Tetrahedral DNA Nanostructure with Interferon Stimulatory DNA Delivers Highly Potent Toxins and Activates the cGAS-STING Pathway for Robust Chemotherapy and Immunotherapy

Mitigating Doxorubicin-Induced Cardiotoxicity and Enhancing Anti-Tumor Efficacy with a Metformin-Integrated Self-Assembled Nanomedicine

Doxorubicin (Dox) is a potent chemotherapeutic agent commonly used in cancer treatment. However, cardiotoxicity severely limited its clinical application. To address this challenge, a novel self-assembled nanomedicine platform, PMDDH, is developed for the co-delivery of Dox and metformin, an antidiabetic drug with cardioprotective and anti-tumor properties. PMDDH integrates metformin into a polyethyleneimine-based bioactive excipient (PMet), with Dox intercalated into double-stranded DNA and a hyaluronic acid (HA) coating to enhance tumor targeting. The PMDDH significantly improves the pharmacokinetics and tumor-targeting capabilities of Dox, while metformin enhances the drug's anti-tumor activity by downregulating programmed cell death ligand 1 (PD-L1) and activating the AMP-activated protein kinase (AMPK) signaling pathway. Additionally, the DNA component stimulates the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which synergizes with Dox-induced immunogenic cell death (ICD) to promote a robust anti-tumor immune response. PMDDH markedly reduces Dox-induced cardiotoxicity by preserving mitochondrial function, reducing reactive oxygen species (ROS) production, and inducing protective autophagy in cardiomyocytes. These findings position PMDDH as a promising dual-function nanomedicine that enhances the anti-tumor efficacy of Dox while minimizing its systemic toxicity, offering a safer and more effective alternative for cancer therapy.

Smart Organic-Inorganic Copolymer Nanoparticles Distinguish Between Microglia and Cancer Cells for Synergistic Immunotherapy in Glioma

The stimulator of interferon genes (STING) pathway has emerged as a new immunotherapy strategy with potent local stimulation specificity, showing promising potential to counteract the immunosuppression in glioma. Herein, a tumor microenvironment (TME) responsive nanoagonists are developed based on an organic-inorganic copolymer composed of the polymer PC6AB coupled with manganous phosphate ionic oligomers (MnP). The degradation of nanoagonists into PC6AB and MnP in the acidic TME enables spatiotemporal control of their delivery to tumor cells and immune cells, respectively. PC6AB with membranolytic activity selectively interacts with tumor cell membranes to induce immunogenic cell death, while manganese metal can activate the STING pathway in immune cells and trigger downstream immunostimulatory signals. Nanoagonists can stimulate robust antitumor immunity after local injection into the brain extracellular space (ECS), showing significant therapeutic efficacy in mouse glioma. Nanoagonists can achieve spatiotemporal orchestration of STING activation in response to TME and enhance immune response against "cold" solid tumors, providing a promising approach for clinical immunotherapy.

Highly Emissive Platinum(II) Metallacage in the Near-Infrared Region for Synergistic Chemo-Photodynamic Therapy

Highly emissive metallacages that generate reactive oxygen species (ROS) are important to synergistic cancer therapy, but it is still challenging to balance the emission and phototheranostic properties. Herein, a metallacage of DTPABT-Mc is prepared. It is observed that emission in the near-infrared region from 600 to 1000 nm with a high photoluminescence quantum yield value of 7.92% in solids is recorded for DTPABT-Mc. In addition, the ability to produce both type I and type II ROS under light irradiation is also observed, leading to potential application in photodynamic therapy (PDT) and chemotherapy. After that, 4T1@DTPABT-Mc-NPs, covering DTPABT-Mc nanoparticles with 4T1 cell membranes, are prepared to enhance their tumor-targeting ability. This finally results in effective therapeutic performance in vivo, effectively inhibiting tumor growth. These results suggest that DTPABT-Mc-NPs exhibit excellent synergistic therapeutic effects by combining PDT and chemotherapy, providing new ideas to design agents for diagnosis and therapy in the future.

Unleashing the Potential of Metal Ions in cGAS-STING Activation: Advancing Nanomaterial-Based Tumor Immunotherapy

Immunotherapy is a critical modality in cancer treatment with diverse activation pathways. In recent years, the stimulator of interferon genes (STING) signaling pathway has exhibited significant potential in tumor immunotherapy. This pathway exerts notable antitumor effects by activating innate and adaptive immunity and regulating the tumor immune microenvironment. Various metal ions have been identified as effective activators of the STING pathway and, through the design and synthesis of nanodelivery platforms, have been applied in immunotherapy as well as in combination therapies, such as chemotherapy, chemodynamic therapy, photodynamic therapy, and cancer vaccines. Metal nanomaterials showcase unique advantages in immunotherapy; however, there are still aspects that require optimization. This review systematically examines existing metal-based nanomaterials, elaborates on the mechanisms by which different metal ions activate the STING pathway, and discusses their application models in tumor combination therapies. We also provide a comparative analysis of the advantages of metal nanomaterials over other treatment methods. Our exploration highlights the broad application prospects of metal nanomaterials in cancer treatment, offering new insights and directions for the advancement of tumor immunotherapy.

