MnO2-melittin nanoparticles serve as an effective anti-tumor immunotherapy by enhancing systemic immune response

Advances in polymer nanomaterials targeting cGAS-STING pathway for enhanced cancer immunotherapy

Cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway has been recognized as a promising target for cancer immunotherapy. Although various STING agonists have been developed, their clinical applications are still severely impeded by various issues, such as non-specific accumulation, adverse effects, rapid clearance, etc. In recent years, the emergence of nanomaterials has profoundly revolutionized STING agonists delivery, which promote tumor-targeted delivery, boost the immunotherapeutic effects and reduce systemic toxicity of STING agonists. In particular, polymer nanomaterials possess inherent advantages including controllable structure, tunable function and degradability. These properties afford them the capacity to serve as delivery vehicles for small-molecule STING agonists. Furthermore, the superior characteristics of polymer nanomaterials can enable their utilization as a novel STING agonist to stimulate anti-tumor immunity. In this review, the molecular mechanisms of cGAS-STING pathway activation are discussed. The recent development of small-molecules STING agonists is described. Then polymer nanomaterials are discussed as carriers for STING agonists in cancer immunotherapy, including polymersomes, polymer micelles, polymer capsules, and polymer nanogels. Additionally, polymer nanomaterials are identified as a novel class of STING agonists for efficient cancer immunotherapy, encompassing both polymer materials and polymer-STING agonists conjugates. The review also presents the combination of polymer-based cGAS-STING immunotherapy with chemotherapy, radiotherapy, phototherapy (both photodynamic and photothermal), chemodynamic therapy, and other therapeutic strategies. Furthermore, the discussion highlights recent advancements targeting the cGAS-STING pathway in clinically approved polymer nanomaterials and corresponding potent innovations. Finally, the potential challenges and perspectives of polymer nanomaterials for activating cGAS-STING pathway are outlined, emphasizing the critical scientific issue and hoping to offer guidance for their clinical translation.

Arginine N-glycosylation of melittin enhances its bacteriostatic activity and antiproliferative therapeutic index

Melittin is a natural antimicrobial peptide isolated from bee venom, and the non-specific cytotoxicity and hemolytic activity severely limit its clinical application. Glycosylation of proteins is very common in physiological and biochemical processes and can modulate the interaction of proteins with their target. In this study, eight glycosyl groups were used to modify the arginine of melittin at sites 22 and/or 24, and single and double arginine N-glycosylated peptides were designed and synthesized. Among the acquired 24 glycopeptides, MLT-1c, MLT-3c, MLT-1f, MLT-3f, MLT-1g, and MLT-3h were found to possess higher helicity, while MLT-3c, MLT-3f and MLT-3h showed dramatically reduced hemolytic activity, especially MLT-3c, whose HC50 value is 199.3 μM. MLT-1a, MLT-3a and MLT-2c exhibited improved inhibitory activity against Puzza streptococcus, and the MIC was 4 μg mL-1. MLT-1e and MLT-2g have the strongest tolerance to trypsase, and MLT-3c has the highest therapeutic index. In general, rhamnosyl-modified melittin MLT-3c could be a potent agent for antibacterial and antitumor therapy with high stability and low hemolytic side effects.

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.

Mechanisms and Applications of Manganese-Based Nanomaterials in Tumor Diagnosis and Therapy

Tumors are the second most common cause of mortality globally, ranking just below heart disease. With continuous advances in diagnostic technology and treatment approaches, the survival rates of some cancers have increased. Nevertheless, due to the complexity of the mechanisms underlying tumors, cancer remains a serious public health issue that threatens the health of the population globally. Manganese (Mn) is an essential trace element for the human body. Its regulatory role in tumor biology has received much attention in recent years. Developments in nanotechnology have led to the emergence of Mn-based nanoparticles that have great potential for use in the diagnosis and treatment of cancers. Mn-based nanomaterials can be integrated with conventional techniques, including chemotherapy, radiation therapy, and gene therapy, to augment their therapeutic effectiveness. Further, Mn-based nanomaterials can play a synergistic role in emerging treatment strategies for tumors, such as immunotherapy, photothermal and photodynamic therapy, electromagnetic hyperthermia, sonodynamic therapy, chemodynamic therapy, and intervention therapy. Moreover, Mn-based nanomaterials can enhance both the precision of tumor diagnostics and the capability for combined diagnosis and treatment. This article examines the roles and associated mechanisms of Mn in the field of physiology and tumor biology, with a focus on the application prospects of Mn-based nanomaterials in tumor diagnosis and treatment.

Tumor-Targeted Catalytic Immunotherapy

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Peptides as Versatile Regulators in Cancer Immunotherapy: Recent Advances, Challenges, and Future Prospects

The emergence of effective immunotherapies has revolutionized therapies for many types of cancer. However, current immunotherapy has limited efficacy in certain patient populations and displays therapeutic resistance after a period of treatment. To address these challenges, a growing number of immunotherapy drugs have been investigated in clinical and preclinical applications. The diverse functionality of peptides has made them attractive as a therapeutic modality, and the global market for peptide-based therapeutics is witnessing significant growth. Peptides can act as immunotherapeutic agents for the treatment of many malignant cancers. However, a systematic understanding of the interactions between different peptides and the host's immune system remains unclear. This review describes in detail the roles of peptides in regulating the function of the immune system for cancer immunotherapy. Initially, we systematically elaborate on the relevant mechanisms of cancer immunotherapy. Subsequently, we categorize peptide-based nanomaterials into the following three categories: peptide-based vaccines, anti-cancer peptides, and peptide-based delivery systems. We carefully analyzed the roles of these peptides in overcoming the current barriers in immunotherapy, including multiple strategies to enhance the immunogenicity of peptide vaccines, the synergistic effect of anti-cancer peptides in combination with other immune agents, and peptide assemblies functioning as immune stimulators or vehicles to deliver immune agents. Furthermore, we introduce the current status of peptide-based immunotherapy in clinical applications and discuss the weaknesses and future prospects of peptide-based materials for cancer immunotherapy. Overall, this review aims to enhance comprehension of the potential applications of peptide-based materials in cancer immunotherapy and lay the groundwork for future research and clinical applications.

