Gas therapy potentiates aggregation-induced emission luminogen-based photoimmunotherapy of poorly immunogenic tumors through cGAS-STING pathway activation

Manganese-coordinated nanoparticles loaded with CHK1 inhibitor dually activate cGAS-STING pathway and enhance efficacy of immune checkpoint therapy

Notable advancements have been made in utilizing immune checkpoint blockade (ICB) for the treatment of various cancers. However, the overall response rates and therapeutic effectiveness remain unsatisfactory. One cause is the inadequate immune environment characterized by poor T cell infiltration in tumors. To address these limitations, enhancing immune infiltration is crucial for optimizing the therapeutic efficacy of ICB. Activating the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is essential for initiating immune response and has become a potential target for developing combination therapies with ICB. In this study, we designed and fabricated manganese-containing nanoparticles loaded with the CHK1 inhibitor PF477736, which were subsequently encapsulated with macrophage membrane (PF/MMSN@MPM). This innovative design achieved excellent tumor targeting and demonstrated potent antitumor effects. The combination therapy dually amplified the cGAS-STING pathway, causing a cascade of enhanced therapeutic effects against tumors. Furthermore, single-cell mass cytometry (CyTOF) analysis revealed that PF/MMSN@MPM enhanced the activation and infiltration of immune cells. Moreover, the combination of PF/MMSN@MPM with anti-PD-1 (αPD-1) exhibited a stronger therapeutic effect compared to αPD-1 alone. PF/MMSN@MPM precisely and synergistically activated the cGAS-STING pathway, significantly improving therapeutic efficacy of ICB, and offering promising potential for tumor therapy.

A self-accelerating 'copper bomb' strategy activated innate and adaptive immune response against triple-negative breast cancer

Triple-negative breast cancer (TNBC) presents therapeutic challenges due to its aggressive, drug-resistance, and low immunological reactivity. Cuproptosis, an emerging therapeutic modality, is a promising strategic intervention for treating TNBC. Nonetheless, the effectiveness of cuproptosis is compromised by tumor adaptations, including the Warburg effect, increased intracellular glutathione (GSH), and copper efflux, thus breaking the barrier of cuproptosis is the basis for developing cuproptosis-based clinical therapies. Herein, a self-accelerating strategy utilizing a pH-responsive copper framework encapsulating glucose oxidase (GOx), modified with polyethylene glycol (PEG) and tumor-penetrating peptide (tLyp1) has been developed. Upon reaching the acidic tumor microenvironment, the released GOx increases intracellular acidity and hydrogen peroxide (H2O2). The elevated intracellular GSH and H2O2 serve as "fuel" to amplify the copper-based catalytic within tumor cells. Concurrently, the reduction of copper efflux proteins (ATP7B) and the depletion of GSH lead to copper overload in tumor cells, leading to cuproptosis via copper overload, mitochondrial disruption, and Fe-S protein instability. This constellation of interrelated events constitutes a potent "Copper Bomb," which concurrently triggers the immune system and effectively kills the tumor. It robustly engages innate and adaptive immunity via the release of mitochondrial DNA, facilitating the cGAS-STING pathway and precipitating immunogenic cell death. This process reverses the immunosuppressive tumor microenvironment, eliminates tumor cells, and suppresses metastasis, thus offering a novel therapeutic modality for the comprehensive treatment of triple-negative breast cancer (TNBC).

Copper-based hollow mesoporous nanogenerator with reactive oxygen species and reactive nitrogen species storm generation for self-augmented immunogenic cell death-mediated triple-negative breast cancer immunotherapy

Although nanotheranostics have great potential in tumor immunotherapy, their effectiveness is often hindered by low immunogenic cell death (ICD) and inactivated immune responses in the tumor immunosuppressive microenvironment (TIME). Such vulnerability may lead to metastasis or recurrence, especially in triple-negative breast cancer (TNBC). Addressing this challenge, the study presents a multimodal immunotherapeutic approach using a self-enhanced ICD copper (Cu)-based hollow nanogenerator. This nanogenerator is activated by a near-infrared (NIR) laser to produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) storms. Specifically, the nitric oxide (NO) donor l-Arginine (l-Arg) is loaded into hollow mesoporous Cu sulfide nanoparticles (HCuSNPs) with inherent NIR absorption and coated with tumor-targeting peptides (RGD), forming l-Arg@HCuSNPs-PEG-RGD (AHPR). In vitro and in vivo experiments demonstrate that AHPR can induce tumor thermal ablation, cuproptosis, and the generation of peroxynitrite anions (ONOO-) under NIR laser irradiation, resulting in multiple antitumor effects. Additionally, the nanogenerator enhances ICD through mechanisms such as mild-photothermal therapy (mPTT), cuproptosis, and ONOO- production, promoting immune cell infiltration and activation, and converting 'cold' tumors into 'hot' ones. By combining AHPR with the immune checkpoint inhibitor anti-programmed cell death protein ligand-1 antibody (αPD-L1), the study significantly improves the immunotherapy response rate in TNBC, offering a promising strategy to enhance TNBC immunotherapy efficacy.

An efficient nanoreactor reverses the tumor immunosuppressive microenvironment through synergetic dual-route reactions

Tumors being immunologically cold is the main reason for the unsatisfactory clinical performance of cancer immunotherapy. An efficient nanoreactor was developed to reverse the tumor immunosuppressive microenvironment. This nanoreactor can effectively convert intracellular glucose and GSH into ROS and H2S in tumors for enhanced chemodynamic therapy and complete energy metabolism block through synergistic dual-route reactions, consequently leading to efficient immunogenic cell death and eliciting a robust immune response.

A nanoparticle platform for the co-delivery of multiple antigen epitope peptides and STING agonist to lymph nodes for cancer immunotherapy

Nanoparticles loaded with cancer epitope peptides have shown great potential for cancer immunotherapy. However, preparing small-sized nanoparticles with a narrow size distribution for the co-delivery of multiple antigen peptides has been a challenge. The lack of scalable and reproducible nanoparticle preparation methods has also hindered the widespread application of nanoparticles in cancer immunotherapy. In this study, we developed lymph node-targeted nanoparticles for the co-delivery of a group of sixteen pancreatic cancer antigen peptides and a STING agonist as an adjuvant using the flash nanocomplexation (FNC) method. The nanoparticles generated by FNC had a smaller particle size and a narrower size distribution compared to the nanoparticles prepared by bulk mixing. The FNC-generated nanoparticles enhanced human monocyte activation, demonstrated lymph node-targeting effect, and activated dendritic cells in vivo, all without any observable toxicity. Additionally, in vivo studies demonstrated the strong anti-tumor efficacy of these nanoparticles in an orthotopic pancreatic cancer mouse model. This nanoparticle platform enables the effective co-delivery of multiple antigen epitope peptides and an adjuvant to the lymph nodes. Furthermore, the scalability and reproducibility of the FNC method could facilitate the rapid clinical translation of this nanoparticle platform.

One-for-All Photoactivatable Manganese-Based Carbon Monoxide-Releasing Molecules (CORMs) for Synergistic Therapy of Mycobacterial Infection

Tuberculosis presents a severe threat to human health. It is of crucial importance to develop novel and effective treatments to combat mycobacterial infections, especially those caused by drug-resistant bacteria. In this study, a tricarbonyl manganese(I) complex (Mn-PTP) was synthesized for the purpose of conducting synergistic therapy against mycobacterial infection. When subjected to white light irradiation, Mn-PTP generated multiple reactive species, including type I/II combined reactive oxygen species (ROS), carbon monoxide (CO), the toxic ligand PTP, and manganese oxides (MnOX) with catalase-like ability. The antibacterial experiment demonstrated that irradiated Mn-PTP exhibited specific antibacterial effects on Mycobacterium smegmatis (M. smegmatis). It was found to cause damage to the bacterial membrane and effectively eradicate biofilms. Moreover, the in vivo experiment revealed that the photoactive Mn-PTP could promote the healing process of M. smegmatis-infected skin wounds. This study pioneers innovative frameworks for developing one-for-all small-molecule pharmaceuticals capable of enabling synergistic therapeutic strategies against mycobacterial infections.

