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

NIR-II AIEgen with high photothermal efficiency for mild PTT: Optimized natural killer cell spatial distribution for boosted immune response

Organic photothermal agents (PTAs) with high photothermal conversion efficiency (PCE) and biocompatibility are ideal for mild photothermal therapy (PTT), which can selectively eliminate tumor cells and elicit an active immune response. However, the challenge lies in developing PTAs with high PCE, and the impact of PTT-induced temperature gradients on the cytolytic potential of natural killer (NK) cells against tumor cells has yet been investigated. Herein a novel NIR-II aggregation-induced emission (AIE) molecule named C12T-BBT is proposed by conjugating an electron donor TPA with a strong electron acceptor BBT, using a long alkyl chain (C12) substituted thiophene as π-bridge. By doing this, C12T-BBT has a relative planar structure to ensure a high extinction coefficient, while the long alkyl chain restricts the π-π interaction and provides more room for molecular motion in excited state. Together, these design strategies assure C12T-BBT with a high PCE of 84.7 %. In vivo experiments exhibit favorable NIR-II imaging and tumor elimination using water-soluble cRGD@C12T-BBT nanoparticles. The application of mild PTT results in an effective induction of NK cell response in terms of shortening its distance with tumor cells from 25.6 μm to 10.6 μm, characterized using a machine-learning based spatial analysis, thereby enhancing the efficacy of cancer therapy. Therefore, this work provides evidence for a novel combined anti-tumor strategy of aligning mild PTT and NK cell immunotherapy by illustrating crucial optimization of NK-tumor intercellular proximity in mild PTT.

A cancer theranostic nanoplatform for second near-infrared fluorescence imaging-guided carbon monoxide-sensitized mild photothermal therapy with ICD induction

Mild-temperature photothermal therapy (mild PTT), utilizing photothermal agents to convert external light into mild heat (<45 °C), holds significant potential as a localized treatment modality to induce cellular thermal damage. This therapeutic strategy not only directly eliminates targeted cells but also induces immunogenic cell death (ICD), activating the immune response. However, the presence of heat shock proteins (HSPs) can significantly reduce the effectiveness of photothermal therapy. Therefore, it is crucial to inhibit HSP repair and minimize damage to surrounding normal cells in order to enhance the efficiency of low-temperature PTT. Additionally, carbon monoxide (CO) has been shown to suppress the upregulation of HSPs in cancer cells under heat treatment. Furthermore, the utilization of second near-infrared (NIR-II) fluorescence particles can improve the precision and suitability of PTT due to their increased penetration depth and novel imaging capabilities. In this study, we developed a NIR-light-activated CO release system using CO-loaded mesoporous organosilica nanoparticles (CO-MON) for enhancing the effectiveness of mild PTT by suppressing HSPs repair through selectively targeted CO delivery. Triiron dodecacarbonyl (Fe3(CO)12), as the source of CO was employed for encapsulation within the pores of the MON. These MON showed emission in the NIR-II range, while also displaying remarkable photostability and a high efficiency in photothermal conversion (34.7 %). Through intratumoral administration, the CO-MON platform demonstrated efficient tumor accumulation and localized photothermal efficacy in vivo. In vitro and in vivo studies demonstrated that this exceptional photothermal effect not only effectively eliminated tumor but also augmented tumor ICD.

Multifunctional nanoparticles and collagenase dual loaded thermosensitive hydrogel system for enhanced tumor-penetration, reversed immune suppression and photodynamic-immunotherapy

Breast cancer is the most prevalent and lethal malignancy among females, with a critical need for safer and less invasive treatments. Photodynamic therapy (PDT) can effectively eliminate tumor cells with minimal side effects. Furthermore, the combination of PDT and immunotherapy using nanoparticles has shown promise in treating both primary and distant metastatic tumor cells. Therefore, this study proposes applying the PDT-immunotherapy combination to breast cancer treatment. However, the low immunogenicity characteristic of "cold" tumors in part of breast cancer significantly diminishes therapeutic efficacy. To address this challenge, here, a nano-gel system (designated as HCSC-gel) is constructed, which co-delivers a mitochondria-targeted photosensitizer and a STING agonist, capable of robustly activating "cold" tumor immunity. This system is further enhanced by collagenase (CN) to improve therapeutic outcomes. Upon injection into the primary tumor site, HCSC-gel rapidly forms a gel matrix, releasing CN to degrade the tumor extracellular matrix and facilitate the penetration of photosensitizers, STING agonists, and oxygen into the tumor tissue. Under laser irradiation, PDT and STING-mediated immune responses are activated, reversing the low immunogenicity of breast cancer and effectively treating both primary and metastatic lesions. This HCSC-gel nano hydrogel delivery platform is anticipated to provide novel insights for the clinical management of breast cancer and other low immunogenic "cold" tumors, offering significant benefits to patients.

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.

