Microenvironment-Responsive Prodrug-Induced Pyroptosis Boosts Cancer Immunotherapy

Bimetallic nanoreactor mediates cascade amplification of oxidative stress for complementary chemodynamic-immunotherapy of tumor

As a promising tumor treatment, chemodynamic therapy (CDT) can specifically catalyze H2O2 into the cytotoxic hydroxyl radical (·OH) via Fenton/Fenton-like reaction. However, the limited H2O2 and weakly acidic pH in tumor microenvironment (TME) would severely restrict the therapeutic efficiency of CDT. Here, a weakly acid activated, H2O2 self-supplied, hyaluronic acid (HA)-functionalized Ce/Cu bimetallic nanoreactor (CBPNs@HA) is elaborately designed for complementary chemodynamic-immunotherapy. In this nanoreactor, the component of peroxide group and Ce/Cu bimetals played the role of H2O2 self-supply and synergistic catalytic Fenton-like reaction, respectively. Specifically, CBPNs@HA can sensitively respond to TME (pH 6.8) and rapidly degrade to generate Ce4+, Cu+ and H2O2. The high-valence Ce4+ would be reduced by the intracellular glutathione (GSH) to generate Ce3+ and this process could be accelerated by Cu + via synergistic effect of Ce4+/Cu+. Particularly, the low-valence metallic ions (Ce3+ and Cu+) can react with the produced H2O2 to generate a multitude of reactive oxygen species (ROS). These cascaded effects can significantly amplify oxidative stress and seriously disturb the redox balance of tumor cells, inducing the potent immunogenic cell death (ICD) to release tumor-specific antigens and thereby activating the powerful antitumor immune responses. After combined with immune checkpoint blockade (ICB), CBPNs@HA can significantly heighten antitumor effects to inhibit the growth of primary and metastatic tumors, and dramatically prolong the survival lifetime of 4T1 tumor-bearing mice to 60 days. This work provides a materials-based strategy for enhanced CDT and highlights new opportunities for complementary chemodynamic-immunotherapy.

Microwave-Responsive AlEu-MOFs Potentiate NLRP3-Mediated Pyroptosis via a "Triple Initiating" Tactic for Breast Cancer Microwave-Immunotherapy

Microwave thermotherapy is favored in clinical practice for breast cancer conservation strategies due to its minimally invasive characteristic. Nevertheless, the immunosuppressive tumor microenvironment (TME) significantly attenuates the therapeutic efficacy of anti-tumor immune response, posing challenges in effectively preventing tumor recurrence and metastasis. Pyroptosis, a recently identified form of programmed cell death triggered by inflammasomes, presents unique inflammatory and immunogenic properties that hold promise for cancer immunotherapy. Herein, microwave-responsive AlEu-MOFs are designed and synthesized to boost NLRP3-mediated pyroptosis via a "Triple Initiating" tactic for breast cancer microwave-immunotherapy. The potent microwave thermal effect of AEM facilitates the up-regulation of HSP90, thereby initiating NLRP3 expression. Concurrently, it induces mitochondrial dysfunction to generate substantial quantities of ROS, further enhancing NLRP3 expression to achieve a targeted amplification of microwave thermotherapy-induced pyroptosis. Simultaneously, the microwave-responsive directed anchoring release of highly active metal ions promotes the activation of the NLRP3 inflammasome jointly, ultimately inducing high-efficiency pyroptosis. This innovative "2M" (materials and methods) dual-pronged strategy not only significantly inhibits primary tumor proliferation, but also further impedes distant tumor progression and lung metastasis. This work provides a novel strategy to accurately and effectively achieve pyroptosis and offers a new approach to overcome the obstacles of clinical microwave thermotherapy.

Targeting pyroptosis for cancer immunotherapy: mechanistic insights and clinical perspectives

Pyroptosis is a distinct form of programmed cell death characterized by the rupture of the cell membrane and robust inflammatory responses. Increasing evidence suggests that pyroptosis significantly affects the tumor microenvironment and antitumor immunity by releasing damage-associated molecular patterns (DAMPs) and pro-inflammatory mediators, thereby establishing it as a pivotal target in cancer immunotherapy. This review thoroughly explores the molecular mechanisms underlying pyroptosis, with a particular focus on inflammasome activation and the gasdermin family of proteins (GSDMs). It examines the role of pyroptotic cell death in reshaping the tumor immune microenvironment (TIME) involving both tumor and immune cells, and discusses recent advancements in targeting pyroptotic pathways through therapeutic strategies such as small molecule modulators, engineered nanocarriers, and combinatory treatments with immune checkpoint inhibitors. We also review recent advances and future directions in targeting pyroptosis to enhance tumor immunotherapy with immune checkpoint inhibitors, adoptive cell therapy, and tumor vaccines. This study suggested that targeting pyroptosis offers a promising avenue to amplify antitumor immune responses and surmount resistance to existing immunotherapies, potentially leading to more efficacious cancer treatments.

TME-responsive nanocomposite hydrogel with targeted capacity for enhanced synergistic chemoimmunotherapy of MYC-amplified osteosarcoma

The oncogene MYC is one of the most commonly activated oncogenic proteins in human tumors, with nearly one-fourth of osteosarcoma showing MYC amplification and exhibiting the worst clinical outcomes. The clinical efficacy of single radiotherapy, chemotherapy, and immunotherapy for such osteosarcoma is poor, and the dysregulation of MYC amplification and immune-suppressive tumor microenvironment (TME) may be potential causes of anti-tumor failure. To address the above issues, we developed an injectable TME-responsive nanocomposite hydrogel to simultaneously deliver an effective MYC inhibitor (NHWD-870) and IL11Rα-targeted liposomes containing cisplatin-loaded MnO2 (Cis/Mn@Lipo-IL11). After in situ administration, NHWD-870 effectively degrades MYC and downregulates CCL2 and IL13 cytokines to trigger M1 type activation of macrophages. Meanwhile, targeted delivery of Cis/Mn@Lipo-IL11 reacts with excess intratumoral GSH to generate Mn2+ and thus inducing excess active oxygen species (ROS) production through Fenton-like reaction, along with cisplatin, thereby inducing immunogenic cell death (ICD) to promote dendritic cell maturation. Through synergistic regulation of MYC and ICD levels, the immune microenvironment was reshaped to enhance immune infiltration. In the osteosarcoma-bearing model, the nanocomposite hydrogel significantly enhanced tumor T cell infiltration, induced effective anti-tumor immunity and attenuated lung metastasis. Therefore, our results reveal a powerful strategy for targeted combination therapy of MYC-amplified osteosarcoma.

Gasdermin E as a potential target and biomarker for CRISPR-Cas9-based cancer therapy

Gasdermin E (GSDME), a protein pivotal in mediating pyroptosis, has gained significant attention due to its role in cancer pathogenesis and its potential as a therapeutic target. The advent of CRISPR-Cas9, a precise genome editing tool, has revolutionized cancer therapy by enabling the manipulation of GSDME expression and function. This review explores the interplay of GSDME and CRISPR-Cas9 in cancer, emphasizing GSDME's unique mechanism of cleavage-dependent pore formation in the cell membrane and its emerging applications as both a therapeutic target and a diagnostic biomarker. We discuss the potential and challenges of using GSDME-induced pyroptosis as a therapeutic strategy and how can enhance its efficacy and specificity. We conclude by highlighting promising future research directions in this emerging field.

A Novel "Double-Responsive" and "Dual-Targeted" Multifunctional Fluorescent Probe Monitors the Level Changes of ONOO- in Mitochondria during Cell Pyroptosis

Pyroptosis, often referred to as inflammatory necrosis, is a type of programmed cell death, characterized by the swelling of cells until the cell membranes rupture, resulting in the release of intracellular substances and a strong inflammatory response. Lipid droplets and mitochondria play important roles in cellular activities. A strong correlation exists between pyroptosis and mitochondrial dysfunction, which can be reflected through physiological functions and involves changes in the mitochondrial microenvironment and morphology. In this work, a "double-responsive" and "dual-targeted" fluorescent probe named WD-2 was constructed. It has excellent response performance to viscosity and ONOO-, and can simultaneously monitor the relevant levels in lipid droplets and mitochondria. Its remarkable targeting ability toward mitochondria and lipid droplets has been verified through colocalization experiments. In cell imaging experiments, the interaction between mitochondria and lipid droplets during nutritional stress was preliminarily studied. With the help of doxorubicin hydrochloride, the changes in the level of ONOO- in mitochondria during pyroptosis were explored, providing a new perspective for understanding the mechanism of this process.

