Dual Synergistic Tumor-Specific Polymeric Nanoparticles for Efficient Chemo-Immunotherapy

Integration of active ingredients from traditional Chinese medicine with nano-delivery systems for tumor immunotherapy

Tumor immune escape presents a significant challenge in cancer treatment, characterized by the upregulation of immune inhibitory molecules and dysfunction of immune cells. Tumor immunotherapy seeks to restore normal anti-tumor immune responses to control and eliminate tumors effectively. The active ingredients of traditional Chinese medicine (TCM) demonstrate a variety of anti-tumor activities and mechanisms, including the modulation of immune cell functions and inhibiting tumor-related suppressive factors, thereby potentially enhancing anti-tumor immune responses. Furthermore, nano-delivery systems function as efficient carriers to enhance the bioavailability and targeted delivery of TCM active ingredients, augmenting therapeutic efficacy. This review comprehensively analyzes the impact of TCM active ingredients on the immune system and explores the synergistic application of nano-delivery systems in combination with TCM active ingredients for enhancing tumor immunotherapy.

Mitochondria-targeting artesunate-rhein conjugates: Linker-modulated cell-permeability, heme-affinity and anticancer activity

Heme, abundant in the mitochondria of cancer cells, is a key target for the anticancer activity of artemisinin (ART). Current strategies to enhance the anticancer activity of ART focus solely on its delivery to heme-enriched subcellular localizations while overlooking the decisive effects of ART-heme interactions. Here, we propose an ingenious strategy that synergizes mitochondria-targeted drug delivery and linker-mediated drug conformation modulation, thereby significantly enhancing the anticancer activity of ART. By strategically conjugating artemisinin (ART) with the mitochondria-targeting rhein (R) using different linkers, we aimed to precisely adjust the conformation of the conjugates. Comprehensive computational analysis revealed that the conjugate with the optimal linker length (C4) displayed a favorable conformation that facilitated cell permeability and exhibited the highest binding affinity to heme and Fe ions. Moreover, it exhibited superior tumor suppression capabilities both in vitro and in vivo, overcoming the uncertainty of in vivo application caused by the rapid clearance of the conventional mitochondria-targeted cation TPP+, and even inducing immunogenic cell death associated with immunotherapy. This novel strategy opens up a new avenue for the development of drug conjugate systems.

Biomaterials enhancing localized cancer therapy activated anti-tumor immunity: a review

Localized cancer therapies such as radiotherapy, phototherapy, and chemotherapy are precise cancer treatment strategies aimed at minimizing systemic side effects. However, cancer metastasis remains the primary cause of mortality among cancer patients in clinical settings, and localized cancer treatments have limited efficacy against metastatic cancer. Therefore, researchers are exploring strategies that combine localized therapy with immunotherapy to activate robust anti-tumor immune responses, thereby eradicating metastatic cancer. Biomaterials, as novel materials, exhibit great potential in biomedical applications and have achieved great progress in clinic translation. This review introduces biomaterials and their applications in research focused on enhancing localized cancer treatment activated anti-tumor immunity. Additionally, the current challenges and future directions of biomaterials are also discussed, providing insights and references for related research.

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).

Engineering macrophage membrane-camouflaged nanoplatforms with enhanced macrophage function for mediating sonodynamic therapy of ovarian cancer

Cancer immunotherapy has demonstrated remarkable efficacy in the treatment of cancer, and it has been successfully applied in the treatment of various solid tumors. However, the response rates to immunotherapy in patients with ovarian cancer remain modest because of the immunosuppressive tumor microenvironment (TME). Tumor-associated macrophages (TAMs) represent the predominant myeloid cell population within the TME, which adopt the protumorigenic M2 phenotype and are blinded by the "don't eat me" signals from tumor cells. These characteristics of TAMs result in insufficient phagocytic activation. In this study, we constructed a SIM@TR-NP-mediated combination therapy of sonodynamic and immunotherapy. SIM@TR-NPs were modified by engineered macrophage membranes with overexpressed sialic acid-binding Ig-like lectin 10 (Siglec-10), and were internally loaded with sonosensitizer 4,4',4'',4'''-(porphine-5,10,15,20-tetrayl)tetrakis(benzoic acid) and immune adjuvant resiquimod. SIM@TR-NPs can block "don't eat me" signals to enhance macrophage phagocytosis and trigger the polarization of TAMs toward the M1 phenotype, thereby improving the immunosuppressive TME. Simultaneously, upon ultrasound irradiation, SIM@TR-NP-mediated sonodynamic therapy (SDT) triggered immunogenic cell death in tumor cells, in combination with TAM-based immunotherapy, transforming the "immune cold tumor" into an "immune hot tumor". SIM@TR-NP-mediated sonodynamic immunotherapy exhibited potent antitumor efficacy in ovarian cancer and exhibited substantial potential for improving the immunosuppressive TME. This study presents an emerging therapeutic regimen for ovarian cancer that synergizes TAM-based antitumor immunotherapy and SDT.

