Biomimetic manganese-based theranostic nanoplatform for cancer multimodal imaging and twofold immunotherapy

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.

DDX10 Exacerbates Exosomal PD-L1-Dependent T Cell Exhaustion via Phase Separation of Rab27b in Oral Squamous Cell Carcinoma

DEAD-box ATPase 10 (DDX10), a prominent RNA-binding protein in the DDX family, has a critical function in cancer progression. Nevertheless, its well-defined mechanisms in oral squamous cell carcinoma (OSCC) are still not well understood. Here, we identify that DDX10 is substantially increased in OSCC, which is positively correlated with poor prognosis and malignant behavior. Mechanistically, we found that DDX10 had physical interaction with Rab27b by undergoing phase separation. Knockdown of DDX10 inhibited Rab27b-mediated exosome secretion and the expression of programmed cell death-ligand 1 (PD-L1) within its contents. Furthermore, knocking down DDX10 could restore the function and infiltration of T cells, hence inhibiting the progression of OSCC. These findings highlight that the oncogenic role of DDX10 in promoting exosomal PD-L1 secretion via phase separation with Rab27b has been preliminarily validated in T cell exhaustion in OSCC. A potential strategy for improving OSCC immunotherapy may involve the inhibition of DDX10.

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.

Covalently Grafted Slippery Surfaces for Transport of Large-Volume Droplets and Bubbles

The directional transport and precise control of droplets and bubbles are crucial for future applications, but remain challenging due to complex fluid dynamics and application limits. In light of existing research on droplet manipulation, a MnO2/carbon microsphere (MnO2/Cs) covalently grafted lubricant-infused slippery surface (SPM) is designed for the manipulation of droplets and bubbles. The structure and morphology of the MnO2/Cs are examined using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), and the elemental composition and chemical bonds of the compounds are characterized by X-ray photoelectron spectroscopy (XPS), Raman spectra and Fourier transform infrared spectrometer (FTIR). The SPM with a sliding angle as low as 3° is prepared. On the SPM, the rapid transportation and precise control of small droplets can be achieved, with the transportation speed of 5 µL droplets reaching 1 mm s-1 and the round-trip control of droplets also being feasible. The surface is capable of controlling the speed of a 100 µL droplet with a precision of 0.49 mm s-1, while a 50 µL droplet can be directed with a load of 1 mg. Moreover, bubbles with a volume of 5 to 20 µL can also be transported.

Nanotechnology-driven strategies in postoperative cancer treatment: innovations in drug delivery systems

Cancer remains a global health challenge, and this challenge comes with a significant burden. Current treatment modalities, such as surgery, chemotherapy, and radiotherapy, have their limitations. The emergence of nanomedicines presents a new frontier in postoperative cancer treatment, offering potential to inhibit tumor recurrence and manage postoperative complications. This review deeply explores the application and potential of nanomedicines in the treatment of cancer after surgery. In particular, it focuses on local drug delivery systems (LDDS), which consist of in situ injection, implantation, and spraying. LDDS can provide targeted drug delivery and controlled release, which enhancing therapeutic efficacy. At the same time, it minimizes damage to healthy tissues and reduces systemic side effects. The nanostructures of these systems are unique. They facilitate the sustained release of drugs, prolong the effects of treatment, and decrease the frequency of dosing. This is especially beneficial in the postoperative period. Despite their potential, nanomedicines have limitations. These include high production costs, concerns regarding long-term toxicity, and complex regulatory approval processes. This paper aims to analyze several aspects. These include the advantages of nanomedicines, their drug delivery systems, how they combine with multiple treatment methods, and the associated challenges. Future research should focus on certain issues. These issues are stability, tumor specificity, and clinical translation. By addressing these, the delivery methods can be optimized and their therapeutic efficacy enhanced. With the advancements in materials science and biomedical engineering, the future design of LDDS is set to become more intelligent and personalized. It will cater to the diverse needs of clinical treatment and offer hope for better outcomes in cancer patients after surgery.

Nanoparticle-Based Strategies to Enhance the Efficacy of STING Activators in Cancer Immunotherapy

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway plays a critical role in triggering innate and adaptive immune responses through type I interferon activation and immune cell recruitment, holding significant promise for cancer therapy. While STING activators targeting this pathway have been developed, their clinical application is hindered by challenges such as poor membrane permeability, rapid degradation, suboptimal pharmacokinetics, off-target biodistribution, and toxicity. Nanoparticle-based delivery systems offer a promising solution by enhancing the stability, circulation time, tumor accumulation, and intracellular release of STING activators. Furthermore, combining nanoparticle-delivered STING activators with radiotherapy, chemotherapy, phototherapy, and other immunotherapies enables synergistic antitumor effects through multimodal mechanisms, addressing resistance to monotherapies and reducing risks of recurrence and metastasis. This review outlines the immunomodulatory mechanisms of the cGAS-STING pathway, surveys current STING-targeted activators, and comprehensively discusses recent advances in nanoparticle-mediated delivery strategies for STING activation. Additionally, we explore combinatorial approaches that integrate STING-targeted nanotherapies with conventional and emerging treatments. Finally, we highlight the current status, prospects, and challenges of nanoparticle-based STING activation for cancer immunotherapy.

Inorganic and hybrid nanomaterials for NIR-II fluorescence imaging-guided therapy of Glioblastoma and perspectives

Glioblastoma (GBM) is the most invasive and lethal brain tumor, with limited therapeutic options due to its highly infiltrative nature, resistance to conventional therapies, and blood-brain barriers. Recent advancements in near-infrared II (NIR-II) fluorescence imaging have facilitated greater tissue penetration, improved resolution, and real-time visualization of GBM, providing a promising approach for precise diagnosis and treatment. The inorganic and hybrid NIR-II fluorescent materials have developed rapidly for NIR-II fluorescence imaging-guided diagnosis and therapy of many diseases, including GBM. Herein, we offer a timely update to explore the contribution of inorganic/hybrid NIR-II fluorescent nanomaterials, such as quantum dots, rare-earth-doped nanoparticles, carbon-based nanomaterials, and metal nanoclusters in imaging-guided treatment for GBM. These nanomaterials provide high photostability, strong fluorescence intensity, and tunable optical properties, allowing for multimodal imaging and enhanced therapeutic efficacy. Additionally, their integration with modern therapeutic strategies, such as photothermal therapy, chemodynamic therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy, has shown significant potential in overcoming the limitations of traditional treatments. Looking forward, future advancements including safe body clearance, long-term biocompatibility, efficient BBB penetration, and extended emission wavelengths beyond 1500 nm could enhance the theranostic outcomes. The integration of dual imaging with immunotherapy and AI-driven strategies will further enhance precision and accelerate the clinical translation of smart theranostic platforms for GBM treatment.

