Polymeric Nanosystems for Immunogenic Cell Death-Based Cancer Immunotherapy

Clinical application of immunogenic cell death inducers in cancer immunotherapy: turning cold tumors hot

Immunotherapy has emerged as a promising cancer treatment option in recent years. In immune "hot" tumors, characterized by abundant immune cell infiltration, immunotherapy can improve patients' prognosis by activating the function of immune cells. By contrast, immune "cold" tumors are often less sensitive to immunotherapy owing to low immunogenicity of tumor cells, an immune inhibitory tumor microenvironment, and a series of immune-escape mechanisms. Immunogenic cell death (ICD) is a promising cellular process to facilitate the transformation of immune "cold" tumors to immune "hot" tumors by eliciting innate and adaptive immune responses through the release of (or exposure to) damage-related molecular patterns. Accumulating evidence suggests that various traditional therapies can induce ICD, including chemotherapy, targeted therapy, radiotherapy, and photodynamic therapy. In this review, we summarize the biological mechanisms and hallmarks of ICD and introduce some newly discovered and technologically innovative inducers that activate the immune system at the molecular level. Furthermore, we also discuss the clinical applications of combing ICD inducers with cancer immunotherapy. This review will provide valuable insights into the future development of ICD-related combination therapeutics and potential management for "cold" tumors.

Nanomedicines for reversing immunosuppressive microenvironment of hepatocellular carcinoma

Although immunotherapeutic strategies such as immune checkpoint inhibitors (ICIs) have gained promising advances, their limited efficacy and significant toxicity remain great challenges for hepatocellular carcinoma (HCC) immunotherapy. The tumor immunosuppressive microenvironment (TIME) with insufficient T-cell infiltration and low immunogenicity accounts for most HCC patients' poor response to ICIs. Worse still, the current immunotherapeutics without precise delivery may elicit enormous autoimmune side effects and systemic toxicity in the clinic. With a better understanding of the TIME in HCC, nanomedicines have emerged as an efficient strategy to achieve remodeling of the TIME and superadditive antitumor effects via targeted delivery of immunotherapeutics or multimodal synergistic therapy. Based on the typical characteristics of the TIME in HCC, this review summarizes the recent advancements in nanomedicine-based strategies for TIME-reversing HCC treatment. Additionally, perspectives on the awaiting challenges and opportunities of nanomedicines in modulating the TIME of HCC are presented. Acquisition of knowledge of nanomedicine-mediated TIME reversal will provide researchers with a better opportunity for clinical translation of HCC immunotherapy.

The application of nanoparticles-based ferroptosis, pyroptosis and autophagy in cancer immunotherapy

Immune checkpoint blockers (ICBs) have been applied for cancer therapy and achieved great success in the field of cancer immunotherapy. Nevertheless, the broad application of ICBs is limited by the low response rate. To address this issue, increasing studies have found that the induction of immunogenic cell death (ICD) in tumor cells is becoming an emerging therapeutic strategy in cancer treatment, not only straightly killing tumor cells but also enhancing dying cells immunogenicity and activating antitumor immunity. ICD is a generic term representing different cell death modes containing ferroptosis, pyroptosis, autophagy and apoptosis. Traditional chemotherapeutic agents usually inhibit tumor growth based on the apoptotic ICD, but most tumor cells are resistant to the apoptosis. Thus, the induction of non-apoptotic ICD is considered to be a more efficient approach for cancer therapy. In addition, due to the ineffective localization of ICD inducers, various types of nanomaterials have been being developed to achieve targeted delivery of therapeutic agents and improved immunotherapeutic efficiency. In this review, we briefly outline molecular mechanisms of ferroptosis, pyroptosis and autophagy, as well as their reciprocal interactions with antitumor immunity, and then summarize the current progress of ICD-induced nanoparticles based on different strategies and illustrate their applications in the cancer therapy.