"All-in-One" MnO2@PtAuRu Nanoreactor for Self-Replenishing and Cascade Catalytic Therapy of Cancer

Limited by the insufficient catalytic substrates such as H2O2 and O2 in the tumor microenvironment (TME), the continual propelling of nanozymes catalysis therapy of cancer remains a challenge. Here, an all-in-one MnO2@PtAuRu nanoreactor is constructed for self-propelled and cascade catalytic therapy of tumors. The MnO2@PtAuRu is constructed by using hollow MnO2 (≈150 nm) as the core-carrier and ultrasmall PtAuRu nanoclusters (≈2 nm) anchoring on the surface MnO2. According to the glucose oxidase (GOD)/catalase (CAT)/peroxidase (POD) mimic multienzyme activity of PtAuRu nanoclusters, cascaded nanocatalytic reactions can be self-replenishing to persistently produce •OH for superior chemodynamic therapy (CDT). Additionally, the MnO2 carrier can protect the ultrasmall PtAuRu nanoclusters during the circulation and the overexpressed glutathione (GSH) in the tumor can also be degraded by the MnO2 to synergy the CDT. The MnO2@PtAuRu displays obvious photothermal properties which further enhance the cascade catalytic ability and synergistic therapeutic effect. Therefore, this all-in-one nanozyme provides a promising strategy for the rational design of self-replenishment and self-replenishing cascade catalytic therapy of cancer.

Metal-based smart nanosystems in cancer immunotherapy

Metals are an emerging topic in cancer immunotherapy that have shown great potential in modulating cancer immunity cycle and promoting antitumor immunity by activating the intrinsic immunostimulatory mechanisms which have been identified in recent years. The main challenge of metal-assisted immunotherapy lies in the fact that the free metals as ion forms are easily cleared during circulation, and even cause systemic metal toxicity due to the off-target effects. With the rapid development of nanomedicine, metal-based smart nanosystems (MSNs) with unique controllable structure become one of the most promising delivery carriers to solve the issue, owing to their various endogenous/external stimuli-responsiveness to release free metal ions for metalloimmunotherapy. In this review, the state-of-the-art research progress in metal-related immunotherapy is comprehensively summarized. First, the mainstream mechanisms of MSNs-assisted immunotherapy will be delineated. The immunological effects of certain metals and categorization of MSNs with different characters and compositions are then provided, followed by the representative exemplar applications of MSNs in cancer treatment, and synergistic combination immunotherapy. Finally, we conclude this review with a summary of the remaining challenges associated with MSNs and provide the authors' perspective on their further advances.

Melittin-incorporated nanomedicines for enhanced cancer immunotherapy

Immunotherapy is a rapidly developing and effective strategy for cancer therapy. Among various immunotherapy approaches, peptides have garnered significant attention due to their potent immunomodulatory effects. In particular, melittin emerged as a promising candidate to enhance cancer immunotherapy by inducing immunogenic cell death, promoting the maturation of antigen-presenting cells, activating T cells, enhancing the infiltration and cytotoxicity of effector lymphocytes, and modulating macrophage phenotypes for relieving immunosuppression. However, the clinical application of melittin is limited by poor targeting and systemic toxicity. To overcome these challenges, melittin has been incorporated into biomaterials and related nanotechnologies, resulting in extended circulation time in vivo, improved targeting, reduced adverse effects, and enhanced anti-cancer immunological action. This review provides an in-depth analysis of the immunomodulatory effects of melittin-incorporated nanomedicines and examines their development and challenges for clinical cancer immunotherapy.

Melittin and phospholipase A2: Promising anti-cancer candidates from bee venom

As the research on cancer-related treatment deepens, integrating traditional therapies with emerging interventions reveals new therapeutic possibilities. Melittin and phospholipase A2, the primary anti-cancer components of bee venom, are currently gaining increasing attention. This article reviews the various formulations of melittin in cancer therapy and its potential applications in clinical treatments. The reviewed formulations include melittin analogs, hydrogels, adenoviruses, fusion toxins, fusion peptides/proteins, conjugates, liposomes, and nanoparticles. The article also explored the collaborative therapeutic effects of melittin with natural products, synthetic drugs, radiotherapy, and gene expression regulatory strategies. Phospholipase A2 plays a key role in bee venom anti-cancer strategy due to its unique biological activity. Using an extensive literature review and the latest scientific results, this paper explores the current state and challenges of this field, with the aim to provide new perspectives that guide future research and potential clinical applications. This will further promote the application of bee venom in cancer therapy.

