Bioengineered Macrophages Can Responsively Transform into Nanovesicles To Target Lung Metastasis

Nanoarchitecting intelligently encapsulated designs for improved cancer therapy

Despite the success in exploring various aspects of origination and therapeutic strategies, cancer has remained one of the most dreadful metabolic disorders due to failure to eradicate tumors comprehensively and frequent recurrence because of acquired resistance to the drugs. Recently, several advancements have been evidenced in the fabrication of various smart nanocarriers encapsulated with multiple components. Several reasons for smart nanoencapsulation include the enhancement of the bioavailability of drugs, precise targetability to reduce adverse effects on normal cells, and the ability to enable controlled drug release rates at the tumor sites. In addition, these smart nanocarriers protect encapsulated therapeutic cargo from deactivation, responsively delivering it based on the physiological or pathological characteristics of tumors. In this review, we present various smart approaches for cancer therapy, including organic materials, inorganic components, and their composites, as well as biomembrane-based nanoencapsulation strategies. These nanoencapsulation strategies, along with practical applications and their potential in cancer treatment, are discussed in depth, highlighting advantages and disadvantages, as well as aiming to reveal the ultimate prospects of nanoencapsulation in enhancing drug delivery efficiency and targeted cancer therapy.

Construction and application of macrophage-based extracellular drug-loaded delivery systems

Given their unique phagocytic function, inflammatory site tropism, and ability to penetrate deep into the lesion sites, macrophages are considered to have promising application potential in the field of living-cell drug delivery. The methods of drug delivery using macrophages primarily include intracellular phagocytic and extracellular drug loading. Comparatively, extracellular drug loading is potential less cytotoxicity and has minimal effects on the motility and orientation of cells. In this review, we provide an overview of the methods of extracellular drug loading, and examine the effects of the different properties of nanoformulations on extracellular drug-loaded delivery systems. In addition, we assess the prospects and challenges of a self-propelled macrophage-based drug delivery system. We hope this research contributes to optimizing the design of these drug delivery systems.

Associations of Serum Legumain with Severity and Prognosis Among Acute Exacerbation of Chronic Obstructive Pulmonary Disease Patients

Background

A number of studies have demonstrated that legumain is engaged in the pulmonary diseases. Nevertheless, the role of legumain is indistinct in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The aim is to identify the correlation of serum legumain with AECOPD patients through a prospective cohort study.

Methods

All 202 patients with AECOPD were enrolled. Fasting venous blood was collected. Serum legumain was detected by ELISA.

Results

On admission, serum legumain concentration was gradually elevated in line with AECOPD severity scores. Additionally, serum legumain was closely associated with clinical characteristics. Linear regression analysis confirmed the positive relationships of serum legumain with COPD severity scores. Moreover, the poor prognoses were tracked in patients of AECOPD. Serum higher legumain at admission increased the risks of death and acute exacerbation during hospitalization.

Conclusion

Serum legumain at admission was positively correlated with the severity and adverse prognosis in AECOPD patients, indicating that legumain plays a vital role in the initiation and development of AECOPD. As a result, serum legumain can become a biomarker in the disease assessment and prognosis prediction for AECOPD.

PAK2 as a therapeutic target in cancer: Mechanisms, challenges, and future perspectives

P21-activated kinases (PAKs) are crucial regulators within cellular signaling pathways and have been implicated in a range of human diseases, including cancer. Among the PAK family, PAK2 is widely expressed across various tissues and has emerged as a significant driver of cancer progression. However, systematic studies on PAK2 remain limited. This review provides a comprehensive overview of PAK2's role in cancer, focusing on its involvement in processes such as angiogenesis, metastasis, cell survival, metabolism, immune response, and drug resistance. We also explore its function in key cancer signaling pathways and the potential of small-molecule inhibitors targeting PAK2 for therapeutic purposes. Despite promising preclinical data, no PAK2 inhibitors have reached clinical practice, underscoring challenges related to their specificity and therapeutic application. This review highlights the biological significance of PAK2 in cancer and its interactions with critical signaling pathways, offering valuable insights for future research. We also discuss the major obstacles in developing PAK inhibitors and propose strategies to overcome these barriers, paving the way for their clinical translation.

Nanotherapeutics for Macrophage Network Modulation in Tumor Microenvironments: Targets and Tools

Macrophage is an important component in the tumor immune microenvironment, which exerts significant influence on tumor development and metastasis. Due to their dual nature of promoting and suppressing inflammation, macrophages can serve as both targets for tumor immunotherapy and tools for treating malignancies. However, the abundant infiltration of tumor-associated macrophages dominated by an immunosuppressive phenotype maintains a pro-tumor microenvironment, and engineering macrophages using nanotechnology to manipulate the tumor immune microenvironment represent a feasible approach for cancer immunotherapy. Additionally, considering the phagocytic and specifically tumor-targeting capabilities of M1 macrophages, macrophages manipulated through cellular engineering and nanotechnology, as well as macrophage-derived exosomes and macrophage membranes, can also become effective tools for cancer treatment. In conclusion, nanotherapeutics targeting macrophages remains immense potential for the development of macrophage-mediated tumor treatment methods and will further enhance our understanding, diagnosis, and treatment of various malignants.

Cell-drug conjugates

By combining living cells with therapeutics, cell-drug conjugates can potentiate the functions of both components, particularly for applications in drug delivery and therapy. The conjugates can be designed to persist in the bloodstream, undergo chemotaxis, evade surveillance by the immune system, proliferate, or maintain or transform their cellular phenotypes. In this Review, we discuss strategies for the design of cell-drug conjugates with specific functions, the techniques for their preparation, and their applications in the treatment of cancers, autoimmune diseases and other pathologies. We also discuss the translational challenges and opportunities of this class of drug-delivery systems and therapeutics.

