T-Cell-Derived Nanovesicles for Cancer Immunotherapy

Extracellular Vesicle-Based Antitumor Nanomedicines

Extracellular vesicles (EVs) have emerged as promising bioactive carriers for delivering therapeutic agents, including nucleic acids, proteins, and small-molecule drugs, owing to their excellent physicochemical stability and biocompatibility. However, comprehensive reviews on the various types of EV-based nanomedicines for cancer therapy remain scarce. This review explores the potential of EVs as antitumor nanomedicines. Methods for EV extraction, drug loading, and engineering modifications are systematically examined, and the strengths and limitations of these technical approaches are critically assessed. Additionally, key strategies for developing EV-based antitumor therapies are highlighted. Finally, the opportunities and challenges associated with advancing EVs toward clinical translation are discussed. With the integration of multiple disciplines, robust EV-based therapeutic platforms are expected to be manufactured to provide more personalized and effective solutions for oncology patients.

Engineering exosomes and exosome-like nanovesicles for improving tissue targeting and retention

Exosomes are natural nano-size particles secreted by human cells, containing numerous bioactive cargos. Serving as crucial mediators of intercellular communication, exosomes are involved in many physiological and pathological processes, such as inflammation, tissue injury, cardiovascular diseases, tumorigenesis and tumor development. Exosomes have exhibited promising results in the diagnosis and treatment of cancer, cardiovascular diseases and others. They are a rapidly growing class of drug delivery vehicles with many advantages over conventional synthetic carriers. Exosomes used in therapeutic applications encounter several challenges, such as the lack of tissue targeting capabilities and short residence time. In this review, we discuss recent advances in exosome engineering to improve tissue targeting and describe the current types of engineered exosome-like nanovesicles, and summarize their preclinical applications in the treatment of diseases. Further, we also highlight the latest engineering strategies developed to extend exosomes retention time in vivo and exosome-like nanovesicles.

Tailoring cell-inspired biomaterials to fuel cancer therapy

Cancer stands as a predominant cause of mortality across the globe. Traditional cancer treatments, including surgery, radiotherapy, and chemotherapy, are effective yet face challenges like normal tissue damage, complications, and drug resistance. Biomaterials, with their advantages of high efficacy, targeting, and spatiotemporal controllability, have been widely used in cancer treatment. However, the biocompatibility limitations of traditional synthetic materials have restricted their clinical translation and application. Natural cell-inspired biomaterials inherently possess the targeting abilities of cells, biocompatibility, and immune evasion capabilities. Therefore, cell-inspired biomaterials can be used alone or in combination with other drugs or treatment strategies for cancer therapy. In this review, we first introduce the timeline of key milestones in cell-inspired biomaterials for cancer therapy. Then, we describe the abnormalities in cancer including biophysics, cellular biology, and molecular biology aspects. Afterwards, we summarize the design strategies of cell-inspired antitumor biomaterials. Subsequently, we elaborate on the application of antitumor biomaterials inspired by various cell types. Finally, we explore the current challenges and prospects of cell-inspired antitumor materials. This review aims to provide new opportunities and references for the development of antitumor cell-inspired biomaterials.

VCP downstream metabolite glycerol-3-phosphate (G3P) inhibits CD8+T cells function in the HCC microenvironment

CD8+T cells within the tumor microenvironment (TME) are often functionally impaired, which limits their ability to mount effective anti-tumor responses. However, the molecular mechanisms behind this dysfunction remain incompletely understood. Here, we identified valosin-containing protein (VCP) as a key regulator of CD8+T cells suppression in hepatocellular carcinoma (HCC). Our findings reveal that VCP suppresses the activation, expansion, and cytotoxic capacity of CD8+T cells both in vitro and in vivo, significantly contributing to the immunosuppressive nature of the TME. Mechanistically, VCP stabilizes the expression of glycerol-3-phosphate dehydrogenase 1-like protein (GPD1L), leading to the accumulation of glycerol-3-phosphate (G3P), a downstream metabolite of GPD1L. The accumulated G3P diffuses into the TME and directly interacts with SRC-family tyrosine kinase LCK, a critical component of the T-cell receptor (TCR) signaling pathway in CD8+T cells. This interaction heightens the phosphorylation of Tyr505, a key inhibitory residue, ultimately reducing LCK activity and impairing downstream TCR signaling. Consequently, CD8+T cells lose their functional capacity, diminishing their ability to fight against HCC. Importantly, we demonstrated that targeting VCP in combination with anti-PD1 therapy significantly suppresses HCC tumor growth and restores the anti-tumor function of CD8+T cells, suggesting synergistic therapeutic potential. These findings highlight a previously unrecognized mechanism involving VCP and G3P in suppressing T-cell-mediated immunity in the TME, positioning VCP as a promising upstream target for enhancing immunotherapy in HCC.

Artificial Nanovesicles Derived from Cells: A Promising Alternative to Extracellular Vesicles

As naturally secreted vesicles by cells, extracellular vesicles (EVs) play essential roles in modulating cell-cell communication and have significant potential in tissue regeneration, immune regulation, and drug delivery. However, the low yield and uncontrollable heterogeneity of EVs have been obstacles to their widespread translation into clinical practice. Recently, it has been discovered that artificial nanovesicles (NVs) produced by cell processing can inherit the components and functions of the parent cells and possess similar structures and functions to EVs, with significantly higher yields and more flexible functionalization, making them a powerful complement to natural EVs. This review focuses on recent advances in the research of artificial NVs as replacements for natural EVs. We provide an overview comparing natural EVs and artificial NVs and summarize the top-down preparation strategies of NVs. The applications of NVs prepared from stem cells, differentiated cells, and engineered cells are presented, as well as the latest advances in NV engineering. Finally, the main challenges of artificial NVs are discussed.