Tumor Treatment by Nano-Photodynamic Agents Embedded in Immune Cell Membrane-Derived Vesicles

Non-invasive phototherapy includes modalities such as photodynamic therapy (PDT) and photothermal therapy (PTT). When combined with tumor immunotherapy, these therapeutic approaches have demonstrated significant efficacy in treating advanced malignancies, thus attracting considerable attention from the scientific community. However, the progress of these therapies is hindered by inherent limitations and potential adverse effects. Recent findings indicate that certain therapeutic strategies, including phototherapy, can induce immunogenic cell death (ICD), thereby opening new avenues for the integration of phototherapy with tumor immunotherapy. Currently, the development of biofilm nanomaterial-encapsulated drug delivery systems has reached a mature stage. Immune cell membrane-encapsulated nano-photosensitizers hold great promise, as they can enhance the tumor immune microenvironment. Based on bioengineering technology, immune cell membranes can be designed according to the tumor immune microenvironment, thereby enhancing the targeting and immune properties of nano-photosensitizers. Additionally, the space provided by the immune cell membrane allows for the co-encapsulation of immunotherapeutic agents and chemotherapy drugs, achieving a synergistic therapeutic effect. At the same time, the timing of photodynamic therapy (PDT) can be precisely controlled to regulate the action timing of both immunotherapeutic and chemotherapy drugs. This article summarizes and analyzes current research based on the aforementioned advancements.

FePt/MnO2@PEG Nanoparticles as Multifunctional Radiosensitizers for Enhancing Ferroptosis and Alleviating Hypoxia in Osteosarcoma Therapy

Radiotherapy (RT) is a widely used cancer treatment, and the use of metal-based nanoradiotherapy sensitizers has demonstrated promise in enhancing its efficacy. However, achieving effective accumulation of these sensitizers within tumors and overcoming resistance induced by the hypoxic tumor microenvironment remain challenging issues. In this study, we developed FePt/MnO2@PEG nanoparticles with multiple radiosensitizing mechanisms, including high-atomic-number element-mediated radiation capture, catalase-mimicking oxygenation, and GSH depletion-induced ferroptosis. Both in vitro and in vivo experiments were conducted to validate the radiosensitizing mechanisms and therapeutic efficacy of FePt/MnO2@PEG. In conclusion, this study presents a novel and clinically relevant strategy and establishes a safe and effective combination radiotherapy approach for cancer treatment. These findings hold significant potential for improving radiotherapy outcomes and advancing the field of nanomedicine in cancer therapy.

Dual-modality immune nano-activator harnessing Mn2⁺ and quercetin to potentiate the cGAS-STING pathway for advanced cancer metalloimmunotherapy

Manganese ions (Mn2+) have emerged as promising activators of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. However, their clinical application was hindered by low bioavailability and limited immune activation pathways, which impaired their ability to trigger robust immune responses and achieve significant antitumor effects. To address these challenges, we developed a dual-modality immune nano-activator by coordinating manganese ions with quercetin. This strategy was designed to enhance the cGAS-STING pathway activation and elicit the immunogenic cell death, thereby strengthening the antitumor immune response. The engineered nano-activator demonstrated superior tumor-targeting ability and efficient cellular internalization. Upon exposure to near-infrared irradiation, the system harnessed photothermal effects to induce apoptosis in tumor cells while simultaneously accelerating the release of manganese ions and quercetin. The released manganese ions facilitated the generation of reactive oxygen species, which in conjunction with quercetin-induced apoptosis, amplified photothermal-induced DNA damage. This DNA damage further promoted the release of cytosolic DNA, which in turn activated the cGAS-STING pathway, thereby intensifying immune activation. Notably, the nano-activator also triggered immunogenic cell death, which synergized with the cGAS-STING activation to promote dendritic cell maturation and activate antigen-specific T-cell, significantly enhancing the immune response against the tumor. Both in vitro and in vivo studies confirmed that this nano-activator effectively inhibited tumor growth, with particularly pronounced effects when combined with anti-CTLA-4 antibodies.

Augmenting Antitumor Immune Effects through the Coactivation of cGAS-STING and NF-κB Crosstalk in Dendritic Cells and Macrophages by Engineered Manganese Ferrite Nanohybrids

The specific activation of dendritic cells (DCs) and tumor-associated macrophages (TAMs) can activate innate and adaptive immune responses to reverse the tumor immunosuppressive microenvironment. In this study, manganese ferrite nanohybrid MnFe5O8@(M1M-DOX) is synthesized to activate cGAS-STING and NF-κB crosstalk in DCs and TAMs. MnFe5O8, as the source of Fe2+/Fe3+ and Mn2+, is encapsulated with a microdose of doxorubicin (DOX) using an M1 macrophage cytomembrane. Fe2+/Fe3+ and DOX can cooperatively induce tumorous ferroptosis, triggering immunogenic cell death (ICD) that exposes tumor antigens. The release of Fe2+/Fe3+ and Mn2+ has intrinsic dual-immunomodulatory effects on the activation of DCs and the reprogramming of TAMs from the M2 to M1 phenotype. Briefly, Fe2+/Fe3+ activates the NF-κB signaling pathway to trigger the activation of STING signaling. Meanwhile, Mn2+ further enhances the activation of STING and stimulates NF-κB in a cascade-activating manner. Thus, the mutually reinforcing dual activation of cGAS-STING and NF-κB crosstalk prompts the strong maturation of DCs and TAMs, synergistically promoting the infiltration of T cells to inhibit primary tumor growth and localized recurrence. This work proposes a strategy for delivering immunomodulatory metal ions in nanoalloy and harnessing the activation of multisignaling pathways in antigen-presenting cells (APCs) to provide perspectives for tumor immunotherapy.

Current status and future prospects of molecular imaging in targeting the tumor immune microenvironment

Molecular imaging technologies have significantly transformed cancer research and clinical practice, offering valuable tools for visualizing and understanding the complex tumor immune microenvironment. These technologies allow for the non-invasive examination of key components within the tumor immune microenvironment, including immune cells, cytokines, and stromal cells, providing crucial insights into tumor biology and treatment responses. This paper reviews the latest advancements in molecular imaging, with a focus on its applications in assessing interactions within the tumor immune microenvironment. Additionally, the challenges faced by molecular imaging technologies are discussed, such as the need for highly sensitive and specific imaging agents, issues with data integration, and difficulties in clinical translation. The future outlook emphasizes the potential of molecular imaging to enhance personalized cancer treatment through the integration of artificial intelligence and the development of novel imaging probes. Addressing these challenges is essential to fully realizing the potential of molecular imaging in improving cancer diagnosis, treatment, and patient outcomes.

Exploring the Potential of Nanocarriers for Cancer Immunotherapy: Insights into Mechanism, Nanocarriers, and Regulatory Perspectives

Immunotherapy is a cutting-edge approach that leverages sophisticated technology to target tumor-specific antibodies and modulate the immune system to eradicate cancer and enhance patients' quality of life. Bioinformatics and genetic science advancements have made it possible to diagnose and treat cancer patients using immunotherapy technology. However, current immunotherapies against cancer have limited clinical benefits due to cancer-associated antigens, which often fail to interact with immune cells and exhibit insufficient therapeutic targeting with unintended side effects. To surmount this challenge, nanoparticle systems have emerged as a potential strategy for transporting immunotherapeutic agents to cancer cells and activating immune cells to combat tumors. Consequently, this process potentially generates an antigen-specific T cells response that effectively suppresses cancer growth. Furthermore, nanoplatforms have high specificity, efficacy, diagnostic potential, and imaging capabilities, making them promising tools for cancer treatment. However, this informative paper delves into the various available immunotherapies, including CAR T cells therapy and immune checkpoint blockade, cytokines, cancer vaccines, and monoclonal antibodies. Furthermore, the paper delves into the concept of theragnostic nanotechnology, which integrates therapy and diagnostics for a more personalized treatment approach for cancer therapy. Additionally, the paper covers the potential benefits of different nanocarrier systems, including marketed immunotherapy products, clinical trials, regulatory considerations, and future prospects for cancer immunotherapy.

