Anti-Tumor Immunity Induced by a Ternary Membrane System Derived From Cancer Cells, Dendritic Cells, and Bacteria

A pH-Sensitive Glucose Oxidase and Hemin Coordination Micelle for Multi-Enzyme Cascade and Amplified Cancer Chemodynamic Therapy

Chemodynamic therapy (CDT) is an emerging therapeutic paradigm for cancer treatment that utilizes reactive oxygen species (ROS) to induce apoptosis of cancer cells but few biomaterials have been developed to differentiate the cancer cells and normal cells to achieve precise and targeted CDT. Herein, a simple cascade enzyme system is developed, termed hemin-micelles-GOx, based on hemin and glucose oxidase (GOx)-encapsulated Pluronic F127 (F127) micelles with pH-sensitive enzymatic activities. Histidine-tagged GOx can be easily chelated to hemin-F127 micelles via the coordination of histidine and ferrous ions in the center of hemin by simple admixture in an aqueous solution. In tumor microenvironment (TME), hemin-micelles-GOx exhibits enhanced peroxidase (POD)-like activities to generate toxic hydroxyl radicals due to the acidic condition, whereas in normal cells the catalase (CAT)-like, but not POD-like activity is amplified, resulting in the elimination of hydrogen peroxide to generate oxygen. In a murine melanoma model, hemin-micelles-GOx significantly suppresses tumor growth, demonstrating its great potential as a pH-mediated enzymatic switch for tumor management by CDT.

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.

Enzyme-Dynamic Extracellular Vesicles for Metalloimmunotherapy of Malignant Pleural Effusions

Malignant pleural effusions (MPEs) are hard to treat, and their onset usually signals terminal cancer. Immunotherapies hold promise but must overcome the immunosuppressive MPE microenvironment. Herein, we treat MPEs via synergistically combining two emerging cancer therapy modalities: enzyme-dynamic therapy (EDT) and metalloimmunotherapy. To do so, a nanoplatform termed "A-R-SOME" was developed which comprises MPE-targeted M1 type extracellular vesicles (EVs) loaded with (1) a manganese-based superoxide dismutase (SOD) enzyme, (2) stimulator of interferon genes (STING) agonist diABZI-2, and (3) signal transducer and an activator of transcription 3 (STAT3) small interfering RNA. Endogenous reactive oxygen species within tumors induced immunogenic cell death by EDT, along with STING activation by both Mn and diABZI-2, and suppression of the STAT3 pathway. Systemically administered A-R-SOME alleviated the MPE immunosuppressive microenvironment, triggered antitumor systemic immunity, and long-term immune memory, leading to the complete eradication of MPE and pleural tumors with 100% survival rate in an aggressive murine model. A-R-SOME-induced immune effects were also observed in human patient-derived MPE, pointing toward the translation potential of A-R-SOME as an experimental malignancy treatment.

Turning Waste into Wealth: A Potent Sono-Immune Strategy Based on Microcystis

Currently, sonodynamic therapy (SDT) has limited therapeutic outcomes and immune responses, highlighting the urgent need for enhanced strategies that can stimulate robust and long-lasting antitumor effects. Microcystis, a notorious microalga, reveals the possibility of mediating SDT owing to the presence of gas vesicles (GVs) and phycocyanin (PC). Herein, a nontoxic strain of Microcystis elabens (labeled Me) is developed as a novel agent for SDT because it generates O2 under red light (RL) illumination, while GVs and PC act as cavitation nuclei and sonosensitizers, respectively. Moreover, algal debris is released after ultrasound (US) irradiation, which primes the Toll-like receptor pathway to initiate a cascade of immune responses. This sono-immune strategy inhibits CT26 colon tumor growth largely by promoting dendritic cell (DC) maturation and cytotoxic T-cell activation. After combination with the immune checkpoint blockade (ICB), the therapeutic outcome is further amplified, accompanied by satisfactory abscopal and immune memory effects; the similar potency is proven in the "cold" 4T1 triple-negative breast tumor. In addition, Me exhibits good biosafety without significant acute or chronic toxicity. Briefly, this study turns waste into wealth by introducing sono-immunotherapy based on Microcystis that achieved encouraging therapeutic effects on cancer, which is expected to be translated into the clinic.

Cancer Cell Membrane-Based Materials for Biomedical Applications

The nanodelivery system provides a novel direction for disease diagnosis and treatment; however, its delivery effectiveness is restricted by the short biological half-life and inadequate tumor targeting. The immune evasion properties and homologous targeting capabilities of natural cell membranes, particularly those of cancer cell membranes (CCM), have gained significant interest. The integration of CCM and nanoparticles has resulted in the emergence of CCM-based nanoplatforms (CCM-NPs), which have gained significant attention due to their unique properties. CCM-NPs not only prolong the blood circulation time of core nanoparticles, but also direct them for homologous tumor targeting. Herein, the history and development of CCM-NPs as well as how these platforms have been used for biomedical applications are discussed. The application of CCM-NPs for cancer therapy will be described in detail. Translational efforts are currently under way and further research to address key areas of need will ultimately be required to facilitate the successful clinical adoption of CCM-NPs.