Yaxuan Liang

Extracellular vesicles (EVs) are important mediators of intercellular communication and promising sources of diagnostic and therapeutic biomarkers, yet effective EV isolation remains challenging due to trade-offs among yield, purity, and adaptability across biofluids. Here, we introduce divalent aptamer-mediated clustering (DAC), a streamlined affinity-based EV isolation strategy that induces controllable vesicle clustering and enables recovery by standard filtration. By exploiting multivalent aptamer binding to EV surface markers, DAC converts nanoscale vesicles into micron-scale clusters while preserving EV integrity and biological activity. We demonstrate robust EV isolation from plasma, urine, and cell culture media, and benchmark DAC against ultracentrifugation, density gradient ultracentrifugation, and size-exclusion chromatography. DAC achieves comparable or improved EV yield and purity with reduced processing time, cost, and operational complexity. Proteomic and metabolomic analyses show that DAC isolates affinity-defined EV subpopulations with cargo profiles distinct from those obtained using conventional methods. Moreover, DAC is readily adapted to alternative EV targets, exemplified by enrichment of EpCAM-positive EVs. Together, DAC provides a versatile and accessible platform for studying EV heterogeneity, function, and molecular composition.

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) hold great promise for therapeutic applications and regenerative medicine. EVs are nanoscale vesicles secreted by all known cell types, carrying diverse cargos including membrane-anchored proteins, soluble factors, multiple RNA species, and metabolites that regulate the physiology and behavior of recipient cells. While MSC-derived or engineered EVs can deliver therapeutic proteins and RNAs, EV-mediated DNA delivery remains challenging due to the lack of efficient mechanisms for sorting DNA sequences into vesicles. Previous work from our group and others demonstrated that adeno-associated virus (AAV)-containing EVs enable targeted nuclear delivery and sustained gene expression in vitro and in vivo. However, their production and isolation have been limited by low yield and time-intensive procedures. Here, we report the development of MSC membrane-enveloped nanovesicles generated by a size-defined extrusion method for efficient gene delivery. These vesicles, approximately 200 nm in diameter, mimic the properties of natural EVs while encapsulating recombinant AAV vectors carrying therapeutic gene sequences. Compared with conventional AAVs, the engineered MSC vesicles improved gene delivery efficiency and achieved significantly higher yields with reduced time and cost relative to naturally secreted EV-AAVs. In summary, we present a novel MSC-based membrane nanovesicle platform that combines the advantages of EV-mimicking structures with AAV-mediated gene transfer. This approach enhances delivery efficiency and production scalability, offering a promising strategy to advance gene therapy toward clinical translation.

Mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) hold great promise for therapeutic applications and regenerative medicine. EVs are nanoscale vesicles secreted by all known cell types, carrying diverse cargos including membrane-anchored proteins, soluble factors, multiple RNA species, and metabolites that regulate the physiology and behavior of recipient cells. While MSC-derived or engineered EVs can deliver therapeutic proteins and RNAs, EV-mediated DNA delivery remains challenging due to the lack of efficient mechanisms for sorting DNA sequences into vesicles. Previous work from our group and others demonstrated that adeno-associated virus (AAV)-containing EVs enable targeted nuclear delivery and sustained gene expression in vitro and in vivo. However, their production and isolation have been limited by low yield and time-intensive procedures. Here, we report the development of MSC membrane-enveloped nanovesicles generated by a size-defined extrusion method for efficient gene delivery. These vesicles, approximately 200 nm in diameter, mimic the properties of natural EVs while encapsulating recombinant AAV vectors carrying therapeutic gene sequences. Compared with conventional AAVs, the engineered MSC vesicles improved gene delivery efficiency and achieved significantly higher yields with reduced time and cost relative to naturally secreted EV-AAVs. In summary, we present a novel MSC-based membrane nanovesicle platform that combines the advantages of EV-mimicking structures with AAV-mediated gene transfer. This approach enhances delivery efficiency and production scalability, offering a promising strategy to advance gene therapy toward clinical translation.

This review uniquely highlights breakthroughs in microfluidics-driven extracellular vesicles therapeutics, offering comprehensive insights into a field rarely explored to date.