Stimulator of Interferon Genes-Activated Biomimetic Dendritic Cell Nanovaccine as a Chemotherapeutic Booster to Enhance Systemic Fibrosarcoma Treatment

Fibrosarcoma, a malignant mesenchymal tumor, is characterized by aggressive invasiveness and a high recurrence rate, leading to poor prognosis. Anthracycline drugs, such as doxorubicin (DOX), represent the frontline chemotherapy for fibrosarcoma, but often exhibit suboptimal efficacy. Recently, exploiting the stimulator of interferon genes (STING)-mediated innate immunity has emerged as a hopeful strategy for cancer treatment. Integrating chemotherapy with immunomodulators in chemo-immunotherapy has shown potential for enhancing treatment outcomes. Herein, we introduce an advanced dendritic cell (DC) nanovaccine, cGAMP@PLGA@CRTM (GP@CRTM), combined with low-dose DOX to enhance fibrosarcoma chemo-immunotherapy. The nanovaccine consists of poly(lactic-co-glycolic acid) (PLGA) nanoparticles encapsulating the STING agonist 2,3-cGAMP (cGAMP@PLGA, GP) as its core, and a calreticulin (CRT) high-expressing fibrosarcoma cell membrane (CRTM) as the shell. Exposing CRT on the vaccine surface aids in recruiting DCs and stimulating uptake, facilitating efficient simultaneous delivery of STING agonists and tumor antigens to DCs. This dual delivery method effectively activates the STING pathway in DCs, triggering sustained immune stimulation. Simultaneously, low-dose DOX reduces chemotherapy-related side effects, directly kills a subset of tumor cells, and increases tumor immunogenicity, thus further amplifying immune therapeutic performance. Hence, these findings demonstrate the potential of DC nanovaccine GP@CRTM as a booster for chemotherapy. Synergistically combining low-dose DOX with the DC nanovaccine emerges as a powerful chemo-immunotherapy strategy, optimizing systemic fibrosarcoma therapy.

Charge-reversal polymeric nanomodulators for ferroptosis-enhanced photodynamic therapy

The clinical application of photodynamic therapy (PDT) has some limitations including poor tumor targeting properties, a high reductive tumor microenvironment, and inefficient activation of single cell death machinery. We herein report pH-sensitive polymeric nanomodulators (NBS-PDMC NPs) for ferroptosis-enhanced photodynamic therapy. NBS-PDMC NPs were constructed using a positively charged type-I photosensitizer (NBS) coordinated with a demethylcantharidin (DMC)-decorated block copolymer via electrostatic interactions. NBS-PDMC NPs had a negative surface charge, which ensures their high stability in bloodstream circulation, while exposure to lysosomal acidic environments reverses their surface charge to positive for tumor penetration and the release of DMC and NBS. Under NIR light irradiation, NBS generated ROS to induce cell damage; in the meantime, DMC inhibited the expression of the GPX4 protein in tumor cells and promoted ferroptosis of tumor cells. This polymer design concept provides some novel insights into smart drug delivery and combinational action to amplify the antitumor effect.

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.

Advances in tumor immunomodulation based on nanodrug delivery systems

Immunotherapy is a therapeutic approach that employs immunological principles and techniques to enhance and amplify the body's immune response, thereby eradicating tumor cells. Immunotherapy has demonstrated effective antitumor effects on a variety of malignant tumors. However, when applied to humans, many immunotherapy drugs fail to target lesions with precision, leading to an array of adverse immune-related reactions that profoundly limit the clinical application of immunotherapy. Nanodrug delivery systems enable the precise delivery of immunotherapeutic drugs to targeted tissues or specific immune cells, enhancing the immune antitumor effect while reducing the number of adverse reactions. A nanodrug delivery system provides a feasible strategy for activating the antitumor immune response by the following mechanisms: 1) increased targeting and uptake of vaccines by DCs, which enhances the efficacy of the immune response; 2) increased tumor cell immunogenicity; 3) regulation of TAMs and other cells by, for example, regulating the polarization of TAMs and interfering with TAN formation, and ECM remodeling by CAFs; and 4) interference with tumor immune escape signaling pathways, namely, the PD-1/PD-L1, FGL1/LAG-3 and IDO signaling pathways. This paper reviews the progress of nanodrug delivery system research with respect to tumor immunotherapy based on tumor immunomodulation over the last few years, discussing the promising future of these delivery systems under this domain.