DNA Nanostructures-Based In Situ Cancer Vaccines: Mechanisms and Applications

Current tumor vaccines suffer from inadequate immune responsive due to the insufficient release of tumor antigens, low tumor infiltration, and immunosuppressive microenvironment. DNA nanostructures with their ability to precisely engineer, controlled release, biocompatibility, and the capability to augment the immunogenicity of tumor microenvironment, have gained significant attention for their potential to revolutionize vaccine designing. This review summarizes various applications of DNA nanostructures in the construction of in situ cancer vaccines, which can generate tumor-associated antigens directly from damaged tumors for cancer immune-stimulation. The mechanisms and components of cancer vaccines are listed, the specific strategies for constructing in situ vaccines using DNA nanostructures are explored and their underlying mechanisms of action are elucidated. The immunogenic cell death (ICD) induced by chemotherapeutic agents, photothermal therapy (PTT), photodynamic therapy (PDT), and radiation therapy (RT) and the related cancer vaccines building strategies are systematically summarized. The applications of different DNA nanostructures in various cancer immunotherapy are elaborated, which exerts precise, long-lasting, and robust immune responses. The current challenges and future prospectives are proposed. This review provides a holistic understanding of the evolving role of DNA nanostructures for in situ vaccine development.

Reactivating P53 to treat osteosarcoma: A tetrahedral framework nucleic acids-based approach

Osteosarcoma is a prevalent malignant tumor among adolescents, and the current five-year survival rate of osteosarcoma remains at 70 %, which has not improved in the last three decades. Therefore, there is an urgent need for drugs that can improve the prognosis of osteosarcoma patients. APR-246, also known as Eprenetapopt, is an activator of mutant P53. It has a good effect on promoting apoptosis of osteosarcoma cells, tetrahedral framework nucleic acids (tFNAs) are a small molecule drug delivery system with good biosafety, in order to improve the anti-osteosarcoma efficiency of APR-246, in the present study, a novel nanoparticle T-APR-246 was successfully synthesized using tFNAs to carry APR-246. In vivo and in vitro experiments showed that T-APR-246 more efficiently promoted osteosarcoma cell apoptosis and inhibited osteosarcoma cell proliferation and metastasis than APR-246. Our findings provide new research insights into the treatment of osteosarcoma.

Mitochondrion-Targeted Type I Photodynamic Therapy for Agonist Independent cGAS-STING Activation

CGAS-STING agonists generally lead to hyperimmunity and systemic toxicity, hindering their immunotherapeutic outcomes. Herein, a mitochondrion-targeted nanoagonist (termed HABH) containing boron dipyrromethene (BODIPY)-derived type I photosensitizer (BDP) and Au nanoparticle-engineered hollow mesoporous silica (HMSN/AuNPs) has been fabricated for light-controlled mitochondrial stress-inducing and agonist-independent cGAS-STING pathway activation. The HABH nanoagonist can actively target tumor tissues and release the mitochondrion-targeted BDP. Under light illumination, BDP achieves type I photodynamic therapy (PDT) in mitochondria, generating massive hydroxyl radicals (•OH) and inducing mitochondrial stress in an oxygen-independent manner, promoting the release of mitochondrial DNA (mtDNA). Simultaneously, the HMSN/AuNPs act as dual nanozymes to derive cascade reactions for •OH production, elevating the intracellular oxidative state, and together with the BDP-induced mitochondrial stress, finally evoking the cGAS-STING pathway and facilitating the release of type I interferon. In the orthotopic breast tumor models, the HABH nanoagonist achieved intratumoral and systemic immunoactivation for eradicating primary tumors and preventing metastasis tumors. Therefore, the constructed mitochondrion-targeted nanoagonist enabled light-controlled and agonist-independent cGAS-STING activation, providing a paradigm for photoimmunotherapy.

Manganese-Loaded pH-Responsive DNA Hydrogels Enable Tg-Guided Thyroid Tumor Targeted Magnetic Resonance Imaging

The diagnosis of metastatic and recurrent occult thyroid cancer presents a significant challenge. This study introduces a DNA-Mn hydrogel (M-TDH) that specifically targets thyroglobulin (Tg). This nanogel is loaded with paramagnetic Mn2+ for facilitating magnetic resonance (MR) imaging. As a cofactor of DNA polymerase, Mn2+ promotes the extension of long-strand DNA and forms Mn2PPi nuclei with PPi4- in the system. The synthesis of M-TDH is achieved through Mn2PPi nucleation and growth with long-strand DNA acting as the structural framework. The X-scaffold functions as a junction point, thereby enhancing structural stability. The Tg aptamer sequence is incorporated into M-TDH, ensuring specific targeting of thyroid cancer cells. Furthermore, M-TDH demonstrates an extended residence time at the thyroid tumor site, thus increasing the duration of enhanced MR imaging. Overall, this study introduces an aptamer-based, thyroid tumor-targeted DNA nanogel for MR imaging diagnostic applications, with the potential to advance a multifunctional magnetic nanosystem toward clinical application.

A Highly Tumor-Permeating DNA Nanoplatform for Efficient Remodeling of Immunosuppressive Tumor Microenvironments

The immunosuppressive tumor microenvironment and limited intratumoral permeation have largely constrained the outcome of tumor therapy. Herein, we report a tailored DNA structure-based nanoplatform with striking tumor-penetrating capability for targeted remodeling of the immunosuppressive tumor microenvironment in vivo. In our design, chemo-immunomodulator (gemcitabine) can be precisely grafted on DNA sequences through a reactive oxygen species (ROS)-sensitive linker. After self-assembly, the gemcitabine-grafted DNA structure can site-specifically organize legumain-activatable melittin pro-peptide (promelittin) on each vertex for intratumoral delivery and further function as the template to load photosensitizers (methylene blue) for ROS production. The tailored DNA nanoplatform can achieve targeted accumulation, highly improved intratumoral permeation, and efficient immunogenic cell death of tumor cells by laser irradiation. Finally, the immunosuppressive tumor microenvironment can be successfully remodeled by reducing multi-type immunosuppressive cells and enhancing the infiltration of cytotoxic lymphocytes in the tumor. This rationally developed multifunctional DNA nanoplatform provides a new avenue for the development of tumor therapy.