Therapeutic connections between pyroptosis and paclitaxel in anti-tumor effects: an updated review

As a form of inflammation-associated cell death, pyroptosis has gained widespread attention in recent years. Accumulating evidence indicates that pyroptosis regulates tumor growth and is associated with autoimmune disorders and inflammatory response. Paclitaxel, a traditional Chinese medicine, usually induces death of cancer cells as a chemotherapeutic agent. Previous studies have revealed that paclitaxel can exert an anti-tumor effect through a variety of cell death mechanisms, of which pyroptosis plays a pivotal role in inhibiting tumor growth and enhancing anti-tumor immunity. In this review, we summarize the current advances in therapeutic connections between pyroptosis and paclitaxel in anti-tumor effects.

Tumor microenvironment-responsive precise delivery nanocarrier potentiating synchronous radionuclide therapy and chemotherapy against cancer

To achieve better therapeutic outcomes in cancer treatment, the combination of radionuclide and chemotherapy is commonly employed in clinical practice. However, the primary challenge lies in achieving precise drug delivery to tumor tissues, often leading to suboptimal therapeutic efficacy. This study presents a novel, tumor microenvironment-responsive drug delivery carrier that integrates real-time MRI/SPECT dual-modal imaging for precise diagnosis and treatment monitoring. The carrier comprised is based on a hybrid structure composed of hyaluronic acid (HA) and human serum albumin (HSA), encapsulating the metal-organic framework MIL-100(Fe). It was loaded with the chemotherapeutic drug doxorubicin (DOX) and modified with the radionuclide 131I, designed to precise diagnosis and treatment of tumors. HA binds specifically to the overexpressed CD44 receptor on the tumor surface, ensuring that the carrier targets tumors selectively. The incorporated 131I emits β rays, which deliver ionizing radiation to eradicate tumor cells. Concurrently, the carrier could release DOX in response to the tumor microenvironment, inhibiting DNA synthesis and sensitizing the tumor cells to radiation. This combined approach results in synchronous radionuclide therapy (RNT) and chemotherapy, maximizing therapeutic impact. In vitro and in vivo experiments demonstrated that the carrier exhibited favorable biocompatibility, stable radionuclide labeling, tumor-specific accumulation, and controlled release of DOX within the tumor microenvironment. Furthermore, MRI/SPECT dual-modal imaging enabled real-time tumor localization and monitoring of the carrier in vivo biodistribution. Experimental outcomes confirmed that this innovative carrier, combining RNT and chemotherapy, significantly inhibited tumor growth. This strategy offers a promising approach for precision radio-chemotherapy guided by dual-modal imaging, providing valuable insights for integrated targeted diagnosis and treatment of tumors.

Functional Materials Targeted Regulation of Gasdermins: From Fundamentals to Functionalities and Applications

Targeted regulation of pyroptosis to modulate the immune landscape has emerged as a novel design strategy for cancer immunotherapy and anti-inflammatory therapy. However, pyroptosis acts as a double-edged sword, making it important to optimize the design strategies of functional materials to appropriately activate pyroptosis for effective disease treatment. This paper summarizes and discusses the structure, pore formation, and molecular mechanisms of "executor" Gasdermins, as well as the events preceding and following these processes. Subsequently, the focus is on reviewing functional materials that directly regulate Gasdermin pore formation to target pyroptosis and those that indirectly regulate the events before and after Gasdermin pore formation to control pyroptosis activity. Finally, the advantages, disadvantages, and future prospects of designing such functional materials are provided, aiming to facilitate the precise design, pharmacological investigation, and clinical translation of pyroptosis-related functional materials.

A NIR-II emissive sonosensitized biotuner for pyroptosis-enhanced sonodynamic therapy of hypoxic tumors

Pyroptosis is considered as a new way to effectively boost the immune response of tumors and inhibit tumor growth. Effective strategies to induce pyroptosis mainly rely on chemotherapeutic drugs and phototherapy, but their potential biotoxicity and phototoxicity limit their application in biomedicine. Herein, we designed a NIR-II emitting pyroptosis biotuner, Rd-TTPA, which induced pyroptosis under ultrasound irradiation to achieve pyroptosis-enhanced sonodynamic therapy (SDT) and immunogenic cell death (ICD) for tumors. Benefiting from its A-π-D1-D2 structure enhanced donor-acceptor interaction, Rd-TTPA can induce cell pyroptosis under both normoxia (21 % O2) and hypoxia (2 % O2) conditions by rapidly generating superoxide radicals (O2-•) upon ultrasound irradiation. The sonodynamic biotuner of pyroptosis overcomes the longstanding weakness of chemical drug and photosensitizer-based pyroptosis, such as drug resistance and limited penetration depth. In-depth studies demonstrated that Rd-TTPA can selectively target tumor cell mitochondria and possess excellent in vivo NIR-II fluorescence imaging capabilities. Administrating a tumor-bearing mouse model with Rd-TPPA, satisfying antitumor efficacy via pyroptosis-augmented SDT was achieved upon the guidance of NIR-II fluorescence imaging.

NIR-II photo-accelerated polymer nanoparticles boost tumor immunotherapy via PD-L1 silencing and immunogenic cell death

Immune checkpoint blockade (ICB) therapy is a widely favored anti-tumor treatment, but it shows limited response to non-immunogenic "cold" tumors and suffers from drug resistance. Photodynamic therapy (PDT), as a powerful localized treatment approach, can convert a "cold tumor" into a "hot tumor" by inducing immunogenic cell death (ICD) in tumor cells, thereby enhancing tumor immunogenicity and promoting tumor immunotherapy. However, the effectiveness of PDT is largely hindered by the limited penetration depth into tumor tissues. To address these issues, we proposed an all-in-one drug system with NIR-II photo-accelerated PDT effects, efficient immune checkpoint gene silencing, and a facile manufacturing process. The so-called all-in-one drug system comprises a multi-modal designed polymer PPNP and siRNA. PPNP is an amphipathic polymer that includes the near infrared-II (NIR-II) photosensitizer Aza-boron-dipyrromethene (Aza-BODIPY), a glutathione (GSH)-cleavable linker, and a cationic monomer derived from cholesterol. PPNP can self-assemble and efficiently load siRNA. Under laser irradiation, PPNP triggers a potent ICD cascade, causing the on-demand release of siPD-L1, reshaping the tumor's immunosuppressive microenvironment, effectively inhibiting the growth of various tumors, and stimulating the immune memory. This study represents a generalized platform for PDT and gene silencing, designed to modulate immune-related signaling pathways for improved anticancer therapy.

The conflicting role highlights the complexity of GSDMs in cancer

Gasdermins (GSDMs) are an important family of proteins that have received extensive attention in tumor research in recent years. They directly induce tumor cell death by mediating pyroptosis and also regulate the recognition and clearance of tumor cells by the immune system by affecting the microenvironment. Therefore, it is of great significance to investigate the role of GSDMs in tumor development and tumor microenvironment. It can not only reveal new mechanisms of cancer development, but also provide theoretical basis for the development of novel anti-tumor therapeutic strategies. This literature review aims to systematically summarize the dual roles of GSDMs in tumor development and their interactions with the tumor microenvironment, and to focus on the importance of GSDM-mediated pyroptosis in anti-cancer therapy, with a view to providing guidance for future research directions.

The Novel Long-Acting Peptide S6-FA Attenuates Liver Fibrosis In Vitro and In Vivo

Liver fibrosis can progress to cirrhosis and hepatocellular carcinoma. Currently, there is no effective drug for liver fibrosis. The peptide 6 (T6) is an endogenous peptide derived from human intrauterine adhesion tissues and has antifibrotic potential. Here, to improve the long-term efficacy and activity of T6, we conducted the rational modified of T6 through studying structure-activity, and synthesized a series of analogues. Among them, S6 and S6-FA exhibited optimal antihepatic fibrosis activity, and S6-FA had a stronger long-acting effect than T6 and S6. The two analogues inhibited the expression of α-SMA and Collagen 1 in TGF-β-induced LX2 cells model and CCl4-induced mouse model of liver fibrosis. Besides, we discovered that S6 and S6-FA remarkably reduced the AST and ALT serum levels. Mechanistic studies have demonstrated that analogues inhibited liver fibrosis through inhibiting Erk, Smad and P65 pathways. This study provided that the novel peptide S6 and S6-FA is potential candidate compounds for treating liver fibrosis.