Macrophage-membrane-engineered NIR II biomimetic nanomaterials for enhanced synergistic chemo-photothermal immunotherapy in cancer treatment

Nanoparticle encapsulated with PEG-based polymers face limitations in their circulation stability and tumor tissue accumulation during blood transport due to the production of anti-PEG antibodies and their inherent nature as foreign substances, which leads to immune surveillance and clearance by the body. The design of biomimetic nanomaterials based on cell membranes offers a solution to these issues. In this context, we have successfully developed a biomimetic nanomaterials designed for the near-infrared region II (NIR II), which leverage the combined power of chemotherapy and photothermal therapy to activate an immune response against tumors. We synthesized nanoparticle loaded with IR1061 and doxorubicin (DOX) using microemulsion and nano-precipitation techniques, and then coated them with the pluronic (F127) polymer to enhance their stability and biocompatibility within biological systems. To further extend their circulation time and minimize the risk of immune detection, we encapsulated the nanoparticle within macrophage membranes. These customized nanoparticle, termed CIN and CDN, are capable of precisely targeting tumors through the bloodstream and effectively eliminating cancer cells under the dual onslaught of photothermal and chemotherapeutic actions. Throughout the treatment, the destruction of tumor cells triggers the release of antigens, which in turn activate CD4+ and CD8+ T cells, stimulating an immune response. Our findings indicate that the integration of chemotherapy with immunotherapy can significantly amplify the immune response by facilitating the demise of tumor cells, representing a highly promising synergistic strategy in the fight against cancer.

Time-performance relationship and the associated mechanism of tumor drug-efflux pump P-glycoprotein reversal induced by mild photothermal therapy

Acquired multidrug resistance (MDR) has been the main cause leading to cancer therapy failure. Even though mild photothermal therapy (PTT) strategy has shown promise in overcoming tumor MDR, the detailed changing patterns of drug-resistant protein P-glycoprotein (P-gp) following photothermal treatment remains poorly understood. Herein, we utilized the iRGD-modified graphene oxide nanosheet (IPHG), a nanocarrier capable of tumor-targeted infiltration and photothermal conversion, to investigate the time-performance relationship and the associated mechanism of mild PTT-mediated P-gp regulation. For the first time we found that mild PTT could induce rapid reduction in P-gp levels within 3 h via ubiquitin-proteasome degradation. Doxorubicin (DOX)-loaded nanodrug (IPHG/DOX) was then fabricated to unveil the significance of P-gp reversal-synchronized drug release. The results exhibited that NIR-irradiated IPHG/DOX remarkably augmented intracellular DOX accumulation, increased DOX infiltration in tumor spheroids, and potentiated cytotoxicity against MCF-7/ADR cells. These novetherapys offer valuable insights into mild PTT-assisted MDR tumor therapies.

Drug-loaded indocyanine green J-aggregates activate metalloimmunotherapy for sustained photothermal therapy of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) poses a significant therapeutic challenge, driving the need for novel treatment strategies. This study investigates the combination of photothermal therapy (PTT) and metalloimmunotherapy for HCC treatment using Co + diABZI@J-dICG nanoparticles. Indocyanine green (ICG), an FDA-approved near-infrared (NIR) dye, is dimerized into J-aggregates to enhance PTT by improving light absorption and photothermal efficiency. The cGAS-STING pathway, a key mediator of innate immunity, is activated by the STING agonist diABZI, while cobalt ions (Co2+) further enhance immune responses. The Co + diABZI@J-dICG nanoparticles take advantage of ICG's hepatotropic properties for sustained tumor accumulation and immune activation, resulting in significant tumor growth inhibition and reduced HCC recurrence following hepatectomy.

Genetically Engineered IL12/CSF1R-Macrophage Membrane-Liposome Hybrid Nanovesicles for NIR-II Fluorescence Imaging-Guided and Membrane-Targeted Mild Photothermal-Immunotherapy of Glioblastoma

It is a big challenge for precision therapy of glioblastoma, mainly due to the existence of blood-brain barrier (BBB), tumor immunosuppressive microenvironment (TIM), and lack of efficient treatment paradigms. Herein, a theranostic nanoplatform for the second near-infrared window (NIR-II) fluorescence imaging-guided membrane-targeted mild photothermal-immunotherapy of glioblastoma using genetically engineered CSF1R/IL12-macrophage membrane (MM)-liposome hybrid nanovesicles, is reported. By mimicking lipophilic membrane probe (Dil) with octadecyl chains, a NIR-II emissive photothermal dye (IRC18), which realizes labeling of nanovesicle lipid bilayers for biodistribution tracing, glioblastoma diagnosis, and molecular imaging of tumoral microenvironment, is synthesized. Importantly, MM and c-RGD-decorated liposome together offer BBB crossing, tumor targeting, and long-term circulation; while, the genetically overexpressed CSF1R and IL12 on MM surface contribute to effective modulation of M2-to-M1 macrophage repolarization and local promotion of T cell cytotoxicity in glioblastoma microenvironment, respectively. Notably, through membrane fusion, IRC18 dyes translocate from nanovesicle lipid bilayers to glioblastoma membranes, which achieve membrane-targeted mild photothermal therapy to ablate primary tumor and induce immunogenic cell death to promote antigen presentation. More importantly, the combined blockade of the CSF1-CSF1R axis and IL-12 enrichment not only reprograms the tumor microenvironment through macrophage M1 repolarization but also activates cytotoxic T cells, ultimately achieving complete glioblastoma eradication. This research provides an efficient theranostic paradigm for glioblastoma treatment.