Embracing cancer immunotherapy with manganese particles

A substance integral to the sustenance and functionality of virtually all forms of life is manganese (Mn), classified as an essential trace metal. Its significance lies in its pivotal role in facilitating metabolic processes crucial for survival. Additionally, Mn exerts influence over various biological functions including bone formation and maintenance, as well as regulation within systems governing immunity, nervous signaling, and digestion. Manganese nanoparticles (Mn-NP) stand out as a beacon of promise within the realm of immunotherapy, their focus honed on intricate mechanisms such as triggering immune pathways, igniting inflammasomes, inducing immunogenic cell death (ICD), and sculpting the nuances of the tumor microenvironment. These minuscule marvels have dazzled researchers with their potential in reshaping the landscape of cancer immunotherapy - serving as potent vaccine enhancers, efficient drug couriers, and formidable allies when paired with immune checkpoint inhibitors (ICIs) or cutting-edge photodynamic/photothermal therapies. Herein, we aim to provide a comprehensive review of recent advances in the application of Mn and Mn-NP in the immunotherapy of cancer. We hope that this review will display an insightful view of Mn-NPs and provide guidance for design and application of them in immune-based cancer therapies.

Manganese-Based Nanotherapeutics for Targeted Treatment of Breast Cancer

Breast cancer (BC) is one of the most common cancers among women and is associated with high mortality. Traditional modalities, including surgery, radiotherapy, and chemotherapy, have achieved certain advancements but continue to combat challenges including harm to healthy tissues, resistance to treatment, and adverse drug reactions. The rapid advancements in nanotechnology recently facilitated the exploration of innovative strategies for breast cancer therapy. Manganese-based nanotherapeutics have attracted great attention because of their unique characteristics such as tunable structures/morphologies, versatility, magnetic/optical properties, strong catalytic activities, excellent biodegradability, and biocompatibility. In this review, we highlighted different types of Mn-based nanotherapeutics to modulate TME, including metal-immunotherapy, alleviating tumor hypoxia, and increasing reactive oxygen species production, and we emphasized its role in magnetic resonance imaging (MRI)-guided therapy, photoacoustic imaging, and theranostic-based therapy along with a therapeutic carrier, all of which were discussed in the context of breast cancer. Hopefully, the present review will provide insights into the current landscape and future directions of multifunctional applications of Mn-based nanotherapeutics in the field of breast cancer treatment.

Manganese-Doped Nanoparticles with Hypoxia-Inducible Factor 2α Inhibitor That Elicit Innate Immune Responses against von Hippel-Lindau Protein-Deficient Tumors

The von Hippel-Lindau (VHL) tumor suppressor gene product, pVHL, is frequently deficient in a variety of human cancers. In addressing the treatment of pVHL-deficient tumors, hypoxia-inducible factor 2α (HIF-2α) has risen as a promising therapeutic target, culminating in the development of specific inhibitors like PT2385 and its analogues. Nonetheless, the absence of targeted delivery capabilities in these inhibitors heightens the risk of on-target toxicities. To mitigate these limitations, we have engineered a nanoparticle, termed PMMF (PT/MMSN@DSPE-PEG-FA), capable of delivering both a HIF-2α antagonist (PT2385) and manganese directly to tumor sites. PMMF has shown effective targeting of pVHL-deficient clear-cell renal cell carcinoma and melanoma, leading to significant therapeutic benefits and alleviating hypoxic and immunosuppressive traits of the tumor microenvironment. Functionally, PMMF boosts the cyclic GMP-AMP synthase-stimulator of interferon genes signaling pathway, which, in turn, stimulates a robust innate immune response. This response activates natural killer (NK) cells and CD8+ T lymphocytes while curbing the infiltration of regulatory T cells. Notably, the therapeutic efficacy of PMMF is markedly reduced when NK cells are blocked but not affected by neutrophil blockade, highlighting the critical role of NK cells in PMMF-induced antitumor immunity. Additionally, the safety profile of PMMF showed minimal systemic post-treatment cytotoxicity. In summary, our findings position PMMF as a promising platform for treating tumors with pVHL deficiency and underscore the therapeutic potential of metalloimmunotherapy.

Hydrogen Sulfide-Responsive MRI Probe for Imaging Colon Cancer in Mice

Hydrogen sulfide (H2S), a significant gaseous signaling molecule, is highly expressed in colon cancer. However, realizing highly sensitive and specific imaging of H2S in deep colon cancer tissues remains an important challenge. In order to overcome this limitation, we have developed a H2S-responsive magnetic probe (HRMP) with a high sensitivity and specificity. HRMP is synthesized using superparamagnetic iron oxide and Mn-porphyrin, coated with a hydrogen sulfide-responsive polymer. Upon reaction with H2S, the released nanoparticles aggregate, producing an enhanced transverse relaxivity (r2) through the dipolar effect. Incorporation of an ortho azide group ensures that HRMP specifically responds to H2S, reacting swiftly within 2 h to induce a change in T2 relaxation time. Additionally, by precisely tuning the feeding ratio of Mn-porphyrin to iron oxide, HRMP was endowed with high sensitivity, achieving a detection limit as low as 8.7 μM. In studies with HCT116 colon cancer, where H2S is overexpressed, HRMP generated a distinct negative contrast at the tumor site. HRMP shows potential for in vivo imaging of colon cancer, offering promise for the early diagnosis of tumors.

Opportunities and Challenges for Nanomaterials as Vaccine Adjuvants

Adjuvants, as a critical component of vaccines, are capable of eliciting more robust and sustained immune responses. Nanomaterials have shown unique advantages and broad application prospects in adjuvant development due to their high adjustability and distinctive physicochemical properties. This review focuses on nanoadjuvants and their immunological mechanisms. First, various types of adjuvants are introduced with an emphasis on metal and metal oxide nanoparticles, coordination polymers, liposomes, polymer nanoparticles, and other inorganic nanoparticles that can serve as vaccine adjuvants. Second, this review describes the current status of the clinical applications of nanoadjuvants. Next, the mechanisms of action for nanoadjuvants have been thoroughly elucidated, including the depot effect, NLRP3 inflammasome activation, targeting C-type lectin receptors, activation of toll-like receptors, and activation of the cGAS-STING signaling pathway. Finally, the challenges and opportunities associated with the development of nanoadjuvants have also been addressed.

Manganese-based nanoadjuvants for the synergistic enhancement of immune responses in breast cancer therapy via disulfidptosis-induced ICD and cGAS-STING activation

Tumor immunotherapy represents one of the most promising strategies for combating tumors by activating the immune system, harnessing anti-tumor immune cells to eliminate tumor cells, and preventing tumor recurrence and metastasis. However, clinical data indicate that the anti-tumor immune response is often inadequate in many cancer patients, resulting in the failure of tumor immunotherapy. Herein, we report a manganese (Mn)-based nanoadjuvant (denoted as BMP-Au) aimed at synergistically enhancing anti-tumor immune responses in breast cancer therapy through disulfidptosis-induced immunogenic cell death and Mn-mediated cGAS-STING pathway activation. BMP-Au is synthesized using bovine serum albumin as a biotemplate for biomimetic mineralization of manganese phosphate nanosheets, followed by the deposition of gold nanoparticles (Au NPs) on their surface. By exploiting the glucose oxidase-like activity of Au NPs alongside the Fenton-like reaction facilitated by Mn2+, BMP-Au orchestrates a cascade catalytic reaction that generates reactive oxygen species from glucose. This process not only initiates disulfidptosis but also leads to DNA fragmentation crucial for activating the cGAS-STING pathway. These concurrent mechanisms compromise cancer cell viability while significantly enhancing tumor immunogenicity, positioning BMP-Au as an innovative nanoadjuvant for cancer treatment that leverages both cellular stress mechanisms and immune activation.

Endogenous nanoplatforms for tumor photoimmunotherapy: Hypoxia modulation and STING pathway activation

Photoimmunotherapy (PIT) holds significant promise for cancer treatment due to its spatial precision and sustained therapeutic effects. However, overcoming the immunosuppression and hypoxia of the tumor microenvironment (TME) remains a major challenge. To solve this problem, we developed a multifunctional PIT nanoplatform (BYMnNps). Its composition plays different roles: i) Biliverdin can induce mild photothermal and photodynamic therapy, enhance the penetration of nanoplatforms into tumors, and induce immunogenic cell death; ii) the immunotherapy peptide tyroserleutide induces tumor cell apoptosis and enhances tumor-specific immune responses; iii) Mn²⁺ can catalyze the generation of oxygen from hydrogen peroxide, reducing tumor hypoxia, while activating the cGAS-STING pathway, further boosting cancer immunotherapy. The nanoplatforms significantly inhibit tumor growth and increase tumor sensitivity to α-PD 1 therapy. Notably, BYMnNps also exhibit photoacoustic and magnetic resonance imaging capabilities. Overall, BYMnNps effectively counteract tumor immune suppression and alleviates TME hypoxia, demonstrating good biocompatibility and antitumor efficacy, with broad potential for precision cancer treatment guided by multimodal imaging. STATEMENT OF SIGNIFICANCE: Photoimmunotherapy holds great promise for cancer treatment due to its spatial precision and sustained therapeutic effects. However, phototherapy-induced tumor hypoxia leads to resistance, posing a significant challenge. This study utilizes endogenous photosensitizer biliverdin, immunotherapy peptide tyroserleutide, and Mn²⁺ to self-assemble into a multifunctional nanoparticle, aimed at simultaneously reversing the immunosuppression of the tumor microenvironment and alleviating hypoxia. It demonstrates good biosafety and antitumor efficacy, enhancing tumor sensitivity to α-PD1 therapy. Additionally, it exhibits photoacoustic and magnetic resonance imaging capabilities, showing broad potential for precision cancer treatment guided by multimodal imaging. It has the potential to overcome the current limitations of photoimmunotherapy, offering a new avenue for cancer treatment.