Photothermal therapy combined with a STING agonist induces pyroptosis, and gasdermin D could be a new biomarker for guiding the treatment of pancreatic cancer

PURPOSE

Although photothermal therapy (PTT) can induce antitumour immunity, the mechanisms underlying its effects in pancreatic cancer (PC) require further exploration. In this study, the mechanism of action of PTT and its connection to pyroptosis as well as the therapeutic potential of PTT alone and in combination with STING agonists, were investigated. In addition, a biomarker of PC was found to stratify patients who are suitable for PTT.

EXPERIMENTAL DESIGN

We explored whether PTT can induce pyroptosis in vitro and evaluated the therapeutic efficacy and antitumour immunity-inducing ability of PTT combined with STING agonist (c-di-GMP) as immune adjuvant in vivo in PC. We also evaluated gasdermin D (GSDMD) expression in tumour tissues and investigated drug sensitivity in patient-derived organoids (PDOs) with differential GSDMD expression.

RESULTS

Our study demonstrated that local PTT induces pyroptosis via the caspase-1/GSDMD pathway and elicits antitumour immunity. PTT combined with a STING agonist exhibits better therapeutic efficacy than PTT alone while limiting distant tumour metastasis, and enhances the immune response by promoting dendritic cell maturation, increasing the frequency of tumour infiltrating T cells, and converting macrophages from the M2 to the M1 phenotype. In addition, we found that GSDMD is highly expressed in tumour tissues and that overexpression of GSDMD in PC might suggest increased resistance to chemotherapy and the potential benefits of local therapy. We further confirmed that PDOs with higher GSDMD expression are less sensitive to a chemotherapeutic agent (5-Fluorouracil) than PDOs with lower GSDMD expression, making GSDMD a new biomarker for identifying patients who may benefit from PTT.

CONCLUSIONS

In this work, c-di-GMP was used as an immune adjuvant for PTT to treat PC for the first time, and the results provide clues for the development of novel combination immunotherapies that simultaneously suppress primary tumours and distant metastases. GSDMD has great potential as a new biomarker for the selection of individualized treatment modalities.

IKZF1 promotes pyroptosis and prevents M2 macrophage polarization by inhibiting JAK2/STAT5 pathway in colon cancer

Pyroptosis and macrophage pro-inflammatory activation play an important role in hepatocellular carcinoma (HCC) progression. However, the specific regulatory mechanisms remain unclear. We identified pyroptosis-related differentially expressed genes (DEGs) based on the GSE4183 and GSE44861 datasets as well as EVenn database. Expression levels of key genes were detected by qRT-PCR. IKZF1 was overexpressed in colon cancer cells and tumor-bearing mice, and its functions were assessed by various cell biology assays in vitro and in vivo. To investigate the interactions between IKZF1 and macrophages, a co-culture system was constructed. The activator RO8191 or inhibitor ruxolitinib of the JAK/STAT pathway was employed to confirm whether IKZF1 inhibited colon cancer development by regulating JAK2/STAT5 pathway. Pyroptosis-related hub genes RBBP7, HSP90AB1, and RBBP4 were highly expressed, while IKZF1, NLRP1, and PYCARD were lowly expressed. These hub genes had good performance in distinguishing colon cancer from controls. Furthermore, overexpression of IKZF1 inhibited tumor growth and promoted pyroptosis. Overexpression of IKZF1 suppressed cell proliferation, metastasis, and inactivated JAK2/STAT5 signaling pathway in colon cancer cells. Furthermore, upregulation of IKZF1 promoted M1 macrophage polarization while inhibiting M2 macrophage polarization in vivo and in vitro by inhibiting the JAK2/STAT5 signaling pathway. This study identifies IKZF1 as a potential biomarker inactivating JAK2/STAT5 pathway for colon cancer.

Nano-Based Strategies Aiming at Tumor Microenvironment for Improved Cancer Therapy

Malignant tumors pose a considerable threat to human life and health. Traditional treatments, such as radiotherapy and chemotherapy, often lack specificity, leading to collateral damage to normal tissues. Tumor microenvironment (TME) is characterized by hypoxia, acidity, redox imbalances, and elevated ATP levels factors that collectively promote tumor growth and metastasis. This review provides a comprehensive overview of the nanoparticles developed in recent years for TME-responsive strategies or TME-modulating methods for tumor therapy. The TME-responsive strategies focus on designing and synthesizing nanoparticles that can interact with the tumor microenvironment to achieve precisely controlled drug release. These nanoparticles activate drug release under specific conditions within the tumor environment, thereby enhancing the efficacy of the drugs while reducing toxicity to normal cells. Moreover, simply eliminating tumor cells does not fundamentally solve the problem. Only by comprehensively regulating the TME to make it unsuitable for tumor cell survival and proliferation can we achieve more thorough therapeutic effects and reduce the risk of tumor recurrence. TME regulation strategies aim to suppress the growth and metastasis of tumor cells by modulating various components within the TME. These strategies not only improve treatment outcomes but also have the potential to lay the foundation for future personalized cancer therapies.

Photon-Driven Dye Induction Pyroptosis: An Emerging Anti-Tumor Immunotherapy Paradigm

Photoimmunotherapy represents a novel and promising modality in anti-tumor immunotherapy, offering new hope in the realm of cancer treatment due to its distinctive mechanism and substantial therapeutic efficacy. This innovative approach synergistically integrates photon technology with immunological principles, utilizing photon energy to activate the body's immune response. Photon-driven pyroptosis, a pivotal element of photoimmunotherapy, has significantly revitalized the advancement of this discipline. To support this critical progress, this minireview offers an exhaustive examination of the organic dyes presently employed for photon-driven pyroptosis, alongside an analysis of the prevailing challenges and opportunities in dye molecule design. It is our aspiration that this minireview will contribute to the acceleration of developments in photon-driven pyroptosis dye and the broader field of photoimmunotherapy.

Analysis of nanomedicine applications for inflammatory bowel disease: structural and temporal dynamics, research hotspots, and emerging trends

Background

The application of nanomedicine in inflammatory bowel disease (IBD) has gained significant attention in the recent years. As the field rapidly evolves, analyzing research trends and identifying research hotpots are essential for guiding future advancements, and a comprehensive bibliometric can provide valuable insights.

Methods

The current research focused on publications from 2001 to 2024, and was sourced from the Web of Science Core Collection (WoSCC). CiteSpace and VOSviewer were employed to visualize authors, institutions, countries, co-cited references, and keywords, thereby mapping the intellectual structure and identifying emerging trends in the field.

Results

The analysis covered 1,518 literature across 447 journals, authored by 9,334 researchers from 5,459 institutions and 287 countries/regions. The global publication numbers exhibited an upward trend, particularly in the last decade, with China leading as the top publishing country and the Chinese Academy of Sciences emerging as the foremost institution. Dr. Xiao Bo is the prominent figure in advanced drug delivery systems. This interdisciplinary field, which spans materials science, pharmacy, and medicine, has seen influential publications mainly concentrated on targeted nanoparticles treatment for IBD. Keyword analysis revealed that current research hotspots include drug delivery, immune cell regulation, antioxidant damage, intestinal microbiota homeostasis, and nanovesicles.

Conclusion

This study offers a comprehensive overview of global research landscape, emphasizing the rapid growth and increasing complexity of this field. It identifies key research hotspots and trends, including efforts to enhance the precision, efficacy, and safety of nanomedicine applications. Emerging directions are highlighted as crucial for further progress in this evolving area.

