Immune cell-derived EVs retain the parent cells ‘characteristics, exhibit immune properties, regulate immune responses, and can deliver drugs for tumor therapy. For instance, EVs from CD4⁺T cells can inhibit tumor growth through CD8+T cell activation (Shin et al., 2022). EVs from CD8⁺ T cells with PD-1 and TGF-β receptors can block PD-L1 on cancer cells, clear TGF-β from the immunosuppressive environment, and prevent cytotoxic T cell depletion. Granzyme B directly kills tumor cells and shows strong anti-tumor effects in mice with solid tumors (Hong et al., 2021). Exosomes from M1 macrophages can repolarize M2 tumor-associated macrophages to M1, enhancing the release of pro-inflammatory cytokines and anti-tumor immunity (Choo et al., 2018). EVs from natural killer (NK) cells induce tumor cell apoptosis via highly expressed cell death receptors, and can inhibit tumor cell proliferation by reducing phosphorylated extracellular signal-regulated kinase and phosphorylated protein kinase B (Aarsund et al., 2022; Matchett and Kornbluth, 2023).

Modified immune cells EVs can boost the anti-tumor effects. For example, exosomes from HEK293T cells with PH20 hyaluronidase degrade hyaluronic acid, improving Doxorubicin (Dox) penetration and CD8⁺ T cells infiltration, thus enhancing Dox’s anticancer activity (Hong et al., 2018). iRGD-modified dendric cell (DC) exosomes effectively deliver Dox to breast cancer (Tian et al., 2014). Dox-loaded macrophage vesicles modified with biotin and folate-conjugated DSPE-PEG also significantly improve Dox’s anti-tumor efficiency (Zhang et al., 2017). A study created hybrid vesicles by fusing platelet-derived, M1 macrophage-derived, and tumor cell-derived vesicles with high SIRP-α mutant expression. These vesicles could effectively accumulate in the wound site after melanoma surgery, block SIRP-α/CD47 interactions, boost macrophage response to cancer recurrence, enhance anti-tumor T cell immunity, and reduce side effects caused by systemic perfusion (Rao et al., 2020). Therefore, immune cell-derived EVs demonstrate good drug transport abilities and corresponding immune functions. However, the availability of immune cells is limited, and the isolation process is intricate. For instance, CD4⁺ T cells were obtained from blood and stimulated by IL2 (Shin et al., 2022), while NK3.3 cells were immortalized using lentivirus encoding to overcome growth arrest (Matchett and Kornbluth, 2023). Clinical trials involving DC-derived EVs demonstrated only modest therapeutic efficacy due to various complex factors (Cao et al., 2022). Future research can focus on more rational construction of immune cells and combination therapies.

Current research aims to enhance drug targeting to tumor cells using tumor extracellular vesicles (TEVs) or tumor cell membranes as nanocarriers (Jiao et al., 2022; Yong et al., 2019; Liu C. et al., 2019). TEVs resemble tumor cells and can be recognized and absorbed by them, aiding targeted molecule delivery. For instance, breast TEVs were electroporated to release the content and load triphenylphosphine-modified P53, eliminating the toxic side effects and hypersensitivity of undesirable tumor cell components and P53. These vesicles effectively targeted breast cancer cells with improved transmembrane infiltration and cell apoptosis (Jiao et al., 2022). A study explored breast TEVs loaded with miRNA and gold-iron oxide nanoparticles, which enhanced cell adhesion and uptake, allowing targeted tumor accumulation of drugs and contrast agents for cancer treatment and nuclear magnetic imaging (Bose et al., 2018). M2pep, a peptide targeting M2 macrophages, was modified on liver cancer cell membranes coated on PLGA nanoparticles with D-lactic acid. By leveraging the homing ability of tumor cell membranes, these engineered vesicles can deliver D-lactic acid to M2 macrophages, thereby converting them into the M1 phenotype within the tumor microenvironment. This transformation enhances the efficacy of anti-CD47 antibody treatment, resulting in improved long-term survival in mouse models of liver cancer (Han S. et al., 2023). In a separate study, vesicles derived from tumor cell membranes and loaded with methotrexate were administered to 11 patients with advanced lung cancer and malignant pleural effusion. The results demonstrate that these vesicles significantly inhibited the progression of malignant pleural effusion without inducing notable toxicity. The presence of tumor cells and CD163⁺ macrophages in malignant pleural effusion was significantly diminished. Concurrently, both CD8⁺ and CD4⁺ T cells were activated to secrete immune factors. These findings indicate that this system can effectively target malignant tumor cells and modulate the immune microenvironment, presenting a promising strategy for cancer therapy (Guo et al., 2019). However, TEVs play a crucial role in shaping the tumor microenvironment, thereby facilitating tumor progression. The proteins present on TEVs have the potential to induce biological toxicity. These risks warrant significant attention. Therefore, a judicious selection of parental cells and delivery systems is imperative to maximize therapeutic efficacy while minimizing the promotion of cancer (Xu et al., 2022).