Biodegradable oxygen-evolving metalloantibiotics for spatiotemporal sono-metalloimmunotherapy against orthopaedic biofilm infections

Pathogen-host competition for manganese and intricate immunostimulatory pathways severely attenuates the efficacy of antibacterial immunotherapy against biofilm infections associated with orthopaedic implants. Herein, we introduce a spatiotemporal sono-metalloimmunotherapy (SMIT) strategy aimed at efficient biofilm ablation by custom design of ingenious biomimetic metal-organic framework (PCN-224)-coated MnO2-hydrangea nanoparticles (MnPM) as a metalloantibiotic. Upon reaching the acidic H2O2-enriched biofilm microenvironment, MnPM can convert abundant H2O2 into oxygen, which is conducive to significantly enhancing the efficacy of ultrasound (US)-triggered sonodynamic therapy (SDT), thereby exposing bacteria-associated antigens (BAAs). Moreover, MnPM disrupts bacterial homeostasis, further killing more bacteria. Then, the Mn ions released from the degraded MnO2 can recharge immune cells to enhance the cGAS-STING signaling pathway sensing of BAAs, further boosting the immune response and suppressing biofilm growth via biofilm-specific T cell responses. Following US withdrawal, the sustained oxygenation promotes the survival and migration of fibroblasts, stimulates the expression of angiogenic growth factors and angiogenesis, and neutralizes excessive inflammation. Our findings highlight that MnPM may act as an immune costimulatory metalloantibiotic to regulate the cGAS-STING signaling pathway, presenting a promising alternative to antibiotics for orthopaedic biofilm infection treatment and pro-tissue repair.

Tumor microenvironment-responsive manganese-based nano-modulator activate the cGAS-STING pathway to enhance innate immune system response

BACKGROUND

Manganese ions (Mn2+) combined with adjuvants capable of damaging and lysing tumor cells form an antitumor nano-modulator that enhances the immune efficacy of cancer therapy through the cascade activation of the cyclic GMP-AMP interferon gene synthase-stimulator (cGAS-STING) pathway, which underscores the importance of developing antitumor nano-modulators, which induce DNA damage and augment cGAS-STING activity, as a critical future research direction. METHODS AND RESULTS: We have successfully synthesized an antitumor nano-modulator, which exhibits good dispersibility and biosafety. This nano-modulator is engineered by loading manganese dioxide nanosheets (M-NS) with zebularine (Zeb), known for its immunogenicity-enhancing effects, and conducting targeted surface modification using hyaluronic acid (HA). After systemic circulation to the tumor site, Mn2+, Zeb, and reactive oxygen species (ROS) are catalytically released in the tumor microenvironment by H+ and H2O2. These components can directly or indirectly damage the DNA or mitochondria of tumor cells, thereby inducing programmed cell death. Furthermore, they promote the accumulation of double-stranded DNA (dsDNA) in the cytoplasm, enhancing the activation of the cGAS-STING signalling pathway and boosting the production of type I interferon and the secretion of pro-inflammatory cytokines. Additionally, Zeb@MH-NS enhances the maturation of dendritic cells, the infiltration of cytotoxic T lymphocytes, and the recruitment of natural killer cells at the tumor site.

CONCLUSIONS

This HA-modified manganese-based hybrid nano-regulator can enhance antitumor therapy by boosting innate immune activity and may provide new directions for immunotherapy and clinical translation in cancer.

Unlocking nature's arsenal: Nanotechnology for targeted delivery of venom toxins in cancer therapy

AIM

The aim of the present review is to shed light on the nanotechnological approaches adopted to overcome the shortcomings associated with the delivery of venom peptides which possess inherent anti-cancer properties.

BACKGROUND

Venom peptides although have been reported to demonstrate anti-cancer effects, they suffer from several disadvantages such as in vivo instability, off-target adverse effects, limited drug loading and low bioavailability. This review presents a comprehensive compilation of different classes of nanocarriers while underscoring their advantages, disadvantages and potential to carry such peptide molecules for in vivo delivery. It also discusses various nanotechnological aspects such as methods of fabrication, analytical tools to assess these nanoparticulate formulations, modulation of nanocarrier polymer properties to enhance loading capacity, stability and improve their suitability to carry toxic peptide drugs.

CONCLUSION

Nanotechnological approaches bear great potential in delivering venom peptide-based molecules as anticancer agents by enhancing their bioavailability, stability, efficacy as well as offering a spatiotemporal delivery approach. However, the challenges associated with toxicity and biocompatibility of nanocarriers must be duly addressed.

PERSPECTIVES

The everlasting quest for new breakthroughs for safer delivery of venom peptides in human subjects is fuelled by unmet clinical needs in the current landscape of chemotherapy. In addition, exhaustive efforts are required in obtaining and purifying the venom peptides followed by designing and optimizing scale up technologies.

Melittin Alleviates Oxidative Stress Injury in Schwann Cells by Targeting Interleukin-1 Receptor Type 1 to Downregulate Nuclear Factor Kappa B-Mediated Inflammatory Response In Vitro

BACKGROUND AND OBJECTIVES

In ancient China, bee venom was widely used to treat various diseases. Although using bee venom is not currently a mainstream medical method, some have applied it to treat certain conditions, including idiopathic facial paralysis (IFP). Recently, melittin (Mel), the main active component of bee venom, has been shown strong anti-inflammatory and analgesic effects. However, how bee venom improves neurological dysfunction in facial paralysis remains unknown. This study aimed to investigate the anti-neurotraumatic effect of Mel on Schwann cells (SCs), the main cells of the neuron sheath, injured by oxidative stress.

METHODS

A model of hypoxic SCs was established, and CCK-8 assay, siRNA transfection, enzyme-linked immunosorbent assay, quantitative reverse transcription-polymerase chain reaction, western blot, immunofluorescence, and cell ultrastructure analyses were conducted to investigate the mitigation of hypoxia-induced damage to SCs in vitro, revealing the effects of Mel on oxidative stress injury in SCs.