NIR light activates upconverting nanoparticles/ZnxMn1-xS core-shell nanoparticles for improved breast cancer treatment

Multimodal combined therapy constitutes an ideal strategy for the treatment of primary tumors and the suppression of distant metastatic tumors. In this study, a 4T1 cell membrane-coated UCNPs@ZnxMn1-xS (TUC@ZMS) nanoplatform is designed for synergistic photodynamic (PDT), chemodynamic (CDT), gas, and immune-based cancer therapy. The 4T1 cell membrane coating enhances tumor-targeting specificity, while TUC@ZMS, under 980 nm near-infrared (NIR) light activation, generates singlet oxygen (1O2) for PDT and induces reactive oxygen species (ROS) via CDT to trigger tumor cell apoptosis. The released Mn4+ ions are reduced to Mn2+in situ, depleting intracellular glutathione (GSH) and further enhancing the efficacy of both PDT and CDT. Notably, PDT also promotes immunogenic cell death (ICD), while Mn2+ and H2S activate the cGAS-STING pathway, inducing systemic immune responses characterized by infiltration of CD8+ T cells and NK cells. This multimodal therapeutic strategy targets primary breast tumors while effectively inhibiting distant lung metastases. Overall, TUC@ZMS demonstrates significant potential as a multifunctional nanoplatform for synergistic cancer treatment and immune activation.

Towards precision medicine using biochemically triggered cleavable conjugation

Personalised and precision medicines are emerging as the future of therapeutic strategies. Biochemically triggered cleavable conjugation is thus crucial and timely due to its potential to response as per the loco-regional environment. It enables targeted release of therapeutic agents in response to specific biochemical signals and thus minimizing off-target effects and improving treatment precision. It holds promise in a range of biomedical applications, including cancer therapy, senolytic therapy, gene therapy, and regenerative medicine. The focus of this review is to offer comprehensive insight into the significance of biochemically cleavable conjugations within intrinsically stimuli-responsive architectures. Pathological conditions and alteration in tissues microenvironment in the body exhibit distinct biochemical settings characterized by change in redox potential, pH level, hypoxia, reactive oxygen species (ROS), and various catalytic protein/enzyme overexpression. Understanding these intrinsic features is crucial for researchers aiming to develop intelligent cleavable bio-engineered systems for biomedicines. By strategically designing cleavable linkage, researchers can leverage the variations in the tumor, infection, inflammation, and senescence microenvironments. Through an extensive examination of relevant literature, we present a comprehensive classification of the intrinsic physicochemical differences found in pathological areas and their applications in drug delivery, prodrug activation, imaging, and theranostics for future personalised medicines. This review will provide comprehensive guidance and critical insights to researchers in both industry and academia who are involved in the design of advanced, functional biochemically cleavable conjugations.

Win-Win Integration of Genetically Engineered Cellular Nanovesicles with High-Absorbing Multimodal Phototheranostic Molecules for Boosted Cancer Photo-Immunotherapy

Photo-immunotherapy is one of the most promising cancer treatment strategies. As immunotherapeutic agents, immune checkpoint blockade antibodies against programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) exhibit substantial potential, but have to face non-specific distribution and the subsequent immune-related adverse events. Meanwhile, high-performance phototheranostic agents concurrently possessing multiple phototheranostic modalities and high light-harvesting capacity are really attractive and highly desired as touching phototheranostic modules. Herein, a win-win strategy that integrates phototheranostic molecule design and targeted immunotherapeutic module preparation is developed to construct high-powered photo-immunotherapy systems. Specifically, the phototheranostic agent (AOTTIT) displaying typical aggregation-induced fluorescence extending to the second near-infrared II window, as well as outstanding reactive oxygen species and heat production capacity is first obtained via ingenious design. Notably, AOTTIT exhibits a record high molar extinction coefficient among the reported organic multimodal phototheranostic molecules. Meanwhile, PD-1 genetically engineered cancer cell membrane-derived nanovesicles (PD-1/CMNVs) are prepared as both nanocarriers and immunotherapeutic agents to camouflage AOTTIT nanoparticles, yielding a multifunctional photo-immunotherapeutic agent (CMNPs/PD-1) with tumor-specific active and homologous targeting ability. The distinct suppression of primary and metastatic lung tumors after only once treatment to the primary tumor substantiated the synergistically strengthened photo-immunotherapeutic efficiency of this win-win strategy.

Tumor-specific liquid metal nitric oxide nanogenerator for enhanced breast cancer therapy

Nitric oxide (NO) modulates several cancer-related physiological processes and has advanced the development of green methods for cancer treatment and integrated platforms for combination or synergistic therapies. Although a nanoengineering strategy has been proposed to overcome deficiencies of NO gas or small NO donor molecules, such as short half-life, lipophilicity, non-selectivity, and poor stability, it remains challenging to prepare NO nanomedicines with simple composition, multiple functions and enhanced therapeutic efficacy. Herein, we build a liquid metal nanodroplet (LMND)-based NO nanogenerator (LMND@HSG) that is stabilized by a bioreducible guanylated hyperbranched poly(amido amine) (HSG) ligand. Mechanically, the tumor microenvironment specifically triggers a cascade process of glutathione elimination, reactive oxygen species (ROS) generation, and NO release. According to actual demand, the ROS and NO concentrations could be readily controlled by tuning the LMND and HSG feed amounts. Along with the intrinsic anticancer property of LMND (ROS-mediated apoptosis and anti-angiogenesis), LMND@HSG administration could further enhance tumor growth suppression compared with LMND and HSG alone. From this study, leveraging LMND for NO gas therapy provides more possibilities for the prospect of LMND-based anticancer nanomedicines.

Harnessing Nanoreactors with Coupled Optical and Molecular Modalities for Photoenzymatic Modulation of Active Species in Cancer Photo-Immunotherapy

The dynamic process in tumor ablation requires both the generation of reactive oxygen species (ROS) to elicit immunogenic cell death (ICD) and the subsequent reduction of ROS levels to maintain the stimulatory activity of signaling proteins and recover T cells' immune function. Inspired by the regulation mechanism of redox homeostasis in myeloid-derived suppressor cells and the high-selectivity in alcohols/aldehydes conversions of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and Fe(III) synergistic catalysis, photoenzymatic modulators with contradictory but synergistic functions are developed for adaptive photo-immunotherapy of cancer. In particular, poly(caffeic acid) (PCA) nanospheres are synthesized by highly efficient oxidative polymerization of CA. The obtained π-conjugated structures have an extended absorbance in the near-infrared (NIR) region, narrow band energy (0.86 eV), and low exciton binding energy (43.56 meV) that lead to polymerization-enhanced type I photosensitization and photostability. Meanwhile, abundant semiquinone radicals existing in PCA bestow them with superior antioxidant function. Under NIR irradiation, the elevated superoxide radical yields (3.5-fold compared with CA) and heat stress elicit robust ICD. When irradiation ceases, active species downregulation and the infiltration of T lymphocytes increase by 2.7-fold compared with conventional photosensitizers. As envisaged, this work demonstrates a novel tactic to remodel redox and immune homeostasis for effective inhibition of tumor growth and metastasis.

Simultaneous Reversal of T Lymphocytes and Cancer Cells Metabolism Via a Biomimetic Heavy-Atom-Free Photosensitizers-Based Combination Therapies to Boost Cancer Photoimmunotherapy

Near-infrared (NIR) activated photosensitizers based on heavy-atom-free have great advantages in photoimmunotherapy, yet the tumor microenvironment often restricts their efficacy. To address this, a NIR-activated heavy-atom-free photosensitizer (named Cy-BF) is developed. Cy-BF is then encapsulated with phospholipids and platelet exosome vesicles to create platelet exosomes vesicles biomimetic and Cy-BF loaded hybrid liposomes (named CHL) Characterized by high phototoxicity, low dark toxicity, and enhanced tumor targeting, CHL demonstrates aggregation-induced broadening of absorption spectra and NIR (760 nm laser) activates photothermal therapy and type I photodynamic therapy. The CHL-mediated phototherapy induces mitochondrial damage and immunogenic cell death in tumor cells, decreases lactate production, and alters the tumor microenvironment by reducing regulatory T cells and increasing CD8+ T cells. To mitigate T cell inhibition by excess lactate, a combination therapy is introduced using lithium carbonate, which repurposes lactate as an energy source for CD8+ T cells, thereby enhancing the effectiveness of CHL-mediated photoimmunotherapy. This combination approach represents a novel strategy for reversing lactate metabolism in both tumor cells and T cells, paving the way for future clinical applications in photoimmunotherapy.