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

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

A review on polysaccharide-based tumor targeted drug nanodelivery systems

The tumor-targeted drug delivery system (TTDNS) uses nanocarriers to transport chemotherapeutic agents to target tumor cells or tissues precisely. This innovative approach considerably increases the effective concentration of these drugs at the tumor site, thereby enhancing their therapeutic efficacy. Many chemotherapeutic agents face challenges, such as low bioavailability, high cytotoxicity, and inadequate drug resistance. To address these obstacles, TTDNS comprising natural polysaccharides have gained increasing popularity in the field of nanotechnology owing to their ability to improve safety, bioavailability, and biocompatibility while reducing toxicity. In addition, it enhances permeability and allows for controlled drug delivery and release. This review focuses on the sources of natural polysaccharides and their direct and indirect mechanisms of anti-tumor activity. We also explored the preparation of various polysaccharide-based nanocarriers, including nanoparticles, nanoemulsions, nanohydrogels, nanoliposomes, nanocapsules, nanomicelles, nanocrystals, and nanofibers. Furthermore, this review delves into the versatile applications of polysaccharide-based nanocarriers, elucidating their capabilities for in vivo targeting, controlled release, and responsiveness to endogenous and exogenous stimuli, such as pH, reactive oxygen species, glutathione, light, ultrasound, and magnetic fields. This sophisticated design substantially enhances the chemotherapeutic efficacy of the encapsulated drugs at tumor sites and provides a basis for preclinical and clinical research. However, the in vivo stability, drug loading, and permeability of these preparations into tumor tissues still need to be improved. Most of the currently developed biomarker-sensitive polysaccharide nanocarriers are still in the laboratory stage, more innovative delivery mechanisms and clinical studies are needed to develop commercial nanocarriers for medical use.

Tumor-Adhesive Chitosan-Derived Multi-Immune Agonist Unleashes Strong and Durable Anti-Cancer Immunity

The immunomodulation of the tumor microenvironment is critical for effective cancer immunotherapy, particularly for tumors that exhibit limited responses to conventional treatments. However, current immune agonists developed for tumor immunomodulation face several challenges, such as poor intratumoral retention, inadequate biocompatibility, and restricted cellular targets, which ultimately hamper their therapeutic efficacy and clinical application. In this study, a tumor-adhesive chitosan-tethered immune agonist construct (TACTIC) is introduced, which demonstrates good biocompatibility and robust immunostimulatory effects, enhancing the immunogenicity of tumor cells while simultaneously stimulating pro-inflammatory responses in various immune cell populations. Mechanistic investigations reveal that TACTIC targets multiple signaling pathways, conferring it to effectively remodel the irradiated tumor microenvironment, improve tumor control on murine cancer models post-radiotherapy, and elicit systemic immune responses with memory effects. The findings highlight the potential of TACTIC as a powerful macromolecular immune adjuvant, paving the way for its broader application in innovative cancer immunotherapies.

Tyrosine Kinase Inhibitor Lenvatinib Based Nano Formulations and Cutting-Edge Scale-Up Technologies in revolutionizing Cancer Therapy

Lenvatinib (LEN), a tyrosine kinase inhibitor, has emerged as a promising therapeutic agent for various solid tumors. Nevertheless, a number of constraints, including diminished bioavailability, incapacity to elicit localized inflammation, and inability to selectively accumulate at the tumor site, may impede the comprehensive exploitation of its versatile tyrosine kinase inhibitory capabilities. In order to achieve targeted delivery of LEN while also reducing its high dose used in conventional therapeutics, nanoformulation approaches can be adopted. The integration of LEN into various nanoformulations, such as nanoparticles, nanocrystals, high density lipoproteins (HDLs), liposomes, and micelles, is discussed, highlighting the advantages of these innovative approaches in a comparative manner; however, given that the current methods of nanoformulation synthesis employ toxic organic solvents and chemicals, there is an imperative need for exploring alternative, environmentally friendly approaches. The multifaceted effects of nanocarriers have rendered them profoundly applicable within the biomedical domain, serving as instrumental entities in various capacities such as vehicles for drug delivery and genetic material, diagnostic agents, facilitators of photothermal therapy, and radiotherapy. However, the scalability of these nanotechnological methodologies must be rigorously investigated and addressed to refine drug delivery mechanisms. This endeavor offers promising prospects for revolutionizing strategies in cancer therapeutics, thereby laying the foundation for future research in scale-up techniques in the pursuit of more effective and less toxic therapies for cancer.