RESULTS

The overexpression of HIF-1α in CoCl2-induced SCs (p < 0.05) indicated the establishment of an SCs hypoxia model. The proliferation and regeneration process of the hypoxic SCs enhanced in the Mel-treated group compared to the CoCl2 group has been proven through the CCK-8 experiment (p < 0.0001) and S-100 mRNA expression detection (p < 0.0001). The increased level of reactive oxygen species (ROS) (p < 0.001) and decreased superoxide dismutase (SOD) levels (p < 0.05) in the CoCl2-induced SCs indicated that Mel can alleviate the oxidative stress damage to SCs induced by CoCl2. Mel alleviated oxidative stress and inflammation in hypoxic SCs by reducing pro-inflammatory cytokines IL-1β (p < 0.0001) and TNF-α (p < 0.0001). In addition, Mel augmented cellular vitality and regulated indicators related to oxygen metabolism, cell repair, neurometabolism, and vascular endothelial formation after hypoxia, such as C-JUN (p < 0.05), glial cell line-derived neurotrophic factor (GDNF; p < 0.001), vascular endothelial growth factor (VEGF; p < 0.05), hypoxia-inducible factor 1-alpha (HIF-1α; p < 0.05), interleukin-1 receptor type 1 (IL-1R1; p < 0.05), enolase1 (ENO1; p < 0.05), aldose reductase (AR; p < 0.01), SOD (p < 0.05), nerve growth factor (NGF; p < 0.05), and inducible nitric oxide synthase (iNOS; p < 0.05). In terms of its mechanism, Mel inhibited the expression of proteins associated with the NF-κB pathway such as IKK (p < 0.01), p65 (p < 0.05), p60 (p < 0.001), IRAK1 (p < 0.05), and increased IKB-α (p < 0.0001). Moreover, knocking out of IL-1R1 in the si-IL-1R1 group enhanced the therapeutic effect of Mel compared to the Mel-treated group (all of which p < 0.05).

CONCLUSION

This research provided evidence of the substantial involvement of IL-1R1 in oxidative stress damage caused by hypoxia in SCs and proved that Mel alleviated oxidative stress injury in SCs by targeting IL-1R1 to downregulate the NF-κB-mediated inflammatory response. Mel could potentially serve as an innovative therapeutic approach for the treatment of IFP.

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.

Homologous-targeting biomimetic nanoparticles co-loaded with melittin and a photosensitizer for the combination therapy of triple negative breast cancer

Melittin (Mel) is considered a promising candidate drug for the treatment of triple negative breast cancer (TNBC) due to its various antitumor effects. However, its clinical application is hampered by notable limitations, including hemolytic activity, rapid clearance, and a lack of tumor selectivity. Here, we designed novel biomimetic nanoparticles based on homologous tumor cell membranes and poly(lactic-co-glycolic acid) (PLGA)/poly(beta-aminoester) (PBAE), denoted MDM@TPP, which efficiently coloaded the cytolytic peptide Mel and the photosensitizer mTHPC. Both in vitro and in vivo, the MDM@TPP nanoparticles effectively mitigated the acute toxicity of melittin and exhibited strong TNBC targeting ability due to the homologous targeting effect of the tumor cell membrane. Under laser irradiation, the MDM@TPP nanoparticles showed excellent photodynamic performance and thus accelerated the release of Mel by disrupting cell membrane integrity. Moreover, Mel combined with photodynamic therapy (PDT) can synergistically kill tumor cells and induce significant immunogenic cell death, thereby stimulating the maturation of dendritic cells (DCs). In 4T1 tumor-bearing mice, MDM@TPP nanoparticles effectively inhibited the growth and metastasis of primary tumors and finally prevented tumor recurrence by improving the immune response.

Dual biomarkers-activatable hollow MnO2-Based theranostic nanoplatform for efficient breast cancer-specific multisite fluorescence imaging and synergistic therapy

BACKGROUND

Theranostic nanoplatforms with integrated diagnostic imaging and multiple therapeutic functions play a vital role in precise diagnosis and efficient treatment for breast cancer, but unfortunately, these nanoplatforms are usually stuck in single-site imaging and single mode of treatment, causing unsatisfactory diagnostic and therapeutic efficiency. Herein, a dual biomarkers-activatable facile hollow mesoporous MnO2 (H-MnO2)-based theranostic nanoplatform, DNAzyme@H-MnO2-MUC1 aptamer (DHMM), was constructed for the simultaneous multi-site diagnosis and multiple treatment of breast cancer.

RESULTS

The DHMM acted as an integrated diagnostic and therapeutic nanoplatform that realizes multi-site fluorescence imaging-guided high-efficient photothermal/chemodynamic/gene synergistic therapy (PTT/CDT/GT) for breast cancer. The H-MnO2 exhibits high loading capacity for Cy5-MUC1 aptamer (3.05 pmoL μg-1) and FAM-DNAzyme (3.37 pmoL μg-1), and excellent quenching for the probes. In the presence of MUC1 on the cell membrane and GSH in the cytoplasm, Cy5-MUC1 aptamer and FAM-DNAzyme was activated triggering dual-channel fluorescence imaging at different sites. Moreover, the self-supplied Mn2+ was further supplied as DNAzyme cofactors to catalytic cleavage intracellular EGR-1 mRNA for high-efficient GT and stimulated the Fenton-like reaction for CDT. The H-MnO2 also showcases a favorable photothermal performance with a photothermal conversion efficiency of 44.16%, which ultimately contributes to multi-site fluorescence imaging-guided synergistic treatment with an apoptosis rate of 71.82%.

SIGNIFICANCE

This dual biomarker-activatable multiple therapeutic nanoplatform was realized multi-site fluorescence imaging-guided PTT/CDT/GT combination therapy for breast cancer with higher specificity and efficiency, which provides a promising theranostic nanoplatform for the precision and efficiency of breast cancer treatment.