A Multifunctional Biomimetic Nanoplatform for Dual Tumor Targeting-Assisted Multimodal Therapy of Colon Cancer

The biomimetic nanoparticles (NPs) possessing abilities of tumor targeting and multimodal therapy show great potential for efficient combat of colon cancer. Herein, we developed a multifunctional biomimetic nanoplatform (Fe3O4@PDA@CaCO3-ICG@CM) based on CaCO3-modified magnetic polydopamine (PDA) loaded with indocyanine green (ICG), which was encapsulated by a mouse lymphoma cell (EL4) membrane (CM) expressing functional proteins (i.e., lymphocyte function-associated antigen 1, LFA-1; transforming growth factor-β receptor, TGF-βR; programmed cell death protein 1, PD-1; and factor related apoptosis ligand, FasL). Under magnetic attraction and LFA-1/PD-1-mediated endocytosis, Fe3O4@PDA@CaCO3-ICG@CM efficiently targeted CT26 colon tumor cells. The released calcium ion (Ca2+) from the NPs triggered by acidic tumor microenvironment, the enhanced photothermal effect contributed by the combination of PDA and ICG, and FasL's direct killing effect together induced tumor cells apoptosis. Moreover, the apoptosis of CT26 cells induced immunogenic cell death (ICD) to promote the maturation of dendritic cells (DCs) to activate CD4+/CD8+ T cells, thereby fighting against tumor cells, which could further be boosted by programmed death-ligand 1 (PD-L1) blockage and transforming growth factor-β (TGF-β) scavenging by Fe3O4@PDA@CaCO3-ICG@CM. As a result, in vivo satisfactory therapeutic effect was observed for CT26 tumor bearing-mice treated with Fe3O4@PDA@CaCO3-ICG@CM under laser irradiation and magnetic attraction, which could eradicate primary tumors and restrain distant tumors through dual tumor targeting-assisted multimodal therapy and eliciting adaptive antitumor immune response, generating the immune memory for inhibiting tumor metastasis and recurrence. Taken together, the multifunctional biomimetic nanoplatform exhibits superior antitumor effects, providing an insightful strategy for the field of nanomaterial-based treatment of cancer.

Targeted therapy of cancer stem cells: inhibition of mTOR in pre-clinical and clinical research

Cancer stem cells (CSCs) are a type of stem cell that possesses not only the intrinsic abilities of stem cells but also the properties of cancer cells. Therefore, CSCs are known to have self-renewal and outstanding proliferation capacity, along with the potential to differentiate into specific types of tumor cells. Cancers typically originate from CSCs, making them a significant target for tumor treatment. Among the related cascades of the CSCs, mammalian target of rapamycin (mTOR) pathway is regarded as one of the most important signaling pathways because of its association with significant upstream signaling: phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) pathway and mitogen‑activated protein kinase (MAPK) cascade, which influence various activities of stem cells, including CSCs. Recent studies have shown that the mTOR pathway not only affects generation of CSCs but also the maintenance of their pluripotency. Furthermore, the maintenance of pluripotency or differentiation into specific types of cancer cells depends on the regulation of the mTOR signal in CSCs. Consequently, the clinical potential and importance of mTOR in effective cancer therapy are increasing. In this review, we demonstrate the association between the mTOR pathway and cancer, including CSCs. Additionally, we discuss a new concept for anti-cancer drug development aimed at overcoming existing drawbacks, such as drug resistance, by targeting CSCs through mTOR inhibition.

Extracellular vesicles for cancer therapy: potential, progress, and clinical challenges

Extracellular vesicles (EVs) play an important role in normal life activities and disease treatment. In recent years, there have been abundant relevant studies focusing on EVs for cancer therapy and showing good performance on tumor inhibition. To enhance the effectiveness of EVs, EV analogs have been developed. This review summarizes the classification, origin, production, purification, modification, drug loading and cancer treatment applications of EVs and their analogs. Also, the characteristics of technologies involved are analyzed, which provides the basis for the development and application of biogenic vesicle-based drug delivery platform for cancer therapy. Meanwhile, challenges in translating these vesicles into clinic, such as limited sources, lack of production standards, and insufficient targeting and effectiveness are discussed. With ongoing exploration and clinical studies, EV-based drugs will make great contributions to cancer therapy.

Multi-modal Ca2+ nanogenerator via reversing T cell exhaustion for enhanced chemo-immunotherapy

Chemo-immunotherapy holds the advantage of specific antitumor effects by activating cytotoxic lymphocyte cells (CTLs) immune response. However, multiple barriers have limited the outcomes partly due to tumor-cell-mediated exhaustion of CTLs in the immunosuppressive tumor microenvironment (iTME). Here, we rationally designed a simple-yet-versatile Ca2+ nanogenerator to modulate iTME for enhancing 2-deoxyglucose (2-DG) mediated chemo-immunotherapy. Briefly, after 2-DG chemotherapy, CaO2 nanoparticles coated with EL4 cell membrane (denoted as CaNP@ECM) could preferentially accumulate in tumor tissue via adhesion between LFA-1 on EL4 cell membrane and ICAM-1 on inflamed endothelial cell in tumor tissues and display a series of benefits for CTLs: i) Increasing glucose availability of CTLs while reducing lactic acid secretion through Ca2+ overloading mediated inhibition of tumor cell glycolysis, as well as relieving hypoxia; ii) Reversing CTLs exhaustion via TGF-β1 scavenging and PD-L1 blockade through PD-1 and TGF-β1R on EL4 cell membrane; iii) Boosting tumor immunotherapy via immunologic death (ICD) of tumor cells induced by Ca2+ overloading. We demonstrate that the multi-modal Ca2+ nanogenerator rescues T cells from exhaustion and inhibits tumor growth both in vitro and in vivo. More importantly, the study also facilitate the development of glucose metabolism inhibition-based tumor immunotherapy via Ca2+ overloading.

Overcoming T Cell Exhaustion in Tumor Microenvironment via Immune Checkpoint Modulation with Nano-Delivery Systems for Enhanced Immunotherapy

Immune checkpoint blockade (ICB) therapy for tumors has arisen in growing interest. However, the low response rate of tumors to ICB is mainly attributed to the inhibitory infiltration of immune cells in the tumor microenvironment (TME). Despite the promising benefits of ICB, the therapeutic effects of antibodies are dependent on a high dose and long-term usage in the clinic, thereby leading to immune-related adverse effects. Accordingly, ICB combined with nano-delivery systems could be used to overcome T cell exhaustion, which reduces the side effects and the usage of antibodies with higher response rates in patients. In this review, the authors aim to overcome T cell exhaustion in TME via immune checkpoint modulation with nano-delivery systems for enhanced immunotherapy. Several strategies are summarized to combine ICB and nano-delivery systems to further enhance immunotherapy: a) expressing immune checkpoint on the surface of nano-delivery systems; b) loading immune checkpoint inhibitors into nano-delivery systems; c) loading gene-editing technology into nano-delivery systems; and d) nano-delivery systems mediated immune checkpoint modulation. Taken together, ICB combined with nano-delivery systems might be a promising strategy to overcome T cell exhaustion in TME for enhanced immunotherapy.