Nanoengineering of Phosphate/Phosphonate Drugs via Competitive Replacement with Metal-Phenolic Networks to Overcome Breast Tumor with Lung and Bone Metastasis

Phosphate and phosphonate drugs are vital in building organisms, regulating physiological processes, and exhibiting diverse biological activities, including antiviral, antibacterial, antineoplastic, and enzyme-inhibitory effects. However, their therapeutic potential is limited by the lack of advanced nanoengineering technologies. Herein, a competitive coordination strategy for nanoengineering phosphate/phosphonate drugs is introduced. By leveraging the difference in coordination capabilities between polyphenols and phosphates/phosphonates with metal ions, various phosphate/phosphonate-based nanodrugs using metal-phenolic networks (MPNs) as templates and phosphate/phosphonate drugs as competitive agents are constructed. The dynamic nature of these coordination bonds imparts stimuli-responsiveness to the nanodrugs, allowing for targeted release and therapy. As a proof of concept, Fe3+ and galangin are used to form the MPN template, zoledronic acid and cGAMP as competitive agents, and DOX as the loaded drug to construct DOX@Fe-galangin@Fe-zoledronic acid-cGAMP nanodrugs. The results demonstrate that, by triggering pyroptosis and activating the cGAS-STING pathway, the nanodrugs exhibit potent cytotoxicity and accurate selectivity in eradicating orthotopic breast tumors, and activate an antitumor immune response against lung and bone metastases. Because the competitive coordination strategy is applicable to a variety of phosphate/phosphonate agents, it holds significant potential for enhancing the clinical efficacy of phosphate/phosphonate drugs and advancing nanodrug development for complex therapeutic applications.

Intrinsic PD-L1 Degradation Induced by a Novel Self-Assembling Hexapeptide for Enhanced Cancer Immunotherapy

Programmed death-ligand 1 (PD-L1) is a critical immune checkpoint protein that facilitates tumor immune evasion. While antibody-based PD-1/PD-L1 inhibitors have shown promise, their limitations necessitate the development of alternative therapeutic strategies. This work addresses these challenges by developing a hexapeptide, KFM (Lys-Phe-Met-Phe-Met-Lys), capable of both directly downregulating PD-L1 and self-assembling into a ROS-responsive supramolecular hydrogel. This dual functionality allows Gel KFM to function as a localized drug delivery system and a PD-L1 inhibitor. Loading the hydrogel with mitoxantrone (MTX) and metformin (MET) further enhances the therapeutic effect by combining chemotherapy with PD-L1 downregulation. In vitro and in vivo studies demonstrate significant tumor growth inhibition, increased CD8+ T cell infiltration, and reduced intratumoral PD-L1 expression following peritumoral administration. Mechanistically, KFM promotes PD-L1 degradation via a ubiquitin-dependent pathway. This "carrier-free" delivery system expands the role of supramolecular hydrogels beyond passive carriers to active immunotherapeutic agents, offering a promising new strategy for cancer therapy.

Injectable Autocatalytic Hydrogel Triggers Pyroptosis to Stimulate Anticancer Immune Response for Preventing Postoperative Tumor Recurrence

Modulating immunosuppression while eliminating residual microscopic tumors is critical for inhibiting the postoperative recurrence of triple-negative breast cancer (TNBC). Although immunotherapy has shown potential in achieving this goal, due to multiple immunosuppression and poor immunogenicity of apoptosis, a satisfactory anti-recurrence effect still faces the challenge. Herein, an injectable hydrogel-encapsulated autocatalytic copper peroxide (CP@Gel) therapeutic platform is designed and combine it with the clinical-grade DNA methyltransferase inhibitor decitabine (DAC) to effectively inhibit TNBC growth and postoperative recurrence via pyroptosis, killing residual cancer cells that bypass apoptosis resistance while also improving immunogenicity and modulating immunosuppression to achieve an intense anti-tumor immune response. Following injection of the CP@Gel, the sustained release of CP leads to the autocatalytic generation of reactive oxygen species, resulting in caspase-3 activation, and the pre-administered DAC inhibits the methylation of Gsdme to elevate the GSDME protein levels, leading to intense pyroptosis and anti-tumor immune responses. The in vivo results show a 67% elimination of local tumor recurrence via treatment with DAC+CP@Gel, suggesting the successful integration of sustained drug release with autocatalysis and epigenetic modification. The results thus suggest great potential for pyroptosis-based and injectable hydrogel-aided strategies for preventing the postoperative recurrence of TNBC.

Igniting tumour microenvironment in triple-negative breast cancer using a mannose/hyaluronic acid dual-coated Ganoderma polysaccharide-superparamagnetic iron oxide nanocomplex for combinational therapies

Eliciting tumour microenvironment (TME) activation in triple-negative breast cancer (TNBC) is crucial for effective anti-tumour therapies. The aim of this study is to employ pharmaceutical approaches to precisely deliver Ganoderma polysaccharide (GPS) to tumour sites, thereby enhancing TME activation. We first established a direct link between the accumulation of GPS within tumours and its efficacy in the TME activation. Building upon this insight, we then engineered a mannose/hyaluronic acid dual-coated GPS-loaded superparamagnetic iron oxide nanocomplex (Man/HA/GPS-SPIONs) with a particle size of 33.8 ± 1.6 nm and a zeta potential of -22.4 ± 3.5 mV, capable of precise tumour accumulation through magnet-assisted targeting and internalisation by tumour-associated macrophages (TAMs) and tumour cells, facilitated by dual ligand modification. In vitro, Man/HA/GPS-SPIONs effectively induced M1 polarisation of macrophages (CD86+ cells: 38.6 ± 2.8%), curbed 4T1 cell proliferation (viability: 47.3 ± 2.9%) and heightened Th1 cytokine release. Significantly, in vivo, Man/HA/GPS-SPIONs notably suppressed tumour growth (tumour index: 0.048 ± 0.005), fostered M1 polarisation of TAMs (CD45+F4/80+CD86+ cells: 26.1 ± 7.2%), consequently bolstering intratumoural T cytotoxic cells. This enhancement was intricately tied to the efficient co-delivery of GPS and iron ions to the tumours, made possible by the Man/HA/GPS-SPIONs delivery system. The synergistic effects with paclitaxel (PTX, inhibition rate: 61.2 ± 4.3%) and PD-1 inhibitors (inhibition rate: 69.8 ± 7.6%) underscored the translational potential of this approach. By harnessing a well-conceived iron-based drug delivery strategy, this study amplifies the tumour immune modulatory potential of natural polysaccharides, offering insightful guidance for interventions in the TME and synergistic therapies.

Intelligent Pyroptosis Inducer for Precise and Augmented Tumor Therapy Through Specific Activation Pyroptosis in Tumor

Pyroptosis inducer, a powerful anti-tumor agent that causes obvious programmed cell death and immune stimulation, has been challenged to trigger specific pyroptotic tumor cell death while keeping pyroptosis silence in normal cells. Here, an intelligent inducer is reported that acts as a reactive oxygen species (ROS) scavenger in normal cells to keep pyroptosis silence, while serving as ROS generator to induce obvious pyroptotic tumor cells death dependent on high hydrogen peroxide levels and near-infrared laser irradiation. This switchable activity ensures this inducer to precisely kill the tumor cells with augmented immunogenicity while causing minimal damage to normal cells. Moreover, the catalase-like activity endows this inducer to overcome limitation of tumor hypoxia on ROS generation and show significant pyroptosis activation, further initiating the immune response to inhibit the tumor metastases in vivo. This study provides valuable insights into design new pyroptosis inducer with controllable pyroptosis activity to specifically induce programmed tumor cell pyroptosis for precise and augmented tumor therapy with minimal side effects.

Pyroptosis-Inducing Biomaterials Pave the Way for Transformative Antitumor Immunotherapy

Pyroptosis can effectively overcome immunosuppression and reactivate antitumor immunity. However, pyroptosis initiation is challenging. First, the underlying biological mechanisms of pyroptosis are complex, and a variety of gasdermin family proteins can be targeted to induce pyroptosis. Second, other intracellular death pathways may also interfere with pyroptosis. The rationally designed gasdermin protein-targeting biomaterials are capable of inducing pyroptosis and have the capacity to stimulate antitumor immune function in a safe and effective manner. This review provides a comprehensive overview of the design, function, and antitumor efficacy of pyroptosis-inducing materials and the associated challenges, with a particular focus on the design options for pyroptosis-inducing biomaterials based on the activation of different gasdermin proteins. This review offers a valuable foundation for the further development of pyroptosis-inducing biomaterials for clinical applications.