Novel Modifications and Delivery Modes of Cyclic Dinucleotides for STING Activation in Cancer Treatment

The microenvironment tends to be immunosuppressive during tumor growth and proliferation. Immunotherapy has attracted much attention because of its ability to activate tumor-specific immune responses for tumor killing. The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway is an innate immune pathway that activates antitumor immunity by producing type I interferons. Cyclic dinucleotides (CDNs), produced by cGAS sensing cytoplasmic abnormal DNA, are major intermediate activating molecules in the STING pathway. Nowadays, CDNs and their derivatives have widely worked as powerful STING agonists in tumor immunotherapy. However, their clinical translation is hindered by the negative electrical properties, sensitivity to hydrolytic enzymes, and systemic toxicity. Recently, various CDN delivery systems have made significant progress in addressing these issues, either through monotherapy or in combination with other treatment modalities. This review details recent advances in CDNs-based pharmaceutical development or delivery strategies for enriching CDNs at tumor sites and activating the STING pathway.

Tumor microenvironment-responsive and modulatory manganese-based nanoenzyme for enhanced tumor immunotherapy

The characteristics of the tumor microenvironment (TME) have a close and internal correlation with the effect of cancer immunotherapy, significantly affecting the progression and metastasis of cancer. The rational design of nanoenzymes that possess the ability to respond to and regulate the TME is driving a new direction in catalytic immunotherapy. In this study, we designed a multifunctional manganese (Mn)-based nanoenzyme that is responsive to acidic pH and overxpressed H2O2 at tumor site and holds capability of modulating hypoxic and immunosuppressive TME for synergistic anti-tumor photothermal/photodynamic/immunotherapy. We found that this artificial nanoenzyme promoted peroxidase-like and catalase-like activities and catalyzed the in-situ decomposition of H2O2, a metabolic waste product in the TME, into ∙OH and O2, resulting in a ROS burst for killing tumors and relieving hypoxic TME to enhance cancer therapy. Besides the photothermal effect and the enhancement of ROS burst-induced immunogenic cell death, combination of Mn2+ released from Mn-based nanoenzyme in acidic TME and programmed death-ligand 1 blockade triggered a significant anti-tumor immune response. A remarkable in vivo synergistic therapeutic effect was achieved with effective inhibition of primary tumor growth and lung metastasis. Therefore, this TME-responsive Mn-based nanoenzyme offers a safe and efficient platform for reversing the immunosuppressive microenvironment and achieving synergistic anti-tumor immunotherapy.

Multi-Chambered Core/Shell Supraparticles for Real-Time, Full-Time Diagnosis and Treatment Integration of Tumors

To a certain extent, theranostic nanoplatforms promote tumor treatment efficiency. However, timely monitoring of the critical stages and signal sustainability of the entire process is challenging. In this study, multi-chambered core/shell magnetic nanoparticles (MC-MNPs) as drug and imaging agent multi-loaded nanocarriers with a synergistic release function are reported. Supraparticles with stable chambers are formed by the supercooling self-assembly of several core/shell magnetic nanoparticles composed of amphiphilic copolymers as the core and hydrophilic magnetic iron oxide nanoparticles as the shell. Desalinized doxorubicin and coumarin 6 are stored in different cavities of nanocarriers, and chitosan is used as an outer encapsulation layer. Based on their construction properties, MC-MNPs can exhibit gradient-degraded and steady-released controllability in the tumor environment. Furthermore, real-time accumulation situations and full-time diagnostic signals of nanocarriers are thoroughly demonstrated using fluorescence imaging and T2-weighted magnetic resonance imaging before and after magnetic hyperthermia in targeted tumors under an alternating magnetic field. Thus, MC-MNPs as theranostic nanocarriers exhibit great potential for the timely monitoring and full-time guidance of tumor treatment.

Enhancing Radiofrequency Ablation for Hepatocellular Carcinoma: Nano-Epidrug Effects on Immune Modulation and Antigenicity Restoration

Radiofrequency ablation (RFA), a critical therapy for hepatocellular carcinoma (HCC), carries a significant risk of recurrence and metastasis, particularly owing to mechanisms involving immune evasion and antigen downregulation via epigenetic modifications. This study introduces a "nano-epidrug" named MFMP. MFMP, which is composed of hollow mesoporous manganese dioxide (MnO2) nanoparticles, FIDAS-5 as an MAT2A inhibitor, macrophage membrane, and anti-PD-L1 (aPD-L1), targets HCC cells. By selectively binding to these cells, MFMP initially reverses immune suppression via PD-L1 inhibition. After endocytosis, MFMP disassembles in the tumor microenvironment, releasing FIDAS-5 and Mn2+. FIDAS-5 prevents cGAS methylation, whereas Mn2+ aids STING pathway restoration. In addition, FIDAS-5 reduces m6A RNA modification, suppressing EGFR expression. These changes enhance HCC antigenicity to promote cytotoxic T cell recognition and cytotoxic killing. Furthermore, MFMP mediates immunogenic cell death in HCC by synergizing with RFA through cGAS DNA demethylation, EGFR mRNA demethylation, and TBK1 protein phosphorylation, thereby inhibiting recurrence and metastasis and enhancing immune memory. Thus, MFMP is a potential adjunctive therapy requiring clinical validation.

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.

Injectable hydrogels for Fenton-like Mn2+/Fe2+ delivery with enhanced chemodynamic therapy prevent osteosarcoma recurrence and promote wound healing after excision surgery

Local recurrence of osteosarcoma and wound healing after excision surgery are major challenges in clinical research. The present anti-tumor treatments could inhibit normal tissues, resulting in difficulties in surgical wound healing. In this study, we constructed an injectable hydrogel as a platform to co-deliver MnO2 nanoparticles and ferrocene Fc, termed as (MnO2/Fc)@PLGA for osteosarcoma treatment and wound healing after excision. By simple local injection, the hydrogel could form a protective barrier on the surgical wound after osteosarcoma excision, which could promote wound healing and steady release of MnO2/Fc nanoparticles. The released MnO2/Fc might undergo the Fenton reaction through Mn2+/Fe2+ to inhibit osteosarcoma cells with chemodynamic therapy (CDT). Furthermore, MnO2 could catalyze endogenous H2O2 to produce O2, which eliminates the adverse effects of H2O2 and remodels the hypoxic state in the local lesions. The increased O2 facilitated surgical wound healing and anti-tumor effects by regulating the hypoxia inducible factor-1 functions. In conclusion, (MnO2/Fc)@PLGA hydrogel could effectively prevent local recurrence of osteosarcoma and promote wound healing after excision surgery, thereby providing a novel strategy for tumor treatment and tissue repair.

