An off-the-shelf small extracellular vesicle nanomedicine for tumor targeting therapy

Cell membrane derived biomimetic nanomedicine for precision delivery of traditional Chinese medicine in cancer therapy

The rapidly developing modern nanotechnology has brought new vitality to the application of traditional Chinese medicine (TCM), improving the pharmacokinetics and bioavailability of unmodified natural drugs. However, synthetic materials inevitably introduce incompatibilities. This has led to focusing on biomimetic drug delivery systems (DDS) based on biologically derived cell membranes. This "top-down" approach to nanomedicine preparation is simple and effective, as the inherited cell membranes and cell surface substances can mimic nature when delivering drugs back into the body, interacting similarly to the source cells at the biological interface. The concept of biologically derived TCM and biomimetic membranes aligns well with nature, the human body, and medicine, thereby enhancing the in vivo compatibility of TCM. This review focused on the recent progress using biomimetic membranes for TCM in cancer therapy, emphasizing the effective integration of biomimetic nanomedicine and TCM in applications such as cancer diagnosis, imaging, precision treatment, and immunotherapy. The review also provided potential suggestions on the challenges and prospects in this field.

Nanobody-based drug delivery systems for cancer therapy

Targeted delivery can elevate the local drug concentration within tumor tissues, while minimizing drug distribution to normal tissues, thus enhancing the effectiveness of anti-tumor medications and reducing adverse effects and systemic toxicities. Nanobodies, the novel molecular pattern of antibodies characterized by their small size, high stability, strong specificity, and low immunogenicity, have been extensively applied in targeted drug delivery for tumor therapy. This review discusses structural disparities and functional advantages of nanobodies compared to other antibody fragments and full-length antibody. It also highlights nanobody applications in targeted tumor therapy, focusing on their use in modifying delivery systems, e.g., liposomes, EVs, micelles, albumin nanoparticles, gold nanoparticles, polymeric nanoparticles, and as nanobody-drug conjugates. This review delves into the methods applied for integrating nanobodies into different drug delivery carriers, in order to provide useful information for researchers developing nanobody-based targeted drug delivery systems.

A novel prostate cancer-specific fluorescent probe based on extracellular vesicles targeting STEAP1 applied in fluorescence guided surgery

Radical prostatectomy with pelvic lymph node dissection is the best treatment for intermediate- to high-risk localized prostate cancer (PCa). However, conventional white light surgery has difficulties in identifying tumor boundary and micrometastases intraoperatively. Fluorescence guided surgery (FGS) can solve the above difficulties, but lacks tumor-specific near-infrared fluorescent (NIRF) probes in PCa. STEAP1 was an ideal target in PCa treatment and imaging. Here, we constructed a PCa specific fluorescent probe based on extracellular vesicles targeting STEAP1 (AS-EVs) loaded with NIRF dye S0456 and evaluated its preclinical profiles. In vitro and in vivo studies both showed S0456@AS-EVs was safe and showed strong targeting ability to PCa in various mice xenograft models. S0456@AS-EVs could clear rapidly from blood (half-time of 4.29 h) and retain in the STEAP1 positive tumor tissues for more than 72 h with the highest tumor background ratio (TBR) of 3:1, which was superior to ICG, free S0456, ICG@Ctrl-EVs and S0456@Ctrl-EVs (p < 0.01). Finally, S0456@AS-EVs was applied in FGS on intramuscular model, and the tumors were resected under white light and fluorescence respectively. Compared with white light surgery, mice undergoing FGS had lower positive margin rate and better postoperative survival (p = 0.0342).

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.

Engineered extracellular vesicles: an emerging nanomedicine therapeutic platform

The intercellular communication role of extracellular vesicles has been widely proved in various organisms. Compelling evidence has illustrated the involvement of these vesicles in both physiological and pathological processes. Various studies indicate that extracellular vesicles surpass conventional synthetic drug carriers, owing to their abundance in organisms, enhanced targeting ability and low immunogenicity. Therefore, extracellular vesicles have been deemed to be potential drug carriers for the treatment of various diseases, and related studies have increased rapidly. Here, we intend to provide a comprehensive and in-depth review of recent advances in the sources, delivery function, extraction and cargo-loading technologies of extracellular vesicles, as well as their clinical potential in constructing emerging nanomedicine therapeutic platforms. In particular, microfluidic-based isolation and drug-loading technologies, as well as the treatment of various diseases, are highlighted. We also make comparisons between extracellular vesicles and other conventional drug carriers and discuss the challenges in developing drug delivery platforms for clinical translation.