Melittin and phospholipase A2: Promising anti-cancer candidates from bee venom

As the research on cancer-related treatment deepens, integrating traditional therapies with emerging interventions reveals new therapeutic possibilities. Melittin and phospholipase A2, the primary anti-cancer components of bee venom, are currently gaining increasing attention. This article reviews the various formulations of melittin in cancer therapy and its potential applications in clinical treatments. The reviewed formulations include melittin analogs, hydrogels, adenoviruses, fusion toxins, fusion peptides/proteins, conjugates, liposomes, and nanoparticles. The article also explored the collaborative therapeutic effects of melittin with natural products, synthetic drugs, radiotherapy, and gene expression regulatory strategies. Phospholipase A2 plays a key role in bee venom anti-cancer strategy due to its unique biological activity. Using an extensive literature review and the latest scientific results, this paper explores the current state and challenges of this field, with the aim to provide new perspectives that guide future research and potential clinical applications. This will further promote the application of bee venom in cancer therapy.

Engineering macrophages and their derivatives: A new hope for antitumor therapy

Macrophages are central to the immune system and are found in nearly all tissues. Recently, the development of therapies based on macrophages has attracted significant interest. These therapies utilize macrophages' key roles in immunity, their ability to navigate biological barriers, and their tendency to accumulate in tumors. This review explores the advancement of macrophage-based treatments. We discuss the bioengineering of macrophages for improved anti-tumor effects, the use of CAR macrophage therapy for targeting cancer cells, and macrophages as vehicles for therapeutic delivery. Additionally, we examine engineered macrophage products, like extracellular vesicles and membrane-coated nanoparticles, for their potential in precise and less toxic tumor therapy. Challenges in moving these therapies from research to clinical practice are also highlighted. The aim is to succinctly summarize the current status, challenges, and future directions of engineered macrophages in cancer therapy.

Site-Specific Cascade-Activatable Fluorogenic Nanomicelles Enable Precision and Accuracy Imaging of Pulmonary Metastatic Tumor

The precise localization of metastatic tumors with subtle growth is crucial for timely intervention and improvement of tumor prognosis but remains a paramount challenging. To date, site-specific activation of fluorogenic probes for single-stimulus-based diagnosis typically targets an occult molecular event in a complex biosystem with limited specificity. Herein, we propose a highly specific site-specific cascade-activated strategy to enhance detection accuracy, aiming to achieve the accurate detection of breast cancer (BC) lung metastasis in a cascade manner. Specifically, cascade-activatable NIR fluorogenic nanomicelles HPNs were constructed using ultra-pH-sensitive (UPS) block copolymers as carriers and nitroreductase (NTR)-activated fluorogenic reporters. HPNs exhibit programmable cascade response characteristics by first instantaneous dissociating under in situ tumor acidity, facilitating deep tumor penetration followed by selective fluorescence activation through NTR-mediated enzymatic reaction resulting in high fluorescence ON/OFF contrast. Notably, this unique feature of HPNs enables high-precision diagnosis of orthotopic BC as well as its lung metastases with a remarkable signal-to-background ratio (SBR). This proposed site-specific cascade activation strategy will offer opportunities for a specific diagnosis with high signal fidelity of various insidious metastatic lesions in situ across different diseases.

Immunomodulatory activities and biomedical applications of melittin and its recent advances

Melittin (MLT), a peptide containing 26 amino acids, is a key constituent of bee venom. It comprises ∼40%-60% of the venom's dry weight and is the main pricing index for bee venom, being the causative factor of pain. The unique properties of MLT extracted from bee venom have made it a very valuable active ingredient in the pharmaceutical industry as this cationic and amphipathic peptide has propitious effects on human health in diverse biological processes. It has the ability to strongly impact the membranes of cells and display hemolytic activity with anticancer characteristics. However, the clinical application of MLT has been limited by its severe hemolytic activity, which poses a challenge for therapeutic use. By employing more efficient mechanisms, such as modifying the MLT sequence, genetic engineering, and nano-delivery systems, it is anticipated that the limitations posed by MLT can be overcome, thereby enabling its wider application in therapeutic contexts. This review has outlined recent advancements in MLT's nano-delivery systems and genetically engineered cells expressing MLT and provided an overview of where the MLTMLT's platforms are and where they will go in the future with the challenges ahead. The focus is on exploring how these approaches can overcome the limitations associated with MLT's hemolytic activity and improve its selectivity and efficacy in targeting cancer cells. These advancements hold promise for the creation of innovative and enhanced therapeutic approaches based on MLT for the treatment of cancer.

Cell membrane-coated biomimetic nanomedicines: productive cancer theranostic tools

As the second-leading cause of human death, cancer has drawn attention in the area of biomedical research and therapy from all around the world. Certainly, the development of nanotechnology has made it possible for nanoparticles (NPs) to be used as a carrier for delivery systems in the treatment of tumors. This is a biomimetic approach established to craft remedial strategies comprising NPs cloaked with membrane obtained from various natural cells like blood cells, bacterial cells, cancer cells, etc. Here we conduct an in-depth exploration of cell membrane-coated NPs (CMNPs) and their extensive array of applications including drug delivery, vaccination, phototherapy, immunotherapy, MRI imaging, PET imaging, multimodal imaging, gene therapy and a combination of photothermal and chemotherapy. This review article provides a thorough summary of the most recent developments in the use of CMNPs for the diagnosis and treatment of cancer. It critically assesses the state of research while recognizing significant accomplishments and innovations. Additionally, it indicates ongoing problems in clinical translation and associated queries that warrant deeper research. By doing so, this study encourages creative thinking for future projects in the field of tumor therapy using CMNPs while also educating academics on the present status of CMNP research.

Drug-Loaded Biomimetic Carriers for Non-Hodgkin's Lymphoma Therapy: Advances and Perspective

Chemotherapy remains the mainstay of treatment for the lymphoma patient population, despite its relatively poor therapeutic results, high toxicity, and low specificity. With the advancement of biotechnology, the significance of drug-loading biomimetic materials in the medical field has become increasingly evident, attracting extensive attention from the scientific community and the pharmaceutical industry. Given that they can cater to the particular requirements of lymphoma patients, drug-loading biomimetic materials have recently become a potent and promising delivery approach for various applications. This review mainly reviews the recent advancements in the treatment of tumors with biological drug carrier-loaded drugs, outlines the mechanisms of lymphoma development and the diverse treatment modalities currently available, and discusses the merits and limitations of biological drug carriers. What is more, the practical application of biocarriers in tumors is explored by providing examples, and the possibility of loading such organisms with antilymphoma drugs for the treatment of lymphoma is conceived.