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

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

Profile of STING agonist and inhibitor research: a bibliometric analysis

Background

STING is a core signaling hub molecule in the innate immune system, involved in various diseases, including infectious diseases, autoimmune diseases, tumors, aging, organ fibrosis, and neurodegenerative diseases. Its activation has shown great potential in anti-tumor and anti-infective therapies, with STING agonists emerging as a promising approach in cancer immunotherapy in recent years. This study identifies research trends and potential directions in the field by collecting and analyzing relevant literature.

Methods

A total of 527 publications regarding STING agonists and 107 about inhibitors were retrieved from the WOS Core Collection database. Bibliometric information was extracted with CiteSpace and VOSviewer software for visualization.

Results

It shows that research on both STING agonists and inhibitors is burgeoning rapidly. The United States and China are leading contributors in this field. Application of STING agonists primarily focuses on cancer immunotherapy, while STING inhibitors target inflammation, particularly neuroinflammation and acute lung injury.

Conclusion

Current research emphasizes optimizing STING agonists for permeability, efficacy, and safety, with nanotechnology and lipid nanoparticles being prominent delivery techniques. Future research is expected to focus on drug development and clinical applications. This comprehensive bibliometric analysis provides clinical insights and a guide for further investigation to STING agonist/inhibitor.

Engineered Strategies to Interfere with Macrophage Fate in Myocardial Infarction

Myocardial infarction (MI), a severe cardiovascular condition, is typically triggered by coronary artery disease, resulting in ischemic damage and the subsequent necrosis of the myocardium. Macrophages, known for their remarkable plasticity, are capable of exhibiting a range of phenotypes and functions as they react to diverse stimuli within their local microenvironment. In recent years, there has been an increasing number of studies on the regulation of macrophage behavior based on tissue engineering strategies, and its regulatory mechanisms deserve further investigation. This review first summarizes the effects of key regulatory factors of engineered biomaterials (including bioactive molecules, conductivity, and some microenvironmental factors) on macrophage behavior, then explores specific methods for inducing macrophage behavior through tissue engineering materials to promote myocardial repair, and summarizes the role of macrophage-host cell crosstalk in regulating inflammation, vascularization, and tissue remodeling. Finally, we propose some future challenges in regulating macrophage-material interactions and tailoring personalized biomaterials to guide macrophage phenotypes.

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

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

Hyaluronic acid-functionalized supramolecular nanophotosensitizers for targeted photoimmunotherapy of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is recognized as a particularly aggressive subtype of breast cancer that is devoid of effective therapeutic targets. Immune checkpoint inhibitors (ICIs) have demonstrated promising results in TNBC treatment. Nonetheless, most patients either develop resistance to ICIs or fail to respond to them initially. Owing to its spatio-temporal precision and non-invasive nature, photoimmunotherapy offers a targeted therapeutic strategy for TNBC. Herein, we report hyaluronic acid (HA)-functionalized indocyanine green-based supramolecular nanoparticles (HGI NPs), with biodegradable characteristics, for high-performance photoacoustic imaging and targeted phototherapy for TNBC. Notably, HGI NPs can significantly gather in TNBC tissues because of the enhanced permeability and retention effect of the tumor, and the tumor-targeting properties of HA. The strong amplification of HGI nanoparticles triggers a significant immunogenic cell death (ICD) response when exposed to 808 nm light, thus shifting the immunosuppressive tumor microenvironment (iTME) into a tumor attack mode and 'hot' state. Antitumor experiments demonstrate the high efficiency of the supramolecular photosensitizers HGI NPs for TNBC elimination and good biosafety. This synergistic strategy reshapes the iTME and amplifies the antitumor immune response, providing a theoretical foundation for combining phototherapy and ICIs as potential treatments for TNBC.

Chemically engineered exogenous organic reactions in living cells for in situ fluorescence imaging and biomedical applications

The unique microenvironment within living cells, characterized by high glutathione levels, reactive oxygen species concentrations, and active enzymes, facilitates the execution of chemical reactions. Recent advances in organic chemistry and chemical biology have leveraged living cells as reactors for chemical synthesis. This review summarizes recent reports on key intracellular in situ synthesis processes, including the synthesis of near-infrared fluorescent dyes, intracellular oxidative cross-linking, bioorthogonal reactions, and intracellular polymerization reactions. These methods have been applied to fluorescence imaging, tumor treatment, and the enhancement of biological functions. Finally, we discuss the challenges and opportunities in the field of in situ intracellular synthesis. We aim to guide the design of chemical molecules for in situ synthesis, improving the efficiency and control of artificial reactions in living cells, and ultimately achieving cell factory-like exogenous biological synthesis, biological function enhancement, and biomedical applications.