Enhancing Gene Delivery to Breast Cancer with Highly Efficient siRNA Loading and pH-Responsive Small Extracellular Vesicles

Small extracellular vesicles (sEVs) are promising nanocarriers for drug delivery to treat a wide range of diseases due to their natural origin and innate homing properties. However, suboptimal therapeutic effects, attributed to ineffective targeting, limited lysosomal escape, and insufficient delivery, remain challenges in effectively delivering therapeutic cargo. Despite advances in sEV-based drug delivery systems, conventional approaches need improvement to address low drug-loading efficiency and to develop surface functionalization techniques for precise targeting of cells of interest, all while preserving the membrane integrity of sEVs. We report an enhanced gene delivery system using multifunctional sEVs for highly efficient siRNA loading and delivery. The integration of chiral graphene quantum dots enhanced the loading capacity while preserving the structural integrity of the sEVs. Additionally, lysosomal escape is facilitated by functionalizing sEVs with pH-responsive peptides, fully harnessing the inherent homing effect of sEVs for targeted and precise delivery. These sEVs achieved a 1.74-fold increase in cytosolic cargo delivery compared to unmodified sEVs, resulting in substantial gene silencing of around 73%. Our approach has significant potential to advance sEV-based gene delivery in order to accelerate clinical progress.

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.

Targeting BRIX1 via Engineered Exosomes Induces Nucleolar Stress to Suppress Cancer Progression

Elevated ribosome biogenesis correlates with the rapid growth and progression of cancer. Targeted blockade of ribosome biogenesis induces nucleolar stress, which preferentially leads to the elimination of malignant cells. In this study, it is reported that the nucleolar protein BRIX1 is a critical regulator for the homeostasis between ribosome biogenesis and p53 activation. BRIX1 facilitated the processing of pre-rRNA by supporting the formation of the PeBoW complex. In addition, BRIX1 prevented p53 activation in response to nucleolar stress by impairing the interactions between MDM2 and the ribosomal proteins, RPL5, and RPL11, thereby triggering the resistance of cancer cells to chemotherapy. Conversely, depletion of BRIX1 induced nucleolar stress, which in turn activated p53 through RPL5 and RPL11, consequently inhibiting the growth of tumors. Moreover, engineered exosomes are developed, which are surface-decorated with iRGD, a tumor-homing peptide, and loaded with siRNAs specific to BRIX1, for the treatment of cancer. iRGD-Exo-siBRIX1 significantly suppressed the growth of colorectal cancer and enhanced the efficacy of 5-FU chemotherapy in vivo. Overall, the study uncovers that BRIX1 functions as an oncoprotein to promote rRNA synthesis and dampen p53 activity, and also implies that targeted inhibition of BRIX1 via engineered exosomes can be a potent approach for cancer therapy.

Ferroptosis and the tumor microenvironment

Ferroptosis is a type of regulated cell death characterized by its non-apoptotic, iron-dependent and oxidative nature. Since its discovery in 2012, extensive research has demonstrated its pivotal roles in tumorigenesis, metastasis and cancer therapy. The tumor microenvironment (TME) is a complex ecosystem comprising cancer cells, non-cancer cells, extracellular matrix, metabolites and cytokines. Recent studies have underscored a new paradigm in which non-cancer cells in the TME, such as immune and stromal cells, also play significant roles in regulating tumor progression and therapeutic resistance typically through complicated crosstalk with cancer cells. Notably, this crosstalk in the TME were partially mediated through ferrotopsis-related mechanisms. This review provides a comprehensive and systematic summary of the current findings concerning the roles of ferroptosis in the TME and how ferroptosis-mediated TME reprogramming impacts cancer therapeutic resistance and progression. Additionally, this review outlines various ferroptosis-related therapeutic strategies aimed at targeting the TME.