"Ice and Fire" Supramolecular Cell-Conjugation Drug Delivery Platform for Deep Tumor Ablation and Boosted Antitumor Immunity

Cancer recurrence and metastasis are two major challenges in the current clinical therapy. In this work, a novel diketopyrrolopyrrole-based photothermal reagent (DCN) with unique J-aggregation-induced redshift is synthesized to achieve efficient tumor thermal ablation under safe power (0.33 W cm-2 ). Meanwhile, S-nitroso-N-acetylpenicillamine (SNAP) is co-loaded with near-infrared-absorbing DCN in amphiphilic polymers to realize heat-induced massive release of nitric oxide (NO), which can form oxidant peroxynitrite (ONOO- ) to active matrix metalloproteinases (MMPs), thereby degrading the compact tumor extracellular matrix to improve the ablation depth and infiltration of immune cells. Through a facile supramolecular assembly method, the DCN/SNAP nanoparticles are anchored to liquid-nitrogen-frozen cancer cells, achieving enhanced antitumor immune responses and effective inhibition of distant tumors and pulmonary metastases after only one treatment. The safety and effectiveness of this supramolecular cell-conjugation platform are verified by 2D/3D cellular experiments and bilateral tumor model, confirming the thermal-ablation-gas-permeation-antigen-presentation therapeutic mode has promising anticancer prospects.

Recent advances in melittin-based nanoparticles for antitumor treatment: from mechanisms to targeted delivery strategies

As a naturally occurring cytolytic peptide, melittin (MLT) not only exhibits a potent direct tumor cell-killing effect but also possesses various immunomodulatory functions. MLT shows minimal chances for developing resistance and has been recognized as a promising broad-spectrum antitumor drug because of this unique dual mechanism of action. However, MLT still displays obvious toxic side effects during treatment, such as nonspecific cytolytic activity, hemolytic toxicity, coagulation disorders, and allergic reactions, seriously hampering its broad clinical applications. With thorough research on antitumor mechanisms and the rapid development of nanotechnology, significant effort has been devoted to shielding against toxicity and achieving tumor-directed drug delivery to improve the therapeutic efficacy of MLT. Herein, we mainly summarize the potential antitumor mechanisms of MLT and recent progress in the targeted delivery strategies for tumor therapy, such as passive targeting, active targeting and stimulus-responsive targeting. Additionally, we also highlight the prospects and challenges of realizing the full potential of MLT in the field of tumor therapy. By exploring the antitumor molecular mechanisms and delivery strategies of MLT, this comprehensive review may inspire new ideas for tumor multimechanism synergistic therapy.

Macrophage-Based Microrobots for Anticancer Therapy: Recent Progress and Future Perspectives

Macrophages, which are part of the mononuclear phagocytic system, possess sensory receptors that enable them to target cancer cells. In addition, they are able to engulf large amounts of particles through phagocytosis, suggesting a potential "Trojan horse" drug delivery approach to tumors by facilitating the engulfment of drug-hidden particles by macrophages. Recent research has focused on the development of macrophage-based microrobots for anticancer therapy, showing promising results and potential for clinical applications. In this review, we summarize the recent development of macrophage-based microrobot research for anticancer therapy. First, we discuss the types of macrophage cells used in the development of these microrobots, the common payloads they carry, and various targeting strategies utilized to guide the microrobots to cancer sites, such as biological, chemical, acoustic, and magnetic actuations. Subsequently, we analyze the applications of these microrobots in different cancer treatment modalities, including photothermal therapy, chemotherapy, immunotherapy, and various synergistic combination therapies. Finally, we present future outlooks for the development of macrophage-based microrobots.

Engineered extracellular vesicles-like biomimetic nanoparticles as an emerging platform for targeted cancer therapy

Nanotechnology offers the possibility of revolutionizing cancer theranostics in the new era of precision oncology. Extracellular vesicles (EVs)-like biomimetic nanoparticles (EBPs) have recently emerged as a promising platform for targeted cancer drug delivery. Compared with conventional synthetic vehicles, EBPs have several advantages, such as lower immunogenicity, longer circulation time, and better targeting capability. Studies on EBPs as cancer therapeutics are rapidly progressing from in vitro experiments to in vivo animal models and early-stage clinical trials. Here, we describe engineering strategies to further improve EBPs as effective anticancer drug carriers, including genetic manipulation of original cells, fusion with synthetic nanomaterials, and direct modification of EVs. These engineering approaches can improve the anticancer performance of EBPs, especially in terms of tumor targeting effectiveness, stealth property, drug loading capacity, and integration with other therapeutic modalities. Finally, the current obstacles and future perspectives of engineered EBPs as the next-generation delivery platform for anticancer drugs are discussed.

Tumor-associated macrophages in nanomaterial-based anti-tumor therapy: as target spots or delivery platforms

Targeting tumor-associated macrophages (TAMs) has emerged as a promising approach in cancer therapy. This article provides a comprehensive review of recent advancements in the field of nanomedicines targeting TAMs. According to the crucial role of TAMs in tumor progression, strategies to inhibit macrophage recruitment, suppress TAM survival, and transform TAM phenotypes are discussed as potential therapeutic avenues. To enhance the targeting capacity of nanomedicines, various approaches such as the use of ligands, immunoglobulins, and short peptides are explored. The utilization of live programmed macrophages, macrophage cell membrane-coated nanoparticles and macrophage-derived extracellular vesicles as drug delivery platforms is also highlighted, offering improved biocompatibility and prolonged circulation time. However, challenges remain in achieving precise targeting and controlled drug release. The heterogeneity of TAMs and the variability of surface markers pose hurdles in achieving specific recognition. Furthermore, the safety and clinical applicability of these nanomedicines requires further investigation. In conclusion, nanomedicines targeting TAMs hold great promise in cancer therapy, offering enhanced specificity and reduced side effects. Addressing the existing limitations and expanding our understanding of TAM biology will pave the way for the successful translation of these nano-therapies into clinical practice.