Homologous-adhering/targeting cell membrane- and cell-mediated delivery systems: a cancer-catch-cancer strategy in cancer therapy

Low tumor enrichment remains a serious and urgent problem for drug delivery in cancer therapy. Accurate targeting of tumor sites is still a critical aim in cancer therapy. Though there have been a variety of delivery strategies to improve the tumor targeting and enrichment, biological barriers still cause most delivered guests to fail or be excreted before they work. Recently, cell membrane-based systems have attracted a huge amount of attention due to their advantages such as easy access, good biocompatibility and immune escape, which contribute to their biomimetic structures and specific surface proteins. Furthermore, cancer cell membrane-based delivery systems are referred to as homologous-targeting function in which they exhibit significantly high adhesion and internalization to homologous-type tumor sites or cells even though the exact mechanism is not entirely revealed. Here, we summarize the sources and characterizations of cancer cell membrane systems, including reconstructed single or hybrid membrane-based nano-/microcarriers, as well as engineered cancer cells. Additionally, advanced applications of these cancer cell membrane systems in cancer therapy are categorized and summarized according to the components of membranes. The potential factors related to homologous targeting of cancer cell membrane-based systems are also discussed. By discussing the applications, challenges and opportunities, we expect the cancer cell membrane-based homologous-targeting systems to have a far-reaching development in preclinic or clinics.

Photothermally Reinforced Nanozyme Remodeling Tumor Microenvironment of Redox and Metabolic Homeostasis to Enhance Ferroptosis in Tumor Therapy

The acidity and high GSH level in the tumor microenvironment (TME) greatly limit the antitumor activity of nanozymes. Thus, enhancing nanozymes' activity is fundamentally challenging in tumor therapy. Although the combination of photothermal therapy (PTT) and nanozymes can enhance the catalytic activity, cancer cells will overexpress heat shock proteins (HSPs) at high temperature, aggravating the heat resistance of tumor cells, which in turn compromises the outcome of chemodynamic therapy. Herein, we propose an iron-doped metal-organic framework nanozyme (IB@Fe-ZIF8@PDFA) that can be activated under the weak acidity and high level of GSH, demonstrating the activities of GSH oxidation (GSH-OXD), peroxidase (POD), and NADH oxidase (NADH-OXD). Under laser irradiation, it displays photothermal-enhanced multienzyme activities to simultaneously eliminate tumors and inhibit tumor metastasis. While consuming endogenous GSH, IB@Fe-ZIF8@PDFA promotes the decomposition of H2O2 into ·OH, enhancing ferroptosis in tumor cells. Surprisingly, IB@Fe-ZIF8@PDFA nanozyme can oxide NADH and subsequently limit the ATP supply, reducing the expression of HSPs and significantly weakening the heat resistance of tumor cells during PTT. Meanwhile, H2O2 is generated during this procedure, which can endogenously replenish the consumed H2O2. Thus, this IB@Fe-ZIF8@PDFA nanozyme constitutes a self-cascading platform to consume GSH and NADH, endogenously replenish the H2O2 and continuously generate ·OH to facilitate ferroptosis by disrupting the redox and metabolic homeostasis in tumor cells, achieving tumor elimination and tumor metastasis inhibition.

A Multifunctional Low-Temperature Photothermal Nanomedicine for Melanoma Treatment via the Oxidative Stress Pathway Therapy

Purpose

Melanoma is a highly aggressive and dangerous malignant skin tumor and there is an urgent need to develop effective therapeutic approaches against melanoma. The main objective of this study was to construct a multifunctional nanomedicine (GNR@PEG-Qu) to investigate its therapeutic effect on melanoma from the oxidative stress pathway.

Methods

First, the nanomedicine GNR@PEG-Qu was synthesized and characterized, and its photothermal and antioxidant properties were confirmed. In addition, in vivo imaging capabilities were observed. Finally, the tumor inhibitory effects of GNR@PEG-Qu in vivo and in vitro as well as its biosafety were observed.

Results

GNR@PEG-Qu shows good photothermal and anti-oxidation properties. Following exposure to 1064 nm laser irradiation in the second near-infrared II (NIR-II) window, GNR@PEG-Qu shows anti-tumor ability through low-temperature photothermal therapy (PTT) adjuvant drug chemotherapy. GNR@PEG-Qu makes full use of the antioxidant capacity of quercetin, reduces ROS levels in melanoma, alleviates oxidative stress state, and achieves "oxidative stress avoidance" at the tumor site. Quercetin can also downregulate the expression of the heat shock protein Hsp70, which will improve the thermal sensitivity of the tumor site and enhance the efficacy of low-temperature PTT.

Conclusion

GNR@PEG-Qu nanoagent exhibits synergistic treatment and high tumor inhibition effects, which is a promising strategy developed to achieve oxidative stress avoidance and synergistic therapy of melanoma using quercetin (Qu)-coated gold nanorod (GNR@PEG).