Targeted delivery of extracellular vesicles: the mechanisms, techniques and therapeutic applications

Extracellular vesicles (EVs) are cell-derived vesicles with a phospholipid bilayer measuring 50-150 nm in diameter with demonstrated therapeutic potentials. Limitations such as the natural biodistribution (mainly concentrated in the liver and spleen) and short plasma half-life of EVs present significant challenges to their clinical translation. In recent years, growing research indicated that engineered EVs with enhanced targeting to lesion sites have markedly promoted therapeutic efficacy. However, there is a dearth of systematic knowledge on the recent advances in engineering EVs for targeted delivery. Herein, we provide an overview of the targeting mechanisms, engineering techniques, and clinical translations of natural and engineered EVs in therapeutic applications. Enrichment of EVs at lesion sites may be achieved through the recognition of tissue markers, pathological changes, and the circumvention of mononuclear phagocyte system (MPS). Alternatively, external stimuli, including magnetic fields and ultrasound, may also be employed. EV engineering techniques that fulfill targeting functions includes genetic engineering, membrane fusion, chemical modification and physical modification. A comparative statistical analysis was conducted to elucidate the discrepancies between the diverse techniques on size, morphology, stability, targeting and therapeutic efficacy in vitro and in vivo. Additionally, a summary of the registered clinical trials utilizing EVs from 2010 to 2023 has been provided, with a full discussion on the perspectives. This review provides a comprehensive overview of the mechanisms and techniques associated with targeted delivery of EVs in therapeutic applications to advocate further explorations of engineered EVs and accelerate their clinical applications.

The role of microglia in neurological diseases with involvement of extracellular vesicles

As a subset of mononuclear phagocytes in the central nervous system, microglia play a crucial role in immune defense and homeostasis maintenance. Microglia can regulate their states in response to specific signals of health and pathology. Microglia-mediated neuroinflammation is a pathological hallmark of neurodegenerative diseases, neurological damage and neurological tumors, underscoring its key immunoregulatory role in these conditions. Intriguingly, a substantial body of research has indicated that extracellular vesicles can mediate intercellular communication by transporting cargoes from parental cells, a property that is also reflected in microenvironmental signaling networks involving microglia. Based on the microglial characteristics, we briefly outline the biological features of extracellular vesicles and focus on summarizing the integrative role played by microglia in the maintenance of nervous system homeostasis and progression of different neurological diseases. Extracellular vesicles may engage in the homeostasis maintenance and pathological process as a medium of intercellular communication. Here, we aim to provide new insights for further exploration of neurological disease pathogenesis, which may provide theoretical foundations for cell-free therapies.

Neoantigen sequestrated autophagosomes as therapeutic cancer vaccines

Neoantigens serve as ideal personalized cancer vaccines because of their high immunogenicity, ability to evade central thymic tolerance, and minimal risk of eliciting autoimmune responses. Herein, we describe a genetically engineered autophagosome-based neoantigen vaccine (APNV) in combination with an immune checkpoint inhibitor (anti-PD-1 antibody) for cancer immunotherapy. The APNV was derived from engineered NIH 3T3 cells, which co-express melanoma neoantigens and autophagosome maker microtubule-associated proteins 1 A/1B light chain 3B (LC3), from which the LC3-labeled neoantigen-autophagosomes were isolated. These purified autophagosomes, in conjunction with vaccine adjuvants high-mobility group box 1 (HMGB1) and granulocyte-macrophage colony-stimulating factor (GM-CSF), were integrated into a hydrogel to create an APNV. The APNV effectively activated dendritic cells both in vitro and in vivo. Moreover, APNV, in combination with checkpoint blockade therapy, significantly hampered post-surgical tumor recurrence in a subcutaneous melanoma tumor model and effectively impeded metastatic progression in a melanoma lung metastasis model. This APNV may be conducive to making personalized therapeutic neoantigen vaccines for cancer immunotherapy.

Engineered exosomes: a potential therapeutic strategy for septic cardiomyopathy

Septic cardiomyopathy, a life-threatening complication of sepsis, can cause acute heart failure and carry a high mortality risk. Current treatments have limitations. Fortunately, engineered exosomes, created through bioengineering technology, may represent a potential new treatment method. These exosomes can both diagnose and treat septic cardiomyopathy, playing a crucial role in its development and progression. This article examines the strategies for using engineered exosomes to protect cardiac function and treat septic cardiomyopathy. It covers three innovative aspects: exosome surface modification technology, the use of exosomes as a multifunctional drug delivery platform, and plant exosome-like nanoparticle carriers. The article highlights the ability of exosomes to deliver small molecules, proteins, and drugs, summarizing several RNA molecules, proteins, and drugs beneficial for treating septic cardiomyopathy. Although engineered exosomes are a promising biotherapeutic carrier, they face challenges in clinical application, such as understanding the interaction mechanism with host cells, distribution within the body, metabolism, and long-term safety. Further research is essential, but engineered exosomes hold promise as an effective treatment for septic cardiomyopathy.

