in PDT and hypoxic tumor sites limit its application. However, another ROS-mediated method, CDT, can generate •OH and O2in situ by Fenton reaction or Fenton-like reaction. Synergistic PDT/CDT therapy is a strategy to overcome the limitations of tumor microenvironment therapy. In this review, PDT and CDT therapies are briefly introduced, with an emphasis on metal-basrd porphyrin nanoparticles constructed in different ways for PDT/CDT dual-mode therapy. By introducing the history and latest design schemes of the treatment model, it provides ideas for researchers engaged in ROS-mediated cancer therapies.

Synthesis of Closely-Contacted Cu2O-CoWO4 Nanosheet Composites for Cuproptosis Therapy to Tumors With Sonodynamic and Photothermal Assistance

Cuproptosis offers a promising and selective therapeutic strategy for cancer therapy. To fully realize its potential, the development of novel cuproptosis therapeutic agents and the achievement of efficient copper release are critical steps forward. Herein, closely-contacted Cu2O-CoWO4 nanosheet heterojunctions (CCW-NH) are successfully synthesized using an in-situ process for cuproptosis therapy. The efficient release of copper ions from CCW-NH can be triggered by ultrasound irradiation, primarily due to the generation of superoxide radicals as the sonodynamic agents via the Z-scheme charge transfer mechanism. When subjected to the combined effects of ultrasound and laser irradiation, the effective release of copper ions is increased by 1.7 times compared to the untreated group, significantly enhancing the efficiency of cuproptosis. And the incorporation of CCW-NH and L-arginine into the temperature-sensitive injectable hydrogel (HP-CCW@LA) ultimately achieved a tumor inhibition rate of up to 95.1%. L-arginine, serving as a reducing agent, enabled the sustained release of highly active Cu+ during treatment. Notably, after treating tumors with HP-CCW@LA, the tumor microenvironment is leveraged to promote copper ion conversion, which offers the potential for monitoring tumor therapy efficacy through magnetic resonance imaging. This work offers a novel integrated strategy for the development of new cuproptosis agents and therapeutic evaluation.

Heterojunction semiconductor nanocatalysts as cancer theranostics

Cancer nanotechnology is a promising area of cross-disciplinary research aiming to develop facile, effective, and noninvasive strategies to improve cancer diagnosis and treatment. Catalytic therapy based on exogenous stimulus-responsive semiconductor nanomaterials has shown its potential to address the challenges under the most global medical needs. Semiconductor nanocatalytic therapy is usually triggered by the catalytic action of hot electrons and holes during local redox reactions within the tumor, which represent the response of nontoxic semiconductor nanocatalysts to pertinent internal or external stimuli. However, careful architecture design of semiconductor nanocatalysts has been the major focus since the catalytic efficiency is often limited by facile hot electron/hole recombination. Addressing these challenges is vital for the progress of cancer catalytic therapy. In recent years, diverse strategies have been developed, with heterojunctions emerging as a prominent and extensively explored method. The efficiency of charge separation under exogenous stimulation can be heightened by manipulating the semiconducting performance of materials through heterojunction structures, thereby enhancing catalytic capabilities. This review summarizes the recent applications of exogenous stimulus-responsive semiconducting nanoheterojunctions for cancer theranostics. The first part of the review outlines the construction of different heterojunction types. The next section summarizes recent designs, properties, and catalytic mechanisms of various semiconductor heterojunctions in tumor therapy. The review concludes by discussing the challenges and providing insights into their prospects within this dynamic and continuously evolving field of research.

Microenvironment-Activatable Probe for Precise NIR-II Monitoring and Synergistic Immunotherapy in Rheumatoid Arthritis

Rheumatoid arthritis (RA) represents an insidious autoimmune inflammatory disorder that severely lowers the life quality by progressively destructing joint functions and eventually causing permanent disability, posing a serious public health problem. Here, an advanced theranostic probe is introduced that integrates activatable second near-infrared (NIR-II) fluorescence imaging for precise RA diagnosis with multi-pronged RA treatments. A novel molecular probe comprising a long-wavelength aggregation-induced emission unit and a manganese carbonyl cage motif is synthesized, which enables NIR-II fluorescence activation and concurrently releasing therapeutic carbon monoxide (CO) gas in inflamed joint microenvironment. This molecular probe self-assembles into a biocompatible nanoprobe, which is subsequently conjugated with anti-IL-6R antibody to afford active-targeting ability of RA. The nanoprobe exhibits significant turn-on NIR-II fluorescence signal at the RA lesion, enabling highly sensitive RA diagnosis and real-time therapeutic monitoring. The combination of ROS scavenging, on-demand CO gas release, and IL-6 signaling blockade results in potent therapeutic effect and synergistic immunomodulation impact, significantly alleviating the RA symptoms and preventing joint destruction. This research introduces a novel paradigm for the development of high-performance, activatable theranostic strategies to facilitate precise detection and enhanced treatment of RA-related diseases.

Facile fabrications of poly (acrylic acid)-mesoporous zinc phosphate/polydopamine Janus nanoparticles as a biosafe photothermal therapy agent and a pH/NIR-responsive drug carrier

Balancing biocompatibility and drug-loading efficiency in nanoparticles presents a significant challenge. In this study, we describe the facile fabrication of poly (acrylic acid)-mesoporous zinc phosphate/polydopamine (PAA-mZnP/PDA) Janus nanoparticles (JNPs). The PDA half-shell itself can serve as a photothermal agent for photothermal therapy (PTT), as well as to offers sites for polyethylene glycol (PEG) to enhance biocompatibility. Concurrently, the mesoporous ZnP core allows high loading of doxorubicin (DOX) for chemotherapy and the Cy5.5 dye for fluorescence imaging. The resultant PAA-mZnP/PDA-PEG JNPs exhibit exceptional biocompatibility, efficient drug loading (0.5 mg DOX/1 mg JNPs), and dual pH/NIR-responsive drug release properties. We demonstrate the JNPs' satisfactory anti-cancer efficacy, highlighting the synergistic effects of chemotherapy and PTT. Furthermore, the potential for synergistic fluorescence imaging-guided chemo-phototherapy in cancer treatment is illustrated. Thus, this work exemplifies the development of biosafe, multifunctional JNPs for advanced applications in cancer theranostics. STATEMENT OF SIGNIFICANCE: Facile fabrication of monodispersed nanomedicine with multi-cancer killing modalities organically integrated is nontrivial and becomes more challenging under the biocompatibility requirement that is necessary for the practical applications of nanomedicines. In this study, we creatively designed PAA-mZnP/PDA JNPs and fabricated them under mild conditions. Our method reliably yields uniform JNPs with excellent monodispersity. To maximize functionalities, we achieve fourfold advantages including efficient drug/fluorescent dye loading, PTT, pH/NIR dual-responsive properties, and optimal biocompatibility. The as-fabricated JNPs exhibit satisfactory anti-cancer performance both in vitro and in vivo, and demonstrate the potential of JNPs in fluorescence imaging-guided synergistic cancer chemo-phototherapy. Overall, our research establishes a pathway in versatile inorganic/polymer JNPs for enhanced cancer diagnosis and therapy.