Endoplasmic Reticulum-Targeted Phototherapy Remodels the Tumor Immunopeptidome to Enhance Immunogenic Cell Death and Adaptive Anti-Tumor Immunity

Background: Endoplasmic reticulum (ER)-targeted phototherapy has emerged as a promising approach to amplify ER stress, induce immunogenic cell death (ICD), and enhance anti-tumor immunity. However, its impact on the antigenicity of dying tumor cells remains poorly understood. Methods: Laser activation of the ER-targeted photosensitizer ER-Cy-poNO2 was performed to investigate its effects on tumor cell antigenicity. Transcriptomic analysis was carried out to assess gene expression changes. Immunopeptidomics profiling was used to identify high-affinity major histocompatibility complex class I (MHC-I) ligands. In vitro functional studies were conducted to evaluate dendritic cell maturation and T lymphocyte activation, while in vivo experiments were performed by combining the identified peptide with poly IC to evaluate anti-tumor immunity. Results: Laser activation of ER-Cy-poNO2 significantly remodeled the antigenic landscape of 4T-1 tumor cells, enhancing their immunogenicity. Transcriptomic analysis revealed upregulation of antigen processing and presentation pathways. Immunopeptidomics profiling identified multiple high-affinity MHC-I ligands, with IF4G3986-994 (QGPKTIEQI) showing exceptional immunogenicity. In vitro, IF4G3986-994 promoted dendritic cell maturation and enhanced T lymphocytes activation. In vivo, the combination of IF4G3986-994 with poly IC elicited robust anti-tumor immunity, characterized by increased CD8+ T lymphocytes infiltration, reduced regulatory T cells (Tregs) in the tumor microenvironment, elevated systemic Interferon-gamma (IFN-γ) levels, and significant tumor growth inhibition without systemic toxicity. Conclusions: These findings establish a mechanistic link between ER stress-driven ICD, immunopeptidome remodeling, and adaptive immune activation, highlighting the potential of ER-targeted phototherapy as a platform for identifying immunogenic peptides and advancing peptide-based cancer vaccines.

Supramolecular polyrotaxane-based nano-theranostics enable cancer-cell stiffening for enhanced T-cell-mediated anticancer immunotherapy

Despite the tremendous therapeutic promise of activating stimulators of interferon genes (STING) enable to prime robust de novo T-cell responses, biomechanics-mediated immune inhibitory pathways hinder the cytotoxicity of T cells against tumor cells. Blocking cancer cell biomechanics-mediated evasion provides a feasible strategy for augmenting STING activation-mediated anti-tumor therapeutic efficacy. Here, we fabricate a redox-responsive Methyl-β-cyclodextrin (MeβCD)-based supramolecular polyrotaxanes (MSPs), where the amphiphilic diselenide-bridged axle polymer loads MeβCD by the host-guest interaction and end-caping with two near-infrared (NIR) fluorescence probes IR783. The MSPs self-assemble with STING agonists diABZIs into nanoparticles (RDPNs@diABZIs), which enable simultaneous release of MeβCD and diABZIs in the redox tumor microenvironment. After the released diABZIs activate STING on antigen-presenting cells (APCs), de novo T-cell responses are initiated. Meanwhile, the released MeβCD depletes membrane cholesterol to overcome cancer-cell mechanical softness, which enhances the CTL-mediated killing of cancer cells. In the female tumor-bearing mouse model, we demonstrate that RDPNs@diABZIs lead to effective tumor regression and generate long-term immunological memory. Furthermore, RDPNs@diABZIs can achieve significant tumor eradication, with these mice remaining survival for at least 2 months.

Pyridinium Rotor Strategy toward a Robust Photothermal Agent for STING Activation and Multimodal Image-Guided Immunotherapy for Triple-Negative Breast Cancer

The immunosuppressive tumor microenvironment in triple-negative breast cancer could hinder the response to thorough immunotherapy and diminish the antitumor efficacy. Although the STING pathway emerges as a promising target to remedy defects, uncertain drug delivery might lead to off-target inflammatory reactions. Here, we manifest a novel phototheranostic agent with an aggregation-induced emission property that guided the pharmacological activation of a STING agonist for photothermal immunotherapy to create an immunologically "hot" tumor. A pyridinium rotor strategy is proposed to develop a positively charged TBTP-Bz, which is stably coincorporated with a STING agonist MSA-2 into thermal-responsive exosome-liposome hybrid nanoparticles for tumor-targeting delivery. TBTP-Bz exhibits aggregation-enhanced NIR-II emission and a photoacoustic signal, accomplishing real-time tumor tracking. Its photothermal stimulation induces immunogenic cancer cell death and promotes the precise release of MSA-2, thus boosting STING activation and STING-mediated type I interferon production. Significantly, single-dose photoimmunotherapy effectively suppresses abscopal tumor growth and provokes an immune memory effect to inhibit postsurgical recurrent and rechallenged tumors. This demonstrates promising clinical potential for poorly immunogenic breast cancer.

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.

Nanomotors activating both cGAS-STING pathway and immune checkpoint blockade for tumor therapy and bioimaging

Cellular innate immune response is closely related to cGAS-STING pathway and PD-1/PD-L1 immune checkpoint blockade. The lack of tissue penetration of STING agonists and nanomedicines in conventional approaches reduces their immunotherapeutic efficacy. At the same time, because the cGAS-STING signaling pathway is silent in many breast cancer cells, it cannot play its role. To address these challenges, here, we developed a silica nanomotor based on bubble propulsion. Its hollow structure was packed with the photosensitizer Ce6 molecule. Under 808 nm laser irradiation, Ce6 produced 1O2, which lead to intracellular DNA damage and further activated the cGAS-STING pathway, stimulating the maturation of DC cells, and enhancing the tumor infiltration of CD8+ T cells. The nanomotor had an asymmetrical structure. One side of the nanomotor was modified with Pt nanoparticle. This asymmetric modification can catalyze H2O2 in the environment, producing an asymmetric concentration of O2, which realized the bubble driving nanomotor movement and enhances penetration into breast cancer cells of nanomotor. The other side of the nanomotor was modified the LXL-1 aptamer, triphenylphosphine and peptide CLP002. Peptide CLP002 specifically bound residues of PD-L1 interaction with PD-1, blocked the mutual binding between PD-1 and PD-L1, and further improved the immune response ability of tumor infiltrating T cells. In this study, we developed a multi-pronged immunotherapy strategy of intelligent target finding, breaking through the physiological barrier through kinetic energy, accurately intervening the target and bioimaging, providing a new idea for breast cancer cells targeted therapy.

A Single-Atom Mn/MoO3- x Nanoagonist for Cascade cGAS/STING Activation in Tumor-Specific Catalytic Metalloimmunotherapy

The cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) pathway plays a crucial role in initiating anti-tumor immunity. Despite the development of various STING agonists, their effectiveness is often limited by suboptimal activation efficiency and poor sustainability. To address this, a Mn/MoO3- x nanoagonist featuring Mn single-atom sites is presented, designed for cascade cGAS/STING activation in tumor-specific catalytic metalloimmunotherapy. The single-atom nanoagonist (SANA) is meticulously crafted by doping Mn atoms into defective molybdenum oxide (MoO3- x), enabling robust peroxidase-mimicking catalysis and inducing severe double-stranded DNA (dsDNA) damage in tumors. Of note, Mn2+ and MoO4 2- can be responsively released from Mn/MoO3- x SANA and enhance the sensitivity of cGAS to dsDNA. Importantly, MoO4 2- with a relatively slow-release profile and facile cellular accumulation compensates for Mn2+ that has poor cellular accumulation due to continuous efflux, thus continuatively triggering the secretion of type I interferon for beyond 72 h. Remarkably, Mn/MoO3- x SANA significantly inhibits tumor growth and metastasis without supplementary STING agonists or external stimulation. This study offers a promising cascade cGAS/STING activation approach to enhance the efficacy and sustainability of catalytic metalloimmunotherapy.