Triggering immunogenic death of cancer cells by nanoparticles overcomes immunotherapy resistance

Immunotherapy resistance poses a significant challenge in oncology, necessitating novel strategies to enhance the therapeutic efficacy. Immunogenic cell death (ICD), including necroptosis, pyroptosis and ferroptosis, triggers the release of tumor-associated antigens and numerous bioactive molecules. This release can potentiate a host immune response, thereby overcoming resistance to immunotherapy. Nanoparticles (NPs) with their biocompatible and immunomodulatory properties, are emerging as promising vehicles for the delivery of ICD-inducing agents and immune-stimulatory adjuvants to enhance immune cells tumoral infiltration and augment immunotherapy efficacy. This review explores the mechanisms underlying immunotherapy resistance, and offers an in-depth examination of ICD, including its principles and diverse modalities of cell death that contribute to it. We also provide a thorough overview of how NPs are being utilized to trigger ICD and bolster antitumor immunity. Lastly, we highlight the potential of NPs in combination with immunotherapy to revolutionize cancer treatment.

Crosstalk of pyroptosis and cytokine in the tumor microenvironment: from mechanisms to clinical implication

In the realm of cancer research, the tumor microenvironment (TME) plays a crucial role in tumor initiation and progression, shaped by complex interactions between cancer cells and surrounding non-cancerous cells. Cytokines, as essential immunomodulatory agents, are secreted by various cellular constituents within the TME, including immune cells, cancer-associated fibroblasts, and cancer cells themselves. These cytokines facilitate intricate communication networks that significantly influence tumor initiation, progression, metastasis, and immune suppression. Pyroptosis contributes to TME remodeling by promoting the release of pro-inflammatory cytokines and sustaining chronic inflammation, impacting processes such as immune escape and angiogenesis. However, challenges remain due to the complex interplay among cytokines, pyroptosis, and the TME, along with the dual effects of pyroptosis on cancer progression and therapy-related complications like cytokine release syndrome. Unraveling these complexities could facilitate strategies that balance inflammatory responses while minimizing tissue damage during therapy. This review delves into the complex crosstalk between cytokines, pyroptosis, and the TME, elucidating their contribution to tumor progression and metastasis. By synthesizing emerging therapeutic targets and innovative technologies concerning TME, this review aims to provide novel insights that could enhance treatment outcomes for cancer patients.

Pyroptosis induced by natural products and their derivatives for cancer therapy

Natural products, which are compounds extracted and/or refined from plants and microbes in nature, have great potential for the discovery of therapeutic agents, especially for infectious diseases and cancer. In recent years, natural products have been reported to induce multiple cell death pathways to exhibit antitumor effects. Among them, pyroptosis is a unique programmed cell death (PCD) characterized by continuous cell membrane permeability and intracellular content leakage. According to the canonical and noncanonical pathways, the formation of gasdermin-N pores involves a variety of transcriptional targets and post-translational modifications. Thus, tailored control of PCD may facilitate dying cells with sufficient immunogenicity to activate the immune system to eliminate other tumor cells. Therefore, we summarized the currently reported natural products or their derivatives and their nano-drugs that induce pyroptosis-related signaling pathways. We reviewed six main categories of bioactive compounds extracted from natural products, including flavonoids, terpenoids, polyphenols, quinones, artemisinins, and alkaloids. Correspondingly, the underlying mechanisms of how these compounds and their derivatives engage in pyroptosis are also discussed. Moreover, the synergistic effect of natural bioactive compounds with other antitumor therapies is proposed as a novel therapeutic strategy for traditional chemotherapy, radiotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, hyperthermal therapy, and sonodynamic therapy. Consequently, we provide insights into natural products to develop a novel antitumor therapy or qualified adjuvant agents by inducing pyroptosis, which may eventually be applied clinically.

Development and Verification of Diagnosis Model for Papillary Thyroid Cancer Based on Pyroptosis-Related Genes: A Bioinformatic and in vitro Investigation

BACKGROUND

The incidence of papillary thyroid cancer (PTC) has been increasing annually; however, early diagnosis can improve patient outcomes. Pyroptosis is a programmed cell death modality that has received considerable attention recently. However, no studies have reported using pyroptosis-related genes in PTC diagnosis.

METHODS

Analyzed 33 pyroptosis-related genes in PTC transcriptome data from the Gene Expression Omnibus database. Subsequently, used the Least Absolute Shrinkage and Selection Operator (LASSO) model to construct a PTC molecular diagnostic model. Furthermore, confirmed differences in the expression of five genes between PTC and non-tumor tissues using immunohistochemistry. Collected 338 PTC and control samples to construct a five-gene PTC diagnostic model, which was then validated using a training set and underwent correlation analysis with immune cell infiltration. Additionally, validated the biological functions of the core gene NOD1 in vitro.

RESULTS

The five-gene PTC diagnostic model demonstrated good diagnostic value for PTC. Moreover, identified three reliable subtypes of pyroptosis and found that NOD1 is involved in tumor-suppressive microenvironment formation. Notably, patients with high NOD1 expression had lower Progression-Free Survival (PFS). Additionally, NOD1 expression was positively correlated with immune markers such as CD47, CD68, CD3, and CD8. Lastly, inhibiting NOD1 showed significant anti-PTC activity in vitro.

CONCLUSION

Our results suggest that pyroptosis-related genes can be used for PTC diagnosis, and NOD1 could be a promising therapeutic target.

A dual-pathway pyroptosis inducer based on Au-Cu2-xSe@ZIF-8 enhances tumor immunotherapy by disrupting the zinc ion homeostasis

The regulation of intracellular ionic homeostasis to trigger antigen-specific immune responses has attracted extensive interest in tumor therapy. In this study, we developed a dual-pathway nanoreactor, Au-Cu2-xSe@ZIF-8@P18 NPs (ACS-Z-P NPs), which targets danger-associated molecular patterns (DAMPs) and releases Zn2+ and reactive oxygen species (ROS) within the tumor microenvironment (TME). Zn2+ released from the metal-organic frameworks (MOFs) was deposited in the cytoplasm, leading to aberrant transcription levels of intracellular zinc-regulated proteins and DNA damage, thereby inducing pyroptosis and immunogenic cell death (ICD) dependent on caspase1/gasdermin D (GSDMD) pathway. Furthermore, upon laser irradiation, ACS-Z-P NPs could break through the limitations of inherent defects of immunosuppression in TME, enhance ROS generation through a Fenton-like reaction cascade, which subsequently triggered the activation of inflammatory vesicles and the release of damage-associated molecular patterns (DAMPs). This cascade effect led to the amplification of pyroptosis and immunogenic cell death (ICD), thereby remodeling the immunosuppressed TME. Consequently, this process improved dendritic cell (DC) antigen presentation and augmented anti-tumor T-cell responses, effectively initiating antigen-specific immune responses and further enhancing pyroptosis and ICD. This study explores the therapeutic properties of these mechanisms in detail. STATEMENT OF SIGNIFICANCE: The synthesized Au-Cu2-xSe@ZIF-8@P18 nanoparticles (ACS-Z-Ps) can effectively enhance the body's immune response by regulating zinc ion levels within cells. This regulation leads to abnormal levels of zinc-regulated protein transcription and DNA damage, which induces cellular pyroptosis. As a result, antigen presentation to dendritic cells (DCs) is improved, and anti-tumor T-cell responses are enhanced. The ACS-Z-P NPs overcome the limitations of ROS deficiency and immunosuppression in the tumor microenvironment by using H2O2 in the tumor microenvironment through a Fenton-like reaction. This leads to an increased production of ROS and O2, remodeling of the immunosuppressed tumor microenvironment, and enhanced induction of cell pyroptosis and immunogenic cell death. ACS-Z-P NPs targeted B16 cells using the photosensitizer P18 in combination with PDT treatment. This approach significantly inhibited the proliferation of B16 cells and effectively inhibited tumor growth.

Pyroptosis: Induction and inhibition strategies for immunotherapy of diseases

Cell death is a central process for organismal health. Pyroptosis, namely pyroptotic cell death, is recognized as a critical type that disrupts membrane and triggers pro-inflammatory cytokine secretion via gasdermins, providing a robust form of cytolysis. Meanwhile, along with the thorough research, a great deal of evidence has demonstrated the dual effects of pyroptosis in host defense and inflammatory diseases. More importantly, the recent identification of abundant gasdermin-like proteins in bacteria and fungi suggests an ancient origin of pyroptosis-based regulated cell death in the life evolution. In this review, we bring a general overview of pyroptosis pathways focusing on gasdermin structural biology, regulatory mechanisms, and recent progress in induction and inhibition strategies for disease treatment. We look forward to providing an insightful perspective for readers to comprehend the frame and challenges of the pyroptosis field, and to accelerating its clinical application.