An immunogenic cell death-related signature predicts prognosis and immunotherapy response in stomach adenocarcinoma

The immunogenic cell death (ICD) is a specific type of regulatory cell death (RCD), which induces adaptive immunity against antigens of dead cells. ICDs have received increasing attention for their potential role in tumor microenvironment reprogramming and immunotherapy. However, the relationship between ICD-related features and stomach adenocarcinoma (STAD) prognosis, immune cell infiltration and immunotherapy remains unclear. Patients were divided into different ICD-related subtypes by consensus clustering. The differences in prognosis, Tumor microenvironment (TME), and immune checkpoint expression between different ICD-related subtypes were systematically assessed. Additionally, we constructed an ICD-related gene risk score (ICDRS). We systematically analyzed the correlation between ICDRS and prognosis, TME, immunotherapy response and drug sensitivity of gastric cancer. In addition, we explored the role of TGM2 in promoting gastric cancer progression through in vitro experiments. We identified three ICD-associated subtypes by consensus clustering. The ICD gene was highly expressed in Cluster B. Compared with the other two subtypes, Cluster B had better prognosis, higher immune response signaling activity, massive immune cell infiltration and lower tumor purity. Immune checkpoint (ICP) and human leukocyte antigen (HLA) related genes were also highly expressed in Cluster B. In addition, we found that ICDRS is an effective indicator for predicting the prognosis and immune efficacy of STAD. The low ICDRS group has the characteristics of good prognosis, high tumor mutation burden (TMB), high microsatellite instability (MSI), and sensitivity to immunotherapy, while the high ICDRS group is prone to immune escape and immunotherapy resistance. In addition, we found that down-regulating TGM2 gene can inhibit the proliferation and migration of gastric cancer cells through in vitro experiments. Our study found that the model based on ICD features is helpful to clarify the TME characteristics of STAD, and has important clinical significance for evaluating the prognosis and immunotherapy response of STAD patients. TGM2 plays an important role in the progression of STAD, suggesting that TGM2 can be used as a new target for the treatment of STAD.

Biomaterials That Induce Immunogenic Cell Death

The immune system takes part in most physiological and pathological processes of the body, including the occurrence and development of cancer. Immunotherapy provides a promising modality for inhibition and even the cure of cancer. During immunotherapy, the immunogenic cell death (ICD) of tumor cells induced by chemotherapy, radiotherapy, phototherapy, bioactive materials, and so forth, triggers a series of cellular responses by causing the release of tumor-associated antigens and damage-associated molecular patterns, which ultimately activate innate and adaptive immune responses. Among them, the ICD-induced biomaterials attract increasing conditions as a benefit of biosafety and multifunctional modifications. This Review summarizes the research progress in biomaterials for inducing ICD via triggering endoplasmic reticulum oxidative stress, mitochondrial dysfunction, and cell membrane rupture and discusses the application prospects of ICD-inducing biomaterials in clinical practice for cancer immunotherapy.

Polymeric nanoparticle-based nanovaccines for cancer immunotherapy

Therapeutic cancer vaccines, which are designed to amplify tumor-specific T cell responses, have been envisioned as one of the most powerful tools for effective cancer immunotherapy. However, increasing the potency, quality and durability of the vaccine response remains a big challenge. In recent years, materials-based delivery systems focusing on the co-delivery of antigens and adjuvants to enhance cancer vaccination therapy have attracted increasing interest. Among various materials, polymeric nanoparticles (NPs) with different physicochemical properties which can incorporate multiple immunological cues are of great interest. In this review, the recent progress in the design and construction of both ex vivo subunit and in situ cancer vaccines using polymeric NPs is summarized. Especially, we will focus on how these NPs improve the adjuvanticity of vaccines. The design principles of polymeric NPs for ex vivo subunit cancer vaccines and in situ cancer vaccination are also discussed. Finally, we want to briefly discuss molecular chaperones in cancer immunity and the applications of our unique self-assembly mixed shell polymeric micelle-based nanochaperones for cancer vaccines.