Multifunctional nanostructures: Intelligent design to overcome biological barriers

Over the past three decades, nanoscience has offered a unique solution for reducing the systemic toxicity of chemotherapy drugs and for increasing drug therapeutic efficiency. However, the poor accumulation and pharmacokinetics of nanoparticles are some of the key reasons for their slow translation into the clinic. The is intimately linked to the non-biological nature of nanoparticles and the aberrant features of solid cancer, which together significantly compromise nanoparticle delivery. New findings on the unique properties of tumors and their interactions with nanoparticles and the human body suggest that, contrary to what was long-believed, tumor features may be more mirage than miracle, as the enhanced permeability and retention based efficacy is estimated to be as low as 1%. In this review, we highlight the current barriers and available solutions to pave the way for approved nanoformulations. Furthermore, we aim to discuss the main solutions to solve inefficient drug delivery with the use of nanobioengineering of nanocarriers and the tumor environment. Finally, we will discuss the suggested strategies to overcome two or more biological barriers with one nanocarrier. The variety of design formats, applications and implications of each of these methods will also be evaluated.

Cellular Drug Delivery System for Disease Treatment

The application of variable novel drug delivery system has shown a flowering trend in recent years. Among them, the cell-based drug delivery system (DDS) utilizes the unique physiological function of cells to deliver drugs to the lesion area, which is the most complex and intelligent DDS at present. Compared with the traditional DDS, the cell-based DDS has the potential of prolonged circulation in body. Cellular DDS is expected to be the best carrier to realize multifunctional drug delivery. This paper introduces and analyzes common cellular DDSs such as blood cells, immune cells, stem cells, tumor cells and bacteria as well as relevant research examples in recent years. We hope that this review can provide a reference for future research on cell vectors and promote the innovative development and clinical transformation of cell-based DDS.

Progress in nanoparticle-based regulation of immune cells

Immune cells are indispensable defenders of the human body, clearing exogenous pathogens and toxicities or endogenous malignant and aging cells. Immune cell dysfunction can cause an inability to recognize, react, and remove these hazards, resulting in cancers, inflammatory diseases, autoimmune diseases, and infections. Immune cells regulation has shown great promise in treating disease, and immune agonists are usually used to treat cancers and infections caused by immune suppression. In contrast, immunosuppressants are used to treat inflammatory and autoimmune diseases. However, the key to maintaining health is to restore balance to the immune system, as excessive activation or inhibition of immune cells is a common complication of immunotherapy. Nanoparticles are efficient drug delivery systems widely used to deliver small molecule inhibitors, nucleic acid, and proteins. Using nanoparticles for the targeted delivery of drugs to immune cells provides opportunities to regulate immune cell function. In this review, we summarize the current progress of nanoparticle-based strategies for regulating immune function and discuss the prospects of future nanoparticle design to improve immunotherapy.

Versatile biomimetic nanomedicine for treating cancer and inflammation disease

Nanosized drug delivery systems (NDDSs) have emerged as a powerful tool to optimize drug delivery in complex diseases, including cancer and inflammation. However, the therapeutic effect of NDDSs is still far from satisfactory due to their poor circulation time, low delivery efficiency, and innate toxicity. Fortunately, biomimetic approaches offer new opportunities to develop nanomedicine, which is derived from a variety of native biomolecules including cells, exosomes, bacteria, and so on. Since inheriting the superior biocompatibility and versatile functions of natural materials, biomimetic nanomedicine can mimic biological processes, prolong blood circulation, and lower immunogenicity, serving as a desired platform for precise drug delivery for treating cancer and inflammatory disease. In this review, we outline recent advances in biomimetic NDDSs, which consist of two concepts: biomimetic exterior camouflage and bioidentical molecule construction. We summarize engineering strategies that further functionalized current biomimetic NDDSs. A series of functional biomimetic NDDSs created by our group are introduced. We conclude with an outlook on remaining challenges and possible directions for biomimetic NDDSs. We hope that better technologies can be inspired and invented to advance drug delivery systems for cancer and inflammation therapy.

Spatial-Drug-Laden Protease-Activatable M1 Macrophage System Targets Lung Metastasis and Potentiates Antitumor Immunity

Lung metastasis is a critical cause of cancer mortality and its therapy is largely challenged by the limited drug delivery efficiency and robust immunosuppression in metastatic tumors. Herein, we designed a spatial-drug-laden M1 macrophage system with liposomal R848 inside and fibroblast activation protein protease (FAP)-sensitive phospholipid-DM4 conjugate on the membrane of M1 macrophage (RDM). RDM could preferentially accumulate at the metastatic lesions in lungs and responsively release the therapeutic agents as free drug molecules or drug-loaded nanovesicles. RDM treatment notably enhanced the infiltration of CD3⁺CD8⁺ T cells to lung metastasis and, respectively, caused an 8.54-, 12.87- and 2.85-fold improvement of the granzyme-B-, interferon-γ-, and Ki67-positive subtypes versus negative control. Moreover, RDM treatment produced a 90.99% inhibition of lung metastasis in 4T1 models and significant prolongation of survival in three murine lung metastatic models. Therefore, the drug-laden FAP-sensitive M1 macrophage system represents a feasible strategy to target lung metastasis and boost antitumor immunity for antimetastasis therapy.

Bio-fabricated nanodrugs with chemo-immunotherapy to inhibit glioma proliferation and recurrence

Glioblastoma multiforme (GBM) is the most malignant brain tumor with high mortality. Knowledge of the stemness concept has developed recently, giving rising to a novel hallmark with therapeutic potential that can help in management of GBM recurrence and prognosis. However, limited blood-brain barrier (BBB) penetration, non-discriminatory distribution, and deficiency of diagnosis remain three major obstacles need to be overcome for further facilitating therapeutic effects. Herein, D4F and α-Melittin (a-Mel) are co-assembled to construct bio-fabricated nanoplatforms, which endowed with inherent BBB permeability, precise tumor accumulation, deep penetration, and immune activation. After carrying arsenic trioxide (ATO) and manganese dichloride (MnCl₂), these elaborated nanodrugs, Mel-LNPs/MnAs, gather in tumor foci by natural pathways and respond to microenvironment to synchronously release Mn²⁺ and As³⁺, achieving real-time navigating-diagnosis and tumor cell proliferation inhibition. Through down regulating CD44 and CD133 expression, the GBM stemness was suppressed to overcome its high recurrence, invasion, and chemoresistance. After being combined with temozolomide (TMZ), the survival rate of GBM-bearing mice is significantly enhanced, and the rate of recurrence is powerfully limited. Collectively, this tumor-specific actuating multi-modality nanotheranostics provide a promising candidate for clinical application with high security.