Tumor cell membrane-based vaccines: A potential boost for cancer immunotherapy

Because therapeutic cancer vaccines can, in theory, eliminate tumor cells specifically with relatively low toxicity, they have long been considered for application in repressing cancer progression. Traditional cancer vaccines containing a single or a few discrete tumor epitopes have failed in the clinic, possibly due to challenges in epitope selection, target downregulation, cancer cell heterogeneity, tumor microenvironment immunosuppression, or a lack of vaccine immunogenicity. Whole cancer cell or cancer membrane vaccines, which provide a rich source of antigens, are emerging as viable alternatives. Autologous and allogenic cellular cancer vaccines have been evaluated as clinical treatments. Tumor cell membranes (TCMs) are an intriguing antigen source, as they provide membrane-accessible targets and, at the same time, serve as integrated carriers of vaccine adjuvants and other therapeutic agents. This review provides a summary of the properties and technologies for TCM cancer vaccines. Characteristics, categories, mechanisms, and preparation methods are discussed, as are the demonstrable additional benefits derived from combining TCM vaccines with chemotherapy, sonodynamic therapy, phototherapy, and oncolytic viruses. Further research in chemistry, biomedicine, cancer immunology, and bioinformatics to address current drawbacks could facilitate the clinical adoption of TCM vaccines.

Manganese drives ferroptosis of cancer cells via YAP/TAZ phase separation activated ACSL4 in OSCC

OBJECTIVE

Ferroptosis has been defined as a novel form of regulated cell death characterized by iron-dependent lipid peroxidation. Manganese has been used to induce ferroptosis in cancer cells recently. This study aims to investigate whether manganese can induce ferroptosis in oral squamous cell carcinoma (OSCC) and the underlying biological mechanisms.

MATERIALS AND METHODS

Cancer cells with or without manganese treatment were analyzed by RNA-sequencing to identify ferroptosis-related genes. Next, the activation of YAP/TAZ/ACSL4-ferroptosis signaling pathway was detected. Bioinformatic analysis and immunofluorescence assay were used to explore the phase separation of YAP/TAZ. Finally, specimens of OSCC patients were applied to analyze the clinical significance of YAP/TAZ/ACSL4.

RESULTS

RNA-sequencing analysis showed the ferroptosis-related genes and YAP/TAZ were upregulated after manganese treatment. The results of immunofluorescence, ELISA, western blotting, etc. further confirmed that manganese-induced ferroptosis depends on YAP/TAZ/ACSL4 signaling pathway. Moreover, the activation of ACSL4 was achieved by YAP/TAZ phase separation. The survival analysis in OSCC specimen suggested that the higher level of YAP/TAZ-ACSL4 axis expression indicates longer survival.

CONCLUSIONS

Manganese induces YAP/TAZ phase separation and subsequent ACSL4 activation via YAP/TAZ nuclear translocation, which facilitates ferroptosis of OSCC. Then YAP/TAZ-ACSL4 axis can be used as a potential prognostic predictor of OSCC patients.

Custom-Design of Multi-Stimuli-Responsive Degradable Silica Nanoparticles for Advanced Cancer-Specific Chemotherapy

Chemotherapy is crucial in oncology for combating malignant tumors but often encounters obatacles such as severe adverse effects, drug resistance, and biocompatibility issues. The advantages of degradable silica nanoparticles in tumor diagnosis and treatment lie in their ability to target drug delivery, minimizing toxicity to normal tissues while enhancing therapeutic efficacy. Moreover, their responsiveness to both endogenous and exogenous stimuli opens up new possibilities for integrating multiple treatment modalities. This review scrutinizes the burgeoning utility of degradable silica nanoparticles in combination with chemotherapy and other treatment modalities. Commencing the elucidation of degradable silica synthesis and degradation mechanisms, emphasis is placed on the responsiveness of these materials to endogenous (e.g., pH, redox reactions, hypoxia, and enzymes) and exogenous stimuli (e.g., light and high-intensity focused ultrasound). Moreover, this exploration delves into strategies harnessing degradable silica nanoparticles in chemotherapy alone, coupled with radiotherapy, photothermal therapy, photodynamic therapy, gas therapy, immunotherapy, starvation therapy, and chemodynamic therapy, elucidating multimodal synergies. Concluding with an assessment of advances, challenges, and constraints in oncology, despite hurdles, future investigations are anticipated to augment the role of degradable silica in cancer therapy. These insights can serve as a compass for devising more efficacious combined tumor treatment strategies.

Manganese Dioxide-Based Nanomaterials for Medical Applications

Manganese dioxide (MnO2) nanomaterials can react with trace hydrogen peroxide (H2O2) to produce paramagnetic manganese (Mn2+) and oxygen (O2), which can be used for magnetic resonance imaging and alleviate the hypoxic environment of tumors, respectively. MnO2 nanomaterials also can oxidize glutathione (GSH) to produce oxidized glutathione (GSSG) to break the balance of intracellular redox reactions. As a consequence of the sensitivity of the tumor microenvironment to MnO2-based nanomaterials, these materials can be used as multifunctional diagnostic and therapeutic platforms for tumor imaging and treatment. Importantly, when MnO2 nanomaterials are implanted along with other therapeutics, synergetic tumor therapy can be achieved. In addition to tumor treatment, MnO2-based nanomaterials display promising prospects for tissue repair, organ protection, and the treatment of other diseases. Herein, we provide a thorough review of recent progress in the use of MnO2-based nanomaterials for biomedical applications, which may be helpful for the design and clinical translation of next-generation MnO2 nanomaterials.

Porphyromonas gingivalis suppresses oral squamous cell carcinoma progression by inhibiting MUC1 expression and remodeling the tumor microenvironment

Bacteria are the causative agents of various infectious diseases; however, the anti-tumor effect of some bacterial species has attracted the attention of many scientists. The human oral cavity is inhabited by abundant and diverse bacterial communities and some of these bacterial communities could play a role in tumor suppression. Therefore, it is crucial to find oral bacterial species that show anti-tumor activity on oral cancers. In the present study, we found that a high abundance of Porphyromonas gingivalis, an anaerobic periodontal pathogen, in the tumor microenvironment (TME) was positively associated with the longer survival of patients with oral squamous cell carcinoma (OSCC). An in vitro assay confirmed that P. gingivalis accelerated the death of OSCC cells by inducing cell cycle arrest at the G2/M phase, thus exerting its anti-tumor effect. We also found that P. gingivalis significantly decreased tumor growth in a 4-nitroquinoline-1-oxide-induced in situ OSCC mouse model. The transcriptomics data demonstrated that P. gingivalis suppressed the biosynthesis of mucin O-glycan and other O-glycans, as well as the expression of chemokines. Validation experiments further confirmed the downregulation of mucin-1 (MUC1) and C-X-C motif chemokine 17 (CXCL17) expression by P. gingivalis treatment. Flow cytometry analysis showed that P. gingivalis successfully reversed the immunosuppressive TME, thereby suppressing OSCC growth. In summary, the findings of the present study indicated that the rational use of P. gingivalis could serve as a promising therapeutic strategy for OSCC.