Oral Heterojunction Coupling Interventional Optical Fiber Mediates Synergistic Therapy for Orthotopic Rectal Cancer

Catalytic therapy has shown great potential for clinical application. However, conventional catalytic therapies rely on reactive oxygen species (ROS) as "therapeutic drugs," which have limitations in effectively inhibiting tumor recurrence and metastasis. Here, a biomimetic heterojunction catalyst is developed that can actively target orthotopic rectal cancer after oral administration. The heterojunction catalyst is composed of quatrefoil star-shaped BiVO4 (BVO) and ZnIn2S4 (ZIS) nanosheets through an in situ direct growth technique. Poly-norepinephrine and macrophage membrane coatings afford the biomimetic heterojunction catalyst (BVO/ZIS@M), which has high rectal cancer targeting and retention abilities. The coupled optical fiber intervention technology activates the multicenter coordination of five catalytic reactions of heterojunction catalysts, including two reduction reactions (O2→·O2 - and CO2→CO) and three oxidation reactions (H2O→·OH, GSH→GSSG, and LA→PA). These catalytic reactions not only induce immunogenic death in tumor cells through the efficient generation of ROS/CO and the consumption of GSH but also specifically lead to the use of lactic acid (LA) as an electron donor to improve catalytic activity and disrupt the LA-mediated immunosuppressive microenvironment, mediating synergistic catalysis and immunotherapy for orthotopic rectal cancer. Therefore, this optical fiber intervention triggered the combination of heterojunction catalytic therapy and immunotherapy, which exhibits prominent antitumor effects.

Facile synthesis of MoS2@red phosphorus heterojunction for synergistically photodynamic and photothermal therapy of renal cell carcinoma

The therapy of the clear cell renal cell carcinoma (ccRCC) is crucial for the human healthcare due to its easy metastasis and recurrence, as well as resistance to radiotherapy and chemotherapy. In this work, we propose the synthesis of MoS2@red phosphorus (MoS2@RP) heterojunction to induce synergistic photodynamic and photothermal therapy (PDT/PTT) of ccRCC. The MoS2@RP heterojunction exhibits enhanced spectra absorption in the NIR range and produce local heat-increasing under the NIR laser irradiation compared with pure MoS2 and RP. The high photocatalytic activity of the MoS2@RP heterojunction contributes to effective transferring of the photo-excited electrons from the RP to MoS2, which promotes the production of various types of radical oxygen species (ROS) to kill the ccRCC cells. After the NIR irradiation, the MoS2@RP can effectively induce the apoptosis in the ccRCC cells through localized hyperthermia and the generation of ROS, while exhibiting low cytotoxicity towards normal kidney cells. In comparison to MoS2, the MoS2@RP heterojunction shows an approximate increase of 22 % in the lethality rate of the ccRCC cells and no significant change in toxicity towards normal cells. Furthermore, the PDT/PTT treatment using the MoS2@RP heterojunction effectively eradicates a substantial number of deep-tissue ccRCC cells in vivo without causing significant damage to major organs. This study presents promising effect of the MoS2@RP heterojunction-based photo-responsive therapy for effective ccRCC treatment.

VMT/ACP/Dextran composite nanosheets against dental caries through promoting mineralization of dentin tubules, pH buffering, and antibacterial

Dental caries is a worldwide public healthcare concern, and is closely related to the acidic environment that caused by bacterial decomposition of food. In this study, a two-step ion exchange liquid-phase stripping method was applied to strip out vermiculite (VMT) nanosheets, then amorphous calcium phosphate (ACP) and dextran were inserted between the VMT nanosheets interlayer to obtain a composite two-dimension nanosheets (VMT/ACP/Dextran). VMT/ACP/Dextran composite nanosheets exhibited excellent biocompatibility and could provide exogenous Ca2+and PO43- from ACP, provide SiO44-, Mg2+, Fe2+ and obtain buffering pH and antibacterial properties from VMT, as well as improve suspension stability and targeting Streptococcus mutans through glucan. The in vitro study showed that the composite materials could promote the mineralization and sealing of dentin tubules by releasing active ions, buffer pH 4.5 (a value close to the pH in the dental plaque environment) to pH 6.6-7.1 (values close to the pH in human saliva) through ion exchange, and exert antibacterial effects by targeting Streptococcus mutans and exerting oxidase like and peroxidase like activities to produce reactive oxygen species (ROS). The in vivo animal study showed that daily cleaning teeth using VMT/ACP/Dextran composite nanosheets could effectively reduce the incidence rate and severity of dental caries in rats. Taking together, the developed VMT/ACP/Dextran composite nanosheets, which integrated the excellent properties of VMT, ACP and dextran, can effectively prevent dental caries through a combination of factors such as buffering acids, antibacterial properties, and promoting calcification, and may be used as an active ingredient for daily oral hygiene or filling materials to prevent and treat dental caries.

Catalytic activity of violet phosphorus-based nanosystems and the role of metabolites in tumor therapy

Although nanocatalytic medicine has demonstrated its advantages in tumor therapy, the outcomes heavily relie on substrate concentration and the metabolic pathways are still indistinct. We discover that violet phosphorus quantum dots (VPQDs) can catalyze the production of reactive oxygen species (ROS) without requiring external stimuli and the catalytic substrates are confirmed to be oxygen (O2) and hydrogen peroxide (H2O2) through the computational simulation and experiments. Considering the short of O2 and H2O2 at the tumor site, we utilize calcium peroxide (CaO2) to supply catalytic substrates for VPQDs and construct nanoparticles together with them, named VPCaNPs. VPCaNPs can induce oxidative stress in tumor cells, particularly characterized by a significant increase in hydroxyl radicals and superoxide radicals, which cause substantial damage to the structure and function of cells, ultimately leading to cell apoptosis. Intriguingly, O2 provided by CaO2 can degrade VPQDs slowly, and the degradation product, phosphate, as well as CaO2-generated calcium ions, can promote tumor calcification. Antitumor immune activation and less metastasis are also observed in VPCaNPs administrated animals. In conclusion, our study unveils the anti-tumor activity of VPQDs as catalysts for generating cytotoxic ROS and the degradation products can promote tumor calcification, providing a promising strategy for treating tumors.