Macrophage Membrane-Coated Nano-Gemcitabine Promotes Lymphocyte Infiltration and Synergizes AntiPD-L1 to Restore the Tumoricidal Function

The limited lymphocyte infiltration and exhaustion of tumoricidal functions in solid tumors remain a formidable obstacle to cancer immunotherapy. Herein, we designed a macrophage membrane-coated nano-gemcitabine system (MNGs) to promote lymphocyte infiltration and then synergized anti-programmed death ligand 1 (antiPD-L1) to reinvigorate the exhausted lymphocytes. MNGs exhibited effective intratumor-permeating and responsive drug-releasing capacity, produced notable elimination of versatile immunosuppressive cells, and promoted lymphocyte infiltration into cancer cell regions in tumors, but over 50% of these infiltrated lymphocytes were in the exhausted state. Compared with MNG monotherapy, the MNGs+antiPD-L1 combination produced 31.77% and 30.63% reduction of exhausted CD3⁺CD8⁺ T cells and natural killer (NK) cells and 2.83- and 3.17-fold increases of interferon-γ (IFN-γ)-positive subtypes, respectively, thereby resulting in considerable therapeutic benefits in several tumor models. Thus, MNGs provide an encouraging strategy to promote lymphocyte infiltration and synergize antiPD-L1 to restore their tumoricidal function for cancer immunotherapy.

Bioinspired nanovehicle of furoxans-oxaliplatin improves tumoral distribution for chemo-radiotherapy

The spatiotemporal distribution of therapeutic agents in tumors remains an essential challenge of radiation-mediated therapy. Herein, we rationally designed a macrophage microvesicle-inspired nanovehicle of nitric oxide donor-oxaliplatin (FO) conjugate (M-PFO), aiming to promote intratumor permeation and distribution profiles for chemo-radiotherapy. FO was responsively released from M-PFO in intracellular acidic environments, and then be activated by glutathione (GSH) into active oxaliplatin and NO molecules in a programmed manner. M-PFO exhibited notable accumulation, permeation and cancer cell accessibility in tumor tissues. Upon radiation, the reactive peroxynitrite species (ONOO^-) were largely produced, which could diffuse into regions over 400 μm away from the tumor vessels and be detectable after 24 h of radiation, thereby exhibiting superior efficacy in improving the spatiotemporal distribution in tumors versus common reactive oxygen species (ROS). Moreover, M-PFO mediated chemo-radiotherapy caused notable inhibition of tumor growth, with an 89.45% inhibition in HT-29 tumor models and a 92.69% suppression in CT-26 tumor models. Therefore, this bioinspired design provides an encouraging platform to improve intratumor spatiotemporal distribution to synergize chemo-radiotherapy.

Nanozyme-laden intelligent macrophage EXPRESS amplifying cancer photothermal-starvation therapy by responsive stimulation

Precise delivery and responsive activation of therapeutic agents are critical for tumor precise therapy. Herein, inspired by intelligent express, a nanozyme-laden intelligent macrophage express was fabricated based on IR 820-macrophage loaded with GOx nanozymes for tumor-targeted photothermal-amplified starvation therapy with fluorescence imaging guidance. The nanozyme-laden intelligent macrophage express exerted precise delivery through cargo loading, conveying and unloading. For efficient cargo loading, H₂O₂-sensitive GOx nanozymes with blocked enzymatic activity were packaged on macrophage expresses with excellent phagocytic ability. Due to the inherent tumor tropism, the therapeutic agents-laden macrophage expresses naturally accumulated at tumor site with fluorescence navigation to track the conveying process. The spatiotemporal unpacking of the laden therapeutic agents at tumor site was triggered by the external laser for the macrophage express photothermal property. The released special tumor-microenvironment responsive GOx nanozymes were activated by H₂O₂ in tumor to start starvation therapy. Photothermal therapy generated mild hyperthermia and starvation therapy produced H₂O₂ further increased the nanozymes enzymatic activity, enhancing GOx-mediated starvation therapy. The nanozyme-laden intelligent macrophage express integrated laser-induce drug release and activation, tumor microenvironment-responsiveness, and circular amplification property, achieving the synergistic effects of PTT and starvation therapy in vitro and in vivo.

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.

Penetrating Macrophage-Based Nanoformulation for Periodontitis Treatment

Periodontitis is a chronic inflammatory disease caused by the interaction of oral microorganisms with the host immune response. Porphyromonas gingivalis (P.g.) acts as a key mediator in subverting the homeostasis of the local immune system. On the one hand, P.g. inhibits phagocytosis and the killing capacity of immune cells. On the other hand, P.g. increases selective cytokine release, which is beneficial to its further proliferation. Here, we prepared a penetrating macrophage-based nanoformulation (MZ@PNM)-encapsulating hydrogel (MZ@PNM@GCP) that responded to the periodontitis microenvironment. MZ@PNM targeted P.g. via the Toll-like receptor complex 2/1 (TLR2/1) on its macrophage-mimicking membrane, then directly killed P.g. through disruption of bacterial structural integrity by the cationic nanoparticles and intracellular release of an antibacterial drug, metronidazole (MZ). Meanwhile, MZ@PNM interrupted the specific binding of P.g. to immune cells and neutralized complement component 5a (C5a), preventing P.g. subversion of periodontal host immune response. Overall, MZ@PNM@GCP showed potent efficacy in periodontitis treatment, restoring local immune function and killing pathogenic bacteria, while exhibiting favorable biocompatibility, all of which have been demonstrated both in vivo and in vitro.