Biomimetic MDSCs membrane coated black phosphorus nanosheets system for photothermal therapy/photodynamic therapy synergized chemotherapy of cancer

Photothermal therapy is favored by cancer researchers due to its advantages such as controllable initiation, direct killing and immune promotion. However, the low enrichment efficiency of photosensitizer in tumor site and the limited effect of single use limits the further development of photothermal therapy. Herein, a photo-responsive multifunctional nanosystem was designed for cancer therapy, in which myeloid-derived suppressor cell (MDSC) membrane vesicle encapsulated decitabine-loaded black phosphorous (BP) nanosheets (BP@ Decitabine @MDSCs, named BDM). The BDM demonstrated excellent biosafety and biochemical characteristics, providing a suitable microenvironment for cancer cell killing. First, the BDM achieves the ability to be highly enriched at tumor sites by inheriting the ability of MDSCs to actively target tumor microenvironment. And then, BP nanosheets achieves hyperthermia and induces mitochondrial damage by its photothermal and photodynamic properties, which enhancing anti-tumor immunity mediated by immunogenic cell death (ICD). Meanwhile, intra-tumoral release of decitabine induced G2/M cell cycle arrest, further promoting tumor cell apoptosis. In vivo, the BMD showed significant inhibition of tumor growth with down-regulation of PCNA expression and increased expression of high mobility group B1 (HMGB1), calreticulin (CRT) and caspase 3. Flow cytometry revealed significantly decreased infiltration of MDSCs and M2-macrophages along with an increased proportion of CD4+, CD8+ T cells as well as CD103+ DCs, suggesting a potentiated anti-tumor immune response. In summary, BDM realizes photothermal therapy/photodynamic therapy synergized chemotherapy for cancer.

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.

CD24 blockade promotes anti-tumor immunity in oral squamous cell carcinoma

OBJECTIVES

Our study elucidates the prognostic role of cluster of differentiation (CD) 24 expression in oral squamous cell carcinoma (OSCC) and determines whether targeting CD24 enhances the anti-tumor immune response by inhibiting tumor-associated macrophages (TAMs).

MATERIALS AND METHODS

The expression of CD24 and CD68 was analyzed immunohistochemically via tissue microarrays constructed using 56 cohorts of patients with OSCC and 20 control specimens. Further, CD24 was inhibited in an allograft squamous cell carcinoma (SCC) related mouse model with CD24mAb to determine the tumor volume and weight. Changes in immune cells such as TAMs and T cells in the tumor microenvironment (TME) were analyzed by Flow cytometry. The expression of CD4, CD8, and Ki67 was analyzed via immunohistochemistry. The inhibition of CD24 was confirmed by Western blot and immunohistochemistry.

RESULTS

CD24 was overexpressed in OSCC. High expression of CD24 indicated poor survival in patients with OSCC (p = 0.0334). CD24 expression was significantly correlated with CD68 (p = 0.0424). The inhibition of CD24 delayed tumor growth in vivo. A decrease in TAMs number and an increase in T cell number were confirmed, while the ability of tumor proliferation was impaired.

CONCLUSION

Targeting CD24 could enhance anti-tumor immune response by inhibiting TAMs.

Microwave-responsive gadolinium metal-organic frameworks nanosystem for MRI-guided cancer thermotherapy and synergistic immunotherapy

The clinical application of cancer immunotherapy is unsatisfied due to low response rates and systemic immune-related adverse events. Microwave hyperthermia can be used as a synergistic immunotherapy to amplify the antitumor effect. Herein, we designed a Gd-based metal-organic framework (Gd-MOF) nanosystem for MRI-guided thermotherapy and synergistic immunotherapy, which featured high performance in drug loading and tumor tissue penetration. The PD-1 inhibitor (aPD-1) was initially loaded in the porous Gd-MOF (Gd/M) nanosystem. Then, the phase change material (PCM) and the cancer cell membrane were further sequentially modified on the surface of Gd/MP to obtain Gd-MOF@aPD-1@CM (Gd/MPC). When entering the tumor microenvironment (TME), Gd/MPC induces immunogenic death of tumor cells through microwave thermal responsiveness, improves tumor suppressive immune microenvironment and further enhances anti-tumor ability of T cells by releasing aPD-1. Meanwhile, Gd/MPC can be used for contrast-enhanced MRI. Transcriptomics data revealed that the downregulation of MSK2 in cancer cells leads to the downregulation of c-fos and c-jun, and ultimately leads to the apoptosis of cancer cells after treatment. In general, Gd/MPC nanosystem not only solves the problem of system side effect, but also achieves the controlled drug release via PCM, providing a promising theranostic nanoplatform for development of cancer combination immunotherapy.

Ca & Mn dual-ion hybrid nanostimulator boosting anti-tumor immunity via ferroptosis and innate immunity awakening

Limited by low tumor immunogenicity and the immunosuppressive tumor microenvironment (TME), triple-negative breast cancer (TNBC) has been poorly responsive to immunotherapy so far. Herein, a Ca & Mn dual-ion hybrid nanostimulator (CMS) is constructed to enhance anti-tumor immunity through ferroptosis inducing and innate immunity awakening, which can serve as a ferroptosis inducer and immunoadjuvant for TNBC concurrently. On one hand, glutathione (GSH) depletion and reactive oxygen species (ROS) generation can be achieved due to the mixed valence state of Mn in CMS. On the other hand, as an exotic Ca2+ supplier, CMS causes mitochondrial Ca2+ overload, which further amplifies the oxidative stress. Significantly, tumor cells undergo ferroptosis because of the inactivation of glutathione peroxidase 4 (GPX4) and accumulation of lipid peroxidation (LPO). More impressively, CMS can act as an immunoadjuvant to awaken innate immunity by alleviating intra-tumor hypoxia and Mn2+-induced activation of the STING signaling pathway, which promotes polarization of tumor-associated macrophages (TAMs) and activation of dendritic cells (DCs) for antigen presentation and subsequent infiltration of tumor-specific cytotoxic T lymphocytes (CTLs) into tumor tissues. Taken together, this work demonstrates a novel strategy of simultaneously inducing ferroptosis and awakening innate immunity, offering a new perspective for effective tumor immunotherapy of TNBC.

Boosting Sono-immunotherapy of Prostate Carcinoma through Amplifying Domino-Effect of Mitochondrial Oxidative Stress Using Biodegradable Cascade-Targeting Nanocomposites

Sono-immunotherapy faces challenges from poor immunogenicity and low response rate due to complex biological barriers. Herein, we prepared MCTH nanocomposites (NCs) consisting of disulfide bonds (S-S) doped mesoporous organosilica (MONs), Cu-modified protoporphyrin (CuPpIX), mitochondria-targeting triphenylphosphine (TPP), and CD44-targeting hyaluronic acid (HA). MCTH NCs efficiently accumulate at the tumor site due to the overexpressed CD44 receptors on the membrane of the cancer cells. Under the function of HAase and glutathione (GSH), MCTH degrades and exposes TPP to deliver CuPpIX to the mitochondrial site and induce a reactive oxygen species (ROS) burst in situ under ultrasound irradiations, thereby causing severe mitochondria dysfunction. This cascade-targeting ability of MCTH NCs not only reinforces oxidative stress in cancer cells but also amplifies immunogenic cell death (ICD) to stimulate the body's immune response and alleviate the tumor immunosuppressive microenvironment. These NCs significantly enhance the infiltration of immune cells into the tumor, particularly CD8+ T cells, for a powerful antitumor sono-immunotherapy. The proposed cascade-targeting strategy holds promise for strengthening sono-immunotherapy for prostate cancer treatment and overcoming the limitations of traditional immunotherapy.