Manganese-based nanomaterials promote synergistic photo-immunotherapy: green synthesis, underlying mechanisms, and multiple applications

Single phototherapy and immunotherapy have individually made great achievements in tumor treatment. However, monotherapy has difficulty in balancing accuracy and efficiency. Combining phototherapy with immunotherapy can realize the growth inhibition of distal metastatic tumors and enable the remote monitoring of tumor treatment. The development of nanomaterials with photo-responsiveness and anti-tumor immunity activation ability is crucial for achieving photo-immunotherapy. As immune adjuvants, photosensitizers and photothermal agents, manganese-based nanoparticles (Mn-based NPs) have become a research hotspot owing to their multiple ways of anti-tumor immunity regulation, photothermal conversion and multimodal imaging. However, systematic studies on the synergistic photo-immunotherapy applications of Mn-based NPs are still limited; especially, the green synthesis and mechanism of Mn-based NPs applied in immunotherapy are rarely comprehensively discussed. In this review, the synthesis strategies and function of Mn-based NPs in immunotherapy are first introduced. Next, the different mechanisms and leading applications of Mn-based NPs in immunotherapy are reviewed. In addition, the advantages of Mn-based NPs in synergistic photo-immunotherapy are highlighted. Finally, the challenges and research focus of Mn-based NPs in combination therapy are discussed, which might provide guidance for future personalized cancer therapy.

Nanoparticles in tumor microenvironment remodeling and cancer immunotherapy

Cancer immunotherapy and vaccine development have significantly improved the fight against cancers. Despite these advancements, challenges remain, particularly in the clinical delivery of immunomodulatory compounds. The tumor microenvironment (TME), comprising macrophages, fibroblasts, and immune cells, plays a crucial role in immune response modulation. Nanoparticles, engineered to reshape the TME, have shown promising results in enhancing immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles further enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells such as dendritic cells. Moreover, exosomes, whether naturally secreted by cells in the body or bioengineered, have been explored to regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit the potential to accelerate immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. With their ability to induce long-term immunity, nanoarchitectures are promising structures in vaccine development. This review underscores the critical role of nanoparticles in overcoming current challenges and driving the advancement of cancer immunotherapy and TME modification.

Application and progress of nanozymes in antitumor therapy

Tumors remain one of the major threats to public health and there is an urgent need to design new pharmaceutical agents for their diagnosis and treatment. In recent years, due to the rapid development of nanotechnology, biotechnology, catalytic science, and theoretical computing, subtlety has gradually made great progress in research related to tumor diagnosis and treatment. Compared to conventional drugs, enzymes can improve drug distribution and enhance drug enrichment at the tumor site, thereby reducing drug side effects and enhancing drug efficacy. Nanozymes can also be used as tumor tracking imaging agents to reshape the tumor microenvironment, providing a versatile platform for the diagnosis and treatment of malignancies. In this paper, we review the current status of research on enzymes in oncology and analyze novel oncology therapeutic approaches and related mechanisms. To date, a large number of nanomaterials, such as noble metal nanomaterials, nonmetallic nanomaterials, and carbon-based nanomaterials, have been shown to be able to function like natural enzymes, particularly with significant advantages in tumor therapy. In light of this, the authors in this review have systematically summarized and evaluated the construction, enzymatic activity, and their characteristics of nanozymes with respect to current modalities of tumor treatment. In addition, the application and research progress of different types of nicknames and their features in recent years are summarized in detail. We conclude with a summary and outlook on the study of nanozymes in tumor diagnosis and treatment. It is hoped that this review will inspire researchers in the fields of nanotechnology, chemistry, biology, materials science and theoretical computing, and contribute to the development of nano-enzymology.

pH-Responsive Amphiphilic Triblock Fluoropolymers as Assemble Oxygen Nanoshuttles for Enhancing PDT against Hypoxic Tumor

Photodynamic therapy (PDT) is a cancer treatment strategy that utilizes photosensitizers to convert oxygen within tumors into reactive singlet oxygen (1O2) to lyse tumor cells. Nevertheless, pre-existing tumor hypoxia and oxygen consumption during PDT can lead to an insufficient oxygen supply, potentially reducing the photodynamic efficacy. In response to this issue, we have devised a pH-responsive amphiphilic triblock fluorinated polymer (PDP) using copper-mediated RDRP. This polymer, composed of poly(ethylene glycol) methyl ether acrylate, 2-(diethylamino)ethyl methacrylate, and (perfluorooctyl)ethyl acrylate, self-assembles in an aqueous environment. Oxygen, chlorine e6 (Ce6), and doxorubicin (DOX) can be codelivered efficiently by PDP. The incorporation of perfluorocarbon into the formulation enhances the oxygen-carrying capacity of PDP, consequently extending the lifetime of 1O2. This increased lifetime, in turn, amplifies the PDT effect and escalates the cellular cytotoxicity. Compared with PDT alone, PDP@Ce6-DOX-O2 NPs demonstrated significant inhibition of tumor growth. This study proposes a novel strategy for enhancing the efficacy of PDT.