Nanosystems for chemodynamic based combination therapy: Strategies and recent advances

Chemodynamic therapy (CDT), a newly developed approach for cancer treatment, can convert hydrogen peroxide (H₂O₂) into toxic hydroxyl radicals (•OH) by using Fenton/Fenton-like reaction to kill tumor cells. However, due to the complexity of the intracellular environment of tumor cells, the therapeutic efficacy of CDT was severely restricted. Recently, combination therapy strategies have become popular approaches for tumor treatment, and there are numerous studies have demonstrated that the CDT-based combination strategies can significantly improve the anti-tumor efficiency of CDT. In this review, we outline some of the recent progress in cancer chemodynamic therapy from 2020, and discuss the progress in the design of nanosystems for CDT synergistic combination therapies.

Immunogenic Cell Death and Role of Nanomaterials Serving as Therapeutic Vaccine for Personalized Cancer Immunotherapy

Immunogenic cell death (ICD) is a rapidly growing research area representing one of the emerging therapeutic strategies of cancer immunotherapy. ICD is an umbrella term covering several cell death modalities including apoptosis, necroptosis, ferroptosis and pyroptosis, and is the product of a balanced combination of adjuvanticity (damage-associated molecular patterns and chemokines/cytokines) and antigenicity (tumor associated antigens). Only a limited number of anti-cancer therapies are available to induce ICD in experimental cancer therapies and even much less is available for clinical use. To overcome this limitation, nanomaterials can be used to increase the immunogenicity of cancer cells killed by anti-cancer therapy, which in themselves are not necessarily immunogenic. In this review, we outline the current state of knowledge of ICD modalities and discuss achievements in using nanomaterials to increase the immunogenicity of dying cancer cells. The emerging trends in modulating the immunogenicity of dying cancer cells in experimental and translational cancer therapies and the challenges facing them are described. In conclusion, nanomaterials are expected to drive further progress in their use to increase efficacy of anti-cancer therapy based on ICD induction and in the future, it is necessary to validate these strategies in clinical settings, which will be a challenging research area.

Tumor cell membrane-camouflaged responsive nanoparticles enable MRI-guided immuno-chemodynamic therapy of orthotopic osteosarcoma

Osteosarcoma is a refractory bone disease in young people that needs the updating and development of effective treatment. Although nanotechnology is widely applied in cancer therapy, poor targeting and inadequate efficiency hinder its development. In this study, we prepared alendronate (ALD)/K7M2 cell membranes-coated hollow manganese dioxide (HMnO₂) nanoparticles as a nanocarrier to load Ginsenoside Rh2 (Rh2) for Magnetic Resonance imaging (MRI)-guided immuno-chemodynamic combination osteosarcoma therapy. Subsequently, the ALD and K7M2 cell membranes were successively modified on the surface of HMnO₂ and loaded with Rh2. The tumor microenvironment (TME)-activated Rh2@HMnO₂-AM nanoparticles have good bone tumor-targeting and tumor-homing capabilities, excellent GSH-sensitive drug release profile and MRI capability, and attractive immuno-chemodynamic combined therapeutic efficiency. The Rh2@HMnO₂-AM nanoparticles can effectively trigger immunogenic cell death (ICD), activate CD4⁺/CD8⁺ T cells in vivo, and upregulate BAX, BCL-2 and Caspase-3 in cellular level. Further results revealed that Rh2@HMnO₂-AM enhanced the secretion of IL-6, IFN-γ and TNF-α in serum and inhibited the generation of FOXP3⁺ T cells (Tregs) in tumors. Moreover, the Rh2@HMnO₂-AM treatment significant restricted tumor growth in-situ tumor-bearing mice. Therefore, Rh2@HMnO₂-AM may serve as an effective and bio-friendly nanoparticle platform combined with immunotherapy and chemodynamic therapy to provide a novel approach to osteosarcoma therapy.

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Ginsenoside Rh2 was loaded in Hollow MnO₂ NPs for enhancing its bioavailability.

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The orthotopic tumor model exhibits a convincing therapeutic effect of nanosystems.

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Alendronate/cell membranes enhance osteosarcoma targeting and tumor-homing ability.

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Tumor microenvironment-induced NPs degradation can release immune stimulant and Mn²⁺.

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The NPs had excellent immuno-chemodynamic combination osteosarcoma therapy effect.