Plant nanovesicles (PNVs), secreted by plant cells, are derived from a diverse range of sources. PNVs, characterized by their rich bioactive substances, excellent biocompatibility and stability, high permeability, and low immunogenicity and toxicity, represent an ideal natural green drug delivery platform (Cao et al., 2023). Xiao and colleagues were the first to identify natural exosome-like nanomaterials derived from tea leaves, which are rich in proteins, lipids, and bioactive small molecules. These tea-derived nanomaterials exhibit the capability to specifically target macrophages and enhance the secretion of anti-inflammatory factors by these cells, thereby providing a therapeutic effect against colon cancer with minimal side effects (Zu et al., 2021). Furthermore, this team discovered that fresh tea contains exosome-like nanovesicles abundant in pharmacologically active molecules, including lipids, proteins, catechins, and flavonoids. The nanovesicles were internalized by tumor cells, thereby stimulating the production of intracellular reactive oxygen and inducing cell apoptosis. Whether they were administered intravenously or orally, these vesicles demonstrated efficacy in controlling the proliferation of breast cancer cells (Chen et al., 2023). Furthermore, vesicles derived from grapefruit, ginger, or purple cabbage have been utilized to transport Dox and nucleic acid microRNA (miRNA) for tumor treatment (Zhuang et al., 2016; Zhang et al., 2016; You et al., 2021).

The vesicles derived from Chinese medicine have garnered significant research interest due to their pharmacological effects. Peng et al. were the first to isolate exosome-like nanovesicles from Brucea javanica, a traditional Chinese medicine. Their study found that these nanovesicles were capable of efficiently delivering 10 functional miRNAs to tumor cells, thereby inducing tumor cell apoptosis through the PI3K/Akt/mTOR signaling pathway and ROS/Caspase mechanisms. This process ultimately inhibited the growth, metastasis and angiogenesis of breast cancer (Yan et al., 2024). Cao’s research involved the intraperitoneal injection of nanoparticles derived from Ginseng into animal models, aiming to regulate myeloid differentiation factor 88 (MyD88) and Toll-like receptors-4 (TLR4) mediated signal transduction, and significantly inhibit melanoma growth (Cao et al., 2019). Subsequent research has demonstrated that Ginseng-derived exosome-like nanoparticles potentiate the anti-tumor efficacy of PD-1 monoclonal antibodies by activating tumor-infiltrating T lymphocytes. This mechanism presents a straightforward approach to modulating the cold tumor microenvironment and augmenting PD-1 monoclonal antibody-based immunotherapy (Han et al., 2022). The consensus statement on research and application of Chinese herbal medicine-derived extracellular vesicles (2023 edition) has articulated 13 consensus opinions, offering a valuable reference for the development of Chinese herbal vesicles. This statement underscores the extensive research efforts and significant potential of these vesicles in disease treatment (Zhao et al., 2023). In conclusion, PNVs, characterized by their strong expanded production capacity and minimal immunogenicity, represent a promising platform for tumor therapy. However, for clinical application, precise extraction and purification methodologies must be established. Additionally, the mechanism and clinical efficacy of PNVs warrant thorough investigation. Further clinical trials are imperative to validate their therapeutic potential.