M1-polarized macrophage-derived cellular nanovesicle-coated lipid nanoparticles for enhanced cancer treatment through hybridization of gene therapy and cancer immunotherapy

Optimum genetic delivery for modulating target genes to diseased tissue is a major obstacle for profitable gene therapy. Lipid nanoparticles (LNPs), considered a prospective vehicle for nucleic acid delivery, have demonstrated efficacy in human use during the COVID-19 pandemic. This study introduces a novel biomaterial-based platform, M1-polarized macrophage-derived cellular nanovesicle-coated LNPs (M1-C-LNPs), specifically engineered for a combined gene-immunotherapy approach against solid tumor. The dual-function system of M1-C-LNPs encapsulates Bcl2-targeting siRNA within LNPs and immune-modulating cytokines within M1 macrophage-derived cellular nanovesicles (M1-NVs), effectively facilitating apoptosis in cancer cells without impacting T and NK cells, which activate the intratumoral immune response to promote granule-mediating killing for solid tumor eradication. Enhanced retention within tumor was observed upon intratumoral administration of M1-C-LNPs, owing to the presence of adhesion molecules on M1-NVs, thereby contributing to superior tumor growth inhibition. These findings represent a promising strategy for the development of targeted and effective nanoparticle-based cancer genetic-immunotherapy, with significant implications for advancing biomaterial use in cancer therapeutics.

The role of transforming growth factor-β (TGF-β) in the formation of exhausted CD8 + T cells

CD8 + T cells exert a critical role in eliminating cancers and chronic infections, and can provide long-term protective immunity. However, under the exposure of persistent antigen, CD8 + T cells can differentiate into terminally exhausted CD8 + T cells and lose the ability of immune surveillance and disease clearance. New insights into the molecular mechanisms of T-cell exhaustion suggest that it is a potential way to improve the efficacy of immunotherapy by restoring the function of exhausted CD8 + T cells. Transforming growth factor-β (TGF-β) is an important executor of immune homeostasis and tolerance, inhibiting the expansion and function of many components of the immune system. Recent studies have shown that TGF-β is one of the drivers for the development of exhausted CD8 + T cells. In this review, we summarized the role and mechanisms of TGF-β in the formation of exhausted CD8 + T cells and discussed ways to target those to ultimately enhance the efficacy of immunotherapy.

Nanomaterial-Based Strategies for Attenuating T-Cell-Mediated Immunodepression in Stroke Patients: Advancing Research Perspectives

This review article discusses the potential of nanomaterials in targeted therapy and immunomodulation for stroke-induced immunosuppression. Although nanomaterials have been extensively studied in various biomedical applications, their specific use in studying and addressing immunosuppression after stroke remains limited. Stroke-induced neuroinflammation is characterized by T-cell-mediated immunodepression, which leads to increased morbidity and mortality. Key observations related to immunodepression after stroke, including lymphopenia, T-cell dysfunction, regulatory T-cell imbalance, and cytokine dysregulation, are discussed. Nanomaterials, such as liposomes, micelles, polymeric nanoparticles, and dendrimers, offer advantages in the precise delivery of drugs to T cells, enabling enhanced targeting and controlled release of immunomodulatory agents. These nanomaterials have the potential to modulate T-cell function, promote neuroregeneration, and restore immune responses, providing new avenues for stroke treatment. However, challenges related to biocompatibility, stability, scalability, and clinical translation need to be addressed. Future research efforts should focus on comprehensive studies to validate the efficacy and safety of nanomaterial-based interventions targeting T cells in stroke-induced immunosuppression. Collaborative interdisciplinary approaches are necessary to advance the field and translate these innovative strategies into clinical practice, ultimately improving stroke outcomes and patient care.

Engineered biological nanoparticles as nanotherapeutics for tumor immunomodulation

Biological nanoparticles, or bionanoparticles, are small molecules manufactured in living systems with complex production and assembly machinery. The products of the assembly systems can be further engineered to generate functionalities for specific purposes. These bionanoparticles have demonstrated advantages such as immune system evasion, minimal toxicity, biocompatibility, and biological clearance. Hence, bionanoparticles are considered the new paradigm in nanoscience research for fabricating safe and effective nanoformulations for therapeutic purposes. Harnessing the power of the immune system to recognize and eradicate malignancies is a viable strategy to achieve better therapeutic outcomes with long-term protection from disease recurrence. However, cancerous tissues have evolved to become invisible to immune recognition and to transform the tumor microenvironment into an immunosuppressive dwelling, thwarting the immune defense systems and creating a hospitable atmosphere for cancer growth and progression. Thus, it is pertinent that efforts in fabricating nanoformulations for immunomodulation are mindful of the tumor-induced immune aberrations that could render cancer nanotherapy inoperable. This review systematically categorizes the immunosuppression mechanisms, the regulatory immunosuppressive cellular players, and critical suppressive molecules currently targeted as breakthrough therapies in the clinic. Finally, this review will summarize the engineering strategies for affording immune moderating functions to bionanoparticles that tip the tumor microenvironment (TME) balance toward cancer elimination, a field still in the nascent stage.

Hydrogel Crosslinked with Nanoparticles for Prevention of Surgical Hemorrhage and Recurrence of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is acknowledged as an immunosuppressive neoplasm, whereby the inactive microenvironment facilitates immune tolerance and evasion of HCC. Post-surgical resected liver cancer exhibits a proclivity for relapse, rendering prevention of recurrence challenging as it may transpire at any point subsequent to surgery. Among the various anti-recurrence interventions, the primary clinical approach involving the administration of regimens atezolizumab and bevacizumab (A+T) is deemed the most efficacious in reversing the tumor microenvironment, albeit still lacking in complete satisfaction. Therefore, the objective is to utilize a recently developed block copolymer as a protective carrier for two specific monoclonal antibody drugs. Subsequently, a modified hemostatic hydrogel will be synthesized for application during hepatic surgery. The immunotherapy impact of this approach is significantly prolonged and intensified due to the combined hemostasis properties and controlled release of the constituents within the synthesized nanocomposite hydrogel. Furthermore, these nanocomposite hydrogels exhibit remarkable efficacy in preventing postoperative wound bleeding and substantially enhancing the safety of liver cancer resection. This research on the anti-recurrence hydrogel system presents a novel therapeutic approach for addressing local recurrence of liver cancer, potentially offering a substantial contribution to the field of surgical treatment for liver cancer in the future.