Repolarizing Tumor-Associated Macrophages and inducing immunogenic cell Death: A targeted liposomal strategy to boost cancer immunotherapy

Cancer immunotherapy has shown promise in treating various malignancies. However, the presence of an immunosuppressive tumor microenvironment (TME) triggered by M2 tumor-associated macrophages (TAMs) and the limited tumor cell antigenicity have hindered its broader application. To address these challenges, we developed DOX/R837@ManL, a liposome loaded with imiquimod (R837) and doxorubicin (DOX), modified with mannose-polyethylene glycol (Man-PEG). DOX/R837@ManL employed a mannose receptor (MRC1)-mediated targeting strategy, allowing it to accumulate selectively at M2 Tumor associated macrophages (TAMs) and tumor sites. R837, an immune adjuvant, promoted the conversion of immunosuppressive M2 TAMs into immunostimulatory M1 TAMs, and reshaped the immunosuppressive TME. Simultaneously, DOX release induced immunogenic cell death (ICD) in tumor cells and enhanced tumor cell antigenicity by promoting dendritic cells (DCs) maturation. Through targeted delivery, the synergistic action of R837 and DOX activated innate immunity and coordinated adaptive immunity, enhancing immunotherapy efficacy. In vivo experiments have demonstrated that DOX/R837@ManL effectively eliminated primary tumors and lung metastases, while also preventing tumor recurrence post-surgery. These findings highlighted the potential of DOX/R837@ManL as a promising strategy for cancer immunotherapy.

Revisiting edible insects as sources of therapeutics and drug delivery systems for cancer therapy

Cancer has been medicine's most formidable foe for long, and the rising incidence of the disease globally has made effective cancer therapy a significant challenge. Drug discovery is targeted at identifying efficacious compounds with minimal side effects and developments in nanotechnology and immunotherapy have shown promise in the fight against this complicated illness. Since ancient times, insects and insect-derived products have played a significant role in traditional medicine across several communities worldwide. The aim of this study was to inspect the traditional use of edible insects in various cultures and to explore their modern use in cancer therapy. Edible insects are sources of nutrients and a variety of beneficial substances with anticancer and immunomodulatory potential. Recently, insect derived bioactive-components have also been used as nanoparticles either in combination with chemotherapeutics or as a nano-cargo for the enhanced delivery of chemotherapeutic drugs due to their high biocompatibility, low bio-toxicity, and their antioxidant and anticancer effects. The crude extracts of different edible insects and their active components such as sericin, cecropin, solenopsin, melittin, antimicrobial peptides and fibroin produce anti-cancer and immunomodulatory effects by various mechanisms which have been discussed in this review.

Nanoenabled Intracellular Metal Ion Homeostasis Regulation for Tumor Therapy

Endogenous essential metal ions play an important role in many life processes, especially in tumor development and immune response. The approval of various metallodrugs for tumor therapy brings more attention to the antitumor effect of metal ions. With the deepening understanding of the regulation mechanisms of metal ion homeostasis in vivo, breaking intracellular metal ion homeostasis becomes a new means to inhibit the proliferation of tumor cells and activate antitumor immune response. Diverse nanomedicines with the loading of small molecular ion regulators or metal ions have been developed to disrupt metal ion homeostasis in tumor cells, with higher safety and efficiency than free small molecular ion regulators or metal compounds. This comprehensive review focuses on the latest progress of various intracellular metal ion homeostasis regulation-based nanomedicines in tumor therapy including calcium ion (Ca2+ ), ferrous ion (Fe2+ ), cuprous ion (Cu+ ), managanese ion (Mn2+ ), and zinc ion (Zn2+ ). The physiological functions and homeostasis regulation processes of ions are summarized to guide the design of metal ion regulation-based nanomedicines. Then the antitumor mechanisms of various ions-based nanomedicines and some efficient synergistic therapies are highlighted. Finally, the challenges and future developments of ion regulation-based antitumor therapy are also discussed, hoping to provide a reference for finding more effective metal ions and synergistic therapies.

The current landscape of the antimicrobial peptide melittin and its therapeutic potential

Melittin, a main component of bee venom, is a cationic amphiphilic peptide with a linear α-helix structure. It has been reported that melittin can exert pharmacological effects, such as antitumor, antiviral and anti-inflammatory effects in vitro and in vivo. In particular, melittin may be beneficial for the treatment of diseases for which no specific clinical therapeutic agents exist. Melittin can effectively enhance the therapeutic properties of some first-line drugs. Elucidating the mechanism underlying melittin-mediated biological function can provide valuable insights for the application of melittin in disease intervention. However, in melittin, the positively charged amino acids enables it to directly punching holes in cell membranes. The hemolysis in red cells and the cytotoxicity triggered by melittin limit its applications. Melittin-based nanomodification, immuno-conjugation, structural regulation and gene technology strategies have been demonstrated to enhance the specificity, reduce the cytotoxicity and limit the off-target cytolysis of melittin, which suggests the potential of melittin to be used clinically. This article summarizes research progress on antiviral, antitumor and anti-inflammatory properties of melittin, and discusses the strategies of melittin-modification for its future potential clinical applications in preventing drug resistance, enhancing the selectivity to target cells and alleviating cytotoxic effects to normal cells.

Anticancer activities of natural antimicrobial peptides from animals

Cancer is the most common cause of human death worldwide, posing a serious threat to human health and having a negative impact on the economy. In the past few decades, significant progress has been made in anticancer therapies, but traditional anticancer therapies, including radiation therapy, surgery, chemotherapy, molecular targeted therapy, immunotherapy and antibody-drug conjugates (ADCs), have serious side effects, low specificity, and the emergence of drug resistance. Therefore, there is an urgent need to develop new treatment methods to improve efficacy and reduce side effects. Antimicrobial peptides (AMPs) exist in the innate immune system of various organisms. As the most promising alternatives to traditional drugs for treating cancers, some AMPs also have been proven to possess anticancer activities, which are defined as anticancer peptides (ACPs). These peptides have the advantages of being able to specifically target cancer cells and have less toxicity to normal tissues. More and more studies have found that marine and terrestrial animals contain a large amount of ACPs. In this article, we introduced the animal derived AMPs with anti-cancer activity, and summarized the types of tumor cells inhibited by ACPs, the mechanisms by which they exert anti-tumor effects and clinical applications of ACPs.