Nanomedicines harnessing cGAS-STING pathway: sparking immune revitalization to transform 'cold' tumors into 'hot' tumors

cGAS-STING pathway stands at the forefront of innate immunity and plays a critical role in regulating adaptive immune responses, making it as a key orchestrator of anti-tumor immunity. Despite the great potential, clinical outcomes with cGAS-STING activators have been disappointing due to their unfavorable in vivo fate, signaling an urgent need for innovative solutions to bridge the gap in clinical translation. Recent advancements in nanotechnology have propelled cGAS-STING-targeting nanomedicines to the cutting-edge of cancer therapy, leveraging precise drug delivery systems and multifunctional platforms to achieve remarkable region-specific biodistribution and potent therapeutic efficacy. In this review, we provide an in-depth exploration of the molecular mechanisms that govern cGAS-STING signaling and its potential to dynamically modulate the anti-tumor immune cycle. We subsequently introduced several investigational cGAS-STING-dependent anti-tumor agents and summarized their clinical trial progress. Additionally, we provided a comprehensive review of the unique advantages of cGAS-STING-targeted nanomedicines, highlighting the transformative potential of nanotechnology in this field. Furthermore, we comprehensively reviewed and comparatively analyzed the latest breakthroughs cGAS-STING-targeting nanomedicine, focusing on strategies that induce cytosolic DNA generation via exogenous DNA delivery, chemotherapy, radiotherapy, or dynamic therapies, as well as the nanodelivery of STING agonists. Lastly, we discuss the future prospects and challenges in cGAS-STING-targeting nanomedicine development, offering new insights to bridge the gap between mechanistic research and drug development, thereby opening new pathways in cancer treatment.

DNA Nanostructures: Advancing Cancer Immunotherapy

Cancer immunotherapy is a groundbreaking medical revolution and a paradigm shift from traditional cancer treatments, harnessing the power of the immune system to target and destroy cancer cells. In recent years, DNA nanostructures have emerged as prominent players in cancer immunotherapy, exhibiting immense potential due to their controllable structure, surface addressability, and biocompatibility. This review provides an overview of the various applications of DNA nanostructures, including scaffolded DNA, DNA hydrogels, tetrahedral DNA nanostructures, DNA origami, spherical nucleic acids, and other DNA-based nanostructures in cancer immunotherapy. These applications explore their roles in vaccine development, immune checkpoint blockade therapies, adoptive cellular therapies, and immune-combination therapies. Through rational design and optimization, DNA nanostructures significantly bolster the immunogenicity of the tumor microenvironment by facilitating antigen presentation, T-cell activation, tumor infiltration, and precise immune-mediated tumor killing. The integration of DNA nanostructures with cancer therapies ushers in a new era of cancer immunotherapy, offering renewed hope and strength in the battle against this formidable foe of human health.

DNA Tetrahedra as Functional Nanostructures: From Basic Principles to Applications

Self-assembled supramolecular DNA tetrahedra composed of programmed sequence-engineered complementary base-paired strands represent elusive nanostructures having key contributions to the development and diverse applications of DNA nanotechnology. By appropriate engineering of the strands, DNA tetrahedra of tuneable sizes and chemical functionalities were designed. Programmed functionalities for diverse applications were integrated into tetrahedra structures including sequence-specific recognition strands (aptamers), catalytic DNAzymes, nanoparticles, proteins, or fluorophore. The article presents a comprehensive review addressing methods to assemble and characterize the DNA tetrahedra nanostructures, and diverse applications of DNA tetrahedra framework are discussed. Topics being addressed include the application of structurally functionalized DNA tetrahedra nanostructure for the assembly of diverse optical or electrochemical sensing platforms and functionalized intracellular sensing and imaging modules. In addition, the triggered reconfiguration of DNA tetrahedra nanostructures and dynamic networks and circuits emulating biological transformations are introduced. Moreover, the functionalization of DNA tetrahedra frameworks with nanoparticles provides building units for the assembly of optical devices and for the programmed crystallization of nanoparticle superlattices. Finally, diverse applications of DNA tetrahedra in the field of nanomedicine are addressed. These include the DNA tetrahedra-assisted permeation of nanocarriers into cells for imaging, controlled drug release, active chemodynamic/photodynamic treatment of target tissues, and regenerative medicine.

Evaluation of Pharmacokinetics, Immunogenicity, and Immunotoxicity of DNA Tetrahedral and DNA Polymeric Nanostructures

Deoxyribonucleic acid (DNA) nanostructures have been extensively explored in biomedical applications and have emerged as a promising platform for drug delivery, bioanalysis, and therapeutics. Their in vivo behaviors have received much attention, a prerequisite for clinical applications. Herein, the pharmacokinetics, immunogenicity, and immunotoxicity of two representative DNA nanostructures: DNA tetrahedron (TDN) and DNA nanoparticle (DNP) are studied. The pharmacokinetics of DNA nanostructures are monitored in a mouse model via tracking of 32P radiolabeled, and the half-lives of TDN and DNP are 9.88 and 19.80 min, respectively. TDN and DNP preferentially accumulate in the liver and kidney in one half-life and are metabolized through liver, kidney, and excreta after 24 h. Meanwhile, TDN and DNP elicit a weak pro-inflammatory immune response with low immunogenicity and are non-immunotoxic, as shown by immunotoxicity evaluation, histopathology, and serum biochemical index analysis. This research shows that the DNA nanostructures of TDN and DNP are safe for biological systems, indicating that TDN and DNP can be developed as promising therapeutic platforms in biomedicine.