In vivo production of CAR-T cells using virus-mimetic fusogenic nanovesicles

Engineered T cells expressing chimeric antigen receptor (CAR) exhibit high response rates in B-cell malignancy treatments and possess therapeutic potentials against various diseases. However, the complicated ex vivo production process of CAR-T cells limits their application. Herein, we use virus-mimetic fusogenic nanovesicles (FuNVs) to produce CAR-T cells in vivo via membrane fusion-mediated CAR protein delivery. Briefly, the FuNVs are modified using T-cell fusogen, adapted from measles virus or reovirus fusogens via displaying anti-CD3 single-chain variable fragment. The FuNVs can efficiently fuse with the T-cell membrane in vivo, thereby delivering the loaded anti-CD19 (αCD19) CAR protein onto T-cells to produce αCD19 CAR-T cells. These αCD19 CAR-T cells alone or in combination with anti-OX40 antibodies can treat B-cell lymphoma without inducing cytokine release syndrome. Thus, our strategy provides a novel method for engineering T cells into CAR-T cells in vivo and can further be employed to deliver other therapeutic membrane proteins.

Photonic control of image-guided ferroptosis cancer nanomedicine

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

Ultrasound-nanovesicles interplay for theranostics

Nanovesicles (NVs) are widely used in the treatment and diagnosis of diseases due to their excellent vascular permeability, good biocompatibility, high loading capacity, and easy functionalization. However, their yield and in vivo penetration depth limitations and their complex preparation processes still constrain their application and development. Ultrasound, as a fundamental external stimulus with deep tissue penetration, concentrated energy sources, and good safety, has been proven to be a patient-friendly and highly efficient strategy to overcome the restrictions of traditional clinical medicine. Recent research has shown that ultrasound can drive the generation of NVs, increase their yield, simplify their preparation process, and provide direct therapeutic effects and intelligent control to enhance the therapeutic effect of NVs. In addition, NVs, as excellent drug carriers, can enhance the targeting efficiency of ultrasound-based sonodynamic therapy or sonogenetic regulation and improve the accuracy of ultrasound imaging. This review provides a detailed introduction to the classification, generation, and modification strategies of NVs, emphasizing the impact of ultrasound on the formation of NVs and summarizing the enhanced treatment and diagnostic effects of NVs combined with ultrasound for various diseases.

Nanoparticle-Based Immunotherapy for Reversing T-Cell Exhaustion

T-cell exhaustion refers to a state of T-cell dysfunction commonly observed in chronic infections and cancer. Immune checkpoint molecules blockading using PD-1 and TIM-3 antibodies have shown promising results in reversing exhaustion, but this approach has several limitations. The treatment of T-cell exhaustion is still facing great challenges, making it imperative to explore new therapeutic strategies. With the development of nanotechnology, nanoparticles have successfully been applied as drug carriers and delivery systems in the treatment of cancer and infectious diseases. Furthermore, nanoparticle-based immunotherapy has emerged as a crucial approach to reverse exhaustion. Here, we have compiled the latest advances in T-cell exhaustion, with a particular focus on the characteristics of exhaustion that can be targeted. Additionally, the emerging nanoparticle-based delivery systems were also reviewed. Moreover, we have discussed, in detail, nanoparticle-based immunotherapies that aim to reverse exhaustion, including targeting immune checkpoint blockades, remodeling the tumor microenvironment, and targeting the metabolism of exhausted T cells, etc. These data could aid in comprehending the immunopathogenesis of exhaustion and accomplishing the objective of preventing and treating chronic diseases or cancer.

Unraveling the surface marker signature of cell-derived vesicles via proteome analysis and nanoparticle flow cytometry

The cell-derived vesicles (CDVs) obtained using a proprietary extrusion process are the foundation of BioDrone platform technology. With superior productivity and versatility, this technology has garnered increasing attention in broad applications, particularly as a drug delivery vehicle. Previously, we showed that CDVs exhibited varying levels of expression for tetraspanin and organelle membrane markers while revealing no discernible differences in physical characteristics compared to naturally produced extracellular vesicles (EVs). To further understand and utilize the therapeutic potentials of CDVs, a more comprehensive study of membrane protein profiles is necessary. In addition, it is crucial to validate that the CDVs produced from extrusion are indeed intact lipid vesicles rather than other impurities. Here, we produced multiple batches of CDVs and EVs from HEK293 cells. CDVs and EVs were subjected to the same purification processes for subsequent proteome and particle analyses. The proteome analyses revealed unique proteome signatures between CDVs, EVs, and parental cells. Extensive proteome analyses identified the nine most prominent membrane markers that are abundant in CDVs compared to cells and EVs. Subsequent western blotting and nanoparticle flow cytometry analyses confirmed that CD63, lysosome-associated membrane glycoprotein 1 (LAMP1), and nicastrin (NCSTN) are highly enriched in CDVs, whereas CD81, CD9, and prostaglandin F2 receptor negative regulator (PTGFRN) are more abundant in EVs. This highlights the unique membrane composition and marker signature of CDVs that are distinct from EVs. Lastly, we demonstrated that more than 90% of the CDVs are genuine lipid vesicles by combining two different classes of vesicle labeling dyes and detergents to disrupt lipid membranes. This indicates that our proprietary extrusion technology is highly compatible with other well-characterized EV production methods. The robust CDV markers identified in this study will also facilitate the engineering of CDVs to achieve enhanced therapeutic effects or tissue-selective cargo delivery.