Tumour microenvironment-responded Fe-doped carbon dots-sensitized cubic Cu2O for Z-scheme heterojunction-enhanced sono-chemodynamic synergistic tumor therapy

The efficacy of electron-hole separation in a single sonosensitizer and the complexities of the tumor microenvironment (TME) present significant challenges to the effectiveness of sonodynamic therapy (SDT). Designing efficient sonosensitizers to enhance electron-hole separation and alleviate TME resistance is crucial yet challenging. Herein, we introduce a novel Z-scheme heterojunctions (HJs) sonosensitizer using Fe-doped carbon dots (CDs) as auxiliary semiconductors to sensitize cubic Cu2O (Fe-CDs@Cu2O) for the first time. Fe-CDs@Cu2O demonstrated enhanced SDT effects due to improved electron-hole separation. Additionally, the introduction of Fe ions in CDs synergistically enhances Fenton-like reactions with Cu ions in Cu2O, resulting in enhanced chemodynamic therapy (CDT) effects. Moreover, Fe-CDs@Cu2O exhibited rapid glutathione (GSH) depletion, effectively mitigating TME resistance. With high rates of 1O2 and OH generated by Fe-CDs@Cu2O, coupled with strong GSH depletion, single drug injection and ultrasound (US) irradiation effectively eliminate tumors. This innovative heterojunction sonosensitizer offers a promising pathway for clinical anti-tumor treatment.

Strategic disruption of cancer's powerhouse: precise nanomedicine targeting of mitochondrial metabolism

Mitochondria occupy a central role in the biology of most eukaryotic cells, functioning as the hub of oxidative metabolism where sugars, fats, and amino acids are ultimately oxidized to release energy. This crucial function fuels a variety of cellular activities. Disruption in mitochondrial metabolism is a common feature in many diseases, including cancer, neurodegenerative conditions and cardiovascular diseases. Targeting tumor cell mitochondrial metabolism with multifunctional nanosystems emerges as a promising strategy for enhancing therapeutic efficacy against cancer. This review comprehensively outlines the pathways of mitochondrial metabolism, emphasizing their critical roles in cellular energy production and metabolic regulation. The associations between aberrant mitochondrial metabolism and the initiation and progression of cancer are highlighted, illustrating how these metabolic disruptions contribute to oncogenesis and tumor sustainability. More importantly, innovative strategies employing nanomedicines to precisely target mitochondrial metabolic pathways in cancer therapy are fully explored. Furthermore, key challenges and future directions in this field are identified and discussed. Collectively, this review provides a comprehensive understanding of the current state and future potential of nanomedicine in targeting mitochondrial metabolism, offering insights for developing more effective cancer therapies.

Biodegradable and Efficient Charge-Migrated Z-Scheme Heterojunction Amplifies Cancer Ferroptosis by Blocking Defensive Redox System

Ferroptosis is an emerging non-apoptotic death process, mainly involving lipid peroxidation (LPO) caused by iron accumulation, which is potentially lethal to the intrinsically apoptotic-resistant malignant tumor. However, it is still restricted by the inherent antioxidant systems of tumor cells and the poor efficacy of traditional iron-based ferroptosis initiators. Herein, the study develops a novel ferroptosis-inducing agent based on PEGylated Cu+/Cu2+-doped black phosphorus@polypyrrole heterojunction (BP@CPP), which is constructed by utilizing the phosphate on the surface of BP to chelate Cu ions and initiating subsequent in situ polymerization of pyrrole. As a novel Z-scheme heterojunction, BP@CPP possesses an excellent photocatalytic activity in which the separated electron-hole pairs under laser irradiation endow it with powerful oxidizing and reducing capacities, which synergy with Cu+/Cu2+ self-cycling catalyzing Fenton-like reaction to further strengthen reactive oxygen species (ROS) accumulation, glutathione (GSH) depletion, and glutathione peroxidase 4 (GPX4) inactivation, ultimately leading to efficient ferroptosis. Systematic in vitro and in vivo evaluations demonstrate that BP@CPP effectively inhibit tumor growth by inducing desired ferroptosis while maintaining a favorable biosafety in the body. Therefore, the developed BP@CPP-based ferroptosis initiator provides a promising strategy for ferroptosis-like cancer therapy.

Boosting Checkpoint Immunotherapy with Biomimetic Nanodrug Delivery Systems

Immune checkpoint blockade (ICB) has achieved unprecedented progress in tumor immunotherapy by blocking specific immune checkpoint molecules. However, the high biodistribution of the drug prevents it from specifically targeting tumor tissues, leading to immune-related adverse events. Biomimetic nanodrug delivery systems (BNDSs) readily applicable to ICB therapy have been widely developed at the preclinical stage to avoid immune-related adverse events. By exploiting or mimicking complex biological structures, the constructed BNDS as a novel drug delivery system has good biocompatibility and certain tumor-targeting properties. Herein, the latest findings regarding the aforementioned therapies associated with ICB therapy are highlighted. Simultaneously, prospective bioinspired engineering strategies can be designed to overcome the four-level barriers to drug entry into lesion sites. In future clinical translation, BNDS-based ICB combination therapy represents a promising avenue for cancer treatment.

A metal-organic framework (MOF) built on surface-modified Cu nanoparticles eliminates tumors via multiple cascading synergistic therapeutic effects

Tumors produce a hypoxic environment that greatly influences cancer treatment, and conventional chemotherapeutic drugs cannot selectively accumulate in the tumor region because of the lack of a tumor targeting mechanism, causing increased systemic toxicities and side effects. Hence, designing and developing new nanoplatforms that combine multimodal therapeutic regimens is essential to improve tumor therapeutic efficacy. Herein, we report the synthesis of ultrafine Cu nanoparticles loaded with a drug combination of cisplatin (Pt) and 1-methyl-d-tryptophan (1-MT) and externally coated with 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) photosensitizer, polydopamine (PDA) and CaO2 of MIL-101(Fe) as a new nanoplatform (Cu@MIL-101@PMTPC). The nanoplatform synergistically combined chemodynamic therapy (CDT), photodynamic therapy (PDT), and immunochemotherapy. The Fe3+ in MIL-101(Fe) and the surface Cu nanoparticles exhibited strong ability to consume intracellular glutathione (GSH), thereby generating a Fenton-like response in the tumor microenvironment (TME) with substantial peroxidase (POD)-like and superoxide dismutase (SOD)-like activities. In this design, we used the indoleamine 2,3-dioxygenase (IDO) inhibitor 1-MT to overcome chemotherapy-induced immune escape phenomena including enhanced CD8+ and CD4+ T cell expression, interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) production, and accelerated immunogenic cell death. The targeted release of cisplatin loaded into Cu@MIL-101@PMTPC also reduced toxic side effects of chemotherapy. TCPP generated a large amount of singlet oxygen (1O2) upon specific laser irradiation to effectively kill tumor cells. CaO2 on the outer layer generated oxygen (O2) and hydrogen peroxide (H2O2) to ameliorate hypoxia in the tumor microenvironment, enhance the PDT effect, and provide a continuous supply of H2O2 for the Fenton-like reaction. Thus, this nanocarrier platform exhibited a powerful chemodynamic, photodynamic, and immunochemotherapeutic cascade, providing a new strategy for cancer treatment.