Applications of pyroptosis activators in tumor immunotherapy

Contemporary progress in tumor immunotherapy has solidified its role as an effective approach in combating cancer. Nonetheless, the prevalent "immune cold" state within the tumor microenvironment poses a substantial barrier to its efficacy. Addressing this, pyroptosis-a gasdermin-mediated programmed cell death characterized by its inflammatory profile-emerges as a crucial mechanism. It catalyzes the release of vast quantities of pro-inflammatory cytokines and immunogens, potentially transforming immunosuppressive "cold" tumors into reactive "hot" ones. Herein, we will initially present an overview of pyroptosis as a distinct form of cell death, along with its molecular mechanisms. Subsequently, we will focus on introducing how pyroptosis activators are utilized in the field of tumor immunotherapy. Insights gained from applications of pyroptosis activators in tumor immunotherapy could lead to the development of safe and efficient pyroptosis activators, significantly enriching the arsenal for tumor immunotherapy.

Programmed Cascade Polydopamine Nanoclusters for Pyroptosis-Based Tumor Immunotherapy

Pyroptosis, an inflammatory cell death, plays a pivotal role in activating inflammatory response, reversing immunosuppression and enhancing anti-tumor immunity. However, challenges remain regarding how to induce pyroptosis efficiently and precisely in tumor cells to amplify anti-tumor immunotherapy. Herein, a pH-responsive polydopamine (PDA) nanocluster, perfluorocarbon (PFC)@octo-arginine (R8)-1-Hexadecylamine (He)-porphyrin (Por)@PDA-gambogic acid (GA)-cRGD (R-P@PDA-GC), is rationally design to augment phototherapy-induced pyroptosis and boost anti-tumor immunity through a two-input programmed cascade therapy. Briefly, oxygen doner PFC is encapsulated within R8 linked photosensitizer Por and He micelles as the core, followed by incorporation of GA and cRGD peptides modified PDA shell, yielding the ultimate R-P@PDA-GC nanoplatforms (NPs). The pH-responsive NPs effectively alleviate hypoxia by delivering oxygen via PFC and mitigate heat resistance in tumor cells through GA. Upon two-input programmed irradiation, R-P@PDA-GC NPs significantly enhance reactive oxygen species production within tumor cells, triggering pyroptosis via the Caspase-1/GSDMD pathway and releasing numerous inflammatory factors into the TME. This leads to the maturation of dendritic cells, robust infiltration of cytotoxic CD8+ T and NK cells, and diminution of immune suppressor Treg cells, thereby amplifying anti-tumor immunity.

pH-sensitive and redox-responsive poly(tetraethylene glycol) nanoparticle-based platform for cancer treatment

Effective drug delivery with precise tumour targeting is crucial for cancer treatment. To address the challenges posed by the specificity and complexity of the tumour microenvironment, we developed a poly(tetraethylene glycol)-based disulfide nanoparticle (NP) platform and explored its potential in cancer treatment, focusing on drug loading and controlled release performance. Poly(tetraethylene glycol) NPs were characterised using nuclear magnetic resonance spectroscopy, mass spectrometry, and ultraviolet-visible spectroscopy. Additionally, we evaluated physicochemical properties, including dynamic light scattering, zeta potential analysis, drug loading capacity (DLC), and drug loading efficiency (DLE). The impact of NPs on the mouse colorectal cancer cell line (CT26) and NIH3T3 cells was assessed using a cytotoxicity assay, live/dead staining assay, flow cytometry, and confocal fluorescence microscopy. The experimental results align with the expected chemical structure and physicochemical properties of poly(tetraethylene glycol) NPs. These NPs exhibit high DLE (78.7%) and DLC (12%), with minimal changes in particle size over time in different media.In vitroexperiments revealed that the NPs can induce significant cytotoxicity and apoptosis in CT26 cells. Cellular uptake notably increases with increasing concentration and exposure time. The confocal microscopic analysis confirmed the effective distribution and accumulation of NPs within cells. In conclusion, poly(tetraethylene glycol) NPs hold promise for improving drug-delivery efficiency, offering potential advancements in cancer treatment.

Dual-stimuli responsive theranostic agents based on small molecules

Stimuli-responsive theranostic agents represent a class of molecules that integrate therapeutic and diagnostic functions, offering the capability to respond to disease-associated biomarkers. Dual-stimuli responsive agents, particularly those based on small molecules, have shown considerable promise for precise imaging-guided therapeutic applications. In this Highlight, we summarize the progress of dual-stimuli responsive theranostic agents based on small molecules, for diagnostic and therapeutic studies in biological systems. The Highlight focuses on comparing different responsive groups and chemical structures of these dual-stimuli responsive theranostic agents towards different biomarkers. The potential future directions of the agents for further applications in biological systems are also discussed.

Stimuli-Responsive Nanomaterials for Tumor Immunotherapy

Cancer remains a significant challenge in extending human life expectancy in the 21st century, with staggering numbers projected by the International Agency for Research on Cancer for upcoming years. While conventional cancer therapies exist, their limitations, in terms of efficacy and side effects, demand the development of novel treatments that selectively target cancer cells. Tumor immunotherapy has emerged as a promising approach, but low response rates and immune-related side effects present significant clinical challenges. Researchers have begun combining immunotherapy with nanomaterials to optimize tumor-killing effects. Stimuli-responsive nanomaterials have become a focus of cancer immunotherapy research due to their unique properties. These nanomaterials target specific signals in the tumor microenvironment, such as pH or temperature changes, to precisely deliver therapeutic agents and minimize damage to healthy tissue. This article reviews the recent developments and clinical applications of endogenous and exogenous stimuli-responsive nanomaterials for tumor immunotherapy, analyzing the advantages and limitations of these materials and highlighting their potential for enhancing the immune response to cancer and improving patient outcomes.

Microenvironment-responsive nanosystems for ischemic stroke therapy

Ischemic stroke, a common neurological disorder caused by impaired blood supply to the brain, presents a therapeutic challenge. Conventional treatments like thrombolysis and neuroprotection drugs lack ideal drug delivery systems, limiting their effectiveness. Selectively delivering therapies to the ischemic cerebral tissue holds great potential for preventing and/or treating ischemia-related pathological symptoms. The unique pathological microenvironment of the brain after ischemic stroke, characterized by hypoxia, acidity, and inflammation, offers new possibilities for targeted drug delivery. Pathological microenvironment-responsive nanosystems, extensively investigated in tumors with hypoxia-responsive systems as an example, could also respond to the ischemic cerebral microenvironment and achieve brain-targeted drug delivery and release. These emerging nanosystems are gaining traction for ischemic stroke treatment. In this review, we expound on the cerebral pathological microenvironment and clinical treatment strategies of ischemic stroke, highlight various stimulus-responsive materials employed in constructing ischemic stroke microenvironment-responsive nano delivery systems, and discuss the application of these microenvironment-responsive nanosystems in microenvironment regulation for ischemic stroke treatment.

Targeting RAC1 reactivates pyroptosis to reverse paclitaxel resistance in ovarian cancer by suppressing P21-activated kinase 4

Pyroptosis may play an important role in the resistance of ovarian cancer (OC) to chemotherapy. However, the mechanism by which pyroptosis modulation can attenuate chemotherapy resistance has not been comprehensively studied in OC. Here, we demonstrated that RAS-associated C3 botulinum toxin substrate 1 (RAC1) is highly expressed in OC and is negatively correlated with patient outcomes. Through cell function tests and in vivo tumor formation tests, we found that RAC1 can promote tumor growth by mediating paclitaxel (PTX) resistance. RAC1 can mediate OC progression by inhibiting pyroptosis, as evidenced by high-throughput automated confocal imaging, the release of lactate dehydrogenase (LDH), the expression of the inflammatory cytokines IL-1β/IL-18 and the nucleotide oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome. Mechanically, RNA-seq, gene set enrichment analysis (GSEA), coimmunoprecipitation (Co-IP), mass spectrometry (MS), and ubiquitination tests further confirmed that RAC1 inhibits caspase-1/gasdermin D (GSDMD)-mediated canonical pyroptosis through the P21-activated kinase 4 (PAK4)/mitogen-activated protein kinase (MAPK) pathway, thereby promoting PTX resistance in OC cells. Finally, the whole molecular pathway was verified by the results of in vivo drug combination tests, clinical specimen detection and the prognosis. In summary, our results suggest that the combination of RAC1 inhibitors with PTX can reverse PTX resistance by inducing pyroptosis through the PAK4/MAPK pathway.