Recent Advances in the Development of Membrane-derived Vesicles for Cancer Immunotherapy

The surface proteins on cell membranes enable the cells to have different properties, such as high biocompatibility, surface modifiability, and homologous targeting ability. Cell-membrane-derived vesicles have features identical to those of their parental cells, which makes them one of the most promising materials for drug delivery. Recently, as a result of the impressive effects of immunotherapy in cancer treatment, an increasing number of researchers have used cell-membrane-derived vesicles to enhance immune responses. To be more specific, the membrane vesicles derived from immune cells, tumor cells, bacteria, or engineered cells have the antigen presentation capacity and can trigger strong anti-tumor effects of the immune system. In this review, we first indicated a brief description of the vesicles and then introduced the detection technology and drug-loading methods for them. Secondly, we concluded the characteristics and applications of vesicles derived from different sources in cancer immunotherapy.

Cellular Membrane Components-Mediated Cancer Immunotherapeutic Platforms

Immune cell engineering is an active field of ongoing research that can be easily applied to nanoscale biomedicine as an alternative to overcoming limitations of nanoparticles. Cell membrane coating and artificial nanovesicle technology have been reported as representative methods with an advantage of good biocompatibility for biomimetic replication of cell membrane characteristics. Cell membrane-mediated biomimetic technique provides properties of natural cell membrane and enables membrane-associated cellular/molecular signaling. Thus, coated nanoparitlces (NPs) and artificial nanovesicles can achieve effective and extended in vivo circulation, enabling execution of target functions. While coated NPs and artificial nanovesicles provide clear advantages, much work remains before clinical application. In this review, first a comprehensive overview of cell membrane coating techniques and artificial nanovesicles is provided. Next, the function and application of various immune cell membrane types are summarized.

Engineering Cell-Derived Nanovesicles for Targeted Immunomodulation

Extracellular vesicles (EVs) show promise for targeted drug delivery but face production challenges with low yields. Cell-derived nanovesicles (CDNVs) made by reconstituting cell membranes could serve as EV substitutes. In this study, CDNVs were generated from mesenchymal stem cells by extrusion. Their proteomic composition, in vitro and in vivo toxicity, and capacity for loading RNA or proteins were assessed. Compared with EVs, CDNVs were produced at higher yields, were comprised of a broader range of proteins, and showed no detrimental effects on cell proliferation, DNA damage, or nitric oxide production in vitro or on developmental toxicity in vivo. CDNVs could be efficiently loaded with RNA and engineered to modify surface proteins. The feasibility of generating immunomodulatory CDNVs was demonstrated by preparing CDNVs with enhanced surface expression of PD1, which could bind to PD-L1 expressing tumor cells, enhance NK and T cell degranulation, and increase immune-mediated tumor cell death. These findings demonstrate the adaptability and therapeutic promise of CDNVs as promising substitutes for natural EVs that can be engineered to enhance immunomodulation.

Sequential Targeting Hybrid Nanovesicles Composed of Chimeric Antigen Receptor T-Cell-Derived Exosomes and Liposomes for Enhanced Cancer Immunochemotherapy

Paclitaxel (PTX)-based chemotherapy remains the main approach to treating lung cancer but systemic toxicity limits its use. As chimeric antigen receptor-T (CAR-T) cell-derived exosomes contain tumor-targeted CARs and cytotoxic granules (granzyme B and perforin), they are considered potential delivery vehicles for PTX. However, the low drug-loading capacity and hepatotropic properties of exosomes are obstacles to their application to extrahepatic cancer. Here, a hybrid nanovesicle named Lip-CExo@PTX was designed for immunochemotherapy of lung cancer by fusing exosomes derived from bispecific CAR-T cells targeting both mesothelin (MSLN) and programmed death ligand-1 (PD-L1) with lung-targeted liposomes. Due to the lung-targeting ability of the liposomes, over 95% of intravenously administered Lip-CExo@PTX accumulated in lung tissue. In addition, with the help of the anti-MSLN single-chain variable fragment (scFv), the PTX and cytotoxic granules inside Lip-CExo@PTX were further delivered into MSLN-positive tumors. Notably, the anti-PD-L1 scFv on Lip-CExo@PTX blocked PD-L1 on the tumors to avoid T cell exhaustion and promoted PTX-induced immunogenic cell death. Furthermore, Lip-CExo@PTX prolonged the survival time of tumor-bearing mice in a CT-26 metastatic lung cancer model. Therefore, Lip-CExo@PTX may deliver PTX to tumor cells through sequential targeted delivery and enhance the antitumor effects, providing a promising strategy for immunochemotherapy of lung cancer.

Engineered CD8+ T cell-derived extracellular vesicles induce enhanced anti-cancer efficacy and targeting to lung cancer cells

Lung cancer is a common and highly malignant tumor. Although lung cancer treatments continue to advance, conventional therapies are limited and the response rate of patients to immuno-oncology drugs is low. This phenomenon raises an urgent need to develop effective therapeutic strategies for lung cancer. In this study, we genetically modified human primary CD8+ T cells and obtained antitumor extracellular vesicles (EVs) from them. The engineered EVs, containing interlekin-2 and the anti-epidermal growth factor receptor (EGFR) antibody cetuximab on their surfaces, exhibited direct cytotoxicity against A549 human lung cancer cells and increased cancer cell susceptibility to human peripheral blood mononuclear cell-mediated cytotoxicity. In addition, the engineered EVs specifically targeted the lung cancer cells in an EGFR-dependent manner. Taken together, these findings show that surface engineering of cytokines and antibodies on CD8+ T cell-derived EVs not only enhances their antitumor effects but also confers target specificity, suggesting a potential of modifying the immune cell-derived EVs in cancer treatment.

Advancement and Applications of Nanotherapy for Cancer Immune Microenvironment

Cancer treatment has evolved rapidly due to major advances in tumor immunity research. However, due to the complexity, heterogeneity, and immunosuppressive microenvironment of tumors, the overall efficacy of immunotherapy is only 20%. In recent years, nanoparticles have attracted more attention in the field of cancer immunotherapy because of their remarkable advantages in biocompatibility, precise targeting, and controlled drug delivery. However, the clinical application of nanomedicine also faces many problems concerning biological safety, and the synergistic mechanism of nano-drugs with immunity remains to be elucidated. Our study summarizes the functional characteristics and regulatory mechanisms of nanoparticles in the cancer immune microenvironment and how nanoparticles activate and long-term stimulate innate immunity and adaptive immunity. Finally, the current problems and future development trends regarding the application of nanoparticles are fully discussed and prospected to promote the transformation and application of nanomedicine used in cancer treatment.