From oncolytic peptides to oncolytic polymers: A new paradigm for oncotherapy

Traditional cancer therapy methods, especially those directed against specific intracellular targets or signaling pathways, are not powerful enough to overcome tumor heterogeneity and therapeutic resistance. Oncolytic peptides that can induce membrane lysis-mediated cancer cell death and subsequent anticancer immune responses, has provided a new paradigm for cancer therapy. However, the clinical application of oncolytic peptides is always limited by some factors such as unsatisfactory bio-distribution, poor stability, and off-target toxicity. To overcome these limitations, oncolytic polymers stand out as prospective therapeutic materials owing to their high stability, chemical versatility, and scalable production capacity, which has the potential to drive a revolution in cancer treatment. This review provides an overview of the mechanism and structure-activity relationship of oncolytic peptides. Then the oncolytic peptides-mediated combination therapy and the nano-delivery strategies for oncolytic peptides are summarized. Emphatically, the current research progress of oncolytic polymers has been highlighted. Lastly, the challenges and prospects in the development of oncolytic polymers are discussed.

Manganese-Based Nanotheranostics for Magnetic Resonance Imaging-Mediated Precise Cancer Management

Manganese (Mn)-based magnetic resonance imaging (MRI) has become a competitive imaging modality for cancer diagnosis due to its advantages of non-invasiveness, high resolution and excellent biocompatibility. In recent years, a variety of Mn contrast agents based on different material systems have been synthesized, and a series of multi-purpose Mn nanocomposites have also emerged, showing satisfactory relaxation efficiency and MRI performance thus possess the transformation and application value in MRI-synergized cancer diagnosis and treatment. This tutorial review starts from the classification and properties of Mn-based nanomaterials, and then summarizes various preparation and functionalization strategies of nanosized Mn contrast agents, especially focuses on the latest progress of Mn contrast agents in MRI-synergized precise cancer theranostics. In addition, present review also discusses the current clinical transformation obstacles such as unclear molecular mechanisms, potential nanotoxicity, and scale production constraints. This paper provides evidence-based recommendations about the future prospects of multifunctional nanoplatforms, as well as technical guidance and panoramic expectations for the design of clinically meaningful cancer management programs.

Research progress of nanovaccine in anti-tumor immunotherapy

Tumor vaccines aim to activate dormant or unresponsive tumor-specific T lymphocytes by using tumor-specific or tumor-associated antigens, thus enhancing the body's natural defense against cancer. However, the effectiveness of tumor vaccines is limited by the presence of tumor heterogeneity, low immunogenicity, and immune evasion mechanisms. Fortunately, multifunctional nanoparticles offer a unique chance to address these issues. With the advantages of their small size, high stability, efficient drug delivery, and controlled surface chemistry, nanomaterials can precisely target tumor sites, improve the delivery of tumor antigens and immune adjuvants, reshape the immunosuppressive tumor microenvironment, and enhance the body's anti-tumor immune response, resulting in improved efficacy and reduced side effects. Nanovaccine, a type of vaccine that uses nanotechnology to deliver antigens and adjuvants to immune cells, has emerged as a promising strategy for cancer immunotherapy due to its ability to stimulate immune responses and induce tumor-specific immunity. In this review, we discussed the compositions and types of nanovaccine, and the mechanisms behind their anti-tumor effects based on the latest research. We hope that this will provide a more scientific basis for designing tumor vaccines and enhancing the effectiveness of tumor immunotherapy.

Recent Advances in Nanoplatform Construction Strategy for Alleviating Tumor Hypoxia

Hypoxia is a typical feature of most solid tumors and has important effects on tumor cells' proliferation, invasion, and metastasis. This is the key factor that leads to poor efficacy of different kinds of therapy including chemotherapy, radiotherapy, photodynamic therapy, etc. In recent years, the construction of hypoxia-relieving functional nanoplatforms through nanotechnology has become a new strategy to reverse the current situation of tumor microenvironment hypoxia and improve the effectiveness of tumor treatment. Here, the main strategies and recent progress in constructing nanoplatforms are focused on to directly carry oxygen, generate oxygen in situ, inhibit mitochondrial respiration, and enhance blood perfusion to alleviate tumor hypoxia. The advantages and disadvantages of these nanoplatforms are compared. Meanwhile, nanoplatforms based on organic and inorganic substances are also summarized and classified. Through the comprehensive overview, it is hoped that the summary of these nanoplatforms for alleviating hypoxia could provide new enlightenment and prospects for the construction of nanomaterials in this field.

Biomaterial-enabled therapeutic modulation of cGAS-STING signaling for enhancing antitumor immunity

cGAS-STING signaling is a central component in the therapeutic action of most existing cancer therapies. The accumulated knowledge of tumor immunoregulatory network in recent years has spurred the development of cGAS-STING agonists for tumor treatment as an effective immunotherapeutic strategy. However, the clinical translation of these agonists is thus far unsatisfactory because of the low immunostimulatory efficacy and unrestricted side effects under clinically relevant conditions. Interestingly, the rational integration of biomaterial technology offers a promising approach to overcome these limitations for more effective and safer cGAS-STING-mediated tumor therapy. Herein, we first outline the cGAS-STING signaling axis and generally discuss its association with tumors. We then symmetrically summarize the recent progress in those biomaterial-based cGAS-STING agonism strategies to generate robust antitumor immunity, categorized by the chemical nature of those cGAS-STING stimulants and carrier substrates. Finally, a perspective is provided to discuss the existing challenges and potential opportunities in cGAS-STING modulation for tumor therapy.

