Eliciting Immunogenic Cell Death via a Unitized Nanoinducer

Non-cytotoxic Nanoparticles Re-educating Macrophages Achieving both Innate and Adaptive Immune Responses for Tumor Therapy

Macrophages are important antigen-presenting cells to combat tumor via both innate and adaptive immunity, while they are programmed to M2 phenotype in established tumors and instead promote cancer development and metastasis. Here, we develop a nanomedicine that can re-educate M2 polarized macrophages to restore their anti-tumor activities. The nanomedicine has a core-shell structure to co-load IPI549, a PI3Kγ inhibitor, and CpG, a Toll-like receptor 9 agonist. Specifically, the hydrophobic IPI549 is self-assembled into a pure drug nano-core, while MOF shell layer is coated for CpG encapsulation, achieving extra-high total drugs loading of 44%. Such nanosystem could facilitate intracellular delivery of the payloads but without any cytotoxicity, displaying excellent biocompatibility. After entering macrophages, the released IPI549 and CpG exert a synergistic effect to switch macrophages from M2 to M1 phenotype, which enables anti-tumor activities via directly engulfing tumor cells or excreting tumor killing cytokines. Moreover, tumor antigens released from the dying tumor cells could be effectively presented by the re-educated macrophages owing to the up-regulation of various antigen presenting mediators, resulting in infiltration and activation of cytotoxic T lymphocytes. As a result, the nanosystem triggers a robust anti-tumor immune response in combination with PD-L1 antibody to inhibit tumor growth and metastasis. This work provides a non-cytotoxic nanomedicine to modulate tumor immune microenvironment by reprograming macrophages.

Glycyrrhetinic acid nanoparticles combined with ferrotherapy for improved cancer immunotherapy

Programmed cell death protein 1 (PD-1)/Programmed Cell Death Ligand 1 (PD-L1) blockade immunotherapy has emerged as a promising strategy to treat both solid and hematological malignancies. Despite the considerable therapeutic effects obtained in pre-clinical and clinical studies, PD-1/PD-L1 blockade therapy is still limited by the low benefit rates and a large number of patients still do not respond to this treatment. In this study, we developed a highly efficient and cancer-specific immunogenic cell death nanoinducer for effective tumor immunotherapy. A leukocyte membrane coated poly (lactic-co-glycolic acid) encapsulating glycyrrhetinic acid (GCMNPs) was developed to enhance targeting, tumor-homing capacity, and reduce toxicity in vivo. GCMNPs could induce ferroptosis in acute myeloid leukemia and colorectal cancer cells by downregulating glutathione-dependent peroxidases 4, leading to increased lipid peroxidation levels. Moreover, GCMNPs and ferumoxytol could synergistically enhance Fe-dependent cytotoxicity through the Fenton reaction. Finally, in vivo studies showed that GCMNPs synergized with ferumoxytol and anti-PD-L1 synergistically improve T-cell immune response against leukemia and colorectal tumor. This study anticipated that the combination of glycyrrhetinic acid-based nanomaterials and ferrotherapy would provide further insights into anti-cancer immune response to PD-1/PD-L1 blockade for both solid and hematological malignancies. STATEMENT OF SIGNIFICANCE: Despite the considerable therapeutic effects obtained in pre-clinical and clinical studies, PD-1/PD-L1 blockade therapy is still limited by the low benefit rates and a large number of patients still do not respond to this treatment. We designed a glycyrrhetinic acid-based nanoplatform as a new ICD inducer (GCMNPs), with high cancer cell specificity and reduced toxicity to AML and CRC. GCMNPs cooperates with ferumoxytol to promote a Fenton reaction and induce ferroptosis. Moreover, the combination of GCMNPs and ferumoxytol enhanced the blockage of PD-1/PD-L1 to activate T cells, subsequently generating a systemic immune response in CRC and AML mouse models. This pre-clinical findings provide the proof-of-concept of combination of glycyrrhetinic acid-based nanomaterials and ferrotherapy as an "ICD nano-inducer" and immunotherapeutic agent for treating cancer.