Recent advances in extracellular vesicles for therapeutic cargo delivery

Exosomes, which are nanosized vesicles secreted by cells, are attracting increasing interest in the field of biomedical research due to their unique properties, including biocompatibility, cargo loading capacity, and deep tissue penetration. They serve as natural signaling agents in intercellular communication, and their inherent ability to carry proteins, lipids, and nucleic acids endows them with remarkable therapeutic potential. Thus, exosomes can be exploited for diverse therapeutic applications, including chemotherapy, gene therapy, and photothermal therapy. Moreover, their capacity for homotypic targeting and self-recognition provides opportunities for personalized medicine. Despite their advantages as novel therapeutic agents, there are several challenges in optimizing cargo loading efficiency and structural stability and in defining exosome origins. Future research should include the development of large-scale, quality-controllable production methods, the refinement of drug loading strategies, and extensive in vivo studies and clinical trials. Despite the unresolved difficulties, the use of exosomes as efficient, stable, and safe therapeutic delivery systems is an interesting area in biomedical research. Therefore, this review describes exosomes and summarizes cutting-edge studies published in high-impact journals that have introduced novel or enhanced therapeutic effects using exosomes as a drug delivery system in the past 2 years. We provide an informative overview of the current state of exosome research, highlighting the unique properties and therapeutic applications of exosomes. We also emphasize challenges and future directions, underscoring the importance of addressing key issues in the field. With this review, we encourage researchers to further develop exosome-based drugs for clinical application, as such drugs may be among the most promising next-generation therapeutics.

Reprogramming tumor-associated macrophages by a dually targeted milk exosome system as a potent monotherapy for cancer

Tumor-associated macrophages (TAMs) play a key role in inducing an immunosuppressive tumor microenvironment (TME) and cancer immune escape. We previously revealed that PDL1 (a key immune checkpoint) was upregulated in TAMs and induced M2 polarization, highlighting PDL1 in TAMs as a promising cancer therapeutic target. In this study, we developed an engineered milk exosome (mExo) system decorated with M2pep (an M2 macrophage binding peptide) and 7D12 (an anti-EGFR nanobody) (7D12-mExo-M2pep-siPDL1) to specifically deliver siPDL1 into M2 TAMs. A series of in vitro and in vivo assays showed that the dually targeted engineered mExos efficiently delivered siPDL1 into M2 TAMs and repolarized them into M1 macrophages, restoring CD8+ T cell immune activity and remodeling TME. Importantly, systemically administered 7D12-mExo-M2pep-siPDL1 showed efficient single-agent antitumor activity, resulting in nearly 90% tumor growth inhibition in a mouse model of orthotopic epidermal growth factor receptor (EGFR) cancer. Collectively, our study indicates that PDL1 is a promising target for TAM-based cancer immunotherapy, and our engineered mExo-based nanomedicine represents a novel tool for specifically targeting M2 TAMs, distinguishing this novel therapeutic method from other TAM-targeting therapies and highlighting its promising clinical potential.

OX40L-expressing M1-like macrophage exosomes for cancer immunotherapy

With only limited clinical patient benefit, focusing on new immune checkpoint pathways could be an important complement to current immune checkpoint drugs. In addition, not only does T cell-mediated adaptive immunity play an important role, but also macrophage-mediated innate immunity, due to its abundant presence in solid tumors. Here, we developed an engineered M1-like macrophage exosome, OX40L M1-exos. OX40L M1-exos can activate the adaptive immunity by activating the OX40/OX40L pathway and can reprogram M2-like tumor-associated macrophages into M1-like macrophages, thereby restoring and enhancing macrophage-mediated innate immunity. Our OX40L M1-exos achieved an effective synergistic effect of innate and adaptive immunity and achieved a potent therapeutic effect in a mouse breast cancer model, effectively inhibiting tumor growth and metastasis. These results suggest that OX40L M1-exos are an attractive therapeutic strategy and may be an important complement to current cancer immunotherapies.