Enhancing Doxorubicin Delivery in Solid Tumor by Superhydrophobic Amorphous Calcium Carbonate-Doxorubicin Silica Nanoparticles with Focused Ultrasound

The current approach of delivering chemotherapy via pH-sensitive amorphous calcium carbonate-doxorubicin silica nanoparticles (ADS NPs) faces the challenge of insufficient drug dose due to drug instability within the bloodstream and poor tumor penetration. To overcome these long-standing obstacles, we proposed a superhydrophobic coating on the surface of the ADS NPs that could be easily modified via fluorination (ADSF NPs). The surface of fluorinated ADS NPs was further modified with a phospholipid layer to reduce aggregation and improve biocompatibility (ADSFL NPs). The contact angle and mean size of ADSFL NPs were 30.2 ± 4.4° and 353.1 ± 54.2 nm, respectively. The superhydrophobic layer generated interfacial nanobubbles on the outer shell of the NPs that reduced water-induced leakage of doxorubicin (DOX) sevenfold compared with the uncoated group and induced a cavitation effect upon ultrasound (US) sonication. Moreover, release of DOX from the ADSFL NPs could be triggered by US, and this release was further improved 1.6-fold in acidic aqueous conditions, indicating that the ADSFL NPs retained pH responsiveness. Enhanced sonography contrast and histological examination demonstrated that US could trigger cavitation activities from ADSFL NPs in vivo to induce vessel disruption and enhance the fluorescence intensity of DOX within the tumor region threefold under US imaging guidance compared with the ADSFL NPs-only group.

Scale-out production of extracellular vesicles derived from natural killer cells via mechanical stimulation in a seesaw-motion bioreactor for cancer therapy

Extracellular vesicles (EVs) derived from immune cells have shown great anti-cancer therapeutic potential. However, inefficiency in EV generation has considerably impeded the development of EV-based basic research and clinical translation. Here, we developed a seesaw-motion bioreactor (SMB) system by leveraging mechanical stimuli such as shear stress and turbulence for generating EVs with high quality and quantity from natural killer (NK) cells. Compared to EV production in traditional static culture (229 ± 74 particles per cell per day), SMB produced NK-92MI-derived EVs at a higher rate of 438 ± 50 particles per cell per day and yielded a total number of 2 × 1011 EVs over two weeks via continuous dynamic fluidic culture. In addition, the EVs generated from NK-92MI cells in SMB shared a similar morphology, size distribution, and protein profile to EVs generated from traditional static culture. Most importantly, the NK-92MI-derived EVs in SMB were functionally active in killing melanoma and liver cancer cells in both 2D and 3D culture conditions in vitro, as well as in suppressing melanoma growth in vivo. We believe that SMB is an attractive approach to producing EVs with high quality and quantity; it can additionally enhance EV production from NK92-MI cells and promote both the basic and translational research of EVs.

Cyclodextrin-mediated conjugation of macrophage and liposomes for treatment of atherosclerosis

Current pharmacological treatments of atherosclerosis often target either cholesterol management or inflammation management, to inhibit atherosclerotic progression, but cannot lead to direct plaque lysis and atherosclerotic regression, partly due to the poor accumulation of medicine in the atherosclerotic plaques. Due to enhanced macrophage recruitment during atheromatous plaque progression, a facilely macrophage-liposome conjugate was constructed for targeted anti-atherosclerosis therapy via synergistic plaque lysis and inflammation alleviation. Endogenous macrophage is utilized as drug-transporting cell, upon membrane-modification with β-cyclodextrin (β-CD) derivative to form β-CD decorated macrophage (CD-MP). Adamantane (ADA) modified quercetin (QT)-loaded liposome (QT-NP), can be conjugated to CD-MP via host-guest interactions between β-CD and ADA to construct macrophage-liposome conjugate (MP-QT-NP). Thus, macrophage carries liposome "hand-in-hand" to significantly increase the accumulation of anchored QT-NP in the aorta plaque in response to the plaque inflammation. In addition to anti-inflammation effects of QT, MP-QT-NP efficiently regresses atherosclerotic plaques from both murine aorta and human carotid arteries via CD-MP mediated cholesterol efflux, due to the binding of cholesterol by excess membrane β-CD. Transcriptome analysis of atherosclerotic murine aorta and human carotid tissues reveal that MP-QT-NP may activate NRF2 pathway to inhibit plaque inflammation, and simultaneously upregulate liver X receptor to promote cholesterol efflux.

Harnessing anti-tumor and tumor-tropism functions of macrophages via nanotechnology for tumor immunotherapy

Reprogramming the immunosuppressive tumor microenvironment by modulating macrophages holds great promise in tumor immunotherapy. As a class of professional phagocytes and antigen-presenting cells in the innate immune system, macrophages can not only directly engulf and clear tumor cells, but also play roles in presenting tumor-specific antigen to initiate adaptive immunity. However, the tumor-associated macrophages (TAMs) usually display tumor-supportive M2 phenotype rather than anti-tumor M1 phenotype. They can support tumor cells to escape immunological surveillance, aggravate tumor progression, and impede tumor-specific T cell immunity. Although many TAMs-modulating agents have shown great success in therapy of multiple tumors, they face enormous challenges including poor tumor accumulation and off-target side effects. An alternative solution is the use of advanced nanostructures, which not only can deliver TAMs-modulating agents to augment therapeutic efficacy, but also can directly serve as modulators of TAMs. Another important strategy is the exploitation of macrophages and macrophage-derived components as tumor-targeting delivery vehicles. Herein, we summarize the recent advances in targeting and engineering macrophages for tumor immunotherapy, including (1) direct and indirect effects of macrophages on the augmentation of immunotherapy and (2) strategies for engineering macrophage-based drug carriers. The existing perspectives and challenges of macrophage-based tumor immunotherapies are also highlighted.

Drug Nanocrystals for Active Tumor-Targeted Drug Delivery

Drug nanocrystals, which are comprised of active pharmaceutical ingredients and only a small amount of essential stabilizers, have the ability to improve the solubility, dissolution and bioavailability of poorly water-soluble drugs; in turn, drug nanocrystal technology can be utilized to develop novel formulations of chemotherapeutic drugs. Compared with passive targeting strategy, active tumor-targeted drug delivery, typically enabled by specific targeting ligands or molecules modified onto the surface of nanomedicines, circumvents the weak and heterogeneous enhanced permeability and retention (EPR) effect in human tumors and overcomes the disadvantages of nonspecific drug distribution, high administration dosage and undesired side effects, thereby contributing to improving the efficacy and safety of conventional nanomedicines for chemotherapy. Continuous efforts have been made in the development of active tumor-targeted drug nanocrystals delivery systems in recent years, most of which are encouraging and also enlightening for further investigation and clinical translation.