Investigation and Regulation of DNA Nanostructures on Activating cGAS-STING Signaling

DNA nanostructures have shown great potential in biomedical fields. However, the immune responses, especially the activation of the cGAS-STING signaling (A-cGSs), induced by DNA nanostructures, remain incompletely understood. Here, the ability of various DNA nanostructures from double-stranded DNA (dsDNA), single-stranded tiles (SSTs) to DNA origami is investigated on A-cGSs. Unlike natural dsDNA which triggers potent A-cGSs, the structural interconnectivity of various DNA configurations can substantially reduce the occurrence of A-cGSs, irrespective of their form, dimensions, and conformation. However, wireframe DNA nanostructures can activate the cGAS-STING signaling, suggesting that decreasing A-cGSs is dsDNA compactness-dependent. Based on this, a reconfigurable DNA Origami Domino Array (DODA) is used to systematically interrogate how dsDNA influences the A-cGSs and demonstrates that the length, number, and space of dsDNA array coordinately influence the activation level of cGAS-STING signaling, realizing a regulation of innate immune response. The above data and findings enhance the understanding of how DNA nanostructures affect cellular innate immune responses and new insights into the modulation of innate immune responses by DNA nanomedicine.

Near Infrared-Fluorescent Dinuclear Iridium(III) Nanoparticles for Immunogenic Sonodynamic Therapy

Dinuclear iridium(III) complexes activated by light-inducible spatiotemporal control are emerging as promising candidates for cancer therapy. However, broader applications of current light-activated dinuclear iridium(III) complexes are limited by the ineffective tissue penetration and undesirable feedback on guidance activation. Here, an ultrasound (US) triggered near infrared-fluorescent dinuclear iridium(III) nanoparticle, NanoIr, is first reported to precisely and spatiotemporally inhibit tumor growth. It is demonstrated that reactive oxygen species can be generated by NanoIr upon exposure to US irradiation (NanoIr + US), thereby inducing immunogenic cell death. When combined with cisplatin, NanoIr + US elicits synergistic effects in patient-derived tumor xenograft mice models of ovarian cancer. This work first provides a design of dinuclear iridium(III) nanoparticles for immunogenic sonodynamic therapy.

Hypoxia Reversion and STING Pathway Activation through Large Mesoporous Nanozyme for Near-Infrared-II Light Amplified Tumor Polymetallic-Immunotherapy

cGAS/STING pathway, which is highly related to tumor hypoxia, is considered as a potential target for remodeling the immunosuppressive microenvironment of solid tumors. Metal ions, such as Mn2+, activate the cGAS/STING pathway, but their efficacy in cancer therapy is limited by insufficient effect on immunogenic tumor cell death of a single ion. Here, we evaluate the association between tumor hypoxia and cGAS/STING inhibition and report a polymetallic-immunotherapy strategy based on large mesoporous trimetal-based nanozyme (AuPdRh) coordinated with Mn2+ (Mn2+@AuPdRh) to activate cGAS/STING signaling for robust adaptive antitumor immunity. Specifically, the inherent CAT-like activity of this polymetallic Mn2+@AuPdRh nanozyme decomposes the endogenous H2O2 into O2 to relieve tumor hypoxia induced suppression of cGAS/STING signaling. Moreover, the Mn2+@AuPdRh nanozyme displays a potent near-infrared-II photothermal effect and strong POD-mimic activity; and the generated hyperthermia and •OH radicals synergistically trigger immunogenic cell death in tumors, releasing abundant dsDNA, while the delivered Mn2+ augments the sensitivity of cGAS to dsDNA and activates the cGAS-STING pathway, thereby triggering downstream immunostimulatory signals to kill primary and distant metastatic tumors. Our study demonstrates the potential of metal-based nanozyme for STING-mediated tumor polymetallic-immunotherapy and may inspire the development of more effective strategies for cancer immunotherapy.

Adoption of a Tetrahedral DNA Nanostructure as a Multifunctional Biomaterial for Drug Delivery

DNA nanostructures have been widely researched in recent years as emerging biomedical materials for drug delivery, biosensing, and cancer therapy, in addition to their hereditary function. Multiple precisely designed single-strand DNAs can be fabricated into complex, three-dimensional DNA nanostructures through a simple self-assembly process. Among all of the synthetic DNA nanostructures, tetrahedral DNA nanostructures (TDNs) stand out as the most promising biomedical nanomaterial. TDNs possess the merits of structural stability, cell membrane permeability, and natural biocompatibility due to their compact structures and DNA origin. In addition to their inherent advantages, TDNs were shown to have great potential in delivering therapeutic agents through multiple functional modifications. As a multifunctional material, TDNs have enabled innovative pharmaceutical applications, including antimicrobial therapy, anticancer treatment, immune modulation, and cartilage regeneration. Given the rapid development of TDNs in the biomedical field, it is critical to understand how to successfully produce and fine-tune the properties of TDNs for specific therapeutic needs and clinical translation. This article provides insights into the synthesis and functionalization of TDNs and summarizes the approaches for TDN-based therapeutics delivery as well as their broad applications in the field of pharmaceutics and nanomedicine, challenges, and future directions.

Self-assembled methodologies for the construction of DNA nanostructures and biological applications

Over the past decades, deoxyribonucleic acid (DNA), as a versatile building block, has been widely employed to construct functionalized nanostructures. Among the diverse types of materials, DNA related nanostructures have gained growing attention due to their intrinsic programmability, favorable biocompatibility, and strong molecular recognition capability. The conventional construction strategy for building DNA structures is based on Watson-Crick base-pairing rules, which are mainly driven by the hydrogen bonding of bases. However, hydrogen bonding-based DNA nanostructures cannot meet the requirements of specific morphology and multifunctionality. Currently, various functional elements have been introduced to expand the synthetic methodologies for constructing the DNA hybrid nanostructures, including small molecules, peptide polymers, organic ligands and transition metal ions. Besides, the potential applications for these DNA hybrid nanostructures have also been explored. It has been demonstrated that DNA hybrid structures with various properties can be extensively applied in the fields of magnetic resonance, luminescence imaging, biomedical detection, and drug delivery systems. In this review, we highlight the pioneering contributions to the methodologies of DNA-based nanostructure assembly. Furthermore, the recent advances in drug delivery systems and biomedical diagnosis based on DNA hybrid nanostructures are briefly summarized.