EVs derived from animals are predominantly focus on milk-derived exosomes (MEs). Bovine milk, which is abundant in EVs, readily accessible, and safe for use, represents a significant source of EVs (Ngu et al., 2022). In a study conducted by Chen Ying et al., MEs were employed as delivery vehicles and were further modified with the M2 macrophage-binding peptide M2pep and the anti-EGFR antibody 7D12. This engineered system demonstrated the capability to specifically deliver siPD-L1 to M2 tumor-associated macrophage (TAM), thereby inhibiting PD-L1 expression, restoring CD8+T cell activity, reconfiguring the immunosuppressive tumor microenvironment, and exerting anticancer effects (Chen et al., 2024). MEs encapsulating anthocyanidins were administered orally and showed the ability to target colon cancer, resulting in a reduction in the number of colon tumors in a mouse model (Mudd et al., 2020). In comparison to control groups, paclitaxel-loaded bovine MEs reduced cancer growth by 60% when administered orally to a mouse model. This delivery system addressed the limitations of paclitaxel, including poor solubility, and mitigated hepatic, renal and systemic toxicity (Agrawal et al., 2017). Additionally, MEs were employed to deliver exogenous hsa-miR148a-3p to HepG2 and Caco-2 cancer cells, exerting a biological effect by modulating gene expression (Del Pozo-Acebo et al., 2021). The pharmaceutical industry has acknowledged and licensed the use of MEs for the delivery of RNA therapeutics to brain tumors (Ngu et al., 2022). MEs represent a cost-effective vesicle-based drug delivery platform and serve as a viable alternative to oral drug administration. However, it is important to note that MEs may pose potential health risks due to the presence of miRNAs, which have been associated with conditions such as type 2 diabetes and obesity. Additionally, certain proteins within MEs may act as allergens, thereby raising biosafety concerns (Zhong et al., 2023). Consequently, rigorous purification protocols are essential for the safe application of MEs.

Bacterial extracellular vesicles (BEVs), derived from Gram-positive bacteria or Gram-negative bacteria, have emerged as an emerging platform for tumor treatment. These vesicles encompass a variety of components, such as proteins, lipids, lipoproteins, DNA, and RNA (Xie et al., 2023). Outer membrane vesicles (OMVs) derived from photosynthetic bacteria are enriched with bioactive constituents of the parent cells. OMVs have the ability to polarize macrophages, activate dendritic cells, enhance antigen presentation, and exhibit significant antitumor activity in tumor models (Xiao et al., 2024). Engineered BEVs can be designed for the development of antibacterial and anticancer vaccines. For instance, a manganese peroxide interface was applied to encapsulate vesicles derived from tumor-symbiotic bacteria. Upon uptake by DC cells, the intracellular lysosome degraded the manganese oxide shell. The released bacterial vesicles subsequently activated humoral immunity by promoting the release of immunoglobulin G (IgG) from B cells, thereby effectively inhibiting the proliferation of tumor-symbiotic bacteria. Simultaneously, manganese ions activated the cGAS-STING pathway, facilitating the maturation of DC cells. This process enabled DC cells to present specific antigens to T cells, thereby enhancing the immune response (Zhang et al., 2024). Genetically engineered bacterial protoplast nanovesicles, produced through extrusion, had potential applications in gene delivery for tumor treatment. These vesicles encapsulated gene-edited ribonucleoprotein (RNP) capable of targeting Pik3cg, thereby promoting the polarization of macrophages towards the M1 phenotype. The bacterial DNA within the vesicles could activate macrophage Toll-like receptor 9 (TLR9), sustaining the proinflammatory state of the macrophages. Additionally, vesicles modified with polyethylene glycol (PEG)-galactosamine could specifically target tumor-associated macrophages, facilitating anti-tumor immunization (Zhao et al., 2024). Rich in bacterial antigens, these vesicles also serve as potent vaccine adjutants, enhancing the immune response. For instance, bacteria-derived vesicles containing the STING agonist cyclic GMP-AMP (cGAMP) were conjugated to denucleated melanoma cells via a click chemistry reaction to generate a live tumor cell vaccine. This vaccine effectively activated the STING pathway, promoted the maturation and activation of DC cells, and polarized M1 macrophages, thereby significantly inhibiting melanoma progression. Furthermore, this vaccine had the potential to enhance the tumor immune microenvironment by facilitating the infiltration of immune cells and promoting the proliferation and activation of tumor-specific T cells, thereby substantially improving the therapeutic efficacy of PD-1 antibody treatment (Fang et al., 2024).