Leveraging macrophages for cancer theranostics

As fundamental immune cells in innate and adaptive immunity, macrophages engage in a double-edged relationship with cancer. Dissecting the character of macrophages in cancer development facilitates the emergence of macrophages-based new strategies that encompass macrophages as theranostic targets/tools of interest for treating cancer. Herein, we provide a concise overview of the mixed roles of macrophages in cancer pathogenesis and invasion as a foundation for the review discussions. We survey the latest progress on macrophage-based cancer theranostic strategies, emphasizing two major strategies, including targeting the endogenous tumor-associated macrophages (TAMs) and engineering the adoptive macrophages to reverse the immunosuppressive environment and augment the cancer theranostic efficacy. We also discuss and provide insights on the major challenges along with exciting opportunities for the future of macrophage-based cancer theranostic approaches.

Research Progress and Prospects for Polymeric Nanovesicles in Anticancer Drug Delivery

Polymeric vesicles served as the most promising candidates of drug delivery nanocarriers are attracting increasing attention in cancer therapy. Significant advantages have been reported, including hydrophilic molecules with high loading capacity, controllable drug release, rapid and smart responses to stimuli and versatile functionalities. In this study, we have made a systematic review of all aspects of nano-vesicles as drug delivery vectors for cancer treatment, mainly including the following aspect: characteristics of polymeric nanovesicles, polymeric nanovesicle synthesis, and recent progress in applying polymeric nanovesicles in antitumor drug delivery. Polymer nanovesicles have the advantages of synergistic photothermal and imaging in improving the anticancer effect. Therefore, we believe that drug carrier of polymer nanovesicles is a key direction for cancer treatment.

Engineering Macrophages via Nanotechnology and Genetic Manipulation for Cancer Therapy

Macrophages play critical roles in tumor progression. In the tumor microenvironment, macrophages display highly diverse phenotypes and may perform antitumorigenic or protumorigenic functions in a context-dependent manner. Recent studies have shown that macrophages can be engineered to transport drug nanoparticles (NPs) to tumor sites in a targeted manner, thereby exerting significant anticancer effects. In addition, macrophages engineered to express chimeric antigen receptors (CARs) were shown to actively migrate to tumor sites and eliminate tumor cells through phagocytosis. Importantly, after reaching tumor sites, these engineered macrophages can significantly change the otherwise immune-suppressive tumor microenvironment and thereby enhance T cell-mediated anticancer immune responses. In this review, we first introduce the multifaceted activities of macrophages and the principles of nanotechnology in cancer therapy and then elaborate on macrophage engineering via nanotechnology or genetic approaches and discuss the effects, mechanisms, and limitations of such engineered macrophages, with a focus on using live macrophages as carriers to actively deliver NP drugs to tumor sites. Several new directions in macrophage engineering are reviewed, such as transporting NP drugs through macrophage cell membranes or extracellular vesicles, reprogramming tumor-associated macrophages (TAMs) by nanotechnology, and engineering macrophages with CARs. Finally, we discuss the possibility of combining engineered macrophages and other treatments to improve outcomes in cancer therapy.

Recent progress of macrophage vesicle-based drug delivery systems

Nanoparticle drug delivery systems (NDDSs) are promising platforms for efficient delivery of drugs. In the past decades, many nanomedicines have received clinical approval and completed translation. With the rapid advance of nanobiotechnology, natural vectors are emerging as novel strategies to carry and delivery nanoparticles and drugs for biomedical applications. Among diverse types of cells, macrophage is of great interest for their essential roles in inflammatory and immune responses. Macrophage-derived vesicles (MVs), including exosomes, microvesicles, and those from reconstructed membranes, may inherit the chemotactic migration ability and high biocompatibility. The unique properties of MVs make them competing candidates as novel drug delivery systems for precision nanomedicine. In this review, the advantages and disadvantages of existing NDDSs and MV-based drug delivery systems (MVDDSs) were compared. Then, we summarized the potential applications of MVDDSs and discuss future perspectives. The development of MVDDS may provide avenues for the treatment of diseases involving an inflammatory process.

Nano drug delivery systems improve metastatic breast cancer therapy

Despite continual progress in the technologies and regimens for cancer therapy, the treatment outcome of fatal metastatic breast cancer is far from satisfactory. Encouragingly, nanotechnology has emerged as a valuable tool to optimize drug delivery process in cancer therapy via preventing the cargos from degradation, improving the tumor-targeting efficiency, enhancing therapeutic agents' retention in specific sites, and controlling drug release. In the last decade, several mechanisms of suppressing tumor metastasis by functional nano drug delivery systems (NDDSs) have been revealed and a guidance for the rational design of anti-metastasis NDDSs is summarized, which consist of three aspects: optimization of physiochemical properties, tumor microenvironment remodeling, and biomimetic strategies. A series of medicinal functional biomaterials and anti-metastatic breast cancer NDDSs constructed by our team are introduced in this review. It is hoped that better anti-metastasis strategies can be inspired and applied in clinic.

Cellular transformers for targeted therapy

Employing natural cells as drug carriers has been a hotspot in recent years, attributing to their biocompatibility and inherent dynamic properties. In the earlier stage, cells were mainly used as vehicles by virtue of their lipid-delimited compartmentalized structures and native membrane proteins. The scope emphasis was 'what cell displays' instead of 'how cell changes'. More recently, the dynamic behaviours, such as changes in surface protein patterns, morphologies, polarities and in-situ generation of therapeutics, of natural cells have drawn more attention for developing advanced drug delivery systems by fully taking advantage of these processes. In this review, we revolve around the dynamic cellular transformation behaviours which facilitate targeted therapy. Cellular deformation in geometry shape, spitting smaller vesicles, activation of antigen present cells, polarization between distinct phenotypes, local production of therapeutics, and hybridization with synthetic materials are involved. Other than focusing on the traditional delivery of concrete cargoes, more functional 'handles' that are derived from the cells themselves are introduced, such as information exchange, cellular communication and interactions between cell and extracellular environment.