Nucleic Acid Materials-Mediated Innate Immune Activation for Cancer Immunotherapy

Abnormally localized nucleic acids (NAs) are considered as pathogen associated molecular patterns (PAMPs) in innate immunity. They are recognized by NAs-specific pattern recognition receptors (PRRs), leading to the activation of associated signaling pathways and subsequent production of type I interferons (IFNs) and pro-inflammatory cytokines, which further trigger the adaptive immunity. Notably, NAs-mediated innate immune activation is highly dependent on the conformation changes, especially the aggregation of PRRs. Evidence indicates that the characteristics of NAs including their length, concentration and even spatial structure play essential roles in inducing the aggregation of PRRs. Therefore, nucleic acid materials (NAMs) with high valency of NAs and high-order structures hold great potential for activating innate and adaptive immunity, making them promising candidates for cancer immunotherapy. In recent years, a variety of NAMs have been developed and have demonstrated significant efficacy in achieving satisfactory anti-tumor immunity in multiple mouse models, exhibiting huge potential for clinical application in cancer treatment. This review aims to discuss the mechanisms of NAMs-mediated innate immune response, and summarize their applications in cancer immunotherapy.

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

Framework Nucleic Acids Combined with 3D Hybridization Chain Reaction Amplifiers for Monitoring Multiple Human Tear Cytokines

Existing tear sensors are difficult to perform multiplexed assays due to the minute amounts of biomolecules in tears and the tiny volume of tears. Herein, the authors leverage DNA tetrahedral frameworks (DTFs) modified on the wireless portable electrodes to effectively capture 3D hybridization chain reaction (HCR) amplifiers for automatic and sensitive monitoring of multiple cytokines in human tears. The developed sensors allow the sensitive determination of various dry eye syndrome (DES)-associated cytokines in human tears with the limit of detection down to 0.1 pg mL-1, consuming as little as 3 mL of tear fluid. Double-blind testing of clinical DES samples using the developed sensor and commercial ELISA shows no significant difference between them. Compared with single-biomarker diagnosis, the diagnostic accuracy of this sensor based on multiple biomarkers has improved by ≈16%. The developed system offers the potential for tear sensors to enable personalized and accurate diagnosis of various ocular diseases.

DNA Hydrogels with Programmable Condensation, Expansion, and Degradation for Molecular Carriers

Molecular carriers are necessary for the controlled release of drugs and genes to achieve the desired therapeutic outcomes. DNA hydrogels can be a promising candidate in this application with their distinctive sequence-dependent programmability, which allows precise encapsulation of specific cargo molecules and stimuli-responsive release of them at the target. However, DNA hydrogels are inherently susceptible to the degradation of nucleases, making them vulnerable in a physiological environment. To be an effective molecular carrier, DNA hydrogels should be able to protect encapsulated cargo molecules until they reach the target and release them once they are reached. Here, we develop a simple way of controlling the enzyme resistance of DNA hydrogels for cargo protection and release by using cation-mediated condensation and expansion. We found that DNA hydrogels condensed by spermine are highly resistant to enzymatic degradation. They become degradable again if expanded back to their original, uncondensed state by sodium ions interfering with the interaction between spermine and DNA. These controllable condensation, expansion, and degradation of DNA hydrogels pave the way for the development of DNA hydrogels as an effective molecular carrier.

Activating CD8+ T Cells by Pt(IV) Prodrug-Based Nanomedicine and aPD-L1 Antibody for Enhanced Cancer Immunotherapy

Recent years have witnessed substantial progress in cancer immunotherapy, specifically T cell-based therapies. However, the application of T cell therapies has been primarily limited to hematologic malignancies, with limited success in the treatment of solid tumors. The main challenge in treating solid tumor is immune escape, which is characterized by reduced antigenicity, diminished immunogenicity, and the development of suppressive tumor immune microenvironments. To address these obstacles and restore T cell-mediated anti-tumor responses, a novel nanoparticle formulation known as PRA@Oxa-c16 is developed. This innovative approach combines retinoic acid and Pt(IV) to specifically target and overcome immune escape. Notably, the therapeutic efficacy of PRA@Oxa-c16 primarily relies on its ability to induce anti-tumor T cell responses, in contrast to the cytotoxicity associated with conventional chemotherapeutic agents. When combined with an immune checkpoint blockade, anti-programmed death-ligand 1 antibody, PRA@Oxa-c16 effectively eliminates solid tumors and induces immune memory responses, which prevent tumor metastasis and recurrence. This promising approach holds great potential for enhancing the treatment of solid tumors with T cell-based immunotherapy.