The aforementioned findings suggest that BEVs possess potential therapeutic applications in cancer treatment. However, it is important to note that not all BEVs are suitable candidates for tumor therapy. For instance, EVs derived from methicillin-resistant Staphylococcus aureus (MRSA) have been shown to stimulate the production of Th-2-ralated cytokines, resulting in anaphylactic shock in murine models. This indicates that such BEVs can elicit IgE-mediated systemic hypersensitivity reactions (Asano et al., 2021). OEVs secreted by Pseudomonas aeruginosa and Escherichia coli have been shown to non-specifically reduce mitochondrial membrane potential, thereby inducing apoptosis and inflammation through the activation of B cell lymphoma 2 (BCL-2)-associated x protein (BAX) and BCL-2 antagonist killer (BAK) proteins and the downregulation of the pro-survival protein BCL-2 (Deo et al., 2020). The biosecurity implications of BEVs remain inadequately understood and warrant further investigation.

The predominant approach involves the collection of EVs secreted by cells in the culture medium (Figure 2A). Initially, serum is subjected to ultracentrifugation at 100,000 g for several hours to eliminate existing vesicles. Subsequently, cells are cultured in a complete medium supplemented with vesicle-depleted serum. The culture medium is then harvested for the subsequent isolation of released EVs. However, EVs obtained through this method exhibit low yield and purity, along with a biased size distribution (Piffoux et al., 2017; Wang et al., 2022). The release of EVs can be augmented by external stimuli, including biological (starvation, hypoxia, or cytokine activation), chemical (cytochalasin B), and physical triggers (mechanical stress) (Piffoux et al., 2019). For instance, starvation has been shown to induce cell stress and subsequent EVs release. So, EVs can be produced from cells after culturing in serum-free basic medium. This production method is relatively efficient, yielding EVs of small size, high purity, and substantial quantity (Stolk and Seifert, 2015; Debbi et al., 2022). Additionally, a microfluidic device has been developed to apply mechanical stress to cells, thereby enhancing EV release. In this process, cells were suspended in a buffer and extruded at 4°C through fabricated microchannels using a syringe. EVs could then be harvested from the extrusion medium. While this method facilitates rapid EV production within hours, it is also destructive to cells, resulting in a high number of debris and apoptotic bodies (Piffoux et al., 2017). Rui Hao et al. have developed a microfluidic device featuring a series of narrow squeezing ridges. Mesenchymal stem cells traversed the channel rapidly and secreted small EVs in response to mechanical stimulation. This device has the potential to enhance EV secretion by approximately 4-fold (Hao et al., 2023).

The lack of standardized methods for EVs production represents a significant barrier to their broader application. The inherent heterogeneity and complex composition of EVs further contribute to potential safety concerns. EVs produced through artificial synthesis offer high yield and uniform size, devoid of unwanted components, thereby garnering increasing attention (Liu Y. et al., 2019). EVs analogs, constructed using cell-derived plasma membrane fragments, can substantially enhance yield and reduce production time while maintaining a relatively uniform size (Figure 2B). The protein composition of these EV analogs more closely resembles that of the source cell compared to natural EVs. A top-down strategy has been employed to generate EV analogs (Raza et al., 2021). This process involves the initial removal of unwanted components from the cell culture medium or plasma via centrifugation, followed by the mechanical or chemical destruction of cells to isolate the cell membrane and other organelles. Finally, the cell membrane is obtained through differential or gradient centrifugation. The size of the cell membrane is ascertained using porous polycarbonate membranes. Typically, cells are sequentially passed through membrane filters with varying pore sizes. Besides, the cell membrane can be extracted through a series of steps, including hypoosmotic treatment, homogenization, ultrasonic treatment, freeze-thaw cycles, filtration, and polyethylene glycol treatment. Subsequently, EV analogs are prepared, resulting in a 50–100-fold increase in yield and a significant reduction in production cost (Rayamajhi et al., 2019).

The limited targeting ability of EVs, particularly exosomes, constrains their application. Further modifications can enhance the efficacy of these vesicles (Figure 2C). By fusing EVs with synthetic liposomes, hybrid EV analogs can be generated to accommodate a broader range of applications (Du et al., 2022). For example, isolated small cell vesicles were added into the aqueous phase to hydrate the phospholipid membrane. Subsequently, the fused exosomes were prepared through extrusion, which combined the multiple advantages of endogenous cell vesicles with the ease of liposome surface modification (Wen et al., 2022). EVs derived from macrophages and cRGD particles were incubated to produce cRGD-modified EVs. In this context, macrophage-derived EVs inherit the tumor-targeting capabilities of macrophages, while cRGD also contribute to tumor cell targeting, thereby achieving a dual-targeting effect (Huang et al., 2022).