Triggering Immune System With Nanomaterials for Cancer Immunotherapy

Cancer is a major cause of incidence rate and mortality worldwide. In recent years, cancer immunotherapy has made great progress in the preclinical and clinical treatment of advanced malignant tumors. However, cancer patients will have transient cancer suppression reaction and serious immune related adverse reactions when receiving immunotherapy. In recent years, nanoparticle-based immunotherapy, which can accurately deliver immunogens, activate antigen presenting cells (APCs) and effector cells, provides a new insight to solve the above problems. In this review, we discuss the research progress of nanomaterials in immunotherapy including nanoparticle-based delivery systems, nanoparticle-based photothermal and photodynamic immunotherapy, nanovaccines, nanoparticle-based T cell cancer immunotherapy and nanoparticle-based bacteria cancer immunotherapy. We also put forward the current challenges and prospects of immunomodulatory therapy.

Near-Infrared II Nanoadjuvant-Mediated Chemodynamic, Photodynamic, and Photothermal Therapy Combines Immunogenic Cell Death with PD-L1 Blockade to Enhance Antitumor Immunity

The efficacy of immune checkpoint inhibition in inducing death of cancer cells is affected by the immunosuppressive "cold" tumor microenvironment, which results in a poor response by the patient's antitumor immune system. However, the immunomodulatory effects of immunogenic cell death in response to irritation by heat energy and reactive oxygen species (ROS) can switch the tumor microenvironment from "cold" to "hot." This study has developed a nanoadjuvant for immune therapy using iron tungsten oxide (FeWOx)-based nanosheets with surface PEGylation (FeWOx-PEG). This FeWOx-PEG nanoadjuvant serves as a chemodynamic reagent via the Fenton reaction and acts as a photosensitizer for photodynamic and photothermal therapy under near-infrared II laser irradiation; however, it could also be used to augment tumor-infiltrating T-cells and provoke a systemic antitumor immune response by combining the immunogenic cell death triggered by ROS and photothermal therapy with the immune checkpoint blockade. This research demonstrates that application of the FeWOx-PEG nanoadjuvant under the guidance of magnetic resonance/computed tomography/photoacoustic imaging can eliminate the primary tumor and suppress the growth of distant tumors.

Nitric Oxide Induces Immunogenic Cell Death and Potentiates Cancer Immunotherapy

Tumor cells undergoing immunogenic cell death (ICD) release immunogenic damage-associated molecular patterns (DAMPs) to trigger a long-term protective antitumor response. ICD can be induced by certain pathogens, chemotherapeutics, and physical modalities. In this work, we demonstrate that a gaseous molecule, specifically nitric oxide (NO), can induce a potent ICD effect. NO exerts cytotoxic effects that are accompanied by the emission of DAMPs based on the endoplasmic reticulum stress and mitochondrial dysfunction pathways. Released DAMPs elicit immunological protection against a subsequent rechallenge of syngeneic tumor cells in immunocompetent mice. We prepare polynitrosated polyesters with high NO storage capacity through a facile polycondensation reaction followed by a postsynthetic modification. The polynitrosated polyesters-based NO nanogenerator (NanoNO) that enables efficient NO delivery and controlled NO release in tumors induces a sufficient ICD effect. In different immune-intact models of tumors, the NanoNO exhibits significant tumor growth suppression and increases the local dose of immunogenic signals and T cell infiltrations, ultimately prolonging survival. In addition, the NanoNO synergizes with the PD-1 blockade to prevent metastasis. We conclude not only that NO is a potent ICD inducer for cancer immunotherapy but also that it expands the range of ICD inducers into the field of gaseous molecules.

Stimuli-Responsive Nanoparticles for Controlled Drug Delivery in Synergistic Cancer Immunotherapy

Cancer immunotherapy has achieved promising clinical progress over the recent years for its potential to treat metastatic tumors and inhibit their recurrences effectively. However, low patient response rates and dose-limiting toxicity remain as major dilemmas for immunotherapy. Stimuli-responsive nanoparticles (srNPs) combined with immunotherapy offer the possibility to amplify anti-tumor immune responses, where the weak acidity, high concentration of glutathione, overexpressions of enzymes, and reactive oxygen species, and external stimuli in tumors act as triggers for controlled drug release. This review highlights the design of srNPs based on tumor microenvironment and/or external stimuli to combine with different anti-tumor drugs, especially the immunoregulatory agents, which eventually realize synergistic immunotherapy of malignant primary or metastatic tumors and acquire a long-term immune memory to prevent tumor recurrence. The authors hope that this review can provide theoretical guidance for the construction and clinical transformation of smart srNPs for controlled drug delivery in synergistic cancer immunotherapy.