Decomposable Nanoagonists Enable NIR-Elicited cGAS-STING Activation for Tandem-Amplified Photodynamic-Metalloimmunotherapy

Activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway has emerged as an efficient strategy to improve the therapeutic outcomes of immunotherapy. However, the "constantly active" mode of current STING agonist delivery strategies typically leads to off-target toxicity and hyperimmunity. To address this critical issue, herein a metal-organic frameworks-based nanoagonist (DZ@A7) featuring tumor-specific and near-infrared (NIR) light-enhanced decomposition is constructed for precisely localized STING activation and photodynamic-metalloimmunotherapy. The engineered nanoagonist enabled the generation of mitochondria-targeted reactive oxygen species under NIR irradiation to specifically release mitochondrial DNA (mtDNA) and inhibit the repair of nuclear DNA via hypoxia-responsive drugs. Oxidized tumor mtDNA serves as an endogenous danger-associated molecular pattern that activates the cGAS-STING pathway. Concurrently, NIR-accelerated zinc ions overloading in cancer cells further enhance the cGAS enzymatic activity through metalloimmune effects. By combining the synergistically enhanced activation of the cGAS-STING pathway triggered by NIR irradiation, the engineered nanoagonist facilitated the maturation of dendritic cells and infiltration of cytotoxic T lymphocytes for primary tumor eradication, which also established a long-term anti-tumor immunity to suppress tumor metastasis. Therefore, the developed nanoagonist enabled NIR-triggered, agonist-free, and tandem-amplified activation of the cGAS-STING pathway, thereby offering a distinct paradigm for photodynamic-metalloimmunotherapy.

Efficient one-pot assembly of higher-order DNA nanostructures by chemically conjugated branched DNA

Chemically conjugated branched DNA was successfully synthesized by a copper-free click reaction to construct sophisticated and higher-order polyhedral DNA nanostructures with pre-defined units in one pot, which can be used as an efficient nanoplatform to precisely organize multiple gold nanoparticles in predesigned patterns.

Platinum Prodrug Nanoparticles with COX-2 Inhibition Amplify Pyroptosis for Enhanced Chemotherapy and Immune Activation of Pancreatic Cancer

Pyroptosis, an emerging mechanism of programmed cell death, holds great potential to trigger a robust antitumor immune response. Platinum-based chemotherapeutic agents can induce pyroptosis via caspase-3 activation. However, these agents also enhance cyclooxygenase-2 (COX-2) expression in tumor tissues, leading to drug resistance and immune evasion in pancreatic cancer and significantly limiting the effectiveness of chemotherapy-induced pyroptosis. Here, an amphiphilic polymer (denoted as PHDT-Pt-In) containing both indomethacin (In, a COX-2 inhibitor) and platinum(IV) prodrug (Pt(IV)) is developed, which is responsive to glutathione (GSH). This polymer self-assemble into nanoparticles (denoted as Pt-In NP) that can disintegrate in cancer cells due to the GSH responsiveness, releasing In to inhibit the COX-2 expression, hence overcoming the chemoresistance and amplifying cisplatin-induced pyroptosis. In a pancreatic cancer mouse model, Pt-In NP significantly inhibit tumor growth and elicit both innate and adaptive immune responses. Moreover, when combined with anti-programmed death ligand (α-PD-L1) treatment, Pt-In NP demonstrate the ability to completely suppress metastatic tumors, transforming "cold tumors" into "hot tumors". Overall, the sustained release of Pt(IV) and In from Pt-In NP amplifies platinum-drug-induced pyroptosis to elicit long-term immune responses, hence presenting a generalizable strategy for pancreatic cancer.

Multipathway Regulation for Targeted Atherosclerosis Therapy Using Anti-miR-33-Loaded DNA Origami

Given the multifactorial pathogenesis of atherosclerosis (AS), a chronic inflammatory disease, combination therapy arises as a compelling approach to effectively address the complex interplay of pathogenic mechanisms for a more desired treatment outcome. Here, we present cRGD/ASOtDON, a nanoformulation based on a self-assembled DNA origami nanostructure for the targeted combination therapy of AS. cRGD/ASOtDON targets αvβ3 integrin receptors overexpressed on pro-inflammatory macrophages and activated endothelial cells in atherosclerotic lesions, alleviates the oxidative stress induced by extracellular and endogenous reactive oxygen species, facilitates the polarization of pro-inflammatory macrophages toward the anti-inflammatory M2 phenotype, and inhibits foam cell formation by promoting cholesterol efflux from macrophages by downregulating miR-33. The antiatherosclerotic efficacy and safety profile of cRGD/ASOtDON, as well as its mechanism of action, were validated in an AS mouse model. cRGD/ASOtDON treatment reversed AS progression and restored normal morphology and tissue homeostasis of the diseased artery. Compared to probucol, a clinical antiatherosclerotic drug with a similar mechanism of action, cRGD/ASOtDON enabled the desired therapeutic outcome at a notably lower dosage. This study demonstrates the benefits of targeted combination therapy in AS management and the potential of self-assembled DNA nanoformulations in addressing multifactorial inflammatory conditions.

DNA nanotechnology-based nucleic acid delivery systems for bioimaging and disease treatment

Nucleic acids, including DNA and RNA, have been considered as powerful and functional biomaterials owing to their programmable structure, good biocompatibility, and ease of synthesis. However, traditional nucleic acid-based probes have always suffered from inherent limitations, including restricted cell internalization efficiency and structural instability. In recent years, DNA nanotechnology has shown great promise for the applications of bioimaging and drug delivery. The attractive superiorities of DNA nanostructures, such as precise geometries, spatial addressability, and improved biostability, have enabled them to be a novel category of nucleic acid delivery systems for biomedical applications. In this review, we introduce the development of DNA nanotechnology, and highlight recent advances of DNA nanostructure-based delivery systems for cellular imaging and therapeutic applications. Finally, we propose the challenges as well as opportunities for the future development of DNA nanotechnology in biomedical research.