The extracellular vesicles targeting tumor microenvironment: a promising therapeutic strategy for melanoma

Extracellular vesicles (EVs) are small particles secreted by numerous cell types and circulate in almost all body fluids, acting as crucial messengers for cell-to-cell communication. EVs involves multiple physiological and pathological processes, including tumor progression, via their multiple cargoes. Therefore, EVs have become attractive candidates for the treatment of tumor, including melanoma. Notably, due to the crucial role of the tumor microenvironment (TME) in promoting tumor malignant phenotype, and the close intercellular communication in TME, EVs-based therapy by targeting TME has become a cutting-edge and prospective strategy for inhibiting melanoma progression and strengthening the anti-tumor immunity. In this review, we aimed to summarize and discuss the role of therapeutic EVs, which target the components of TME in melanoma, thereby providing insights into these promising clinical strategies for the treatment of melanoma patients.

Biomimetic Cell-Derived Nanoparticles: Emerging Platforms for Cancer Immunotherapy

Cancer immunotherapy can significantly prevent tumor growth and metastasis by activating the autoimmune system without destroying normal cells. Although cancer immunotherapy has made some achievements in clinical cancer treatment, it is still restricted by systemic immunotoxicity, immune cell dysfunction, cancer heterogeneity, and the immunosuppressive tumor microenvironment (ITME). Biomimetic cell-derived nanoparticles are attracting considerable interest due to their better biocompatibility and lower immunogenicity. Moreover, biomimetic cell-derived nanoparticles can achieve different preferred biological effects due to their inherent abundant source cell-relevant functions. This review summarizes the latest developments in biomimetic cell-derived nanoparticles for cancer immunotherapy, discusses the applications of each biomimetic system in cancer immunotherapy, and analyzes the challenges for clinical transformation.

Tumor cell membrane-coated continuous electrochemical sensor for GLUT1 inhibitor screening

Glucose transporter 1 (GLUT1) overexpression in tumor cells is a potential target for drug therapy, but few studies have reported screening GLUT1 inhibitors from natural or synthetic compounds. With current analysis techniques, it is difficult to accurately monitor the GLUT1 inhibitory effect of drug molecules in real-time. We developed a cell membrane-based glucose sensor (CMGS) that integrated a hydrogel electrode with tumor cell membranes to monitor GLUT1 transmembrane transport and screen for GLUT1 inhibitors in traditional Chinese medicines (TCMs). CMGS is compatible with cell membranes of various origins, including different types of tumors and cell lines with GLUT1 expression knocked down by small interfering RNA or small molecules. Based on CMGS continuous monitoring technique, we investigated the glucose transport kinetics of cell membranes with varying levels of GLUT1 expression. We used CMGS to determine the GLUT1-inhibitory effects of drug monomers with similar structures from Scutellaria baicalensis and catechins families. Results were consistent with those of the cellular glucose uptake test and molecular-docking simulation. CMGS could accurately screen drug molecules in TCMs that inhibit GLUT1, providing a new strategy for studying transmembrane protein-receptor interactions.

Cellular nanovesicles for therapeutic immunomodulation: A perspective on engineering strategies and new advances

Cellular nanovesicles which are referred to as cell-derived, nanosized lipid bilayer structures, have emerged as a promising platform for regulating immune responses. Owing to their outstanding advantages such as high biocompatibility, prominent structural stability, and high loading capacity, cellular nanovesicles are suitable for delivering various immunomodulatory molecules, such as small molecules, nucleic acids, peptides, and proteins. Immunomodulation induced by cellular nanovesicles has been exploited to modulate immune cell behaviors, which is considered as a novel cell-free immunotherapeutic strategy for the prevention and treatment of diverse diseases. Here we review emerging concepts and new advances in leveraging cellular nanovesicles to activate or suppress immune responses, with the aim to explicate their applications for immunomodulation. We overview the general considerations and principles for the design of engineered cellular nanovesicles with tailored immunomodulatory activities. We also discuss new advances in engineering cellular nanovesicles as immunotherapies for treating major diseases.

Senescent cancer cell-derived nanovesicle as a personalized therapeutic cancer vaccine

The development of therapeutic cancer vaccines (TCVs) that provide clinical benefits is challenging mainly due to difficulties in identifying immunogenic tumor antigens and effectively inducing antitumor immunity. Furthermore, there is an urgent need for personalized TCVs because only a limited number of tumor antigens are shared among cancer patients. Several autologous nanovaccines that do not require the identification of immunogenic tumor antigens have been proposed as personalized TCVs. However, these nanovaccines generally require exogenous adjuvants (e.g., Toll-like receptor agonists) to improve vaccine immunogenicity, which raises safety concerns. Here, we present senescent cancer cell-derived nanovesicle (SCCNV) as a personalized TCV that provides patient-specific tumor antigens and improved vaccine immunogenicity without the use of exogenous adjuvants. SCCNVs are prepared by inducing senescence in cancer cells ex vivo and subsequently extruding the senescent cancer cells through nanoporous membranes. In the clinical setting, SCCNVs can be prepared from autologous cancer cells from the blood of liquid tumor patients or from tumors surgically removed from solid cancer patients. SCCNVs also contain interferon-γ and tumor necrosis factor-α, which are expressed during senescence. These endogenous cytokines act as adjuvants and enhance vaccine immunogenicity, avoiding the need for exogenous adjuvants. Intradermally injected SCCNVs effectively activate dendritic cells and tumor-specific T cells and inhibit primary and metastatic tumor growth and tumor recurrence. SCCNV therapy showed an efficacy similar to that of immune checkpoint blockade (ICB) therapy and synergized with ICB. SCCNVs, which can be prepared using a simple and facile procedure, show potential as personalized TCVs.

Boosting Checkpoint Immunotherapy with Biomaterials

The immune checkpoint blockade (ICB) therapy has revolutionized the field of cancer treatment, while low response rates and systemic toxicity limit its clinical outcomes. With the rapid advances in nanotechnology and materials science, various types of biomaterials have been developed to maximize therapeutic efficacy while minimizing side effects by increasing tumor antigenicity, reversing immunosuppressive microenvironment, amplifying antitumor immune response, and reducing extratumoral distribution of checkpoint inhibitors as well as enhancing their retention within target sites. In this review, we reviewed current design strategies for different types of biomaterials to augment ICB therapy effectively and then discussed present representative biomaterial-assisted immune modulation and targeted delivery of checkpoint inhibitors to boost ICB therapy. Current challenges and future development prospects for expanding the ICB with biomaterials were also summarized. We anticipate this review will be helpful for developing emerging biomaterials for ICB therapy and promoting the clinical application of ICB therapy.