Polymeric Indoximod Based Prodrug Nanoparticles with Doxorubicin Entrapment for Inducing Immunogenic Cell Death and Improving Immunotherapy for Breast caner

Immunotherapy using host immunity has emerged as a powerful therapeutic strategy in tumor treatment. However, facilitating immune system against tumor often fails to obtain a durable immune response due to...

Engineered Cell Membrane-Derived Nanoparticles in Immune Modulation

Immune modulation is one of the most effective approaches in the therapy of complex diseases, including public health emergency. However, most immune therapeutics such as drugs, vaccines, and cellular therapy suffer from the limitations of poor efficacy and adverse side effects. Fortunately, cell membrane-derived nanoparticles (CMDNs) have superior compatibility with other therapeutics and offer new opportunities to push the limits of current treatments in immune modulation. As the interface between cells and outer surroundings, cell membrane contains components which instruct intercellular communication and the plasticity of cytomembrane has significantly potentiated CMDNs to leverage our immune system. Therefore, cell membranes employed in immunomodulatory CMDNs have gradually shifted from natural to engineered. In this review, unique properties of immunomodulatory CMDNs and engineering strategies of emerging CMDNs for immune modulation, with an emphasis on the design logic are summarized. Further, this review points out some pressing problems to be solved during clinical translation and put forward some suggestions on the prospect of immunoregulatory CMDNs. It is anticipated that this review can provide new insights on the design of immunoregulatory CMDNs and expand their potentiation in the precise control of the dysregulated immune system.

Enhancement of CD8+ T-Cell-Mediated Tumor Immunotherapy via Magnetic Hyperthermia

Magnetic hyperthermia (MHT) uses magnetic iron oxide nanoparticles (MIONs) to irradiate heat when subjected to an alternating magnetic field (AMF), which then trigger a series of biological effects to realize rapid tumor-killing effects. With the deepening in research, MHT has also shown significant potential in achieving antitumor immunity. On the other hand, immunotherapy in cancer treatment has gained increasing attention over recent years and excellent results have generally been reported. Using MHT to activate antitumor immunity and clarifying its synergistic mechanism, i. e., immunogenic cell death (ICD) and immunosuppressive tumor microenvironment (TME) reversal, can achieve a synergistically enhanced therapeutic effect on primary tumors and metastatic lesions, and this can prevent cancer recurrence and metastasis, which thus prolong survival. In this review, we discussed the role of MHT when utilized alone and combining MHT with other treatments (such as radiotherapy, photodynamic therapy, and immune checkpoint blockers) in the process of tumor immunotherapy, including antigen release, dendritic cells (DCs) maturation, and activation of CD8⁺ cytotoxic T lymphocytes. Finally, the challenges and future development of current MHT and immunotherapy are discussed.

Soft X-Ray Stimulated Lanthanide@MOF Nanoprobe for Amplifying Deep Tissue Synergistic Photodynamic and Antitumor Immunotherapy

Combining photodynamic therapy (PDT) and immunotherapy has shown profound impact for synergistic treatment of malignant tumors. However, the shallow penetration depth of the traditional visible light activated PDT, immunosuppressive tumor microenvironment (TME), and poor immunogenicity of deep-seated solid tumors have significantly impeded the therapeutic efficiency. Herein, a soft X-ray activated nanoprobe is rationally engineered via integrating porphyrin Zr-based metal-organic framework with lanthanide NaYF₄ :Gd,Tb@NaYF₄ scintillator nanoparticles (SNPs) by a new in situ growth strategy for synergistic PDT and immunotherapy of tumor. The nanoprobe possesses remarkably enhanced reactive oxygen species (ROS) generation triggered by soft X-ray via further covalently grafting rose bengal on the nanoprobe, even at tissue depths of 3 cm. Moreover, the soft X-ray induced ROS can act as potential immunogenic cell death (ICD) trigger, subsequently leading to the activation of the adaptive antitumor immune-response. Significantly, the boosted ROS generation can further modulate the immunosuppressive TME. This work provides new strategy of designing antitumor nanoprobes for soft X-ray triggered deep-tissue PDT and immune response, breaking the depth barriers suffered by the traditional photoactivated PDT or ICD using visible and near infrared light.