Biomimetic piezoelectric nanomaterial-modified oral microrobots for targeted catalytic and immunotherapy of colorectal cancer

Lactic acid (LA) accumulation in the tumor microenvironment poses notable challenges to effective tumor immunotherapy. Here, an intelligent tumor treatment microrobot based on the unique physiological structure and metabolic characteristics of Veillonella atypica (VA) is proposed by loading Staphylococcus aureus cell membrane-coating BaTiO3 nanocubes (SAM@BTO) on the surface of VA cells (VA-SAM@BTO) via click chemical reaction. Following oral administration, VA-SAM@BTO accurately targeted orthotopic colorectal cancer through inflammatory targeting of SAM and hypoxic targeting of VA. Under in vitro ultrasonic stimulation, BTO catalyzed two reduction reactions (O2 → •O2- and CO2 → CO) and three oxidation reactions (H2O → •OH, GSH → GSSG, and LA → PA) simultaneously, effectively inducing immunogenic death of tumor cells. BTO catalyzed the oxidative coupling of VA cells metabolized LA, effectively disrupting the immunosuppressive microenvironment, improving dendritic cell maturation and macrophage M1 polarization, and increasing effector T cell proportions while decreasing regulatory T cell numbers, which facilitates synergetic catalysis and immunotherapy.

Black phosphorus, an advanced versatile nanoparticles of antitumor, antibacterial and bone regeneration for OS therapy

Osteosarcoma (OS) is the most common primary malignant bone tumor. In the clinic, usual strategies for OS treatment include surgery, chemotherapy, and radiation. However, all of these therapies have complications that cannot be ignored. Therefore, the search for better OS treatments is urgent. Black phosphorus (BP), a rising star of 2D inorganic nanoparticles, has shown excellent results in OS therapy due to its outstanding photothermal, photodynamic, biodegradable and biocompatible properties. This review aims to present current advances in the use of BP nanoparticles in OS therapy, including the synthesis of BP nanoparticles, properties of BP nanoparticles, types of BP nanoparticles, and modification strategies for BP nanoparticles. In addition, we have discussed comprehensively the application of BP in OS therapy, including single, dual, and multimodal synergistic OS therapies, as well as studies about bone regeneration and antibacterial properties. Finally, we have summarized the conclusions, limitations and perspectives of BP nanoparticles for OS therapy.

Low-Frequency Ultrasound Sensitive Piezo1 Channels Regulate Keloid-Related Characteristics of Fibroblasts

Keloids are benign fibroproliferative tumors that severely diminish the quality of life due to discomfort, dysfunction, and disfigurement. Recently, ultrasound technology as a noninvasive adjuvant therapy is developed to optimize treatment protocols. However, the biophysical mechanisms have not yet been fully elucidated. Here, it is proposed that piezo-type mechanosensitive ion channel component 1 (Piezo1) plays an important role in low-frequency sonophoresis (LFS) induced mechanical transduction pathways that trigger downstream cellular signaling processes. It is demonstrated that patient-derived primary keloid fibroblasts (PKF), NIH 3T3, and HFF-1 cell migration are inhibited, and PKF apoptosis is significantly increased by LFS stimulation. And the effects of LFS is diminished by the application of GsMTx-4, the selective inhibitor of Piezo1, and the knockdown of Piezo1. More importantly, the effects of LFS can be imitated by Yoda1, an agonist of Piezo1 channels. Establishing a patient-derived xenograft keloid implantation mouse model further verified these results, as LFS significantly decreased the volume and weight of the keloids. Moreover, blocking the Piezo1 channel impaired the effectiveness of LFS treatment. These results suggest that LFS inhibits the malignant characteristics of keloids by activating the Piezo1 channel, thus providing a theoretical basis for improving the clinical treatment of keloids.

Fabrication of Interface Engineered S-Scheme Heterojunction Nanocatalyst for Ultrasound-Triggered Sustainable Cancer Therapy

In order to establish a set of perfect heterojunction designs and characterization schemes, step-scheme (S-scheme) BiOBr@Bi2S3 nanoheterojunctions that enable the charge separation and expand the scope of catalytic reactions, aiming to promote the development and improvement of heterojunction engineering is developed. In this kind of heterojunction system, the Fermi levels mediate the formation of the internal electric field at the interface and guide the recombination of the weak redox carriers, while the strong redox carriers are retained. Thus, these high-energy electrons and holes are able to catalyze a variety of substrates in the tumor microenvironment, such as the reduction of oxygen and carbon dioxide to superoxide radicals and carbon monoxide (CO), and the oxidation of H2O to hydroxyl radicals, thus achieving sonodynamic therapy and CO combined therapy. Mechanistically, the generated reactive oxygen species and CO damage DNA and inhibit cancer cell energy levels, respectively, to synergistically induce tumor cell apoptosis. This study provides new insights into the realization of high efficiency and low toxicity in catalytic therapy from a unique perspective of materials design. It is anticipated that this catalytic therapeutic method will garner significant interest in the sonocatalytic nanomedicine field.

Oxygen Vacancy Defect Enhanced NIR-II Photothermal Performance of BiOxCl Nanosheets for Combined Phototherapy of Cancer Guided by Multimodal Imaging

Narrow photo-absorption range and low carrier utilization are significant barriers that restrict the antitumor efficiency of 2D bismuth oxyhalide (BiOX, X = Cl, Br, I) nanosheets (NSs). Introducing oxygen vacancy (OV) defects can expand the absorption range and improve carrier utilization, which are crucial but also challenging. In this study, a series of BiOxCl NSs with different OV defect concentrations (x = 1, 0.7, 0.5) is developed, which shows full spectrum absorption and strong absorption in the second near-infrared region (NIR-II). Density functional theory calculations are utilized to calculate the crystal structure and density states of BiOxCl, which confirm that part of the carriers is separated by OV enhanced internal electric field to improve carrier utilization. The carriers without redox reaction can be trapped in the OV, leading to great majority of photo-generated carriers promoting the photothermal performance. Triggered by single NIR-II (1064 nm), BiOxCl NSs' bidirectional efficient utilization of carriers achieves synchronously combined phototherapy, leading to enhanced tumor ablation and multimodal diagnostic in vitro and vivo. It is thus believed that this work provides an innovative strategy to design and construct nanoplatforms of indirect band gap semiconductors for clinical phototheranostics.