Engineered manganese-BODIPY coordinated nanoadjuvants for enhanced NIR-II photo-metalloimmunotherapy

Immunotherapy, a pivotal and promising approach for tumor treatment, has demonstrated prominent clinical efficacy. However, its effectiveness is often impeded by insufficient antitumor immune responses attributed to the immunosuppressive tumor microenvironment (TME). The combination of immune activation through the stimulator of interferon genes (STING) pathway and phototherapy holds great potential for surmounting this challenge in advanced tumor immunotherapy. Herein, a novel manganese-boosted NIR-II photo-metalloimmunotherapy is proposed to synergistically enhance antitumour efficacy by fabricating Mn2+-BODIPY-based coordinated photo-immune nanoadjuvants (BMR), modified with tumor-targeted peptide cRGD. The obtained BMR could effectively deliver Mn2+ to tumor sites, and immunogenic cell death (ICD) was evoked by localized photothermal ablation of tumors using NIR-II laser irradiation. Simultaneously, pH-responsive release of Mn2+ would trigger the activation of STING pathway to promote the production of type I interferons (I-IFNs), significantly facilitating the maturation of dendritic cells (DCs) and polarization of macrophages to M1 phenotypes. Furthermore, by synergistically initiating systematic and robust antitumour immune responses, the BMR-mediated NIR-II photo-metalloimmunotherapy achieved remarkable therapeutic efficacy against both primary and lung metastasis of B16F10 tumors. Overall, in light of the versatile functionalities and synthetic flexibility of coordinated nanoadjuvants, formulated with photofunctional ligands and diverse metal ions, this work provides new insights into the design of metal coordination nanomedicine for effective antitumor photo-metalloimmunotherapy.

Highly Efficient Synergistic Chemotherapy and Magnetic Resonance Imaging for Targeted Ovarian Cancer Therapy Using Hyaluronic Acid-Coated Coordination Polymer Nanoparticles

The diagnosis and treatment of ovarian cancer (OC) are still a grand challenge, more than 70% of patients are diagnosed at an advanced stage with a dismal prognosis. Magnetic resonance imaging (MRI) has shown superior results to other examinations in preoperative assessment, while cisplatin-based chemotherapy is the first-line treatment for OC. However, few previous studies have brought together the two rapidly expanding fields. Here a technique is presented using cisplatin prodrug (Pt-COOH), Fe3+, and natural polyphenols (Gossypol) to construct the nanoparticles (HA@PFG NPs) that have a stable structure, controllable drug release behavior, and high drug loading capacity. The acidic pH values in tumor sites facilitate the release of Fe3+, Pt-COOH, and Gossypol from HA@PFG NPs. Pt-COOH with GSH consumption and cisplatin-based chemotherapy plus Gossypol with pro-apoptotic effects displays a synergistic effect for killing tumor cells. Furthermore, the release of Fe3+ at the tumor sites promotes ferroptosis and enables MRI imaging of OC. In the patient-derived tumor xenograft (PDX) model, HA@PFG NPs alleviate the tumor activity. RNA sequencing analysis reveals that HA@PFG NPs ameliorate OC symptoms mainly through IL-6 signal pathways. This work combines MRI imaging with cisplatin-based chemotherapy, which holds great promise for OC diagnosis and synergistic therapy.

J-aggregates of multi-groups cyanine dye for NIR-IIa fluorescence-guided mild photothermal therapy under 1064 nm irradiation

NIR-IIa fluorescence imaging (FI) and NIR-II photothermal therapy (PTT) have gained popularity due to the advantages of high temporal and spatial resolution and deep penetration. However, the hyperthermia (>48 °C) of conventional PTT with nonspecific warming and thermal diffusion may inevitably cause damage to healthy tissues or organs surrounding the tumor. Therefore, it is highly desirable to provide effective cancer treatment by implementing mild photothermal therapy (mPTT) at mild temperatures with lower laser power density. Here, the nanotheranostic platform FN@P-GA NPs with NIR-II absorption and NIR-IIa emission was developed by constructing J-aggregates. FN@P-GA possesses good biocompatibility, favorable NIR-IIa FI performance, decent stability, and high photothermal conversion efficiency (57.6 %), which lays a solid foundation for FI-guided mPTT. Due to its ability to effectively down-regulate the expression of HSP90 and reduce cellular thermoresistance to kill cancer cells, FN@P-GA successfully achieved NIR-IIa FI-guided mPTT and demonstrated its potent anti-tumor effect under 1064 nm laser irradiation at mild temperature and low power density (0.3 W/cm2).

Temperature Self-Limited Intelligent Thermo-chemotherapeutic Lipid Nanosystem for P-gp Reversal Time Window Matched Pulse Treatment of MDR Tumor

Mild photothermal therapy (PTT) shows the potential for chemosensitization by tumor-localized P-glycoprotein (P-gp) modulation. However, conventional mild PTT struggles with real-time uniform temperature control, obscuring the temperature-performance relationship and resulting in thermal damage. Besides, the time-performance relationship and the underlying mechanism of mild PTT-mediated P-gp reversal remains elusive. Herein, we developed a temperature self-limiting lipid nanosystem (RFE@PD) that integrated a reversible organic heat generator (metal-phenolic complexes) and metal chelator (deferiprone, DFP) encapsulated phase change material. Upon NIR irradiation, RFE@PD released DFP for blocking ligand-metal charge transfer to self-limit temperature below 45 °C, and rapidly reduced P-gp within 3 h via Ubiquitin-proteasome degradation. Consequently, the DOX·HCl-loaded thermo-chemotherapeutic lipid nanosystem (RFE@PD-DOX) led to dramatically improved drug accumulation and 5-fold chemosensitization in MCF-7/ADR tumor models by synchronizing P-gp reversal and drug pulse liberation, achieving a tumor inhibition ratio of 82.42%. This lipid nanosystem integrated with "intrinsic temperature-control" and "temperature-responsive pulse release" casts new light on MDR tumor therapy.

