Extracellular vesicles (EVs) have emerged as one of the most exciting modalities in biotherapeutics over the past decade. These nanoscale, membrane‑derived particles, naturally secreted by virtually all cell types, are no longer just objects of basic research curiosity. They are emerging as realistic tools for both vaccine applications and as delivery vehicles capable of transporting therapeutic cargo to target tissues with a precision that synthetic systems struggle to match [1]. At the same time, translating this promise into GMP‑compliant products introduces a set of manufacturing and regulatory realities that are often underestimated. That transition, from biological promise to GMP‑ready products, is something we work with in practice, supporting EV‑ and OMV‑based programs as they move from early development into scalable, controlled manufacturing processes suitable for clinical use.
Why EVs are effective delivery vehicles
EVs, including exosomes and microvesicles, carry a diverse payload of proteins, lipids, and nucleic acids and are enclosed by a phospholipid bilayer derived from the producing cell. This natural origin confers several compelling advantages. Firstly, EVs are inherently biocompatible as the immune system is accustomed to encountering them, which in turn reduces the risk for adverse immunogenic responses that can arise with synthetic nanoparticles [2]. Second, they can cross biological barriers that have traditionally been difficult to traverse, most notably the blood-brain barrier, opening new avenues for neurological conditions [3]. Third, their surface can be engineered through genetic modification of producer cells or post-isolation functionalization to display targeting ligands that direct EVs to specific cell types or tissues [4].
From a cargo perspective, EVs have been explored as delivery systems for small molecules, mRNA, siRNA, proteins, and CRISPR components [5]. This closely aligns with our existing expertise in mRNA manufacturing and plasmid DNA production. The ability to package mRNA within an EV rather than a lipid nanoparticle could offer improved stability and cell-type selectivity, which are areas of intense investigation in both academic and industry settings.
Emerging therapeutic applications of EVs
The therapeutic pipeline for EV-based delivery is broad. Oncology leads the way, with EV platforms being engineered to deliver chemotherapeutics or gene-silencing RNA directly to tumor cells, potentially reducing off-target toxicity [6]. In regenerative medicine, EVs derived from mesenchymal stromal cells have shown promise for modulating inflammation and promoting tissue repair [7]. Vaccine applications are another emerging area: EVs presenting antigens on their surface can elicit robust immune responses, and their particulate nature may enhance uptake by antigen-presenting cells.
We have already been exploring the EV space through work on bacterial-derived membrane vesicle products, progressing several projects through scale-up to clinical manufacturing. The convergence of EV biology with cell and gene therapy manufacturing, both core areas for us, positions us well to support customers as their EV programs advance through development.
Manufacturing and regulatory challenges that remain
Despite the promise, EVs face significant manufacturing and regulatory challenges that must be addressed before widespread clinical adoption. Scalable, reproducible production is among the foremost hurdles. EVs are produced by cells in culture, and yields are inherently variable depending on cell type, culture conditions, and production scale. Moving from research-scale preparations to GMP-compliant manufacturing at clinically relevant quantities requires robust bioprocess development, an area where CDMOs like us can add real value [8].
Isolation and purification are equally demanding. EV preparations from bioreactor cultures contain a complex mixture of vesicle subpopulations alongside soluble proteins, nucleic acids, and cell debris. Achieving the purity and consistency required for a therapeutic product demands careful selection and optimization of downstream processing steps, tangential flow filtration, size-exclusion chromatography, and density gradient ultracentrifugation each have trade-offs in scalability and recovery [9]. Endotoxin control, which is a challenge in any Biologic, deserves particular attention in bacterial-based EV manufacturing given the large surface area and complex matrix involved.
Characterization presents a further complexity. Unlike small molecules or even monoclonal antibodies, EVs are not a single molecular entity. Regulatory agencies expect comprehensive characterization of size distribution, surface markers, cargo loading efficiency, and potency but standardized assays are still maturing across the field. The MISEV2023 guidelines, published by the International Society for Extracellular Vesicles (ISEV), represent the most current consensus framework for EV characterization and reporting, and provide an essential reference for developers navigating this landscape [10].
The future of EV therapeutics
EV-based therapeutics are transitioning from scientific novelty to genuine clinical candidates. The opportunities they present, including natural biocompatibility, barrier-crossing capability, and versatile cargo capacity, are difficult to replicate with any other delivery modality. The limitations in manufacturing scalability, purification complexity, and characterization challenges, are real but manageable, particularly when addressed with the kind of process development expertise and GMP infrastructure that we bring to the table.
With experience from multiple EV‑based programs, we support customers in translating EV concepts into robust, scalable manufacturing processes. As the field matures, CDMOs with deep biologics manufacturing experience, flexible production platforms, and a strong scientific partnership approach will be essential enablers—and we continue to expand our role in this evolving space.
References
1. Herrmann IK, Wood MJA, Fuhrmann G. Extracellular vesicles as a next-generation drug delivery platform. Nat Nanotechnol. 2021;16(7):748–759. doi:10.1038/s41565-021-00931-2
2. Zhang Y et al. Extracellular vesicle-based drug overview: research landscape, quality control and nonclinical evaluation strategies. Signal Transduct Target Ther. 2025;10:275. doi:10.1038/s41392-025-02312-w
3. Xu J et al. Engineering Extracellular Vesicles as Delivery Systems in Therapeutic Applications. Adv Sci. 2023;10(18):2300552. doi:10.1002/advs.202300552
4. Li Z et al. Extracellular vesicles for targeted drug delivery: advances in surface modification strategies and therapeutic applications. Front Bioeng Biotechnol (review). PMC12486671. 2025.
5. Cecchin R, Troyer Z, Witwer K, Morris KV. Extracellular vesicles: the next generation in gene therapy delivery. Mol Ther. 2023;31(5):1225–1230. doi:10.1016/j.ymthe.2023.01.020
6. Teng F et al. Clinical applications of extracellular vesicles: recent advances and emerging trends. Front Bioeng Biotechnol. 2025;13:1671963. doi:10.3389/fbioe.2025.1671963
7. Cheng L, Hill AF. Therapeutically harnessing extracellular vesicles. Nat Rev Drug Discov. 2022;21(5):379–399. doi:10.1038/s41573-022-00410-w
8. Agrawal M et al. Global requirements for manufacturing and validation of clinical grade extracellular vesicles. Curr Res Transl Med. 2024;72(4):103476. doi:10.1016/j.retram.2024.103476. PMC11863704.
9. Li X et al. Recent advances in scalable exosome production: Challenges and innovations. Bioact Mater. 2025 (online). doi:10.1016/j.bioactmat.2025.03.012
10. Welsh JA, Goberdhan DCI, O’Driscoll L, Buzas EI et al.; MISEV Consortium. Minimal information for studies of extracellular vesicles (MISEV2023): from basic to advanced approaches. J Extracell Vesicles. 2024;13(2):e12404. doi:10.1002/jev2.12404