Tumor microenviroment-responsive self-assembly of barium titanate nanoparticles with enhanced piezoelectric catalysis capabilities for efficient tumor therapy

Catalytic therapy based on piezoelectric nanoparticles has become one of the effective strategies to eliminate tumors. However, it is still a challenge to improve the tumor delivery efficiency of piezoelectric nanoparticles, so that they can penetrate normal tissues while specifically aggregating at tumor sites and subsequently generating large amounts of reactive oxygen species (ROS) to achieve precise and efficient tumor clearance. In the present study, we successfully fabricated tumor microenvironment-responsive assembled barium titanate nanoparticles (tma-BTO NPs): in the neutral pH environment of normal tissues, tma-BTO NPs were monodisperse and possessed the ability to cross the intercellular space; whereas, the acidic environment of the tumor triggered the self-assembly of tma-BTO NPs to form submicron-scale aggregates, and deposited in the tumor microenvironment. The self-assembled tma-BTO NPs not only caused mechanical damage to tumor cells; more interestingly, they also exhibited enhanced piezoelectric catalytic efficiency and produced more ROS than monodisperse nanoparticles under ultrasonic excitation, attributed to the mutual extrusion of neighboring particles within the confined space of the assembly. tma-BTO NPs exhibited differential cytotoxicity against tumor cells and normal cells, and the stronger piezoelectric catalysis and mechanical damage induced by the assemblies resulted in significant apoptosis of mouse breast cancer cells (4T1); while there was little damage to mouse embryo osteoblast precursor cells (MC3T3-E1) under the same treatment conditions. Animal experiments confirmed that peritumoral injection of tma-BTO NPs combined with ultrasound therapy can effectively inhibit tumor progression non-invasively. The tumor microenvironment-responsive self-assembly strategy opens up new perspectives for future precise piezoelectric-catalyzed tumor therapy.

Building Block Metal Nanocluster-Based Growth in 1D Direction

Metal nanoclusters with precisely modulated structures at the nanoscale give us the opportunity to synthesize and investigate 1D nanomaterials at the atomic level. Herein, it realizes selective 1D growth of building block nanocluster "Au13 Cd2 " into three structurally different nanoclusters: "hand-in-hand" (Au13 Cd2 )2 O, "head-to-head" Au25 , and "shoulder-to-shoulder" Au33 . Detailed studies further reveals the growth mechanism and the growth-related tunable properties. This work provides new hints for the predictable structural transformation of nanoclusters and atomically precise construction of 1D nanomaterials.

Oxygen self-supplying small size magnetic nanoenzymes for synergistic photodynamic and catalytic therapy of breast cancer

In recent years, tumor catalytic therapy based on nanozymes has attracted widespread attention. However, its application is limited by the tumor hypoxic microenvironment (TME). In this study, we developed oxygen-supplying magnetic bead nanozymes that integrate hemoglobin and encapsulate the photosensitizer curcumin, demonstrating reactive oxygen species (ROS)-induced synergistic breast cancer therapy. Fe3O4 magnetic bead-mediated catalytic dynamic therapy (CDT) generates hydroxyl radicals (˙OH) through the Fenton reaction in the tumor microenvironment. The Hb-encapsulated Fe3O4 magnetic beads can be co-loaded with the photosensitizer/chemotherapeutic agent curcumin (cur), resulting in Fe3O4-Hb@cur. Under hypoxic conditions, oxygen molecules are released from Fe3O4-Hb@cur to overcome the TME hypoxia, resulting in comprehensive effects favoring anti-tumor responses. Upon near-infrared (NIR) irradiation, Fe3O4-Hb@cur activates the surrounding molecular oxygen to generate a certain amount of singlet oxygen (1O2), which is utilized for photodynamic therapy (PDT) in cancer treatment. Meanwhile, we validated that the O2 carried by Hb significantly enhances the intracellular ROS level, intensifying the catalytic therapy mediated by Fe3O4 magnetic beads and inflicting lethal damage to cancer cells, effectively inhibiting tumor growth. Therefore, significant in vivo synergistic therapeutic effects can be achieved through catalytic-photodynamic combination therapy.

Topology-regulated nanocatalysts for ferroptosis-mediated cancer phototherapy

Ferroptosis-mediated tumor treatment is constrained by the absence of single-component, activatable multifunctional inducers. Given this, a topological synthesis strategy is employed to develop an efficient bismuth-based semiconductor nano-photocatalyst (Bi2O3:S) for tumor ferroptosis therapy. Photo-excited electrons can participate in the reduction reaction to produce harmful reactive oxygen species (ROS) when exposed to near-infrared light. Meanwhile, photo-excited holes can contribute to the oxidation reaction to utilize extra glutathione (GSH) in tumors. In the acidic tumor microenvironment, bismuth ions generated from Bi2O3:S may further cooperate with GSH to amplify oxidative stress damage and achieve biodegradation. Both promote ferroptosis by downregulating glutathione peroxidase 4 (GPX4) expression. Besides, sulfur doping optimizes its near-infrared light-induced photothermal conversion efficiency, benefiting its therapeutic effect. Thus, bismuth ions and holes synergistically drive photo-activable ferroptosis in this nanoplatform, opening up new avenues for tumor therapy.

Symmetrical Localized Built-in Electric Field by Induced Polarization Effect in Ionic Covalent Organic Frameworks for Selective Imaging and Killing Bacteria

Photocatalytic materials are some of the most promising substitutes for antibiotics. However, the antibacterial efficiency is still inhibited by the rapid recombination of the photogenerated carriers. Herein, we design a cationic covalent organic framework (COF), which has a symmetrical localized built-in electric field due to the induced polarization effect caused by the electron-transfer reaction between the Zn-porphyrin unit and the guanidinium unit. Density functional theory calculations indicate that there is a symmetrical electrophilic/nucleophilic region in the COF structure, which results from increased electron density around the Zn-porphyrin unit. The formed local electric field can further inhibit the recombination of photogenerated carriers by driving rapid electron transfer from Zn-porphyrin to guanidinium under light irradiation, which greatly increases the yield of reactive oxygen species. This COF wrapped by DSPE-PEG2000 can selectively target the lipoteichoic acid of Gram-positive bacteria by electrostatic interaction, which can be used for selective discrimination and imaging of bacteria. Furthermore, this nanoparticle can rapidly kill Gram-positive bacteria including 99.75% of Staphylococcus aureus and 99.77% of Enterococcus faecalis at an abnormally low concentration (2.00 ppm) under light irradiation for 20 min. This work will provide insight into designing photoresponsive COFs through engineering charge behavior.