Metal-Phenolic Vehicles Potentiate Cycle-Cascade Activation of Pyroptosis and cGAS-STING Pathway for Tumor Immunotherapy

The treatment of triple-negative breast cancer (TNBC) faces challenges due to its limited immune response and weak tumor immunogenicity. A collaborative strategy involves combining the activation of pyroptosis and the stimulator of interferon genes (STING) pathway to enhance tumor immunogenicity and fortify the antitumor immune response, which may improve therapeutic outcomes in TNBC. In this study, we report the fabrication of a zinc-phenolic nanocapsule (RMP@Cap), which is loaded with mitoxantrone (MTO) and anti-PD-L1 antibodies (aPD-L1) and coated with erythrocyte membrane, for TNBC immunotherapy. The delivery of RMP@Cap can induce tumor cell pyroptosis and, therefore, trigger the release of mitochondrial DNA, which further combines with zinc agonists to intensify STING activation, resulting in a cascade amplification of the therapeutic effect on tumors. Additionally, the incorporation of aPD-L1 into the zinc-phenolic nanocapsule relieves the inhibitory effect of tumor cells on recruited cytotoxic T cells, thereby improving the tumor-killing capacity. Furthermore, the incorporation of a camouflaged erythrocyte membrane coating enables nanocapsules to achieve prolonged in vivo circulation, resulting in improved tumor accumulation for effective antitumor therapy. This study demonstrates a synergistic therapeutic modality involving pyroptosis, coupled with the simultaneous activation and cyclic amplification of the STING pathway in immunotherapy.

Recent Progress in Photothermal, Photodynamic and Sonodynamic Cancer Therapy: Through the cGAS-STING Pathway to Efficacy-Enhancing Strategies

Photothermal, photodynamic and sonodynamic cancer therapies offer opportunities for precise tumor ablation and reduce side effects. The cyclic guanylate adenylate synthase-stimulator of interferon genes (cGAS-STING) pathway has been considered a potential target to stimulate the immune system in patients and achieve a sustained immune response. Combining photothermal, photodynamic and sonodynamic therapies with cGAS-STING agonists represents a newly developed cancer treatment demonstrating noticeable innovation in its impact on the immune system. Recent reviews have concentrated on diverse materials and their function in cancer therapy. In this review, we focus on the molecular mechanism of photothermal, photodynamic and sonodynamic cancer therapies and the connected role of cGAS-STING agonists in treating cancer.

V-doped MoS2 nanozymes providing reactive oxygen species and depleting glutathione for photothermally-enhanced nanocatalytic therapy

Introduction: The tumor microenvironment and multidrug resistance of tumor cells seriously impair the activity of the nanozymes. Methods: Herein, a polyethylene glycol (PEG)-modified vanadium-doped molybdenum disulfide (V-MoS2@PEG) nanozymes were constructed to enhance anti-tumor activity through multi-enzymatic catalysis and photothermal effect with simultaneous reactive oxygen species replenishment and glutathione depletion. Results and discussion: V-MoS2@PEG nanosheets exerted peroxidase activity by causing molybdenum ion (Mo4+) to react with hydrogen peroxide to form toxic hydroxyl radicals (·OH). Meanwhile, the V-doping can deplete glutathione avoiding ·OH consumption. In addition, the high heat generated by V-MoS2@PEG nanozymes under near-infrared laser irradiation brought about a desirable local temperature gradient, which produced an enhanced catalytic effect by promoting band bending. Furthermore, the photothermally inspired polarized charge increased the permeability of the tumor cell membrane and promoted further aggregation of the nanozymes, which realized the combination of photothermal therapy with multi-enzymatic catalysis, solved the problem of multi-enzyme catalysis, and improved the anti-tumor efficiency.

Paclitaxel Overload Supramolecular Oxidative Stress Nanoamplifier with a CDK12 Inhibitor for Enhanced Cancer Therapy

Combination therapy has emerged as a promising approach for treating tumors, although there is room for improvement. This study introduced a novel strategy that combined the enhancement of apoptosis, ferroptosis, and DNA damage to improve therapeutic outcomes for prostate cancer. Specifically, we have developed a supramolecular oxidative stress nanoamplifier, which was comprised of β-cyclodextrin, paclitaxel, and ferrocene-poly(ethylene glycol). Paclitaxel within the system disrupted microtubule dynamics, inducing G2/M phase arrest and apoptosis. Concurrently, ferrocene utilized hydrogen peroxide to generate toxic hydroxyl radicals in cells through the Fenton reaction, triggering a cascade of reactive oxygen species expansion, reduction of glutathione levels, lipid peroxidation, and ferroptosis. The increased number of hydroxyl radicals and the inhibitory effect of THZ531 on DNA repair mechanisms exacerbated DNA damage within tumor cells. As expected, the supramolecular nanoparticles demonstrated excellent drug delivery ability to tumor cells or tissues, exhibited favorable biological safety in vivo, and enhanced the killing effect on prostate cancer.