M2 macrophage microvesicle-inspired nanovehicles improve accessibility to cancer cells and cancer stem cells in tumors

Cancer cells and cancer stem cells (CSCs) are the major players of cancer malignancy and metastasis, but they are extremely difficult to access. Inspired by the vital role of macrophages and microvesicle-mediated cell–cell communication in tumors, we herein designed M2 macrophage microvesicle-inspired nanovehicle of cabazitaxel (M-CFN) to promote accessibility to cancer cells and CSCs in tumors. In the 4T1 tumor model, M-CFN flexibly permeated the tumor mass, accessed cancer cells and CD90-positive cells, and significantly promoted their entry into CSC fractions in tumors. Moreover, M-CFN treatment profoundly eliminated aldehyde dehydrogenase (ALDH)-expressing CSCs in 4T1 and MCF-7 tumors, produced notable depression of tumor growth and caused 93.86% suppression of lung metastasis in 4T1 models. Therefore, the M2 macrophage microvesicle-inspired nanovehicle provides an encouraging strategy to penetrate the tumor tissues and access these insult cells in tumors for effective cancer therapy.

Nano-engineered immune cells as "guided missiles" for cancer therapy

Immune cells can actively regulate tumors or inflammatory sites and have good biocompatibility and safety. Currently, they are one of the most promising candidates for drug delivery systems. Moreover, immune cells can significantly extend the circulation time of nanoparticles and have broad-spectrum tumor-targeting properties. This article first introduces the immune cell types most commonly used in recent years, analyzes their advantages and disadvantages, and elucidates their application in anti-tumor therapy. Next, the various ways of loading nanoparticles on immune cells that have been used in recent years are summarized and simply divided into two categories: backpacks and Trojan horses. Finally, the two "mountains" that stand in front of us when using immune cells as cell carriers, off-target problems and effective release strategies, are discussed.

Advances of nanomedicines in breast cancer metastasis treatment targeting different metastatic stages

Breast cancer is the most common tumor in women, and the metastasis further increases the malignancy with extremely high mortality. However, there is almost no effective method in the clinic to completely inhibit breast cancer metastasis due to the dynamic multistep process with complex pathways and scattered occurring site. Nowadays, nanomedicines have been evidenced with great potential in treating cancer metastasis. In this review, we summarize the latest research advances of nanomedicines in anti-metastasis treatment. Strategies are categorized according to the metastasis dynamics, including primary tumor, circulating tumor cells, pre-metastatic niches and secondary tumor. In each different stage of metastasis process, nanomedicines are designed specifically with different functions. At the end of the review, we give our perspectives on current limitations and future directions in anti-metastasis therapy. We expect the review provides comprehensive understandings of anti-metastasis therapy for breast cancer, and boosts the clinical translation in the future to improve women's health.

Nanoparticulation of Prodrug into Medicines for Cancer Therapy

This article provides a broad spectrum about the nanoprodrug fabrication advances co-driven by prodrug and nanotechnology development to potentiate cancer treatment. The nanoprodrug inherits the features of both prodrug concept and nanomedicine know-how, attempts to solve underexploited challenge in cancer treatment cooperatively. Prodrugs can release bioactive drugs on-demand at specific sites to reduce systemic toxicity, this is done by using the special properties of the tumor microenvironment, such as pH value, glutathione concentration, and specific overexpressed enzymes; or by using exogenous stimulation, such as light, heat, and ultrasound. The nanotechnology, manipulating the matter within nanoscale, has high relevance to certain biological conditions, and has been widely utilized in cancer therapy. Together, the marriage of prodrug strategy which shield the side effects of parent drug and nanotechnology with pinpoint delivery capability has conceived highly camouflaged Trojan horse to maneuver cancerous threats.

Protease-triggered bioresponsive drug delivery for the targeted theranostics of malignancy

Proteases have a fundamental role in maintaining physiological homeostasis, but their dysregulation results in severe activity imbalance and pathological conditions, including cancer onset, progression, invasion, and metastasis. This striking importance plus superior biological recognition and catalytic performance of proteases, combining with the excellent physicochemical characteristics of nanomaterials, results in enzyme-activated nano-drug delivery systems (nanoDDS) that perform theranostic functions in highly specific response to the tumor phenotype stimulus. In the tutorial review, the key advances of protease-responsive nanoDDS in the specific diagnosis and targeted treatment for malignancies are emphatically classified according to the effector biomolecule types, on the premise of summarizing the structure and function of each protease. Subsequently, the incomplete matching and recognition between enzyme and substrate, structural design complexity, volume production, and toxicological issues related to the nanocomposites are highlighted to clarify the direction of efforts in nanotheranostics. This will facilitate the promotion of nanotechnology in the management of malignant tumors.

Systemic metastasis-targeted nanotherapeutic reinforces tumor surgical resection and chemotherapy

Failure of conventional clinical therapies such as tumor resection and chemotherapy are mainly due to the ineffective control of tumor metastasis. Metastasis consists of three steps: (i) tumor cells extravasate from the primary sites into the circulation system via epithelial-mesenchymal transition (EMT), (ii) the circulating tumor cells (CTCs) form “micro-thrombi” with platelets to evade the immune surveillance in circulation, and (iii) the CTCs colonize in the pre-metastatic niche. Here, we design a systemic metastasis-targeted nanotherapeutic (H@CaPP) composed of an anti-inflammatory agent, piceatannol, and an anti-thrombotic agent, low molecular weight heparin, to hinder the multiple steps of tumor metastasis. H@CaPP is found efficiently impeded EMT, inhibited the formation of “micro-thrombi”, and prevented the development of pre-metastatic niche. When combined with surgical resection or chemotherapy, H@CaPP efficiently inhibits tumor metastasis and prolonged overall survival of tumor-bearing mice. Collectively, we provide a simple and effective systemic metastasis-targeted nanotherapeutic for combating tumor metastasis.

Failure of conventional clinical therapies such as tumor resection and chemotherapy are mainly due to the ineffective control of tumor metastasis. Here, the authors show that a systemic metastasis-targeted nanotherapeutic may offer a powerful adjunct therapy for suppressing tumor metastasis.

Delivery Strategies for Melittin-Based Cancer Therapy

Melittin (MLT) has been studied preclinically as an anticancer agent based on its broad lytic effects in multiple tumor types. However, unsatisfactory tissue distribution, hemolysis, rapid metabolism, and limited specificity are critical obstacles that limit the translation of MLT. Emerging drug delivery strategies hold promise for targeting, controlled drug release, reduced side effects, and ultimately improved treatment efficiency. In this review, we discuss recent advances in the use of diverse carriers to deliver MLT, with an emphasis on the design and mechanisms of action. We further outline the opportunities for MLT-based cancer immunotherapy.