Functional Nucleic Acid-Based Immunomodulation for T Cell-Mediated Cancer Therapy

T cell-mediated immunity plays a pivotal role in cancer immunotherapy. The anticancer actions of T cells are coordinated by a sequence of biological processes, including the capture and presentation of antigens by antigen-presenting cells (APCs), the activation of T cells by APCs, and the subsequent killing of cancer cells by activated T cells. However, cancer cells have various means to evade immune responses. Meanwhile, these vulnerabilities provide potential targets for cancer treatments. Functional nucleic acids (FNAs) make up a class of synthetic nucleic acids with specific biological functions. With their diverse functionality, good biocompatibility, and high programmability, FNAs have attracted widespread interest in cancer immunotherapy. This Review focuses on recent research progress in employing FNAs as molecular tools for T cell-mediated cancer immunotherapy, including corresponding challenges and prospects.

Targeting DNA Damage and Repair Machinery via Delivering WEE1 Inhibitor and Platinum (IV) Prodrugs to Stimulate STING Pathway for Maximizing Chemo-Immunotherapy in Bladder Cancer

Both cisplatin-based chemotherapy and immune checkpoint blockers (ICBs)-based immunotherapy are the first-line treatments for patients with advanced bladder cancer. Cancer cells can develop resistance to cisplatin through extensive DNA repair, while a low response rate to ICBs is mostly due to the presence of an immunosuppressive microenvironment and low PD-L1 expression. Herein, a glutathione (GSH)-responsive nanoparticle (NP2) loaded with cisplatin prodrug (Pt (IV)) and WEE1 inhibitor (MK1775) is designed. NP2 can be triggered by GSH in cancer cells, and the released MK1775 can inhibit the activity of WEE1 protein, which ultimately increases DNA damage by cisplatin. Genome-wide RNA sequencing first reveals that NP2 can inhibit DNA repair machinery by interfering with the cell cycle and significantly activate the stimulator of interferon genes pathway. Tumor growth is significantly inhibited by NP2 in vivo. As innate and adaptive immune responses are stimulated, the immunosuppressive microenvironment is modified, and the "immune cold tumor" is transformed into an "immune hot tumor". In addition, NP2 can upregulate PD-L1 expression in tumor cells, thereby increasing the response rate of PD-L1 monoclonal antibody (αPD-L1) and eliciting long-term immune responses in both primary and metastatic tumors.

Metal-Organic Framework-Based Nano-Activators Facilitating Microwave Combined Therapy via a Divide-and-Conquer Tactic for Triple-Negative Breast Cancer

Aiming at the clinical problems of high recurrence and metastasis rate of triple-negative breast cancer, a divide-and-conquer tactic is developed. The designed nanoactivators enhance microwave thermo-dynamic-chemotherapy to efficiently kill primary tumors, simultaneously ameliorate the immunosuppressive microenvironment, activate the tumor infiltration of T lymphocytes, and enhance the accumulation and penetration of PD-1/PD-L1 immune agents, ultimately boosting the efficacy of immune checkpoint blocking therapy to achieve efficient inhibition of distal tumors and metastases. Metal-organic framework (MOF)-based MPPT nano-activator is synthesized by packaging chemotherapeutic drug Pyrotinib and immunosuppressant PD-1/PD-L1 inhibitor 2 into MnCa-MOF and then coupling target molecule triphenylphosphine, which significantly improved the accumulation and penetration of Pyrotinib and immunosuppressant in tumors. In addition to the combined treatment of microwave thermo-dynamic-chemotherapy under microwave irradiation, Mn2+ in the nano-activator comprehensively promotes the cGAS-STING pathway to activate innate immunity, microwave therapy, and hypoxia relief are combined to ameliorate the tumor immunosuppressive microenvironment. The released Pyrotinib down-regulates epidermal growth factor receptor and its downstream pathways PI3K/AKT/mTOR and MAPK/ERK signaling pathways to maximize the therapeutic effect of immune checkpoint blocking, which helps to enhance the antitumor efficacy and promote long-term memory immunity. This nano-activator offers a generally promising paradigm for existing clinical triple-negative breast cancer treatment through a divide-and-conquer strategy.

Synthesis and Characterisation of Platinum(II) Diaminocyclohexane Complexes with Pyridine Derivatives as Anticancer Agents

Cisplatin-type covalent chemotherapeutics are a cornerstone of modern medicinal oncology. However, these drugs remain encumbered with dose-limiting side effects and are susceptible to innate and acquired resistance. The bulk of platinum anticancer research has focused on Cisplatin and its derivatives. Here, we take inspiration from the design of platinum complexes and ligands used successfully with other metals to create six novel complexes. Herein, the synthesis, characterization, DNA binding affinities, and lipophilicity of a series of non-traditional organometallic Pt(II)-complexes are described. These complexes have a basic [Pt(PL)(AL)]Cl2 molecular formula which incorporates either 2-pyrrolidin-2-ylpyridine, 2-(1H-Imidazol-2-yl)pyridine, or 2-(2-pyridyl)benzimidazole as the PL; the AL is resolved diaminocyclohexane. Precursor [Pt(PL)(Cl)2] complexes were also characterized for comparison. While the cytotoxicity and DNA binding properties of the three precursors were unexceptional, the corresponding [Pt(PL)(AL)]2+ complexes were promising; they exhibited different DNA binding interactions compared with Cisplatin but with similar, if not slightly better, cytotoxicity results. Complexes with 2-pyrrolidin-2-ylpyridine or 2-(2-pyridyl)benzimidazole ligands had similar DNA binding properties to those with 2-(1H-Imidazol-2-yl)pyridine ligands but were not as cytotoxic to all cell lines. The variation in activity between cell lines was remarkable and resulted in significant selectivity indices in MCF10A and MCF-7 breast cancer cell lines, compared with previously described similar Pt(II) complexes such as 56MESS.