Manganese dioxide-based in situ vaccine boosts antitumor immunity via simultaneous activation of immunogenic cell death and the STING pathway

In situ vaccine (ISV) can activate the anti-tumor immune system by inducing immunogenic cell death (ICD) at the tumor site. However, the development of tumor ISV still faces challenges due to insufficient tumor antigens released by tumor cells and the existence of tumor immunosuppressive microenvironment (TIME). Targeting the STING pathway has been reported to enhance the adjuvant effects of in situ tumor vaccines by initiating innate immunity. Based on this, we developed a potent in situ cancer vaccine, MBMA-RGD ISV, which simultaneously induces ICD and activates the STING pathway to achieve sustained anti-tumor immunity. Specifically, a water-soluble prodrug Mit-ALA was synthesized from the chemotherapeutic agent mitoxantrone (Mit) and the photosensitizer precursor 5-aminolevulinic acid (5-ALA) by pH-responsive ester bonds, which was then loaded into pre-synthesized BSA-MnO2 nanoparticles and functionalized with the targeting Arg-Gly-Asp (RGD) peptide to obtain MBMA-RGD ISV. This ISV actively targets tumor cells by binding integrin receptors and then gradually releases antitumor components in response to tumor microenvironment (TME). The released 5-ALA is metabolized in mitochondria to produce photosensitizer PpIX. Under laser irradiation, the photodynamic property of PpIX coupled with the photothermal effect of Mit synergistically induced ICD, resulting in the release of tumor antigens and evoking adaptive immunity. Meanwhile, released Mn2+ and Mit synergistically activate the STING pathway by inducing DNA damage, further enhancing antitumor immunity. Moreover, large amounts of oxygen released by MnO2 relieved the hypoxia microenvironment, thus sensitizing photodynamic therapy and improving the immunosuppressive state of TME. Therefore, MBMA-RGD ISV efficiently activates systemic antitumor immunity in vitro and in vivo, providing new strategies and ideas for the development of tumor ISV. STATEMENT OF SIGNIFICANCE: Using a biocompatible BSA-MnO2 nanoplatform, we developed a dual-prodrug tumor in situ vaccine (ISV) with tumor microenvironment-responsive action for synergistic cancer immunotherapy. Once internalized by tumor cells, the MBMA-RGD ISV responded to intracellular H+, H2O2, and GSH, releasing its therapeutic "cargo." Under laser irradiation, the combined effects of photodynamic therapy (PDT) and photothermal therapy (PTT) induced immunogenic cell death (ICD), effectively recruiting and stimulating dendritic cells (DCs). Concurrently, STING pathway activation, triggered by DNA damage, enhanced DC maturation. Moreover, the MnO2 component alleviated hypoxia within the tumor microenvironment by releasing significant amounts of oxygen, which facilitated the repolarization of macrophages from the M2 phenotype to the M1 phenotype. Therefore, MBMA-RGD ISV demonstrated potent suppression of tumor metastasis and recurrence without notable side effects in mouse tumor models.

Cold Exposure Therapy Enhances Single-Atom Nanozyme-Mediated Cancer Vaccine Therapy

Single-atom nanozymes are highly effective in the preparation of tumor vaccines (TV) due to their superior peroxidase (POD) activity and excellent biocompatibility. However, the immunosuppressive environment within tumors can diminish the efficacy of these vaccines. Cold exposure (CE) therapy, a noninvasive and straightforward antitumor method, not only suppresses tumor metabolism but also ameliorates the immunosuppressive tumor milieu. In this study, we developed personalized TV using copper single-atom nanozyme (Cu SAZ) and enhanced their long-term antitumor efficacy by introducing CE. We initially synthesized the Cu SAZ via high-temperature carbonization, which demonstrated robust POD activity and photothermal characteristics. Upon exposure to 808 nm laser irradiation, the nanozyme generated reactive oxygen species (ROS) and heat, inducing immunogenic cell death in 4T1 breast cancer cells or CT26 colon cancer cells and facilitating TV production. In our in vivo tumor prevention and treatment model, we noted that CE significantly boosted the efficacy of the TV. The primary mechanism involves CE's ability to lower the ratio of myeloid-derived suppressor cells (MDSCs), decrease glucose metabolism in tumor cells, and increase the proportions of CD8+ T cells and memory T cells. Collectively, our findings offer promising avenues for designing innovative TV systems.

Metal-organic framework nanoparticles activate cGAS-STING pathway to improve radiotherapy sensitivity

Tumor immunotherapy aims to harness the immune system to identify and eliminate cancer cells. However, its full potential is hindered by the immunosuppressive nature of tumors. Radiotherapy remains a key treatment modality for local tumor control and immunomodulation within the tumor microenvironment. Yet, the efficacy of radiotherapy is often limited by tumor radiosensitivity, and traditional radiosensitizers have shown limited effectiveness in hepatocellular carcinoma (HCC). To address these challenges, we developed a novel multifunctional nanoparticle system, ZIF-8@MnCO@DOX (ZMD), designed to enhance drug delivery to tumor tissues. In the tumor microenvironment, Zn²⁺ and Mn²⁺ ions released from ZMD participate in a Fenton-like reaction, generating reactive oxygen species (ROS) that promote tumor cell death and improve radiosensitivity. Additionally, the release of doxorubicin (DOX)-an anthracycline chemotherapeutic agent-induces DNA damage and apoptosis in cancer cells. The combined action of metal ions and double-stranded DNA (dsDNA) from damaged tumor cells synergistically activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, thereby initiating a robust anti-tumor immune response. Both in vitro and in vivo experiments demonstrated that ZMD effectively activates the cGAS-STING pathway, promotes anti-tumor immune responses, and exerts a potent tumor-killing effect in combination with radiotherapy, leading to regression of both primary tumors and distant metastases. Our work provides a straightforward, safe, and effective strategy for combining immunotherapy with radiotherapy to treat advanced cancer.

Application of nanoparticles with activating STING pathway function in tumor synergistic therapy

Although immunotherapy is currently one of the most promising methods for cancer treatment, its clinical application is limited due to issues such as excessive autoimmune responses and lack of specificity. Therefore, there is a need to improve immunotherapy by integrating emerging medical technologies with traditional treatments. The activation of the cGAS-STING pathway plays a crucial role in innate immunity and antiviral defense, making it highly promising for immunotherapy and attracting significant attention. In recent years, research on nanomaterials and immunotherapy has achieved groundbreaking progress in the medical field. Due to their unique size, shape, stiffness, surface effects, and quantum size effects, nanomaterials can either carry STING activators or directly activate the STING pathway, offering new opportunities for tumor-specific immunotherapy. These unique advantages of nanomaterials have opened up broader prospects for nanoparticle-based therapies targeting the STING pathway. This paper summarizes the current research on utilizing nanomaterials to activate the STING pathway, detailing the characteristics, classifications, and different approaches for targeting tumor cells. Additionally, it focuses on the latest advancements in combined nanotherapies based on cGAS-STING pathway activation, including the integration of nanomaterial-mediated STING pathway activation with immunotherapy, radiotherapy, chemotherapy, targeted therapy, and photodynamic therapy. This provides new ideas for nanoparticle-based combination therapies involving the STING pathway.

An electrically activable nanochip to intensify gas-ionic-immunotherapy

Excess intracellular H2S induces destructive mitochondrial toxicity, while overload of Zn2+ results in cell pyroptosis and potentiates the tumor immunogenicity for immunotherapy. However, the precise delivery of both therapeutics remains a great challenge. Herein, an electrically activable ZnS nanochip for the controlled release of H2S and Zn2+ was developed for enhanced gas-ionic-immunotherapy (GIIT). Under an electric field, a locality with particularly high concentrations of H2S and Zn2+ was established by the voltage-controlled degradation of the ZnS nanoparticles (NPs). Consequently, the ZnS nanochip-mediated gas-ionic therapy (GIT) resulted in mitochondrial membrane potential depolarization, energy generation inhibition, and oxidative stress imbalance in tumor cells. Interestingly, the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) signaling pathway was activated due to the mitochondrial destruction. Moreover, the released Zn2+ resulted in the increase of the intracellular Zn levels and cell pyroptosis, which enhanced the immunogenicity via the release of damage-associated molecular patterns (DAMPs). In vitro and in vivo studies revealed that the ZnS nanochip-based GIT effectively eliminated the tumors under an electric field and mobilized the cytotoxic T lymphocytes for immunotherapy. The combination with αCTLA-4 further promoted the adaptive immune response and inhibited tumor metastasis and long-term tumor recurrence. This work presented an electrically activable ZnS nanochip for combined immunotherapy, which might inspire the development of electric stimulation therapy.