Furthermore, the integration of magnetic materials with EVs can augment their targeting efficacy. Superparamagnetic iron oxide nanoparticles (SPIONs) with magnetic navigation can be loaded into EVs through various techniques, such as electroporation, natural incubation, cell extrusion, or post-modification bonding with ligands (Zhuo et al., 2021). EVs loaded with SPIONs and therapeutic agents such as Dox or tumor necrosis factor-alpha (TNF-α) have demonstrated improved targeting and tumor inhibition when subjected to applied magnetic fields (Qi et al., 2016; Zhuang et al., 2020). Additionally, SPION-loaded exosomes can serve as agents for magnetic hyperthermia therapy (MHT), facilitating tumor cell eradication, and as contrast agents for tumor magnetic resonance imaging (MRI) diagnostics (Altanerova et al., 2017).

In addition to preserving source cell proteins during preparation for targeted delivery via protein-protein interactions, surface modification of EVs with targeting moieties can enhance recognition-mediated targeting. Surface targeting modification can be realized by genetic engineering or chemical modification. For the former, plasmids were engineered to encode homing peptides or ligands fused with transmembrane proteins. Subsequently, donor cells transfected with these plasmids were capable of secreting engineered vesicles that displayed targeted groups on their surfaces (Zhu et al., 2022; Chiang et al., 2023). The fusion of the αγ integrin-specific iRGD with LAMP-2B enabled exosomes to deliver Dox to integrin-positive breast cancer cells (Jia et al., 2018). GE11(YHWYGYTPQNVI) was genetically fused to the transmembrane protein platelet-derived growth factor receptor (PDGFR), resulting in the production of GE11 exosome, which exhibited high affinity for EGFR-overexpressing cancer cells (Ohno et al., 2013). Chemical modification is another way to achieving targeted functionality in vesicles. In this context, proteins present on the vesicle surface serve as anchors for attaching chemical groups and targeted molecules. For instance, an alkyne group was conjugated to a protein on the exosome membrane via an EDC-NHS condensation reaction. Subsequently, an RGE-peptide containing an azido group was linked to the alkyne group through triazole linkages. These glioma-targeted exosomes were capable of crossing the blood-brain barrier and inhibiting glioma progression (Jia et al., 2018). In addition, surface modification can be accomplished by synthesizing amphiphilic molecules with specific targeting groups and incorporating them into vesicles. For example, aminoethyl anisamide (AA) linked DSPE-PEG was conjugated to the exosome membrane, resulting in enhanced paclitaxel (PTX) uptake in lung cancer cells (Kim et al., 2018).

Differential centrifugation is performed under varying centrifugal forces, leveraging the differential densities of EVs in the sample. The samples are derived from a diverse array of sources, including cell supernatant, serum, saliva, urine, and cerebrospinal fluid, among others (Yang et al., 2020). The liquid samples undergo a series of centrifugation steps: initially at 300 g for 10 min to eliminate dead cells, subsequently at 2,000 g for 10 min to remove cell debris, followed by centrifugation at 10,000 g for 30 min to exclude large vesicles, and finally at 120,000 g for 90 min to isolate small EVs (Zhu et al., 2022). Johnstone pioneered the use of ultracentrifugation (UC) for the extraction of exosomes from reticulocyte culture medium (Johnstone, 1992). Currently, this technique is wildly regarded as the “gold standard” for exosome isolation. The dead cells, cell fragments, and large vesicles were initially re-moved via low-speed centrifugation. Subsequently, exosomes were isolated through UC at 100,000 g. This method is well-established and does not require the addition of supplementary separation reagents. However, it has several limitations, including low specificity, poor reproducibility, the aggregation and fragmentation of exosomes, increased contamination with soluble protein impurities, and high costs associated with the use of expensive equipment (Gardiner et al., 2016; Konoshenko et al., 2018).

Density gradient centrifugation isolates exosomes based on differences in particle size and density. Typically, sucrose is employed as the medium to establish a density gradient layer that progressively increases from the upper to the lower strata. When subjected to centrifugal force, exosomes are ultimately distributed within a density range of 1.10–1.18 g/mL. The exosomes obtained through this method are largely devoid of extraneous proteins. However, the equipment required for this process is costly, and prolonged centrifugation can compromise the structural integrity of the exosomes, rendering it un-suitable for processing large sample volumes (Zhu et al., 2020; Onódi et al., 2018).