Adeno-associated virus (AAV)-mediated gene transfer has demonstrated potential in effectively promoting re-epithelialization and angiogenesis. AAV vector has a safety profile; however, the relatively low delivery efficacy in chronic wound with an inflammatory microenvironment and external exposure has limited its prospective clinical translation. Here, we generated AAV-containing EVs (EV-AAVs) from cultured HEK 293T cells and confirmed that the gene transfer efficiency of VEGF-EV-AAV significantly surpassed that of free AAV. Subsequently, a biomimetic gene delivery system VEGF-EV-AAV/MSC-Exo@FHCCgel developing, and synergistically enhances anti-inflammation and transfection efficiency in the combination of human umbilical cord mesenchymal stem cell-derived exosomes (hUC-MSC-Exo). Upon reaching physiological temperature, this hydrogel system transitions to a gel state, maintaining AAV bioactivity and facilitating a sustained release of the encapsulated vesicles. The encapsulation strategy enables the vesicles to rapidly fuse with endothelial cell membranes, ensuring controlled expression of endogenous VEGF. Results revealed that VEGF-EV-AAV/MSC-Exo@FHCCgel alleviates mitochondrial function in endotheliocyte under oxidative stress. Furthermore, it eliminates senescent macrophages by inhabitation of cyclic GMP-AMP (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway to promote efferocytosis. The system increases Treg cells accumulation, leading to a reduction of inflammatory cytokines. Collectively, the biomimetic gene delivery system represents a promising multi-faceted strategy for chronic wound healing.

Cancers are defined by genetic defects, which underlines the prospect of using gene therapy in patient care. During the past decade, CRISPR technology has rapidly evolved into a powerful gene editing tool with high fidelity and precision. However, one of the impediments slowing down the clinical translation of CRISPR-based gene therapy concerns the lack of ideal delivery vectors. Extracellular vesicles (EVs) are nano-sized membrane sacs naturally released from nearly all types of cells. Although EVs are secreted for bio-information conveyance among cells or tissues, they have been recognized as superior vectors for drug or gene delivery. Recently, emerging evidence has spotlighted EVs in CRISPR delivery towards cancer treatment. In this review, we briefly introduce the biology and function of the CRISPR system and follow this with a summary of current delivery methods for CRISPR applications. We emphasize the recent progress in EV-mediated CRISPR editing for various cancer types and target genes. The reported strategies for constructing EV-CRISPR vectors, as well as their limitations, are discussed in detail. The review aims to throw light on the clinical potential of engineered EVs and encourage the expansion of our available toolkit to defeat cancer.

Lung carcinoma is the most common type of cancer and the leading cause of cancer-related death worldwide. Among the numerous therapeutic strategies for the treatment of lung cancer, adeno-associated virus (AAV)-mediated gene transfer has been demonstrated to have the potential to effectively suppress tumor growth or reverse the progression of the disease in a number of preclinical studies. AAV vector has a safety profile; however, the relatively low delivery efficacy to particular subtypes of lung carcinoma has limited its prospective clinical translation. Exosomes are nanosized extracellular vesicles secreted from nearly all known cell types. Exosomes have a membrane-enclosed structure carrying a range of cargo molecules for efficient intercellular transfer of functional entities, thus are considered as a superior vector for drug delivery. In the present study, we developed a novel strategy to produce and purify AAV-containing exosomes (AAVExo) from AAV-packaging HEK 293T cells. The cellular uptake capacity of exosomes assisted and enhanced AAV entry into cells and protected AAV from antibody neutralization, which was a serious challenge for AAV in vivo application. We tested a list of lung cancer cell lines representing non-small-cell lung cancer and small-cell lung cancer and found that AAVExo apparently improved the gene transfer efficiency compared to conventional AAV vector. Our in vitro results were supported in vivo in a lung cancer xenograft rodent model. Additionally, we evaluated the gene delivery efficiency in the presence of neutralizing antibody on lung cancer cells. The results demonstrated that AAVExo-mediated gene transfer was not impacted, while the AAV vectors were significantly blocked by the neutralizing antibody. Taken together, we established an efficient methodology for AAVExo purification, and the purified AAVExo largely enhanced gene delivery to lung cancer cells with remarkable resistance to antibody neutralization.

Extracellular vesicles (EVs) are released by many cell types and distributed within various biofluids. EVs have a lipid membrane‐confined structure that allows for carrying unique molecular information originating from their parent cells. The species and quantity of EV cargo molecules, including nucleic acids, proteins, lipids, and metabolites, may vary largely owing to their parent cell types and the pathophysiologic status. Such heterogeneity in EV populations provides immense challenges to researchers, yet allows for the possibility to prognosticate the pathogenesis of a particular tissue from unique molecular signatures of dispersing EVs within biofluids. However, the inherent nature of EV's small size requires advanced methods for EV purification and evaluation from the complex biofluid. Recently, the interdisciplinary significance of EV research has attracted growing interests, and the EV analytical platforms for their diagnostic prospect have markedly progressed. This review summarizes the recent advances in these EV detection techniques and methods with the intention of translating an EV‐based liquid biopsy into clinical practice. This article aims to present an overview of current EV assessment techniques, with a focus on their progress and limitations, as well as an outlook on the clinical translation of an EV‐based liquid biopsy that may augment current paradigms for the diagnosis, prognosis, and monitoring the response to therapy in a variety of disease settings.