Intracellular Co-Delivery of Carbon Monoxide and Nitric Oxide Induces Mitochondrial Apoptosis for Cancer Therapy

Understanding the interplay between gasotransmitters is essential for unlocking their therapeutic potential. However, achieving spatiotemporally controlled co-delivery to target cells remains a significant challenge. Herein, we propose an innovative strategy for the intracellular co-delivery of carbon monoxide (CO) and nitric oxide (NO) gasotransmitters under clinically relevant wavelengths. This approach rationally couples aerobic photooxidative and anaerobic photocatalytic reactions within a polymeric micelle platform, using palladium(II) tetraphenyltetrabenzoporphyrin (PdTPTBP) as both photosensitizer and photocatalyst. Notably, the photooxidation-mediated release of CO generates a local hypoxic microenvironment, which facilitates the photoredox catalyzed release of NO. This self-adaptive micelle platform enables efficient uptake by tumor cells and intracellular co-delivery of CO and NO under 630 nm light irradiation, demonstrating potent anti-tumor activity in a 4T1 tumor-bearing mouse model via the synergistic induction of mitochondrial apoptosis.

Manipulating the cGAS-STING Axis: advancing innovative strategies for osteosarcoma therapeutics

This paper explored the novel approach of targeting the cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase-stimulator of interferon genes (cGAS-STING) pathway for the treatment of osteosarcoma (OS). Osteosarcoma is a common malignancy in adolescents. Most patients die from lung metastasis. It reviewed the epidemiology and pathological characteristics of OS, highlighting its highly malignant nature and tendency for pulmonary metastasis, underscoring the importance of identifying new therapeutic targets. The cGAS-STING pathway was closely associated with the malignant biological behaviors of OS cells, suggesting that targeting this pathway could be a promising therapeutic strategy. Currently, research on the role of the cGAS-STING pathway in OS treatment has been limited, and the underlying mechanisms remain unclear. Therefore, further investigation into the mechanisms of the cGAS-STING pathway in OS and the exploration of therapeutic strategies based on this pathway are of great significance for developing more effective treatments for OS. This paper offered a fresh perspective on the treatment of OS, providing hope for new therapeutic options for OS patients by targeting the cGAS-STING pathway.

Aggregation Induced Emission Based Luminogenic (AIEgenic) Probes for the Biomarker Detection

Various biomarkers such as proteins play key roles in controlling crucial biochemical processes. The critical concentration of the biomarkers is important to maintain a healthy life. In fact, imbalance in concentration or irregular activity of these can lead to various diseases like Cancer, Alzheimer's etc. Therefore, the disease related biomarkers and their timely detection are key to control the illness. In the literature, a few activity-based probes for the detection of such biomarkers are available. As per the requirement an ideal probe should be very specific to recognize the target analyte and that could be achieved by virtue of having a robust structure and stimuli responsive nature. In this regard, several fluorescent probes are of great choice. Although these fluorescent probes face certain challenges such as aggregation caused quenching, which heavily affects the sensitivity and photostability is another major concern for many fluorescent probes. To overcome these challenges aggregation-induced emissive fluorescent probes found to be an excellent alternative. Aggregation induced emissive luminogens (AIEgens) offer higher signal to noise ratios and found to possess better photostability during sensing and imaging. In the present review we have summarized the development of AIEgenic probes for sensing and imaging of disease related biomarkers. We believe this review could be a guide to design efficient AIEgenic probes for the diagnostics development.

A Dual-Targeting Biomimetic Nanoplatform Integrates SDT/CDT/Gas Therapy to Boost Synergistic Ferroptosis for Orthotopic Hepatocellular Carcinoma Therapy

The development of efficient therapeutic strategies to promote ferroptotic cell death offers significant potential for hepatocellular carcinoma (HCC) treatment. Herein, this study presents an HCC-targeted nanoplatform that integrates bimetallic FeMoO4 nanoparticles with CO-releasing molecules, and further camouflaged with SP94 peptide-modified macrophage membrane for enhanced ferroptosis-driven multi-modal therapy of HCC. Leveraging the multi-enzyme activities of the multivalent metallic elements, the nanoplatform not only decomposes H2O2 to generate oxygen and alleviate tumor hypoxia but also depletes glutathione to inactivate glutathione peroxides 4, which amplify sonodynamic therapy and ferroptotic tumor death under ultrasound (US) irradiation. Meanwhile, the nanoplatform catalyzes the Fenton reaction to produce hydroxyl radicals for chemodynamic therapy. Elevated intracellular reactive oxygen species trigger the cascade release of CO, leading to lethal lipid peroxidation and further enhancing ferroptosis-mediated tumor therapy. This nanoplatform demonstrates robust anti-tumor efficacy under US irradiation with favorable biosafety in both subcutaneous and orthotopic HCC models, representing a promising therapeutic approach for HCC. Additionally, the findings offer new insights into tumor microenvironment modulation to optimize US-triggered multi-modal cancer therapy.

Nucleotide coordinated polymers, a ROS-based immunomodulatory antimicrobial, doubly kill Pseudomonas aeruginosa biofilms of implant infections

Pseudomonas aeruginosa causes high morbidity and mortality in nosocomial infections, and newly approved antibiotics have been declining for decades. A green and universal deprotonation-driven strategy is used to screen the guanylic acid-metal ion coordination polymer nanoparticles (GMC), instead of the failure of binding occurs when specific metal ion participation. We find that the precise pH-dependent oxidase-like activity of GMC-2 orchestrates a duple symphony of immune modulation for Pseudomonas aeruginosa biofilm infections. Specifically, GMC-2-mediated reactive oxygen species (ROS) regulation triggers mitochondrial dysfunction and releases damage-associated molecular patterns, engaging pattern recognition receptors and resulting in endogenous innate immune activation. Meanwhile, GMC-2-triggered ROS generation in a mildly acidic biofilm environment destroys the biofilm, exposing exogenous pathogen-associated molecular patterns. GMC-2 cannot cause resistance for Pseudomonas aeruginosa compared with conventional antibiotics. In an infected implant mouse model, Pseudomonas aeruginosa biofilms were effectively eliminated by GMC-2-mediated triggering of innate and adaptive immunity. These findings provide a universal approach for facilitating the binding of biomolecules with metal ions and highlight the precise ROS-regulating platform plays a critical role in initiating endogenous and exogenous immune activation targeted for bacterial biofilm infection.

Drug delivery systems based on mesoporous silica nanoparticles for the management of hepatic diseases

The liver performs multiple life-sustaining functions. Hepatic diseases, including hepatitis, cirrhosis, and hepatoma, pose significant health and economic burdens globally. Along with the advances in nanotechnology, mesoporous silica nanoparticles (MSNs) exhibiting diversiform size and shape, distinct morphological properties, and favorable physico-chemical features have become an ideal choice for drug delivery systems and inspire alternative thinking for the management of hepatic diseases. Initially, we introduce the physiological structure of the liver and highlight its intrinsic cell types and correlative functions. Next, we detail the synthesis methods and physicochemical properties of MSNs and their capacity for controlled drug loading and release. Particularly, we discuss the interactions between liver and MSNs with respect to the passive targeting mechanisms of MSNs within the liver by adjusting their particle size, pore diameter, surface charge, hydrophobicity/hydrophilicity, and surface functionalization. Subsequently, we emphasize the role of MSNs in regulating liver pathophysiology, exploring their value in addressing liver pathological states, such as tumors and inflammation, combined with multi-functional designs and intelligent modes to enhance drug targeting and minimize side effects. Lastly, we put forward the problems, challenges, opportunities, as well as clinical translational issues faced by MSNs in the management of liver diseases.

Metalloparticle-Engineered Pickering Emulsion Displaying AAV-Vectored Vaccine for Enhancing Antigen Expression and Immunogenicity Against Pathogens

Recombinant adeno-associated viruses (rAAVs) have emerged as promising vaccine vectors due to their enduring efficacy with a single dose. However, insufficient cellular immune responses and the random and non-specific distribution of AAVs post-injection may hinder the development of AAV vaccines. Here, a novel Pickering emulsion platform stabilized by biomineralized manganese nanoparticles and aluminum hydroxide, which can rapidly and efficiently load AAVs, is reported. This platform confers AAVs with favorable in vivo distribution kinetics, diversifying AAV endocytic pathways with reduced dependency on the sialic acid receptor-mediated route, and ultimately enhancing AAV infection efficiency in antigen present cells (APCs). Concurrently, the Pickering emulsion substantially boosts endogenous 2'3'-cGAMP production, further activating the cGAS-STING pathway for stronger immune responses and improving protective efficacy in bacterial infection models. The STING pathway activation also increases AAV target gene expression, potently augmenting the cross-protective potential of AAV vaccines for COVID-19. These synergistic effects ensure that effective immune responses are induced even at one-fifth of the AAV vaccination dose, while the Pickering emulsion further reduces the accumulation of AAV in the liver, thereby improving their safety. The findings highlight the potential of Pickering emulsions as valuable enhancers for viral vectors, providing insights for their broader clinical applicability.