Self-Driven Electric Field Control of Orbital Electrons in AuPd Alloy Nanoparticles for Cancer Catalytic Therapy

The free radical generation efficiency of nanozymes in cancer therapy is crucial, but current methods fall short. Alloy nanoparticles (ANs) hold promise for improving catalytic performance due to their inherent electronic effect, but there are limited ways to modulate this effect. Here, a self-driven electric field (E) system utilizing triboelectric nanogenerator (TENG) and AuPd ANs with glucose oxidase (GOx)-like, catalase (CAT)-like, and peroxidase (POD)-like activities is presented to enhance the treatment of 4T1 breast cancer in mice. The E stimulation from TENG enhances the orbital electrons of AuPd ANs, resulting in increased CAT-like, GOx-like, and POD-like activities. Meanwhile, the catalytic cascade reaction of AuPd ANs is further amplified after catalyzing the production of H2 O2 from the GOx-like activities. This leads to 89.5% tumor inhibition after treatment. The self-driven E strategy offers a new way to enhance electronic effects and improve cascade catalytic therapeutic performance of AuPd ANs in cancer therapy.

Cancer Nanobombs Delivering Artoxplatin with a Polyigniter Bearing Hydrophobic Ferrocene Units Upregulate PD-L1 Expression and Stimulate Stronger Anticancer Immunity

Poor immunogenicity seriously hampers the broader implementation of antitumor immunotherapy. Enhanced immunogenicity capable of achieving greater antitumor immunity is urgently required. Here, a novel polymer that contains hydrophobic ferrocene (Fc) units and thioketal bonds in the main chain, which further delivered a prodrug of oxaliplatin and artesunate, i.e., Artoxplatin, to cancer cells is described. This polymer with Fc units in the nanoparticle can work as a polyigniter to spark the peroxide bonds in Artoxplatin and generate abundant reactive oxygen species (ROS) to kill cancers as nanobombig for cancer therapy. Moreover, ROS can trigger the breakdown of thioketal bonds in the polymer, resulting in the biodegradation of the polymer. Importantly, nanobombig can facilitate the maturation of dendritic cells and promote the activation of antitumor immunity, through the enhanced immunogenic cell death effect by ROS generated in situ. Furthermore, metabolomics analysis reveals a decrease in glutamine in nanobombig -treated cancer cells, resulting in the upregulation of programmed death ligand 1 (PD-L1). Consequently, it is further demonstrated enhanced tumor inhibitory effects when using nanobombig combined with anti-PD-L1 therapy. Overall, the nanosystem offers a rational design of an efficient chemo-immunotherapy regimen to promote antitumor immunity by improving tumor immunogenicity, addressing the key challenges cancer immunotherapy faced.

Sonocatalytic cancer therapy: theories, advanced catalysts and system design

Treating cancer remains one of the most formidable challenges in modern medicine, with traditional treatment options often being limited by poor therapeutic outcomes and unacceptable side effects. Nanocatalytic therapy activates tumor-localized catalytic reactions in situ via nontoxic or minimally toxic nanocatalysts responding to unique cues from the tumor microenvironment or external stimuli. In particular, sonocatalytic cancer therapy is a promising approach that has emerged as a potential solution to this problem through the combination of ultrasound waves and catalytic materials to selectively target and destroy cancer cells. Compared to light, ultrasound exhibits higher spatial precision, lower energy attenuation, and superior tissue penetrability, furnishing more energy to catalysts. Multidimensional modulation of nanocatalyst structures and properties is pivotal to maximizing catalytic efficiency given constraints in external stimulative energy as well as substrate types and levels. In this review, we discuss the various theories and mechanisms underlying sonocatalytic cancer therapy, as well as advanced catalysts that have been developed for this application. Additionally, we explore the design of sonocatalytic cancer therapy systems, including the use of heterojunction catalysts and the optimal conditions for achieving maximum therapeutic effects. Finally, we highlight the potential benefits of sonocatalytic cancer therapy over traditional cancer treatments, including its noninvasive nature and lower toxicity.

PdMo nanoflowers for endogenous/exogenous-stimulated nanocatalytic therapy

The clinical application of reactive oxygen species (ROS)-mediated tumor treatment has been critically limited by inefficient ROS generation. Herein, we rationally synthesized and constructed the three-dimensional PdMo nanoflowers through a one-pot solvothermal reduction method for elaborately regulated peroxidase-like enzymatic activity and glutathione peroxidase-like enzymatic activity, to promote oxidation ROS evolvement and antioxidation glutathione depletion for achieving intensive ROS-mediated tumor therapy. The three-dimensional superstructure composed of two-dimensional nanosheet subunits can solve the issues by avoiding the appearance of tightly stacked crystalline nanostructures. Significantly, Mo is chosen as a second metal to alloy with Pd because of its more chemical valence and negative ionization energy than Pd for improved electron transfer efficiencies and enhanced enzyme-like activities. In addition, the photothermal effect generated by PdMo nanoflowers could also enhance its enzymatic activities. Thus, this work provides a promising paradigm for achieving highly ROS-mediated tumor therapeutic efficacy by regulating the multi-enzymatic activities of Pd-based nanoalloys.

2D Ultrathin Iron Doped Bismuth Oxychloride Nanosheets with Rich Oxygen Vacancies for Enhanced Sonodynamic Therapy

Sonodynamic therapy (SDT) combines ultrasound and sonosensitizers to produce toxic reactive oxygen species (ROS) for cancer cell killing. Due to the high penetration depth of ultrasound (US), SDT breaks the depth penetration barrier of conventional photodynamic therapy for the treatment of deeply seated tumors. A key point to enhance the therapeutic efficiency of SDT is the development of novel sonosensitizers with promoted ability for ROS production. Herein, ultrathin Fe-doped bismuth oxychloride nanosheets with rich oxygen vacancies and bovine serum albumin coating on surface are designed as piezoelectric sonosensitizers (BOC-Fe NSs) for enhanced SDT. The oxygen vacancies of BOC-Fe NSs provide electron trapping sites to promote the separation of e- -h+ from the band structure, which facilitates the ROS production under the ultrasonic waves. The piezoelectric BOC-Fe NSs create a built-in field and the bending bands, further accelerating the ROS generation with US irradiation. Furthermore, BOC-Fe NSs can induce ROS generation by a Fenton reaction catalyzed by Fe ion with endogenous H2 O2 in tumor tissues for chemodynamic therapy. The as-prepared BOC-Fe NSs efficiently inhibited breast cancer cell growth in both in vitro and in vivo tests. The successfully development of BOC-Fe NSs provides a new nano-sonosensitiser option for enhanced SDT for cancer therapy.