Bioactivable STING Nanoagonists to Synergize NIR-II Mild Photothermal Therapy Primed Robust and Long-Term Anticancer Immunity

Pharmacological activation of the stimulator of interferon genes (STING) pathway has become a promising strategy for cancer immunotherapy. However, the insufficient tumorous accumulation, rapid clearance, and short duration of drug efficacy in the tumor microenvironment of small structural STING agonists greatly compromise the therapeutic efficacy. Herein, a tumorous extracellular matrix (ECM) is presented anchoring STING agonist-based photoimmunothernostic nanomedicine (SAPTN) that can be activated by mild-temperature photothermal therapy (mild PTT) induced neutrophilic inflammation. The SAPTN owns second window near-infrared (NIR-II) photonics properties fitting for NIR-II fluorescence and photoacoustic imaging-guided cancer therapy. The aggregates SAPTN targeting to the ECM provide slow and continuous release of potent STING agonists diABZIs. The mild PTT and long-lasting STING agonists released in the ECM synergistically prime systematic, robust, and long-term anticancer immunity. In a tumor model, this approach leads to complete tumor eradication in about 100% of mice with orthotopic breast tumors, and the mice regained tumor-free survival of at least 2 months. In addition, the immune-mediated abscopal effect shows inhibition of the distant solid tumor growth by intratumoral administration of SAPTN with laser irradiation. Overall, this approach represents a generalized photoactivable nanomedicine to prime anticancer immunity for improved cancer theranostics.

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

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

Multicolor-Encoded DNA Framework Enables Specific and Amplified In Situ Detection of the Mitochondrial Apoptotic Signaling Pathway

Monitoring the molecular activation networks of cellular processes through fluorescence imaging to accurately elucidate the signaling pathways of mitochondrial apoptosis and the regulation of upstream and downstream molecules remains a current major challenge. In this work, a multicolor-encoded tetrahedral DNA framework (meTDF) carrying two pairs of catalytic hairpins is synthesized to monitor the intracellular upstream manganese superoxide dismutase (MnSOD) mRNA and the downstream cytochrome c (Cyt c) molecules for specific and sensitive detection of the mitochondrial apoptotic signaling pathway. These two types of molecules can trigger catalytic hairpin assembly (CHA) reactions with accelerated reaction kinetics for the hairpin pairs confined on meTDF to show highly amplified fluorescence for sensitive and simultaneous detection of MnSOD mRNA and Cyt c with detection limits of 3.7 pM and 0.23 nM in vitro, respectively. Moreover, the high stability and biocompatibility of the designed meTDF can facilitate efficient delivery of the probes into cells to monitor intracellular MnSOD mRNA and Cyt c for specific detection of the mitochondrial apoptosis pathway regulated by different drugs. With the successful demonstration of their robust capability, the meTDF nanoprobes can thus open new opportunities for detecting cell apoptotic mechanisms for studying the corresponding apoptotic signaling pathways and for screening potential therapeutic drugs.

Cuproptosis Induced by ROS Responsive Nanoparticles with Elesclomol and Copper Combined with αPD-L1 for Enhanced Cancer Immunotherapy

Cuproptosis is a new cell death that depends on copper (Cu) ionophores to transport Cu into cancer cells, which induces cell death. However, existing Cu ionophores are small molecules with a short blood half-life making it hard to transport enough Cu into cancer cells. Herein, a reactive oxygen species (ROS)-sensitive polymer (PHPM) is designed, which is used to co-encapsulate elesclomol (ES) and Cu to form nanoparticles (NP@ESCu). After entering cancer cells, ES and Cu, triggered by excessive intracellular ROS, are readily released. ES and Cu work in a concerted way to not only kill cancer cells by cuproptosis, but also induce immune responses. In vitro, the ability of NP@ESCu to efficiently transport Cu and induce cuproptosis is investigated. In addition, the change in the transcriptomes of cancer cells treated with NP@ESCu is explored by RNA-Seq. In vivo, NP@ESCu is found to induce cuproptosis in the mice model with subcutaneous bladder cancer, reprograming the tumor microenvironment. Additionally, NP@ESCu is further combined with anti-programmed cell death protein ligand-1 antibody (αPD-L1). This study provides the first report of combining nanomedicine that can induce cuproptosis with αPD-L1 for enhanced cancer therapy, thereby providing a novel strategy for future cancer therapy.

Acid-Ionizable Iron Nanoadjuvant Augments STING Activation for Personalized Vaccination Immunotherapy of Cancer

The critical challenge for cancer vaccine-induced T-cell immunity is the sustained activation of antigen cross-presentation in antigen-presenting cells (APCs) with innate immune stimulation. In this study, it is first discovered that the clinically used magnetic contrast agents, iron oxide nanoparticles (IONPs), markedly augment the type-I interferon (IFN-I) production profile of the stimulator of interferon genes (STING) agonist MSA-2 and achieve a 16-fold dosage-sparing effect in the human STING haplotype. Acid-ionizable copolymers are coassembled with IONPs and MSA-2 into iron nanoadjuvants to concentrate STING activation in the draining lymph nodes. The top candidate iron nanoadjuvant (PEIM) efficiently delivers the model antigen ovalbumin (OVA) to CD169+ APCs and facilitates antigen cross-presentation to elicit a 55-fold greater frequency of antigen-specific CD8⁺ cytotoxic T-lymphocyte response than soluble antigen. PEIM@OVA nanovaccine immunization induces potent and durable antitumor immunity to prevent tumor lung metastasis and eliminate established tumors. Moreover, PEIM nanoadjuvant is applicable to deliver autologous tumor antigen and synergizes with immune checkpoint blockade therapy for prevention of postoperative tumor recurrence and distant metastasis in B16-OVA melanoma and MC38 colorectal tumor models. The acid-ionizable iron nanoadjuvant offers a generalizable and readily translatable strategy to augment STING cascade activation and antigen cross-presentation for personalized cancer vaccination immunotherapy.