Tailored design of NHS-SS-NHS cross-linked chitosan nano-hydrogels for enhanced anti-tumor efficacy by GSH-responsive drug release

The traditional chemotherapeutic agents' disadvantages such as high toxicity, untargeting and poor water solubility lead to disappointing chemotherapy effects, which restricts its clinical application. In this work, novel size-appropriate and glutathione (GSH)-responsive nano-hydrogels were successfully prepared via the active ester method between chitosan (containing -NH2) and cross-linker (containing NHS). Especially, the cross-linker was elaborately designed to possess a disulfide linkage (SS) as well as two terminal NHS groups, namely NHS-SS-NHS. These functionalities endowed chitosan-based cross-linked scaffolds with capabilities for drug loading and delivery, as well as a GSH-responsive mechanism for drug release. The prepared nano-hydrogels demonstrated excellent performance applicable morphology, excellent drug loading efficiency (∼22.5%), suitable size (∼100 nm) and long-term stability. The prepared nano-hydrogels released over 80% doxorubicin (DOX) after incubation in 10 mM GSH while a minimal DOX release less than 25% was tested in normal physiological buffer (pH = 7.4). The unloaded nano-hydrogels did not show any apparent cytotoxicity to A 549 cells. In contrast, DOX-loaded nano-hydrogels exhibited marked anti-tumor activity against A 549 cells, especially in high GSH environment. Finally, through fluorescent imaging and flow cytometry analysis, fluorescein isothiocyanate-labeled nano-hydrogels show obvious specific binding to the GSH high-expressing A549 cells and nonspecific binding to the GSH low-expressing A549 cells. Therefore, with this cross-linking approach, our present finding suggests that cross-linked chitosan nano-hydrogel drug carrier improves the anti-tumor effect of the A 549 cells and may serve as a potential injectable delivery carrier.

Breaking-Down Tumoral Physical Barrier by Remotely Unwrapping Metal-Polyphenol-Packaged Hyaluronidase for Optimizing Photothermal/Photodynamic Therapy-Induced Immune Response

The therapy of solid tumors is often hindered by the compact and rigid tumoral extracellular matrix (TECM). Precise reduction of TECM by hyaluronidase (HAase) in combination with nanotechnology is promising for solid tumor therapeutics, yet remains an enormous challenge. Inspired by the treatment of iron poisoning, here a remotely unwrapping strategy is proposed of metal-polyphenol-packaged HAase (named PPFH) by sequentially injecting PPFH and a clinically used iron-chelator deferoxamine (DFO). The in situ dynamic disassembly of PPFH can be triggered by the intravenously injected DFO, resulting in the release, reactivation, and deep penetration of encapsulated HAase inside tumors. Such a cost-effective HAase delivery strategy memorably improves the subsequent photothermal and photodynamic therapy (PTT/PDT)-induced intratumoral infiltration of cytotoxic T lymphocyte cells and the cross-talk between tumor and tumor-draining lymph nodes (TDLN), thereby decreasing the immunosuppression and optimizing tumoricidal immune response that can efficiently protect mice from tumor growth, metastasis, and recurrence in multiple mouse cancer models. Overall, this work presents a proof-of-concept of the dynamic disassembly of metal-polyphenol nanoparticles for extracellular drug delivery as well as the modulation of TECM and immunosuppressive tumor microenvironment.

Advancements in pH-responsive nanocarriers: enhancing drug delivery for tumor therapy

INTRODUCTION

Tumors pose a significant global economic and health burden, with conventional cancer treatments lacking tumor specificity, leading to limited efficiency and undesirable side effects. Targeted tumor therapy is imminent. Tumor cells produce lactate and hydrogen ions (H+) by Warburg effect, forming an acidic tumor microenvironment (TME), which can be employed to design targeted tumor therapy. Recently, progress in nanotechnology has led to the development of pH-responsive nanocarriers, which have gathered significant attention. Under acidic tumor conditions, they exhibit targeted accumulation within tumor sites and controlled release profiles of therapeutic reagents, enabling precise tumor therapy.

AREAS COVERED

This review comprehensively summarize the principles underlying pH-responsive features, discussing various types of pH-responsive nanocarriers, their advantages, and limitations. Innovative therapeutic drugs are also examined, followed by an exploration of recent advancements in applying various pH-responsive nanocarriers as delivery systems for enhanced tumor therapy.

EXPERT OPINIONS

pH-responsive nanocarriers have garnered significant attention for their capability to achieve targeted accumulation of therapeutic agents at tumor sites and controlled drug delivery profiles, ultimately increasing the efficiency of tumor eradication. It is anticipated that the employment of pH-responsive nanocarriers will elevate the effectiveness and safety of tumor therapy, contributing to improved overall outcomes.