Copper-Loaded Nanoheterojunction Enables Superb Orthotopic Osteosarcoma Therapy via Oxidative Stress and Cell Cuproptosis

Catalytic tumor therapy based on two-dimensional (2D) nanomaterials is a burgeoning and promising tumor therapeutic modality. However, the inefficient utilization and conversion of exogenous stimulation, single catalytic modality, and unsatisfactory therapeutic efficiency in the tumor microenvironment (TME) have seriously restricted their further application in tumor therapy. Herein, the heterogeneous carbon nitride-based nanoagent named T-HCN@CuMS was successfully developed, which dramatically improved the efficiency of the tumor therapeutic modality. Benefiting from the donor-acceptor (triazine-heptazine) structure within the heterogeneous carbon nitride nanosheets (HCN) and the construction of interplanar heterostructure with copper loaded metallic molybdenum bisulfide nanosheets (CuMS), T-HCN@CuMS presented a favorable photo-induced catalytic property to generate abundant reactive oxygen species (ROS) under near-infrared (NIR) light irradiation. Besides, the choice of CuMS simultaneously enabled this nanoagent to efficiently catalyze the Fenton-like reaction and trigger cell cuproptosis, a recently recognized regulated cell death mode characterized by imbalanced intracellular copper homeostasis and aggregation of lipoylated mitochondrial proteins. Moreover, upon surface modification with cRGDfk-PEG2k-DSPE, T-HCN@CuMS was prepared and endowed with improved dispersibility and αvβ3 integrins targeting ability. In general, through the rational design, T-HCN@CuMS was facilely prepared and had achieved satisfactory antitumor and antimetastasis outcomes both in vitro and in a high-metastatic orthotopic osteosarcoma model. This strategy could offer an idea to treat malignant diseases based on 2D nanomaterials.

Sonocatalytic In Situ Induced Oxygen Storm Precision Enhanced Reactive Oxygen Therapy for Pancreatic Cancer

Deep‐buried tissue, extremely hypoxic blood supply, and complex tumor microenvironment are considered to be the hardest difficult barriers to the accurate treatment of pancreatic cancer. Herein, a novel Au@Co3O4 (AC)‐polyvinylpyrrolidone (AC‐PVP) sonocatalytic agent and radiation sensitizer with a multicore–shell structure are synthesized by a mild reduction method for reshaping the special physiological environment of pancreatic cancer. Oxygen storms can be generated under ultrasonic activation by in situ catalyzed H2O2 in tumor tissue. The oxygen storm improves the ability to produce superoxide anions by sonodynamic therapy as well as rapidly supplements the oxygen‐dependent on active oxygen such as auger electrons produced by high‐energy ray ionization during radiotherapy (RT), further enhancing the efficiency of RT. Interestingly, AC‐PVP can reduce the intracellular glutathione (GSH) level, thus preventing the generated reactive oxygen species from being consumed by GSH. More importantly, the glucose oxidase‐like of AC‐PVP can catalyze glucose in tumor tissue to produce H2O2, and continuously provide substrates for sonocatalytic to form self‐cycling oxygen production. This study offers a novel paradigm for achieving in situ precise self‐oxygenation to overcome the special physiological barrier of pancreatic cancer and efficient sonodynamic synergistic radiotherapy.

Advances in the two-dimensional layer materials for cancer diagnosis and treatment: unique advantages beyond the microsphere

In recent years, two-dimensional (2D) layer materials have shown great potential in the field of cancer diagnosis and treatment due to their unique structural, electronic, and chemical properties. These non-spherical materials have attracted increasing attention around the world because of its widely used biological characteristics. The application of 2D layer materials like lamellar graphene, transition metal dichalcogenides (TMDs), and black phosphorus (BPs) and so on have been developed for CT/MRI imaging, serum biosensing, drug targeting delivery, photothermal therapy, and photodynamic therapy. These unique applications for tumor are due to the multi-variable synthesis of 2D materials and the structural characteristics of good ductility different from microsphere. Based on the above considerations, the application of 2D materials in cancer is mainly carried out in the following three aspects: 1) In terms of accurate and rapid screening of tumor patients, we will focus on the enrichment of serum markers and sensitive signal transformation of 2D materials; 2) The progress of 2D nanomaterials in tumor MRI and CT imaging was described by comparing the performance of traditional contrast agents; 3) In the most important aspect, we will focus on the progress of 2D materials in the field of precision drug delivery and collaborative therapy, such as photothermal ablation, sonodynamic therapy, chemokinetic therapy, etc. In summary, this review provides a comprehensive overview of the advances in the application of 2D layer materials for tumor diagnosis and treatment, and emphasizes the performance difference between 2D materials and other types of nanoparticles (mainly spherical). With further research and development, these multifunctional layer materials hold great promise in the prospects, and challenges of 2D materials development are discussed.

Self-triggered thermoelectric nanoheterojunction for cancer catalytic and immunotherapy

The exogenous excitation requirement and electron-hole recombination are the key elements limiting the application of catalytic therapies. Here a tumor microenvironment (TME)-specific self-triggered thermoelectric nanoheterojunction (Bi0.5Sb1.5Te3/CaO2 nanosheets, BST/CaO2 NSs) with self-built-in electric field facilitated charge separation is fabricated. Upon exposure to TME, the CaO2 coating undergoes rapid hydrolysis, releasing Ca2+, H2O2, and heat. The resulting temperature difference on the BST NSs initiates a thermoelectric effect, driving reactive oxygen species production. H2O2 not only serves as a substrate supplement for ROS generation but also dysregulates Ca2+ channels, preventing Ca2+ efflux. This further exacerbates calcium overload-mediated therapy. Additionally, Ca2+ promotes DC maturation and tumor antigen presentation, facilitating immunotherapy. It is worth noting that the CaO2 NP coating hydrolyzes very slowly in normal cells, releasing Ca2+ and O2 without causing any adverse effects. Tumor-specific self-triggered thermoelectric nanoheterojunction combined catalytic therapy, ion interference therapy, and immunotherapy exhibit excellent antitumor performance in female mice.

Two-dimensional porous vermiculite-based nanocatalysts for synergetic catalytic therapy

This study reports an ultrasound-mediated and two-dimensional (2D) porous vermiculite nanosheets (VMT NSs)-based nanocatalyst platform (Arg@VMT@PDA-PEG) that synergistically harnessed the Fenton reaction-based chemodynamic therapy (CDT), 2D semiconductor-based sonodynamic therapy (SDT) and nitric oxide (NO)-based gas therapy for combination cancer therapy. The tumor microenvironment responsive degradation of polydopamine (PDA) shell could not only prevent L-Arg, a NO donor, leakage during blood circulation, but also selectively release the active sites of VMT NSs for catalytic reactions in tumor cells. Additionally, the Fenton reactions mediated by the abundant Fe²⁺/Fe³⁺ in VMT NSs could efficiently produce ·OH and consume glutathione (GSH) for CDT. Moreover, the reactive oxygen species (ROS, ·OH and ·O₂^-) produced by ultrasound-triggered Arg@VMT@PDA-PEG could not only execute SDT but also oxidize L-Arg to NO for synergetic gas therapy. The results show that the transformation of ROS to NO can enhance curative efficacy owing to the ability of NO with much longer life-time in freely diffusing into cells from intercellular space. This biodegradable Arg@VMT@PDA-PEG nanocatalytic platform integrating three different catalytic reactions provides a new therapeutic paradigm for combination cancer therapy.