Mechanistic Insights Into NIR-II AIEgens Boosted Multimodal Phototheranostics

Exploiting single molecular species synchronously affording powerful second near-infrared (NIR-II) fluorescence, superior photoacoustic output, prominent reactive oxygen species generation, and satisfactory photothermal conversion is supremely appealing for phototheranostics, yet remains formidably challenging. In this work, electron donor/π-bridge engineering is implemented on the basis of 6,7-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline moiety. The optimal molecule, namely TPATO-TTQ, is demonstrates to exhibit those notable features requested by exceptional phototheranostics, which are systematically elucidated through the depictions of excited-state energy dissipation pathways and the influence of intramolecular motion on the photophysical properties, with assistances of quantum chemical calculation and molecular dynamic simulation. By utilizing TPATO-TTQ nanoparticles, unprecedented performance on NIR-II fluorescence-photoacoustic-photothermal trimodal imaging-navigated type I photodynamic-photothermal synergistic therapy to orthotopic breast cancer is authenticates by the precise tumor diagnosis and complete tumor ablation.

Mitochondrial DNA-activated cGAS-STING pathway in cancer: Mechanisms and therapeutic implications

Mitochondrial DNA (mtDNA), a circular double-stranded DNA located within mitochondria, plays a pivotal role in mitochondrial-induced innate immunity, particularly via the cyclic GMP-AMP synthase (cGAS)-STING pathway, which recognizes double-stranded DNA and is crucial for pathogen resistance. Recent studies elucidate the interplay among mtDNA, the cGAS-STING pathway, and neutrophil extracellular traps (NETs) in the context of cancer. mtDNA uptake by recipient cells activates the cGAS-STING pathway, while mtDNA leakage reciprocally regulates NET release, amplifying inflammation and promoting NETosis, a mechanism of tumor cell death. Autophagy modulates these processes by clearing damaged mitochondria and degrading cGAS, thus preventing mtDNA recognition. Tumor microenvironmental factors, such as metabolic reprogramming and lipid accumulation, induce mitochondrial stress, ROS production, and further mtDNA leakage. This review explores strategies in cancer drug development that leverage mtDNA leakage to activate the cGAS-STING pathway, potentially converting 'cold tumors' into 'hot tumors,' while discussing advancements in targeted therapies and proposing new research methodologies.

Manganese Galvanic Cells Intervene in Tumor Metabolism to Reinforce cGAS-STING Activation for Bidirectional Synergistic Hydrogen-Immunotherapy

The cGAS-STING pathway is pivotal in initiating antitumor immunity. However, tumor metabolism, particularly glycolysis, negatively regulates the activation of the cGAS-STING pathway. Herein, Mn galvanic cells (MnG) are prepared via liquid-phase exfoliation and in situ galvanic replacement to modulate tumor metabolism, thereby enhancing cGAS-STING activation for bidirectional synergistic H2-immunotherapy. The obtained MnG can be etched by water, enabling efficient and sustained generation of H2 gas and Mn2+. MnG not only activated and amplified the cGAS-STING pathway through the sustained release of Mn2+ but also regulated tumor glucose metabolism to inhibit the expression of three prime repair exonuclease 2 (TREX2), thereby synergistically enhancing the activation of the cGAS-STING pathway. The injection of MnG into tumors resulted in a robust immune response, thereby providing favorable support for antitumor therapy. Consequently, the combination of MnG with immune checkpoint blockade therapy resulted in significant suppression of both primary tumors and distant tumors. Furthermore, the MnG-lipiodol dispersion exhibited remarkable efficacy in combination with transarterial embolization (TAE)-gas-immunotherapy in a rabbit orthotopic liver tumor model. The present study underscores the significance of employing a metal galvanic cell strategy for enhanced immunotherapy, thereby offering a novel approach for rational design of bioactive materials to augment immunotherapeutic effectiveness.

Self-Cascaded Pyroptosis-STING Initiators for Catalytic Metalloimmunotherapy

Gasdermin (GSDM)-mediated pyroptosis involves the induction of mitochondrial damage and the subsequent release of mitochondrial DNA (mtDNA), which is anticipated to activate the cGAS-STING pathway, thereby augmenting the antitumor immune response. However, challenges lie in effectively triggering pyroptosis in cancer cells and subsequently enhancing the cGAS-STING activation with specificity. Herein, we developed intelligent self-cascaded pyroptosis-STING initiators of cobalt fluoride (CoF2) nanocatalysts for catalytic metalloimmunotherapy. CoF2 nanocatalysts with a semiconductor structure and enzyme-like activity generated a substantial amount of reactive oxygen species (ROS) under stimulation by endogenous H2O2 and exogenous ultrasound. Importantly, we discovered that Co-based nanomaterials themselves induce pyroptosis in cancer cells. Therefore, CoF2 nanocatalysts initially acted as pyroptosis inducers, triggering caspase-1/GSDMD-dependent pyroptosis in cancer cells via Co2+ and ROS, leading to mtDNA release. Subsequently, CoF2 nanocatalysts were further utilized as intelligent STING agonists that were specifically capable of detecting mtDNA and augmenting the activation of the cGAS-STING pathway. These cascade events triggered a robust immune response, effectively modulating the immunosuppressive tumor microenvironment into an immune-supportive state, thereby providing favorable support for antitumor therapy. This innovative strategy not only significantly impeded the growth of the primary tumor but also elicited an immune response to further augment the efficacy of immune checkpoint inhibitors in preventing distant tumor progression. Overall, this study proposed a self-cascade strategy for activating and amplifying the cGAS-STING pathway with specificity mediated by pyroptosis, representing a valuable avenue for future cancer catalytic metalloimmunotherapy.

DNA lesion-gated dumbbell nanodevices enable on-demand activation of the cGAS-STING pathway for enhancing cancer immunotherapy

Utilizing the cGAS-STING pathway to combat immune evasion is one of the most promising strategies for enhancing cancer immunotherapy. However, current techniques for activating the cGAS-STING pathway often face a dilemma, mainly due to the balance between efficacy and safety. Here, we develop a uracil base lesion-gated dumbbell DNA nanodevice (UBLE) that allows on-demand activation and termination of the cGAS-STING pathway in tumor cells, thereby enhancing cancer immunotherapy. The UBLE integrates two deoxyuridines (dU) in the stem for DNA lesion recognition, two locked complementary primer sequences (primers A and B) for DNA self-assembly, and a Förster resonance energy transfer pair (Cy3 and Cy5) attached to the loop for activation assessment. Upon the orthogonal recognition of tumor-specific repair indicators (UDG and APE1), the UBLE undergoes a conformational change to create massive nicked double-stranded DNA (dsDNA) units. These units self-assemble to generate long fluorescent dsDNA structures, permitting selective evaluation and on-demand activation of the cGAS-STING pathway. Furthermore, we demonstrate that the UBLE can effectively activate the cGAS-STING pathway in tumor cells, enhancing NK cell-targeted cancer immunotherapy. This work develops a DNA lesion-gated strategy for on-demand activation and termination of the cGAS-STING pathway, affording an innovative avenue for enhancing cancer immunotherapy.

Inhalable nanovesicles loaded with a STING agonist enhance CAR-T cell activity against solid tumors in the lung

Suppression of chimeric antigen receptor-modified T (CAR-T) cells by the immunosuppressive tumor microenvironment remains a major barrier to their efficacy against solid tumors. To address this, we develop an anti-PD-L1-expressing nanovesicle loaded with the STING agonist cGAMP (aPD-L1 NVs@cGAMP) to remodel the tumor microenvironment and thereby enhance CAR-T cell activity. Following pulmonary delivery, the nanovesicles rapidly accumulate in the lung and selectively deliver STING agonists to PD-L1-overexpressing cells via the PD-1/PD-L1 interaction. This targeted delivery effectively avoids the systemic inflammation and poor cellular uptake that plague free STING agonists. Internalized STING agonists trigger STING signaling and induce interferon responses, which diminish immunosuppressive cell populations such as myeloid-derived suppressor cells in the tumor microenvironment and promote CAR-T cell infiltration. Importantly, the anti-PD-L1 single chain variable fragment on the nanovesicle surface blocks PD-L1 upregulation induced by STING agonists and prevents CAR-T cell exhaustion. In both orthotopic lung cancer and lung metastasis model, combined therapy with CAR-T cells and aPD-L1 NVs@cGAMP potently inhibits tumor growth and prevents recurrence. Therefore, aPD-L1 NVs@cGAMP is expected to serve as an effective CAR-T cell enhancer to improve the efficacy of CAR-T cells against solid tumors.