Fenton Metal Nanomedicines for Imaging-guided Combinatorial Chemodynamic Therapy against Cancer

Chemodynamic therapy (CDT) is considered as a promising modality for selective cancer therapy, which is realized via Fenton reaction-mediated decomposition of endogenous H₂O₂ to produce toxic hydroxyl radical (•OH) for tumor ablation. While extensive efforts have been made to develop CDT-based therapeutics, their in vivo efficacy is usually unsatisfactory due to poor catalytic activity limited by tumor microenvironment, such as anti-oxidative systems, insufficient H₂O₂, and mild acidity. To mitigate these issues, we have witnessed a surge in the development of CDT-based combinatorial nanomedicines with complementary or synergistic mechanisms for enhanced tumor therapy. By virtue of their bio-imaging capabilities, Fenton metal nanomedicines (FMNs) are equipped with intrinsic properties of imaging-guided tumor therapies. In this critical review, we summarize recent progress of this field, focusing on FMNs for imaging-guided combinatorial tumor therapy. First, various Fenton metals with inherent catalytic performances and imaging properties, including Fe, Cu and Mn, were introduced to illustrate their possible applications for tumor theranostics. Then, CDT-based combinatorial systems were reviewed by incorporating many other treatment means, including chemotherapy, photodynamic therapy (PDT), sonodynamic therapy (SDT), photothermal therapy (PTT), starvation therapy and immunotherapy. Next, various imaging approaches based on Fenton metals were presented in detail. Finally, challenges are discussed, and future prospects are speculated in the field to pave way for future developments.

Reinforcing the Induction of Immunogenic Cell Death Via Artificial Engineered Cascade Bioreactor-Enhanced Chemo-Immunotherapy for Optimizing Cancer Immunotherapy

Traditional chemo-immunotherapy can elicit T cell immune response by inducing immunogenic cell death (ICD), however, insufficient ICD limits the lasting antitumor immunotherapeutic efficacy. Herein, tadpole-ovoid manganese-doped hollow mesoporous silica coated gold nanoparticles (Au@HMnMSNs) as biodegradable catalytic cascade nanoreactors are constructed to generate intratumoral high-toxic hydroxyl radicals combined with DOX and Aspirin (ASA) for enhancing the induction of ICD and maturation of dendritic cells (DCs). The released Mn²⁺ can catalyze endogenous H₂ O₂ to hydroxyl radicals, while internal gold nanoparticles mimetic glucose oxidase (GOx) converted glucose into H₂ O₂ to accelerate the generation of hydroxyl radicals. On the other hand, tadpole oval-structured Au@HMnMSNs can avoid the inactivation of gold nanoparticles due to strong protein adsorption. The introduction of ASA is to recruit DCs and cytotoxic T lymphocytes (CTLs) to tumor sites and restrain the intratumoral infiltration of immunosuppressive cells by decreasing the expression of prostaglandin E2 (PGE₂ ). Accordingly, this work presents a novel insight to introduce GOx-like catalytic cascade ICD nano-inducer into antitumor immunotherapy for synergistic tumor therapy.

Nanotechnology for Boosting Cancer Immunotherapy and Remodeling Tumor Microenvironment: The Horizons in Cancer Treatment

Immunotherapy that harnesses the human immune system to fight cancer has received widespread attention and become a mainstream strategy for cancer treatment. Cancer immunotherapy not only eliminates primary tumors but also treats metastasis and recurrence, representing a major advantage over traditional cancer treatments. Recently with the development of nanotechnology, there exists much work applying nanomaterials to cancer immunotherapy on the basis of their excellent physiochemical properties, such as efficient tissue-specific delivery function, huge specific surface area, and controllable surface chemistry. Consequently, nanotechnology holds significant potential in improving the efficacy of cancer immunotherapy. Nanotechnology-based immunotherapy mainly manifests its inhibitory effect on tumors via two different approaches: one is to produce an effective anti-tumor immune response during tumorigenesis, and the other is to enhance tumor immune defense ability by modulating the immune suppression mechanism in the tumor microenvironment. With the success of tumor immunotherapy, understanding the interaction between the immune system and smart nanomedicine has provided vigorous vitality for the development of cancer treatment. This review highlights the application, progress, and prospect of nanomedicine in the process of tumor immunoediting and also discusses several engineering methods to improve the efficiency of tumor treatment.