Harnessing Engineered Immune Cells and Bacteria as Drug Carriers for Cancer Immunotherapy

Immunotherapy continues to be in the spotlight of oncology therapy research in the past few years and has been proven to be a promising option to modulate one's innate and adaptive immune systems for cancer treatment. However, the poor delivery efficiency of immune agents, potential off-target toxicity, and nonimmunogenic tumors significantly limit its effectiveness and extensive application. Recently, emerging biomaterial-based drug carriers, including but not limited to immune cells and bacteria, are expected to be potential candidates to break the dilemma of immunotherapy, with their excellent natures of intrinsic tumor tropism and immunomodulatory activity. More than that, the tiny vesicles and physiological components derived from them have similar functions with their source cells due to the inheritance of various surface signal molecules and proteins. Herein, we presented representative examples about the latest advances of biomaterial-based delivery systems employed in cancer immunotherapy, including immune cells, bacteria, and their derivatives. Simultaneously, opportunities and challenges of immune cells and bacteria-based carriers are discussed to provide reference for their future application in cancer immunotherapy.

T cell-derived exosomes in tumor immune modulation and immunotherapy

Exosomes are nanoscale vesicles secreted by most cells and have a phospholipid bilayer structure. Exosomes contain DNA, small RNA, proteins, and other substances that can carry proteins and nucleic acids and participate in communication between cells. T cells are an indispensable part of adaptive immunity, and the functions of T cell-derived exosomes have been widely studied. In the more than three decades since the discovery of exosomes, several studies have revealed that T cell-derived exosomes play a novel role in cell-to-cell signaling, especially in the tumor immune response. In this review, we discuss the function of exosomes derived from different T cell subsets, explore applications in tumor immunotherapy, and consider the associated challenges.

Extracellular vesicles: emerging anti-cancer drugs and advanced functionalization platforms for cancer therapy

Increasing evidences show that unmodified extracellular vesicles (EVs) derived from various cells can effectively inhibit the malignant progression of different types of tumors by delivering the bioactive molecules. Therefore, EVs are expected to be developed as emerging anticancer drugs. Meanwhile, unmodified EVs as an advanced and promising nanocarrier that is frequently used in targeted delivery therapeutic cargos and personalized reagents for the treatment and diagnosis of cancer. To improve the efficacy of EV-based treatments, researchers are trying to engineering EVs as an emerging nanomedicine translational therapy platform through biological, physical and chemical approaches, which can be broaden and altered to enhance their therapeutic capability. EVs loaded with therapeutic components such as tumor suppressor drugs, siRNAs, proteins, peptides, and conjugates exhibit significantly enhanced anti-tumor effects. Moreover, the design and preparation of tumor-targeted modified EVs greatly enhance the specificity and effectiveness of tumor therapy, and these strategies are expected to become novel ideas for tumor precision medicine. This review will focus on reviewing the latest research progress of functionalized EVs, clarifying the superior biological functions and powerful therapeutic potential of EVs, for researchers to explore new design concepts based on EVs and build next-generation nanomedicine therapeutic platforms.

Exosomes Derived from Immune Cells: The New Role of Tumor Immune Microenvironment and Tumor Therapy

Exosomes are small vesicles secreted by living cells, with a typical lipid bilayer structure. They carry a variety of proteins, lipids, RNA and other important information, play an important role in the transmission of substances and information between cells, and gradually become a marker for early diagnosis of many diseases and an important tool in drug delivery system. Immune cells are an important part of tumor microenvironment, and they can affect tumor progression by secreting a variety of immunoreactive substances. This review focuses on the effects of various immune cell-derived exosomes on tumor cells, different immune cells and other stromal cells in tumor microenvironment. Exosomes derived from different immune cells can not only reshape a pro-inflammatory microenvironment to inhibit tumor progression, but also promote tumor progression by inhibiting the killing effect of NK cells, CD8⁺T cells and other cells or promoting tumor cells and immunosuppressive immune cells. In addition, we also discussed that some exosomes derived from immune cells (such as DC, M1 macrophages and neutrophils) play a tumor inhibitory role after being engineered.

GMP-compliant manufacturing of biologically active cell-derived vesicles produced by extrusion technology

Extracellular vesicles (EVs) released by a variety of cell types have been shown to act as a natural delivery system for bioactive molecules such as RNAs and proteins. EV therapy holds great promise as a safe and cell-free therapy for many immunological and degenerative diseases. However, translation to clinical application is limited by several factors, including insufficient large-scale manufacturing technologies and low yield. We have developed a novel drug delivery platform technology, BioDrone™, based on cell-derived vesicles (CDVs) produced from diverse cell sources by using a proprietary extrusion process. This extrusion technology generates nanosized vesicles in far greater numbers than naturally obtained EVs. We demonstrate that the CDVs are surrounded by a lipid bilayer membrane with a correct membrane topology. Physical, biochemical and functional characterisation results demonstrate the potential of CDVs to act as effective therapeutics. Umbilical cord mesenchymal stem cell (UCMSC)-derived CDVs exhibit a biological activity that is similar to UCMSCs or UCMSC-derived EVs. Lastly, we present the establishment of a GMP-compliant process to allow the production of a large number of UCMSC-CDVs in a reproducible manner. GMP-compliant manufacturing of CDVs will facilitate the preclinical and clinical evaluation of these emerging therapeutics in anti-inflammatory or regenerative medicine. This study also represents a crucial step in the development of this novel drug delivery platform based on CDVs.