Bioengineering strategies to enhance the interleukin-18 bioactivity in the modern toolbox of cancer immunotherapy

Cytokines are the first modern immunotherapeutic agents used for activation immunotherapy. Interleukin-18 (IL-18) has emerged as a potent anticancer immunostimulatory cytokine over the past three decades. IL-18, structurally is a stable protein with very low toxicity at biological doses. IL-18 promotes the process of antigen presentation and also enhances innate and acquired immune responses. It can induce the production of proinflammatory cytokines and increase tumor infiltration of effector immune cells to revert the immunosuppressive milieu of tumors. Furthermore, IL-18 can reduce tumorigenesis, suppress tumor angiogenesis, and induce tumor cell apoptosis. These characteristics present IL-18 as a promising option for cancer immunotherapy. Although several preclinical studies have reported the immunotherapeutic potential of IL-18, clinical trials using it as a monotherapy agent have reported disappointing results. These results may be due to some biological characteristics of IL-18. Several bioengineering approaches have been successfully used to correct its defects as a bioadjuvant. Currently, the challenge with this anticancer immunotherapeutic agent is mainly how to use its capabilities in a rational combinatorial therapy for clinical applications. The present study discussed the strengths and weaknesses of IL-18 as an immunotherapeutic agent, followed by comprehensive review of various promising bioengineering approaches that have been used to overcome its disadvantages. Finally, this study highlights the promising application of IL-18 in modern combinatorial therapies, such as chemotherapy, immune checkpoint blockade therapy, cell-based immunotherapy and cancer vaccines to guide future studies, circumventing the barriers to administration of IL-18 for clinical applications, and bring it to fruition as a potent immunotherapy agent in cancer treatment.

3D-printed bioink loading with stem cells and cellular vesicles for periodontitis-derived bone defect repair

The suitable microenvironment of bone regeneration is critically important for periodontitis-derived bone defect repair. Three major challenges in achieving a robust osteogenic reaction are the exist of oral inflammation, pathogenic bacteria invasion and unaffluent seed cells. Herein, a customizable and multifunctional 3D-printing module was designed with glycidyl methacrylate (GMA) modified epsilon-poly-L-lysine (EPLGMA) loading periodontal ligament stem cells (PDLSCs) and myeloid-derived suppressive cells membrane vesicles (MDSCs-MV) bioink (EPLGMA/PDLSCs/MDSCs-MVs, abbreviated as EPM) for periodontitis-derived bone defect repair. The EPM showed excellent mechanical properties and physicochemical characteristics, providing a suitable microenvironment for bone regeneration.In vitro, EPMs presented effectively kill the periodontopathic bacteria depend on the natural antibacterial properties of the EPL. Meanwhile, MDSCs-MV was confirmed to inhibit T cells through CD73/CD39/adenosine signal pathway, exerting an anti-inflammatory role. Additionally, seed cells of PDLSCs provide an adequate supply for osteoblasts. Moreover, MDSCs-MV could significantly enhance the mineralizing capacity of PDLSCs-derived osteoblast. In the periodontal bone defect rat model, the results of micro-CT and histological staining demonstrated that the EPM scaffold similarly had an excellent anti-inflammatory and bone regeneration efficacyin vivo. This biomimetic and multifunctional 3D-printing bioink opens new avenues for periodontitis-derived bone defect repair and future clinical application.

Amplifying "eat me signal" by immunogenic cell death for potentiating cancer immunotherapy

Immunogenic cell death (ICD) is a unique mode of cell death, which can release immunogenic damage-associated molecular patterns (DAMPs) and tumor-associated antigens to trigger long-term protective antitumor immune responses. Thus, amplifying "eat me signal" during tumor ICD cascade is critical for cancer immunotherapy. Some therapies (radiotherapy, photodynamic therapy (PDT), photothermal therapy (PTT), etc.) and inducers (chemotherapeutic agents, etc.) have enabled to initiate and/or facilitate ICD and activate antitumor immune responses. Recently, nanostructure-based drug delivery systems have been synthesized for inducing ICD through combining treatment of chemotherapeutic agents, photosensitizers for PDT, photothermal transformation agents for PTT, radiosensitizers for radiotherapy, etc., which can release loaded agents at an appropriate dosage in the designated place at the appropriate time, contributing to higher efficiency and lower toxicity. Also, immunotherapeutic agents in combination with nanostructure-based drug delivery systems can produce synergetic antitumor effects, thus potentiating immunotherapy. Overall, our review outlines the emerging ICD inducers, and nanostructure drug delivery systems loading diverse agents to evoke ICD through chemoradiotherapy, PDT, and PTT or combining immunotherapeutic agents. Moreover, we discuss the prospects and challenges of harnessing ICD induction-based immunotherapy, and highlight the significance of multidisciplinary and interprofessional collaboration to promote the optimal translation of this treatment strategy.

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

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

Ultra-efficient radio-immunotherapy for reprogramming the hypoxic and immunosuppressive tumor microenvironment with durable innate immune memory

Radiosensitization efficacy of conventional tumor radiosensitizers has been frequently limited by insufficient competence for tumor microenvironment (TME) regulation and unfavorable cellular uptake at biological barriers. Here, we reported an ultra-efficient radiotherapy (RT) strategy by synthesizing an extracellular vesicles (EVs)-encapsulated hollow MnO2 to load metformin (Met@HMnER). It demonstrated significant RT enhancement by morphological control of catalyst and cellular respiratory depression against conventional solid MnO2. Furthermore, the target-modified EVs clothing retains outstanding metformin loading capacity while endowing enhanced biological barrier penetration. A noticeably durable innate immune activation of NK cells was triggered with this nanoplatform via the cGAS-STING pathway. The enhanced immunocompetence was verified on distal metastasis and in-situ recurrence model in vivo, This work paved a new path for synergistic and robust innate immunity in clinical cancer treatment.

Reactive X (where X = O, N, S, C, Cl, Br, and I) species nanomedicine

Reactive oxygen, nitrogen, sulfur, carbonyl, chlorine, bromine, and iodine species (RXS, where X = O, N, S, C, Cl, Br, and I) have important roles in various normal physiological processes and act as essential regulators of cell metabolism; their inherent biological activities govern cell signaling, immune balance, and tissue homeostasis. However, an imbalance between RXS production and consumption will induce the occurrence and development of various diseases. Due to the considerable progress of nanomedicine, a variety of nanosystems that can regulate RXS has been rationally designed and engineered for restoring RXS balance to halt the pathological processes of different diseases. The invention of radical-regulating nanomaterials creates the possibility of intriguing projects for disease treatment and promotes advances in nanomedicine. In this comprehensive review, we summarize, discuss, and highlight very-recent advances in RXS-based nanomedicine for versatile disease treatments. This review particularly focuses on the types and pathological effects of these reactive species and explores the biological effects of RXS-based nanomaterials, accompanied by a discussion and the outlook of the challenges faced and future clinical translations of RXS nanomedicines.