AI-powered omics-based drug pair discovery for pyroptosis therapy targeting triple-negative breast cancer

Due to low success rates and long cycles of traditional drug development, the clinical tendency is to apply omics techniques to reveal patient-level disease characteristics and individualized responses to treatment. However, the heterogeneous form of data and uneven distribution of targets make drug discovery and precision medicine a non-trivial task. This study takes pyroptosis therapy for triple-negative breast cancer (TNBC) as a paradigm and uses data mining of a large TNBC cohort and drug databases to establish a biofactor-regulated neural network for rapidly screening and optimizing compound pyroptosis drug pairs. Subsequently, biomimetic nanococrystals are prepared using the preferred combination of mitoxantrone and gambogic acid for rational drug delivery. The unique mechanism of obtained nanococrystals regulating pyroptosis genes through ribosomal stress and triggering pyroptosis cascade immune effects are revealed in TNBC models. In this work, a target omics-based intelligent compound drug discovery framework explores an innovative drug development paradigm, which repurposes existing drugs and enables precise treatment of refractory diseases.

Nanoparticle-mediated cell pyroptosis: a new therapeutic strategy for inflammatory diseases and cancer

Pyroptosis, a lytic form of cell death mediated by the gasdermin family, is characterized by cell swelling and membrane rupture. Inducing pyroptosis in cancer cells can enhance antitumor immune responses and is a promising strategy for cancer therapy. However, excessive pyroptosis may trigger the development of inflammatory diseases due to immoderate and continuous inflammatory reactions. Nanomaterials and nanobiotechnology, renowned for their unique advantages and diverse structures, have garnered increasing attention owing to their potential to induce pyroptosis in diseases such as cancer. A nano-delivery system for drug-induced pyroptosis in cancer cells can overcome the limitations of small molecules. Furthermore, nanomedicines can directly induce and manipulate pyroptosis. This review summarizes and discusses the latest advancements in nanoparticle-based treatments with pyroptosis among inflammatory diseases and cancer, focusing on their functions and mechanisms and providing valuable insights into selecting nanodrugs for pyroptosis. However, the clinical application of these strategies still faces challenges owing to a limited understanding of nanobiological interactions. Finally, future perspectives on the emerging field of pyroptotic nanomaterials are presented.

Nanohybrid-Based Redox Homeostasis Perturbators Escaped from Early Lysosomes toward Amplified Sensitization of Tumor Cells and Photothermally Maneuvered Pyroptosis Therapy

Reactive oxygen species (ROS) hold great potential in tumor pyroptosis therapy, yet they are still limited by short species lifespan and limited diffusion distance. Inducing cells into a metastable state and then applying external energy can effectively trigger pyroptosis, but systemic sensitization still faces challenges, such as limited ROS content, rapid decay, and short treatment windows. Herein, a nanohybrid-based redox homeostasis-perturbator system was designed that synergistically induce early lysosomal escape, autophagy inhibition, and redox perturbation functions to effectively sensitize cells to address these challenges. Specifically, weakly alkaline layered double hydroxide nanosheets (LDH NSs) with pH-responsive degradation properties enabled early lysosomal escape within 4 h, releasing poly(L-dopa) nanoparticles for inducing catechol-quinone redox cycling in the cytoplasm. The intracellular ROS levels were systematically rebounded by 3-4 times in tumor cells and lasted for over 4 h. Subsequently induced lysosomal stress and Ca2+ signaling activation resulted in severe mitochondrial dysfunction, as well as a perilous metastable state. Thereby, sequential near-infrared light was applied to trigger amplified stress through a local photothermal conversion. This led to sufficiently high levels of cleaved caspase-1 and GSDMD activation (2.5-2.8-fold increment) and subsequent pyroptosis response. In addition, OH- released by LDH elevated pH to alleviate the limitation of glutathione depletion by quinones at acidic pH and inhibit protective autophagy. Largely secreted inflammatory factors (2.5-5.6-fold increment), efficient maturation of dendritic cells, and further immune stimulation were boosted for tumor inhibition as a consequence. This study offers a new paradigm and insights into the synergy of internal systematic cellular sensitization and sequential external energy treatment to achieve tumor suppression through pyroptosis.

Research progress on the effect of pyroptosis on the occurrence, development, invasion and metastasis of colorectal cancer

Pyroptosis is a type of programmed cell death mediated by gasdermines (GSDMs). The N-terminal domain of GSDMs forms pores in the plasma membrane, causing cell membrane rupture and the release of cell contents, leading to an inflammatory response and mediating pyrodeath. Pyroptosis plays an important role in inflammatory diseases and malignant tumors. With the further study of pyroptosis, an increasing number of studies have shown that the pyroptosis pathway can regulate the tumor microenvironment and antitumor immunity of colorectal cancer and is closely related to the occurrence, development, treatment and prognosis of colorectal cancer. This review aimed to explore the molecular mechanism of pyroptosis and the role of pyroptosis in the occurrence, development, treatment and prognosis of colorectal cancer (CRC) and to provide ideas for the clinical diagnosis and treatment of CRC.

Nanomaterials: leading immunogenic cell death-based cancer therapies

The field of oncology has transformed in recent years, with treatments shifting from traditional surgical resection and radiation therapy to more diverse and customized approaches, one of which is immunotherapy. ICD (immunogenic cell death) belongs to a class of regulatory cell death modalities that reactivate the immune response by facilitating the interaction between apoptotic cells and immune cells and releasing specific signaling molecules, and DAMPs (damage-associated molecular patterns). The inducers of ICD can elevate the expression of specific proteins to optimize the TME (tumor microenvironment). The use of nanotechnology has shown its unique potential. Nanomaterials, due to their tunability, targeting, and biocompatibility, have become powerful tools for drug delivery, immunomodulators, etc., and have shown significant efficacy in clinical trials. In particular, these nanomaterials can effectively activate the ICD, trigger a potent anti-tumor immune response, and maintain long-term tumor suppression. Different types of nanomaterials, such as biological cell membrane-modified nanoparticles, self-assembled nanostructures, metallic nanoparticles, mesoporous materials, and hydrogels, play their respective roles in ICD induction due to their unique structures and mechanisms of action. Therefore, this review will explore the latest advances in the application of these common nanomaterials in tumor ICD induction and discuss how they can provide new strategies and tools for cancer therapy. By gaining a deeper understanding of the mechanism of action of these nanomaterials, researchers can develop more precise and effective therapeutic approaches to improve the prognosis and quality of life of cancer patients. Moreover, these strategies hold the promise to overcome resistance to conventional therapies, minimize side effects, and lead to more personalized treatment regimens, ultimately benefiting cancer treatment.

Hyaluronic acid-based multifunctional nanoplatform for glucose deprivation-enhanced chemodynamic/photothermal synergistic cancer therapy

We present a hyaluronic acid (HA)-based nanoplatform (CMGH) integrating starvation therapy (ST), chemodynamic therapy (CDT), and photothermal therapy (PTT) for targeted cancer treatment. CMGH fabrication involved the encapsulation of glucose oxidase (GOx) within a copper-based metal-organic framework (CM) followed by surface modification with HA. CMGH exerts its antitumor effects by catalyzing glucose depletion at tumor sites, leading to tumor cell starvation and the concomitant generation of glucuronic acid and H2O2. The decreased pH and elevated H2O2 promote the Fenton-like reaction of Cu ions, leading to hydroxyl radical production. HA modification enables targeted accumulation of CMGH at tumor sites via the CD44 receptor. Under near-infrared light irradiation, CM exhibits photothermal conversion capability, enhancing the antitumor effects of CMGH. In vitro and in vivo studies demonstrate the effective inhibition of tumor growth by CMGH. This study highlights the potential of CMGH as a targeted cancer therapeutic platform.