Readily constructed squaraine J-aggregates with an 86.0 % photothermal conversion efficiency for photothermal therapy

The development of photothermal agents with high photothermal conversion efficiency (PCE) and long absorption wavelengths is crucial for safe and effective anti-cancer treatment. However, achieving these advantages often requires precise molecular design and complex synthetic procedures. In this study, we present a simple, precise, and effective method for fabricating photothermal agents with high PCE using long wavelength excitation. This approach involves linking two electron-donating components, diphenylamine (DPA), and an electron-withdrawing squaraine (SQ), via a π-bridge thiophene (T). The resulting D-π-A-π-D structure leads to a red-shifted absorption band. Within the DTS structure, DPA functions as a molecular rotor, T serves as a coplanar backbone, and SQ promotes J aggregation. When DTS nanoparticles (NPs) are fabricated using an amphiphilic nano-carrier, the maximum absorption wavelength shifts from 701 to 803 nm. This shift is accompanied by reduced fluorescence and an exceptionally high PCE of 86.0 %. Both in vitro and in vivo assessments confirm that DTS NPs exhibit strong potential for photothermal antitumor therapy. Overall, this strategy offers a valuable framework for designing photothermal agents with clinical applications in mind, offering a simpler and more efficient approach to achieving high PCE and long absorption wavelengths.

Engineered Biomimetic Cancer Cell Membrane Nanosystems Trigger Gas-Immunometabolic Therapy for Spinal-Metastasized Tumors

Despite great progress in enhancing tumor immunogenicity, conventional gas therapy cannot effectively reverse the tumor immunosuppressive microenvironment (TIME), limiting immunotherapy. The development of therapeutic gases that are tumor microenvironment responsive and efficiently reverse the TIME for precisely targeted tumor gas-immunometabolic therapy remains a great challenge. In this study, a novel cancer cell membrane-encapsulated pH-responsive nitric oxide (NO)-releasing biomimetic nanosystem (MP@AL) is prepared. Lactate oxidase (Lox) in MP@AL consumed oxygen to promote the decomposition of lactate, a metabolic by-product of tumor glycolysis, and the generation of H2O2, while L-arginine (L-Arg) in MP@AL is oxidized by H2O2 to generate nitric oxide (NO). For one thing, NO led to mitochondrial dysfunction in tumor cells to reduce oxygen consumption and promote the efficiency of Lox in lactate decomposition, thus reversing lactate-induced TIME; for another, NO effectively triggered immunogenic cell death, activated anti-tumor immune response and long-term immune memory, and ensured a favorable effect in the synergistic interaction with PD-L1 antibody for inhibiting tumor growth and recurrence. Therefore, a novel gas-immunometabolic therapy dual closed-loop nanosystem for enhancing tumor immunogenicity and remodeling lactate-induced TIME is established. Overall, this work will provide new ideas for gas therapy to effectively remodel the TIME to enhance cancer immunotherapy.

A Hydrogel for Nitric Oxide Sensitization Chemotherapy Mediated by Tumor Microenvironment Changes in 3D Spheroids and Breast Tumor Models

BACKGROUND

Nitric oxide (NO) is a low-toxicity and high-efficiency anticancer treatment that can augment the cytotoxicity of doxorubicin (DOX) towards breast cancer cells, thereby exhibiting a favorable effect on chemotherapy sensitization.

OBJECTIVE

The study aimed to establish a hydrogel that sensitizes chemotherapy by inducing local inflammatory stimulation to change the tumor microenvironment and promote NO production. The purpose of the study was to examine the anti-tumor effect in vivo and in vitro.

METHODS

The functional properties of the composite hydrogels were tested by UV spectrophotometry and NO detection kit. CCK8, DCFH-DA fluorescent probe, Calcein-AM/PI detection kit, and confocal detection methods were used for the cytocompatibility and cytotoxicity of the composite hydrogels. The subcutaneous tumor volume, weight, and tumor inhibition rate of 4T1 breast cancer cells were evaluated for pharmacodynamic study in vivo.

RESULTS

Each component of hydrogel has good biocompatibility. The combination of gas therapy and chemotherapy can significantly enhance the effect of inhibiting tumor cell growth. The tumor growth of tumor- bearing mice in the hydrogel administration group was slow, and the tumor inhibition rate was 85.10%. The body weight grew steadily, and no significant pathological changes were observed in the H&E staining of major organs.

CONCLUSION

A composite hydrogel with alginate as the carrier was successfully established, which was based on improving the tumor microenvironment to trigger gas therapy combined with chemotherapy for tumor treatment.

Living Therapeutics for Synergistic Hydrogen-Photothermal Cancer Treatment by Photosynthetic Bacteria

Hydrogen gas (H2) therapy, recognized for its inherent biosafety, holds significant promise as an anti-cancer strategy. However, the efficacy of H2 treatment modalities is compromised by their reliance on systemic gas administration or chemical reactions generation, which suffers from low efficiency, poor targeting, and suboptimal utilization. In this study, living therapeutics are employed using photosynthetic bacteria Rhodobacter sphaeroides for in situ H2 production combined with near-infrared (NIR) mediated photothermal therapy. Living R. sphaeroides exhibits strong absorption in the NIR spectrum, effectively converting light energy into thermal energy while concurrently generating H2. This dual functionality facilitates the targeted induction of tumor cell death and substantially reduces collateral damage to adjacent normal tissues. The findings reveal that integrating hydrogen therapy with photothermal effects, mediated through photosynthetic bacteria, provides a robust, dual-modality approach that enhances the overall efficacy of tumor treatments. This living therapeutic strategy not only leverages the therapeutic potential of both hydrogen and photothermal therapeutic modalities but also protects healthy tissues, marking a significant advancement in cancer therapy techniques.

Recent advances in ferrocene-based nanomedicines for enhanced chemodynamic therapy

Malignant tumors have been a serious threat to human health with their increasing incidence. Difficulties with conventional treatments are toxicity, drug resistance, and recurrence. For this reason, non-invasive treatment modalities such as photothermal therapy (PTT), photodynamic therapy (PDT), chemodynamic therapy (CDT), and others have received much attention. Among them, Ferrocene (Fc)-based nanomedicines for enhanced Chemodynamic Therapy (ECDT) is a new therapeutic strategy based on the Fenton reaction. Based on ferrocene's good biocompatibility, potentiation in medicinal chemistry, and good stability of divalent iron ions, scientists are increasingly using it as a Fenton's iron donor for tumor therapy. Such ferrocene-based ECDT nanoplatforms have shown remarkable promise for clinical applications and have significantly increased the efficacy of CDT treatment. Ferrocene-based nanomedicines exhibit exceptional consistency owing to their low toxicity, high stability, enhanced bioavailability, and a multitude of advantages over conventional approaches to cancer treatment. As a consequence, a number of tactics have been investigated in recent years to raise the effectiveness of ferrocene-based ECDT. In this review, we detail the different forms and strategies used to enhance Ferrocene-based ECDT efficiency.

Ultrasound-responsive nanoparticles for nitric oxide release to inhibit the growth of breast cancer

Gas therapy represents a promising strategy for cancer treatment, with nitric oxide (NO) therapy showing particular potential in tumor therapy. However, ensuring sufficient production of NO remains a significant challenge. Leveraging ultrasound-responsive nanoparticles to promote the release of NO is an emerging way to solve this challenge. In this study, we successfully constructed ultrasound-responsive nanoparticles, which consisted of poly (D, L-lactide-co-glycolic acid) (PLGA) nanoparticles, natural L-arginine (LA), and superparamagnetic iron oxide nanoparticles (SPIO, Fe3O4 NPs), denote as Fe3O4-LA-PLGA NPs. The Fe3O4-LA-PLGA NPs exhibited effective therapeutic effects both in vitro and in vivo, particularly in NO-assisted antitumor gas therapy and photoacoustic (PA) imaging properties. Upon exposure to ultrasound irradiation, LA and Fe3O4 NPs were rapidly released from the PLGA NPs. It was demonstrated that LA could spontaneously react with hydrogen peroxide (H2O2) present in the tumor microenvironment to generate NO for gas therapy. Concurrently, Fe3O4 NPs could rapidly react with H2O2 to produce a substantial quantity of reactive oxygen species (ROS), which can oxidize LA to further facilitate the release of NO. In conclusion, the proposed ultrasound-responsive NO delivery platform exhibits significant potential in effectively inhibiting the growth of breast cancer.