Polysaccharide-based tumor microenvironment-responsive drug delivery systems for cancer therapy

The biochemical indicators of tumor microenvironment (TME) that are different from normal tissues provide the possibility for constructing intelligent drug delivery systems (DDSs). Polysaccharides with good biocompatibility, biodegradability, and unique biological properties are ideal materials for constructing DDSs. Nanogels, micelles, organic-inorganic nanocomposites, hydrogels, and microneedles (MNs) are common polysaccharide-based DDSs. Polysaccharide-based DDSs enable precise control of drug delivery and release processes by incorporating TME-specific biochemical indicators. The classification and design strategies of polysaccharide-based TME-responsive DDSs are comprehensively reviewed. The advantages and challenges of current polysaccharide-based DDSs are summarized and the future directions of development are foreseen. The polysaccharide-based TME-responsive DDSs are expected to provide new strategies and solutions for cancer therapy and make important contributions to the realization of precision medicine.

Synergist for antitumor therapy: Astragalus polysaccharides acting on immune microenvironment

Various new treatments are emerging constantly in anti-tumor therapies, including chemotherapy, immunotherapy, and targeted therapy. However, the efficacy is still not satisfactory. Astragalus polysaccharide is an important bioactive component derived from the dry root of Radix astragali. Studies found that astragalus polysaccharides have gained great significance in increasing the sensitivity of anti-tumor treatment, reducing the side effects of anti-tumor treatment, reversing the drug resistance of anti-tumor drugs, etc. In this review, we focused on the role of astragalus polysaccharides in tumor immune microenvironment. We reviewed the immunomodulatory effect of astragalus polysaccharides on macrophages, dendritic cells, natural killer cells, T lymphocytes, and B lymphocytes. We found that astragalus polysaccharides can promote the activities of macrophages, dendritic cells, natural killer cells, T lymphocytes, and B lymphocytes and induce the expression of a variety of cytokines and chemokines. Furthermore, we summarized the clinical applications of astragalus polysaccharides in patients with digestive tract tumors. We summarized the effective mechanism of astragalus polysaccharides on digestive tract tumors, including apoptosis induction, proliferation inhibition, immunoactivity regulation, enhancement of the anticancer effect and chemosensitivity. Therefore, in view of the multiple functions of astragalus polysaccharides in tumor immune microenvironment and its clinical efficacy, the combination of astragalus polysaccharides with antitumor therapy such as immunotherapy may provide new sparks to the bottleneck of current treatment methods.

Research progress of cancer cell membrane coated nanoparticles for the diagnosis and therapy of breast cancer

Nanoparticles (NPs) disguised in the cell membrane are a new type of biomimetic platform. Due to their ability to simulate the unique biological functions of membrane-derived cells, they have become one of the hotspots of research at home and abroad. The tumor-specific antigen antibody carried by breast cancer cell membranes can modify nanoparticles to have homologous tumor targeting. Therefore, nanoparticles wrapped in cancer cell membranes have been widely used in research on the diagnosis and treatment of breast cancer. This article reviews the current situation, prospects, advantages and limitations of nanoparticles modified by cancer cell membranes in the treatment and diagnosis of breast cancer.

Record-High Ultrasound-Sensitive NO Nanogenerators for Cascade Tumor Pyroptosis and Immunotherapy

Pyroptosis is a pro-inflammatory cell death that is associated with innate immunity promotion against tumors. Excess nitric oxide (NO)-triggered nitric stress has potential to induce pyroptosis, but the precise delivery of NO is challenging. Ultrasound (US)-responsive NO production has dominant priority due to its deep penetration, low side effects, noninvasion, and local activation manner. In this work, US-sensitive NO donor N-methyl-N-nitrosoaniline (NMA) with thermodynamically favorable structure is selected and loaded into hyaluronic acid (HA)-modified hollow manganese dioxide nanoparticles (hMnO2 NPs) to fabricate hMnO2 @HA@NMA (MHN) nanogenerators (NGs). The obtained NGs have a record-high NO generation efficiency under US irradiation and can release Mn2+ after targeting the tumor sites. Later on, cascade tumor pyroptosis and cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING)-based immunotherapy is achieved and tumor growth is effectively inhibited.

Neutralization of Intracellular pH Homeostasis to Inhibit Osteoclasts Based on a Spatiotemporally Selective Delivery System

Osteoporosis is a global disease caused by abnormal overactivation of osteoclasts. The acidic environment in sealing zone of osteoclasts with H⁺ pumped from cytoplasm is critical to the maturation of osteoclasts. Therefore, reducing the intracellular H⁺ concentration can reduce the H⁺ secretion of osteoclasts from the source. In our study, we developed a novel nanovesicle which encapsulates Na₂HPO₄ with a liposome hybridizes with preosteoclast membrane (Na₂HPO₄@Lipo-pOCm). These nanovesicles release Na₂HPO₄ into the preosteoclast by targeting preosteoclasts and membrane fusion, reducing the intracellular H⁺ concentration, and achieve biological cascade regulation of osteoclasts through simple pH regulation. In vitro and in vivo experiments confirmed that these nanovesicles reduce mitochondrial membrane potential by decreasing intracellular H⁺ concentration, thereby reducing the ROS in osteoclasts as well as the expression of the upstream transcription factor FOXM1 of Acp5. In short, this nanovesicle can significantly inhibit the osteoclasts and ameliorate osteoporosis caused by OVX.

Boosting Checkpoint Immunotherapy with Biomaterials

The immune checkpoint blockade (ICB) therapy has revolutionized the field of cancer treatment, while low response rates and systemic toxicity limit its clinical outcomes. With the rapid advances in nanotechnology and materials science, various types of biomaterials have been developed to maximize therapeutic efficacy while minimizing side effects by increasing tumor antigenicity, reversing immunosuppressive microenvironment, amplifying antitumor immune response, and reducing extratumoral distribution of checkpoint inhibitors as well as enhancing their retention within target sites. In this review, we reviewed current design strategies for different types of biomaterials to augment ICB therapy effectively and then discussed present representative biomaterial-assisted immune modulation and targeted delivery of checkpoint inhibitors to boost ICB therapy. Current challenges and future development prospects for expanding the ICB with biomaterials were also summarized. We anticipate this review will be helpful for developing emerging biomaterials for ICB therapy and promoting the clinical application of ICB therapy.