Integrating Bacteria with a Ternary Combination of Photosensitizers for Monochromatic Irradiation-Mediated Photoacoustic Imaging-Guided Synergistic Photothermal Therapy

Photosensitizer-based therapy often suffers from unitary and easily attenuated photosensitive effects, limited tumor penetration and retention, and requirement of multiple irradiation for combination therapy, which largely restrict its application. Here, bacteria are integrated with a monochromatic irradiation-mediated ternary combination of photosensitizers for photoacoustic imaging-guided synergistic photothermal therapy. Bacteria that are bioengineered to express natural melanin are decorated with dual synthetic photosensitizers by nanodeposition with indocyanine green and polydopamine under a cytocompatible condition. The combined photosensitizers, which share an adequate excitation at 808 nm, endow integrated bacteria with a stable triple photoacoustic and photothermal effect under a monochromatic irradiation. Due to their living characteristics, these bacteria preferentially colonize hypoxic tumor tissue with homogeneous distribution and durable retention and generate uniform imaging signals and a sufficient heating of tumor upon laser irradiation. Supported by significantly inhibited tumor growth and extended survival of animals in different tumor-bearing murine models, our work proposes the development of bacteria-based innovative photosensitizers for imaging-guided therapy.

ROS-Responsive Self-activatable Photosensitizing Agent for Photodynamic-Immunotherapy of cancer

Photodynamic therapy (PDT), as a non-invasive and spatiotemporally controllable modality, exhibits great potential in cancer treatment. However, the efficiency of reactive oxygen species (ROS) production was restricted to the hydrophobic characteristics and aggregation-caused quenching (ACQ) of photosensitizers. Herein, we designed a ROS self-activatable nano system (denoted as PTKPa) based on poly(thioketal) conjugated with photosensitizers (PSs) pheophorbide A (Ppa) on the polymer side chains for suppressing ACQ and enhancing PDT. The process of self-activation is that ROS, which is derived from laser irradiated PTKPa, as an activating agent accelerates poly(thioketal) cleavage with the release of Ppa from PTKPa. This in turn generates abundant ROS, accelerates degradation of the remaining PTKPa and amplifies the efficacy of PDT with more tremendous ROS generated. Moreover, these abundant ROS can amplify PDT-induced oxidative stress, cause irreversible damage to tumor cells and achieve immunogenic cell death (ICD), thereby boosting the efficacy of photodynamic-immunotherapy. These findings provide new insights into ROS self-activatable strategy for enhancing cancer photodynamic- immunotherapy. STATEMENT OF SIGNIFICANCE: This work described an approach to utilize ROS-responsive self-activatable poly(thioketal) conjugated with pheophorbide A (Ppa) for suppressing aggregation-caused quenching (ACQ) and enhancing photodynamic-immunotherapy. The ROS, generated from the conjugated Ppa upon 660nm laser irradiation, as a triggering agent which initiates the release of Ppa with poly(thioketal) degradation. That in turn generates abundant ROS and facilitates degradation of the remaining PTKPa, resulting in oxidative stress to tumor cells and achieving immunogenic cell death (ICD). This work provides a promising solution to improve tumor photodynamic therapeutic effects.

Nanoheterojunction-Mediated Thermoelectric Strategy for Cancer Surgical Adjuvant Treatment and β-Elemene Combination Therapy

As an indispensable strategy for tumor treatment, surgery may cause two major challenges: tumor recurrence and wound infection. Here, a thermoelectric therapeutic strategy is provided as either an independent cancer therapy or surgical adjuvant treatment. Bi_0.5 Sb_1.5 Te₃ (BST) and Bi₂ Te_2.8 Se_0.2 (BTS) nanoplates composed of Z-scheme thermoelectric heterojunction (BST/BTS) are fabricated via a two-step hydrothermal processes. The contact between BST and BTS constructs an interfacial electric field due to Fermi energy level rearrangement, guiding electrons in the conductive band (CB) of BTS combine with the holes in the valance band (VB) of BST, leaving stronger reduction/oxidation potentials of electrons and holes in the CB of BST and the VB of BTS. Moreover, under a mild temperature gradient, another self-built-in electric field is formed facilitating the migration of electrons and holes to their surfaces. Based on the PEGylated BST/BTS heterojunction, a novel thermoelectric therapy platform is developed through intravenous injection of BST/BTS and external cooling of the tumors. This thermoelectric strategy is also proved effective for combination cancer therapy with β-elemene. Moreover, the combination of heterojunction and hydrogel is administrated on the wound after surgery, achieving efficient residual tumor treatment and antibacterial effects.

Knowledge mapping of image-guided tumor ablation and immunity: A bibliometric analysis

Background

Various ablation techniques have been successfully applied in tumor therapy by locally destroying tumor. In the process of tumor ablation, a large number of tumor cell debris is released, which can be used as a source of tumor antigens and trigger a series of immune responses. With the deepening of the research on the immune microenvironment and immunotherapy, researches exploring tumor ablation and immunity are continuously published. However, no research has systematically analyzed the intellectual landscape and emerging trends for tumor ablation and immunity using scientometric analysis. Therefore, this study aimed to conduct a bibliometric analysis to quantify and identify the status quo and trend of tumor ablation and immunity.

Methods

Data of publications were downloaded from the Web of Science Core Collection database. CiteSpace and VOSviewer were used to conduct bibliometric analysis to evaluate the contribution and co-occurrence relationship of different countries/regions, institutions and authors in the field, and to determine the research hotspots in this field.

Results

By searching in the database, a total of 3531 English articles published between 2012 and 2021 were obtained. We observed rapid growth in the number of publications since 2012. The two most active countries were China and the United States, with more than 1,000 articles. Chinese Academy of Sciences contributed the most publications (n = 153). Jibing Chen and Xianzheng Zhang might have a keen interest in tumor ablation and immunity, with more publications (n = 14; n = 13). Among the top 10 co-cited authors, Castano AP (284 citations) was ranked first, followed by Agostinis P (270 citations) and Chen Qian (246 citations). According to the co-occurrence and cluster analysis, the results indicated that the focus of research was "photothermal therapy" and "immune checkpoint blockade".

Conclusions

In the past decade, the neighborhood of tumor ablation domain immunity has been paid more and more attention. Nowadays, the research hotspots in this field are mainly focused on exploring the immunological mechanism in photothermal therapy to improve its efficacy, and the combination of ablation therapy and immune checkpoint inhibitor therapy.