Extracellular-Vesicle-Based Drug Delivery Systems for Enhanced Antitumor Therapies through Modulating the Cancer-Immunity Cycle

Although immunotherapy harnessing activity of the immune system against tumors has made great progress, the treatment efficacy remains limited in most cancers. Current anticancer immunotherapy is primarily based on T-cell-mediated cellular immunity, which highly relies on efficiency of triggering the cancer-immunity cycle, namely, tumor antigen release, antigen presentation by antigen presenting cells, T cell activation, recruitment and infiltration of T cells into tumors, and recognition and killing of tumor cells by T cells. Unfortunately, these immunotherapies are restricted by inefficient drug delivery and acting on only a single step of the cancer-immunity cycle. Due to high biocompatibility, low immunogenicity, intrinsic cell targeting, and easy chemical and genetic manipulation, extracellular vesicle (EV)-based drug delivery systems are widely used to amplify anticancer immune responses by serving as an integrated platform for multiple drugs or therapeutic strategies to synergistically activate several steps of cancer-immunity cycle. This review summarizes various mechanisms related to affecting cancer-immunity cycle disorders. Meanwhile, preparation and application of EV-based drug delivery systems in modulating cancer-immunity cycle are introduced, especially in the improvement of T cell recruitment and infiltration into tumors. Finally, opportunities and challenges of EV-based drug delivery systems in translational clinical applications are briefly discussed.

Biofunctional Layered Double Hydroxide Nanohybrids for Cancer Therapy

Layered double hydroxides (LDHs) with two-dimensional nanostructure are inorganic materials that have attractive advantages such as biocompatibility, facile preparation, and high drug loading capacity for therapeutic bioapplications. Since the intercalation chemistry of DNA molecules into the LDH materials were reported, various LDH nanohybrids have been developed for biomedical drug delivery system. For these reasons, LDHs hybridized with numerous therapeutic agents have a significant role in cancer imaging and therapy with targeting functions. In this review, we summarized the recent advances in the preparation of LDH nanohybrids for cancer therapeutic strategies including gene therapy, chemotherapy, immunotherapy, and combination therapy.

Engineered extracellular vesicles and their mimetics for cancer immunotherapy

Extracellular vesicles (EVs) are heterogeneous membranous vesicles secreted by living cells that are involved in many physiological and pathological processes as intermediaries for intercellular communication and molecular transfer. Recent studies have shown that EVs can regulate the occurrence and development of tumors by transferring proteins, lipids and nucleic acids to immune cells as signaling molecules. As a new diagnostic biomarker and drug delivery system, EVs have broad application prospects in immunotherapy. In addition, the breakthrough of nanotechnology has promoted the development and exploration of engineered EVs for immune-targeted therapy. Herein, we review the uniqueness of EVs in immune regulation and the engineering strategies used for immunotherapy and highlight the logic of their design through typical examples. The present situation and challenges of clinical transformation are discussed, and the development prospects of EVs in immunotherapy are proposed. The goal of this review is to provide new insights into the design of immune-regulatory EVs and expand their application in cancer immunotherapy.

Immune-Cell-Derived Exosomes for Cancer Therapy

Exosomes are a type of extracellular vesicles secreted by cells in normal or pathological conditions for cell-cell communication. With immunomodulatory characteristics and potential therapeutic properties, immune-cell-derived exosomes play an important role in cancer therapy. They express various antigens on their surface, which can be employed for antigen presentation, immunological activation, and metabolic regulation, leading to the killing of cancerous cells. In addition, immune-cell-derived exosomes have received extensive attention as a drug delivery platform in effective antitumor therapy due to their excellent biocompatibility, low immunogenicity, and high loading capacity. In this review, the biological and therapeutic characteristics of immune-cell-derived exosomes are comprehensively outlined. The antitumor mechanism of exosomes secreted by immune cells, including macrophages, dendritic cells, T cells, B cells, and natural killer cells, are systematically summarized. Moreover, the applications of immune-cell-derived exosomes as nanocarriers to transport antitumor agents (chemotherapeutic drugs, genes, proteins, etc.) are discussed. More importantly, the existing challenges of immune-cell-derived exosomes are pointed out, and their antitumor potentials are also discussed.

Cell Membrane-Derived Vesicle: A Novel Vehicle for Cancer Immunotherapy

As nano-sized materials prepared by isolating, disrupting and extruding cell membranes, cellular vesicles are emerging as a novel vehicle for immunotherapeutic drugs to activate antitumor immunity. Cell membrane-derived vesicles inherit the surface characteristics and functional properties of parental cells, thus having superior biocompatibility, low immunogenicity and long circulation. Moreover, the potent antitumor effect of cellular vesicles can be achieved through surface modification, genetic engineering, hybridization, drug encapsulation, and exogenous stimulation. The capacity of cellular vesicles to combine drugs of different compositions and functions in physical space provides a promising vehicle for combinational immunotherapy of cancer. In this review, the latest advances in cellular vesicles as vehicles for combinational cancer immunotherapy are systematically summarized with focuses on manufacturing processes, cell sources, therapeutic strategies and applications, providing an insight into the potential and existing challenges of using cellular vesicles for cancer immunotherapy.

Biomimetic and Materials-Potentiated Cell Engineering for Cancer Immunotherapy

In cancer immunotherapy, immune cells are the main force for tumor eradication. However, they appear to be dysfunctional due to the taming of the tumor immunosuppressive microenvironment. Recently, many materials-engineered strategies are proposed to enhance the anti-tumor effect of immune cells. These strategies either utilize biomimetic materials, as building blocks to construct inanimate entities whose functions are similar to natural living cells, or engineer immune cells with functional materials, to potentiate their anti-tumor effects. In this review, we will summarize these advanced strategies in different cell types, as well as discussing the prospects of this field.

Recent advances of engineered and artificial drug delivery system towards solid tumor based on immune cells

Precise drug delivery in cancer treatment is a long-standing concern of modern medicine. Compared with traditional molecular medicines and nano-medicines, emerging cell-based biomimetic delivery strategies display numerous merits, including successive biological functions, innate biocompatibility and superior security since they originate from living organisms, providing a very promising approach. Among them, immune cells receive increasing attention because of their inherent ability in tumor resistance, pathogen elimination, and other significant physiological functions. Herein, we investigated the recent advances on immune cell-based high efficient delivery and therapeutic strategies in solid tumor treatment, mainly focus on T cells, NK cells and macrophages, which have been used as drug cargos directly or provided membrane/exosomes as nanoscale drug delivery systems. We also discuss the further potential applications and perspective of this innovative strategy, as well as the predictable challenges in forward exploration in this emerging area.