NIR responsive nanoenzymes via photothermal ablation and hypoxia reversal to potentiate the STING-dependent innate antitumor immunity

Despite advances in combined photothermal/immunotherapy of tumor, the therapeutic effect has been impaired due to hypoxic microenvironment and inadequate immune activation. Manganese ions directly activated the stimulator of interferon genes (STING) pathway and induced innate antitumor immunity. Herein, a near infrared light (NIR)-responsive nanoenzyme (PB-Mn/OVA NE) was constructed by doping manganese into the ovalbumin (OVA)-templated Prussian blue (PB) nanoparticles. The resultant PB-Mn/OVA NEs exhibited favorable catalase activity to produce oxygen, which was conducive to alleviate the tumor hypoxic microenvironment. Under 808 ​nm NIR irradiation, the PB-Mn/OVA NEs with outstanding photothermal conversion efficiency of 30% significantly destroyed tumor cells by inducing immunogenic cell death (ICD). Impressively, the PB-Mn/OVA NEs could activate the cGAS-STING pathway to promote the maturation and the antigen cross-presentation ability of dendritic cells (DCs), which further activated cytotoxic T lymphocytes and memory T lymphocytes. Overall, this work presents a powerful nanoenzyme formula to integrate photothermal ablation and hypoxic reversal for triggering robust innate and adaptive antitumor immune response.

Metal ions and nanometallic materials in antitumor immunity: Function, application, and perspective

The slightest change in the extra/intracellular concentration of metal ions results in amplified effects by signaling cascades that regulate both cell fate within the tumor microenvironment and immune status, which influences the network of antitumor immunity through various pathways. Based on the fact that metal ions influence the fate of cancer cells and participate in both innate and adaptive immunity, they are widely applied in antitumor therapy as immune modulators. Moreover, nanomedicine possesses the advantage of precise delivery and responsive release, which can perfectly remedy the drawbacks of metal ions, such as low target selectivity and systematic toxicity, thus providing an ideal platform for metal ion application in cancer treatment. Emerging evidence has shown that immunotherapy applied with nanometallic materials may significantly enhance therapeutic efficacy. Here, we focus on the physiopathology of metal ions in tumorigenesis and discuss several breakthroughs regarding the use of nanometallic materials in antitumor immunotherapeutics. These findings demonstrate the prominence of metal ion-based nanomedicine in cancer therapy and prophylaxis, providing many new ideas for basic immunity research and clinical application. Consequently, we provide innovative insights into the comprehensive understanding of the application of metal ions combined with nanomedicine in cancer immunotherapy in the past few years.

PFC@O2 Targets HIF-1α to Reverse the Immunosuppressive TME in OSCC

As a typical hallmark of solid tumors, hypoxia affects the effects of tumor radiotherapy, chemotherapy, and photodynamic therapy. Therefore, targeting the hypoxic tumor microenvironment (TME) is a promising treatment strategy for cancer therapy. Here, we prepared an Albumin Human Serum (HSA)-coated perfluorocarbon (PFC) carrying oxygen (PFC@O₂) to minimize OSCC hypoxia. The results showed that PFC@O₂ significantly downregulated the expression of HIF-1α and the number of M2-like macrophages in vitro. Furthermore, PFC@O₂ effectively inhibited the growth of oral squamous cell carcinoma (OSCC) and reduced the proportion of negative immunoregulatory cells, including myeloid-derived suppressor cells (MDSCs) and M2-like macrophages of TME in a 4-nitroquinoline N-oxide (4NQO)-induced mouse model. Conversely, the infiltration of CD4⁺ and CD8⁺ T cells was significantly increased in TME, suggesting that the anti-tumor immune response was enhanced. However, we also found that hypoxia-relative genes expression was positively correlated with CD68⁺/CD163⁺ TAMs in human tissue specimens. In summary, PFC@O₂ could effectively inhibit the progression of OSCC by alleviating hypoxia, which provides a practical basis for gas therapy and gas synergistic therapy for OSCC.

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.

The cGAS-STING-autophagy pathway: Novel perspectives in neurotoxicity induced by manganese exposure

Chronic high-level heavy metal exposure increases the risk of developing different neurodegenerative diseases. Chronic excessive manganese (Mn) exposure is known to lead to neurodegenerative diseases. In addition, some evidence suggests that autophagy dysfunction plays an important role in the pathogenesis of various neurodegenerative diseases. Over the past decade, the DNA-sensing receptor cyclic GMP-AMP synthase (cGAS) and its downstream signal-efficient interferon gene stimulator (STING), as well as the molecular composition and regulatory mechanisms of this pathway have been well understood. The cGAS-STING pathway has emerged as a crucial mechanism to induce effective innate immune responses by inducing type I interferons in mammalian cells. Moreover, recent studies have found that Mn²⁺ is the second activator of the cGAS-STING pathway besides dsDNA, and inducing autophagy is a primitive function for the activation of the cGAS-STING pathway. However, overactivation of the immune response can lead to tissue damage. This review discusses the mechanism of neurotoxicity induced by Mn exposure from the cGAS-STING-autophagy pathway. Future work exploiting the cGAS-STING-autophagy pathway may provide a novel perspective for manganese neurotoxicity.

Metal-Cyclic Dinucleotide Nanomodulator-Stimulated STING Signaling for Strengthened Radioimmunotherapy of Large Tumor

Combined treatment of immunotherapy and radiotherapy shows promising therapeutic effects for the regression of a variety of cancers. However, even multi-modality therapies often fail to antagonize the regression of large tumors due to the extremely immunosuppressive tumor microenvironment (TME). Here, a radioimmunotherapeutic paradigm based on stimulator of interferon genes (STING)-dependent signaling is applied to preclude large tumor progression by utilizing the metal-cyclic dinucleotide (CDN) nanoplatform, which integrates STING agonist c-di-AMP and immunomodulating microelement manganese (II) within the tannic acid nanostructure (TMA-NPs). As observed by magnetic resonance imaging, the localized administration of TMA-NPs effectively relieves hypoxia within TME and causes radical oxygen species overproduction and apoptosis in cancer cells after exposure to X-ray irradiation. The DNA fragments released from the apoptotic cells after the combined treatment augment the production of endogenous CDNs in cancer cells, hence significantly activating the STING-mediated pathway for stronger anti-tumor immunity. The localized therapy of TMA-NPs + X-ray not only inhibits the primary large tumor progression but also retards distant tumor growth by promoting dendritic cell maturation and activating cytotoxic immune cells whil suppressing immunosuppressive cells. Therefore, this work represents the combinatorial potency of TMA-NPs and X-rays on large tumor regression through strengthened STING-mediated radioimmunotherapeutics.

Immunosuppression in tumor immune microenvironment and its optimization from CAR-T cell therapy

Chimeric antigen receptor (CAR)-T cell therapy represents a landmark advance in personalized cancer treatment. CAR-T strategy generally engineers T cells from a specific patient with a new antigen-specificity, which has achieved considerable success in hematological malignancies, but scarce benefits in solid tumors. Recent studies have demonstrated that tumor immune microenvironment (TIME) cast a profound impact on the immunotherapeutic response. The immunosuppressive landscape of TIME is a critical obstacle to the effector activity of CAR-T cells. Nevertheless, every cloud has a silver lining. The immunosuppressive components also shed new inspiration on reshaping a friendly TIME by targeting them with engineered CARs. Herein, we summarize recent advances in disincentives of TIME and discuss approaches and technologies to enhance CAR-T cell efficacy via addressing current hindrances. Simultaneously, we firmly believe that by parsing the immunosuppressive components of TIME, rationally manipulating the complex interactions of immunosuppressive components, and optimizing CAR-T cell therapy for each patient, the CAR-T cell immunotherapy responsiveness for solid malignancies will be substantially enhanced, and novel therapeutic targets will be revealed.