Research on endoplasmic reticulum-targeting fluorescent probes and endoplasmic reticulum stress-mediated nanoanticancer strategies: A review

Subcellular localization of organelles can achieve accurate drug delivery and maximize drug efficacy. As the largest organelle in eukaryotic cells, the endoplasmic reticulum (ER) plays an important role in protein synthesis, folding, and posttranslational modification; lipid biosynthesis; and calcium homeostasis. Observing the changes in various metal ions, active substances, and the microenvironment in the ER is crucial for diagnosing and treating many diseases, including cancer. Excessive endoplasmic reticulum stress (ERS) can have a killing effect on malignant cells and can mediate cell apoptosis, proper modulation of ERS can provide new perspectives for the treatment of many diseases, including cancer. Therefore, the ER is used as a new anticancer target in cancer treatment. This review discusses ER-targeting fluorescent probes and ERS-mediated nanoanticancer strategies.

Engineering nanomedicine for glutathione depletion-augmented cancer therapy

Glutathione (GSH), the main redox buffer, has long been recognized as a pivotal modulator of tumor initiation, progression and metastasis. It is also implicated in the resistance of platinum-based chemotherapy and radiation therapy. Therefore, depleting intracellular GSH was considered a potent solution to combating cancer. However, reducing GSH within cancer cells alone always failed to yield desirable therapeutic effects. In this regard, the convergence of GSH-scavenging agents with therapeutic drugs has thus been pursued in clinical practice. Unfortunately, the therapeutic outcomes are still unsatisfactory due to untargeted drug delivery. Advanced nanomedicine of synergistic GSH depletion and cancer treatment has attracted tremendous interest because they promise to deliver superior therapeutic benefits while alleviating life-threatening side effects. In the past five years, the authors and others have demonstrated that numerous nanomedicines, by simultaneously delivering GSH-depleting agents and therapeutic components, boost not only traditional chemotherapy and radiotherapy but also multifarious emerging treatment modalities, including photodynamic therapy, sonodynamic therapy, chemodynamic therapy, ferroptosis, and immunotherapy, to name a few, and achieved decent treatment outcomes in a large number of rodent tumor models. In this review, we summarize the most recent progress in engineering nanomedicine for GSH depletion-enhanced cancer therapies. Biosynthesis of GSH and various types of GSH-consuming strategies will be briefly introduced. The challenges and perspectives of leveraging nanomedicine for GSH consumption-augmented cancer therapies will be discussed at the end.

"Lighting-up" curcumin nanoparticles triggered by pH for developing improved enzyme-linked immunosorbent assay

In the field of precision medicine, the anticipated features of ideal drug delivery systems (DDS) have high drug loading capacity and effective stimuli-triggered mechanism, which are fitting well with the expected merits of signal labels for enhanced enzyme-linked immunosorbent assay (ELISA). Inspired by this, poly (diallyldimethylammonium chloride)-capped curcumin nanoparticles (PDDA@CUR NPs) with high loading capacity were synthesized as signal labels and further applied to dual-model colorimetric and fluorescence ELISA for the detection of C-reactive protein (CRP). Curcumin (CUR) was elaborately selected as report molecule similar to the roles of drugs in DDS, which dispersed in neutral water exhibits a negligible fluorescence response due to the aggregation of CUR molecules induced quenching effect, stimulated by basic water (BW, pH 12.36), the allochroic effect from colorless to orange occurred and fluorescence restored because of the keto-enol tautomerism in the molecular structure of CUR, just like lighting-up (from signal "OFF" to signal "ON"), yielded a dual-model colorimetric and fluorescent signal readout. PDDA, as a polycationic electrolyte, provided a biological platform that is capable of interacting with CRP label antibodies by virtue of its positive centers. The results show that "lighting-up" CUR NPs-based dual-modal colorimetric and fluorescent ELISA for CRP detection has the merits of easy-to-use, good enough sensitivity and reliability. And more importantly, it brings innovative ideas for the precise identification and quantification of protein biomarkers.