Nanoparticle-Mediated STING Activation for Cancer Immunotherapy

As the first line of host defense against pathogenic infections, innate immunity plays a key role in antitumor immunotherapy. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) (cGAS-STING) pathway has attracted much attention because of the secretion of various proinflammatory cytokines and chemokines. Many STING agonists have been identified and applied into preclinical or clinical trials for cancer immunotherapy. However, the fast excretion, low bioavailability, nonspecificity, and adverse effects of the small molecule STING agonists limit their therapeutic efficacy and in vivo application. Nanodelivery systems with appropriate size, charge, and surface modification are capable of addressing these dilemmas. In this review, the mechanism of the cGAS-STING pathway is discussed and the STING agonists, focusing on nanoparticle-mediated STING therapy and combined therapy for cancers, are summarized. Finally, the future direction and challenges of nano-STING therapy are expounded, emphasizing the pivotal scientific problems and technical bottlenecks and hoping to provide general guidance for its clinical application.

Immunomodulatory activity of manganese dioxide nanoparticles: Promising for novel vaccines and immunotherapeutics

Manganese (Mn), a nutrient inorganic trace element, is necessary for a variety of physiological processes of animal body due to their important roles in oxidative regulation effects and other aspects of activities. Moreover, manganese ion (Mn²⁺) has widely reported to be crucial for the regulations of different immunological responses, thus showing promising application as potential adjuvants and immunotherapeutics. Taking the advantages of Mn-based biological and immunological activities, Manganese dioxide nanoparticles (MnO₂ NPs) are a new type of inorganic nanomaterials with numerous advantages, including simple preparation, low cost, environmental friendliness, low toxicity, biodegradable metabolism and high bioavailability. MnO₂ NPs, as a kind of drug carrier, have also shown the ability to catalyze hydrogen peroxide (H₂O₂) to produce oxygen (O₂) under acidic conditions, which can enhance the efficacy of radiotherapy, chemotherapy and other therapeutics for tumor treatment by remodeling the tumor microenvironment. More importantly, MnO₂ NPs also play important roles in immune regulations both in innate and adaptive immunity. In this review, we summarize the biological activities of Manganese, followed by the introduction for the biological and medical functions and mechanisms of MnO₂ NPs. What's more, we emphatically discussed the immunological regulation effects and mechanisms of MnO₂ NPs, as well as their potentials to serve as adjuvants and immunomodulators, which might benefit the development of novel vaccines and immunotherapies for more effective disease control.

Advances of MnO2 nanomaterials as novel agonists for the development of cGAS-STING-mediated therapeutics

As an essential micronutrient, manganese plays an important role in the physiological process and immune process. In recent decades, cGAS-STING pathway, which can congenitally recognize exogenous and endogenous DNA for activation, has been widely reported to play critical roles in the innate immunity against some important diseases, such as infections and tumor. Manganese ion (Mn²⁺) has been recently proved to specifically bind with cGAS and activate cGAS-STING pathway as a potential cGAS agonist, however, is significantly restricted by the low stability of Mn²⁺ for further medical application. As one of the most stable forms of manganese, manganese dioxide (MnO₂) nanomaterials have been reported to show multiple promising functions, such as drug delivery, anti-tumor and anti-infection activities. More importantly, MnO₂ nanomaterials are also found to be a potential candidate as cGAS agonist by transforming into Mn²⁺, which indicates their potential for cGAS-STING regulations in different diseased conditions. In this review, we introduced the methods for the preparation of MnO₂ nanomaterials as well as their biological activities. Moreover, we emphatically introduced the cGAS-STING pathway and discussed the detailed mechanisms of MnO₂ nanomaterials for cGAS activation by converting into Mn²⁺. And we also discussed the application of MnO₂ nanomaterials for disease treatment by regulating cGAS-STING pathway, which might benefit the future development of novel cGAS-STING targeted treatments based on MnO₂ nanoplatforms.

Nano-drug delivery system for pancreatic cancer: A visualization and bibliometric analysis

Background: Nano drug delivery system (NDDS) can significantly improve the delivery and efficacy of drugs against pancreatic cancer (PC) in many ways. The purpose of this study is to explore the related research fields of NDDS for PC from the perspective of bibliometrics. Methods: Articles and reviews on NDDS for PC published between 2003 and 2022 were obtained from the Web of Science Core Collection. CiteSpace, VOSviewer, R-bibliometrix, and Microsoft Excel were comprehensively used for bibliometric and visual analysis. Results: A total of 1329 papers on NDDS for PC were included. The number of papers showed an upward trend over the past 20 years. The United States contributed the most papers, followed by China, and India. Also, the United States had the highest number of total citations and H-index. The institution with the most papers was Chinese Acad Sci, which was also the most important in international institutional cooperation. Professors Couvreur P and Kazuoka K made great achievements in this field. JOURNAL OF CONTROLLED RELEASE published the most papers and was cited the most. The topics related to the tumor microenvironment such as "tumor microenvironment", "tumor penetration", "hypoxia", "exosome", and "autophagy", PC treatment-related topics such as "immunotherapy", "combination therapy", "alternating magnetic field/magnetic hyperthermia", and "ultrasound", and gene therapy dominated by "siRNA" and "miRNA" were the research hotspots in the field of NDDS for PC. Conclusion: This study systematically uncovered a holistic picture of the performance of NDDS for PC-related literature over the past 20 years. We provided scholars to understand key information in this field with the perspective of bibliometrics, which we believe may greatly facilitate future research in this field.