Filtration separation techniques are predicated on particle size differentiation. For example, ultrafiltration is achieved by obstructing particles larger than 200 nm in diameter from passing through the membrane pores, while allowing smaller vesicles, typically less than 20 nm in diameter, to permeate. This process can be expedited through pressurization or brief periods of low-speed centrifugation. The selection of vesicles of specific sizes is facilitated by the diameter of the membrane pores, often serving as an auxiliary step in ultrafast centrifugation methods. However, the membrane pores are prone to blockage, and exosomes are susceptible to damage during the process (Xiang et al., 2021). The tangential flow filtration (TFF) method alters the flow direction of the liquid from perpendicular to parallel relative to the filter membrane. This adjustment mitigates exosome damage, reduces membrane pore clogging, and extends the service life of the filter membrane. Consequently, TFF is suitable for the industrial preparation of vesicles (McNamara et al., 2018).

Size-exclusion chromatography (SEC) is employed based on differential particle sizes. During SEC, vesicles traverse the separation matrix and are eluted using phosphate-buffered saline (PBS). Larger particles or molecules, unable to penetrate the separation matrix, are rapidly and directly eluted. Small volume particles may infiltrate the matrix, resulting in prolonged retention times and delayed elution. EVs are collected at various elution times. Commonly utilized substrates include Sephadex, Sepharose, and Sephacryl. The process is gravity-driven, ensuring the integrity of the exosomes and yielding a high-purity product however, the eluent exhibits a dilutive effect (Xu et al., 2016; Guo et al., 2021).

Immunoaffinity chromatography leverages specific antigens present on the vesicle surface. Exosomes are isolated through solid-phase antibody adsorption, a method that holds potential for disease diagnosis. Typically, exosome surface biomarkers, such as the four-transmembrane protein superfamily, are employed as ligands in this process. Anti-bodies can be adsorbed onto magnetic beads, porous silica monoliths, or membrane affinity filters. Exosomes can be isolated through the specific binding of their surface proteins to a solid phase during the passage of the solution. For instance, exosomes can be extract-ed by targeting the exosome surface protein CD81 with antibodies or by utilizing the interaction between the Tim4 protein immobilized on magnetic beads and phosphatidyl-serine (PS) on the exosome surface. This method achieves high extraction efficiency within a short duration. However, the potential impact on the biological function of the extracted exosomes warrants further investigation (Park et al., 2021; Zhang et al., 2018).

The polymer coprecipitation method employs PEG as the separation medium. In this separation process, PEG interacts with the water molecules on the exosome surface, thereby reducing their solubility and facilitating sedimentation separation. Initially, the sample to be separated is incubated with PEG (the molecular weight is 8,000Da) at 4°C for a duration of 8–16 h. Subsequently, exosomes are isolated through low-speed centrifugation. At present, the associated kits are user-friendly and exhibit a high acquisition rate, making them suitable for large-scale exosome extraction. However, it is important to note that PEG not only precipitates exosomes but also co-precipitates hydrophilic nucleic acids, lipoproteins, and other components, resulting in lower purity (Yang et al., 2020; Martínez-Greene et al., 2021).

Microfluidics offers significant potential for the separation and real-time detection of EVs due to its inherent advantages, including low sample consumption, rapid reaction times, and precise fluid control. The primary methods employed in the context are based on immune affinity capture and size separation, and also encompass techniques such as membrane filtration, on-chip microstructures, the application of acoustic or electric fields, and the utilization of viscoelastic flow characteristics (Salaf et al., 2016; Yang et al., 2017). Despite these advancements, there remains considerable scope for enhancing the degree of automation and reducing processing time. Hongju Mao et al. Have introduced an EVs processing platform based on digital microfluidic technology, achieving a capture efficiency of 77% within 20 min (Tong et al., 2024). The ExoTIC device demonstrates superior efficacy in isolating exosomes from bodily samples compared to PEG precipitation and UC (Lin et al., 2020). Utilizing a viscoelastic-based microfluidic platform, small cell vesicles could be isolated from whole blood without the need for labels, achieving purity and recovery rates of 97% and 87%, respectively (Meng Y. et al., 2023). Additionally, a dean-flow-coupled elasto-inertial microfluidic chip has been developed to purify exosomes from cell culture medium and human serum, yielding a 70.6% recovery rate and a 91.4% protein removal rate (Bai et al., 2023).