Molecular probes for monitoring pyroptosis: design, imaging and theranostic application

Pyroptosis is a recently discovered process of programmed cell death that is linked with tumor progression and potential treatment strategies. Unlike other forms of programmed cell death, such as apoptosis or necrosis, pyroptosis is associated with pore-forming proteins gasdermin D (GSDMD), which are cleaved by caspase enzymes to form oligomers. These oligomers are then inserted into the cell surface membrane, causing pores to consequently result in rapid cell death. Pyroptosis, in conjunction with immunotherapy, represents a promising avenue for prognostication and antitumor therapy, providing a more precise direction for disease treatment. To gain deeper insight into the mechanisms underlying pyroptosis in real-time, non-invasive and live cell imaging techniques are urgently needed. Non-invasive imaging techniques can enhance future diagnostic and therapeutic approaches for inflammatory diseases, including different types of tumors. This review article discusses various non-invasive molecular probes for detecting pyroptosis, including genetic reporters and nanomaterials. These strategies can enhance scientists' understanding of pyroptosis and help discover personalized and effective ways to treat inflammatory diseases, particularly tumors.

Oxygen-carrying semiconducting polymer nanoprodrugs induce sono-pyroptosis for deep-tissue tumor treatment

Sonodynamic therapy (SDT) has been explored for cancer therapy, especially for deep tumors due to its low tissue penetration restriction. The therapeutic efficacy of SDT is limited due to the complicated tumor microenvironment. This study reports the construction of oxygen-carrying semiconducting polymer nanoprodrugs (OSPNpro) for deep tumor treatment via combining amplified SDT with pyroptosis. An oxygen carrier perfluorohexane, sonodynamic semiconducting polymer as the sonosensitizer, and reactive oxygen species (ROS)-responsive prodrug are co-loaded into a nanoparticle system, leading to the formation of these polymer nanoprodrugs. Such OSPNpro show an effective accumulation in tumor tissues after systemic administration, in which they deliver oxygen to relieve tumor hypoxia microenvironment and thus mediate amplified SDT via producing ROS under ultrasound (US) irradiation, even when the tumors are covered with a 2-cm chicken breast tissue. In addition, the ROS-responsive prodrugs are activated by the generated ROS to trigger pyroptosis of tumor cells. Such a sono-pyroptosis induces a strong antitumor immunity with obviously higher level infiltrations of effector immune cells into tumors. Therefore, OSPNpro-based combinational therapy can greatly inhibit the growth of 2-cm chicken breast tissue-covered deep tumors and suppress tumor metastasis. This study offers a prodrug nanoplatform for treatment of deep tumor via sono-pyroptosis strategy.

Targeting ROS in cancer: rationale and strategies

Reactive oxygen species (ROS) in biological systems are transient but essential molecules that are generated and eliminated by a complex set of delicately balanced molecular machineries. Disruption of redox homeostasis has been associated with various human diseases, especially cancer, in which increased ROS levels are thought to have a major role in tumour development and progression. As such, modulation of cellular redox status by targeting ROS and their regulatory machineries is considered a promising therapeutic strategy for cancer treatment. Recently, there has been major progress in this field, including the discovery of novel redox signalling pathways that affect the metabolism of tumour cells as well as immune cells in the tumour microenvironment, and the intriguing ROS regulation of biomolecular phase separation. Progress has also been made in exploring redox regulation in cancer stem cells, the role of ROS in determining cell fate and new anticancer agents that target ROS. This Review discusses these research developments and their implications for cancer therapy and drug discovery, as well as emerging concepts, paradoxes and future perspectives.

Enhanced pyroptosis induction with pore-forming gene delivery for osteosarcoma microenvironment reshaping

Osteosarcoma is the most common malignant bone tumor without efficient management for improving 5-year event-free survival. Immunotherapy is also limited due to its highly immunosuppressive tumor microenvironment (TME). Pore-forming gasdermins (GSDMs)-mediated pyroptosis has gained increasing concern in reshaping TME, however, the expressions and relationships of GSDMs with osteosarcoma remain unclear. Herein, gasdermin E (GSDME) expression is found to be positively correlated with the prognosis and immune infiltration of osteosarcoma patients, and low GSDME expression was observed. A vector termed as LPAD contains abundant hydroxyl groups for hydrating layer formation was then prepared to deliver the GSDME gene to upregulate protein expression in osteosarcoma for efficient TME reshaping via enhanced pyroptosis induction. Atomistic molecular dynamics simulations analysis proved that the hydroxyl groups increased LPAD hydration abilities by enhancing coulombic interaction. The upregulated GSDME expression together with cleaved caspase-3 provided impressive pyroptosis induction. The pyroptosis further initiated proinflammatory cytokines release, increased immune cell infiltration, activated adaptive immune responses and create a favorable immunogenic hot TME. The study not only confirms the role of GSDME in the immune infiltration and prognosis of osteosarcoma, but also provides a promising strategy for the inhibition of osteosarcoma by pore-forming GSDME gene delivery induced enhanced pyroptosis to reshape the TME of osteosarcoma.

The Role and Therapeutic Potential of Pyroptosis in Colorectal Cancer: A Review

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. The unlimited proliferation of tumor cells is one of the key features resulting in the malignant development and progression of CRC. Consequently, understanding the potential proliferation and growth molecular mechanisms and developing effective therapeutic strategies have become key in CRC treatment. Pyroptosis is an emerging type of regulated cell death (RCD) that has a significant role in cells proliferation and growth. For the last few years, numerous studies have indicated a close correlation between pyroptosis and the occurrence, progression, and treatment of many malignancies, including CRC. The development of effective therapeutic strategies to inhibit tumor growth and proliferation has become a key area in CRC treatment. Thus, this review mainly summarized the different pyroptosis pathways and mechanisms, the anti-tumor (tumor suppressor) and protective roles of pyroptosis in CRC, and the clinical and prognostic value of pyroptosis in CRC, which may contribute to exploring new therapeutic strategies for CRC.

Photothermal Particle-Loaded Panax Notoginseng Polysaccharide Cryogels As Personalized Tumor Vaccines

Combination immunotherapy is being increasingly explored for cancer treatment, leading to various vector materials for the codelivery of immune agents and drugs. However, current tumor vaccines exhibit poor immunogenicity, severely compromising their therapeutic efficacy. Herein, an injectable hydrogel was developed based on dopamine (DA) and Panax notoginseng polysaccharide (PNPS) loaded with hair microparticles (HMPs) to enhance the immunogenicity of tumor vaccines. Photothermal effects of incorporated HMPs can trigger immunogenic cancer cell death and the release of abundant autologous tumor antigens, which are captured by catechol groups. Concomitant breakdown of PNPS recruits and activates dendritic cells (DCs). The macroporous structure of cryogels allows immune cell infiltration and interaction with antigens adsorbed on PNPS and DA cryogels (PD cryogels), thereby provoking potent cytotoxic T-cell responses. Hence, PD cryogels enabling cell infiltration and accelerated DC maturation may serve as a therapeutic vaccination platform against cancer.

Amino Acid Metabolism-Regulated Nanomedicine for Enhanced Tumor Immunotherapy through Synergistic Regulation of Immune Microenvironment

The reprogramming of tumor metabolism presents a substantial challenge for effective immunotherapy, playing a crucial role in developing an immunosuppressive microenvironment. In particular, the degradation of the amino acid L-tryptophan (Trp) to kynurenine (Kyn) by indoleamine-pyrrole 2,3-dioxygenase 1 (IDO1) is one of the most clinically validated pathways for immune suppression. Thus, regulating the Trp/Kyn metabolism by IDO1 inhibition represents a promising strategy for enhancing immunotherapy. Herein, metabolism-regulated nanoparticles are prepared through metal coordination-driven assembly of an IDO1 inhibitor (NLG919) and a stimulator of interferon genes (STING) agonist (MSA-2) for enhanced immunotherapy. After intravenous administration, the assembled nanoparticles could efficiently accumulate in tumors, enhancing the bioavailability of NLG919 and down-regulating the metabolism of Trp to Kyn to remodel the immunosuppressive tumor microenvironment. Meanwhile, the released MSA-2 evoked potent STING pathway activation in tumors, triggering an effective immune response. The antitumor immunity induced by nanoparticles significantly inhibited the development of primary and metastatic tumors, as well as B16 melanoma. Overall, this study provided a novel paradigm for enhancing tumor immunotherapy through synergistic amino acid metabolism and STING pathway activation.