What Are Exosomes?

Exosomes are extracellular vesicles with diameters ranging from 30 to 150 nm. They carry informational molecules from their parent cells—including DNA, RNA, proteins, and lipids—and participate in intercellular material transport and signal communication, regulating both physiological and pathological processes. They also possess certain repair and awakening functions for damaged and senescent cells. However, the composition of exosomes varies depending on their cellular origin.

In 1983, exosomes were first discovered in sheep reticulocytes and were initially considered merely a vehicle for cellular waste disposal. With deeper research into their biogenesis and structural composition, it was revealed that exosomes play a critical role in cell-to-cell communication. They have the ability to cross biological barriers (such as the plasma membrane, bloodbrain barrier, and gastrointestinal tract), acting as natural carriers of "cargo" throughout the body.

In 2013, American scientists James E. Rothman and Randy W. Schekman, together with German scientist Thomas C. Südhof, were awarded the Nobel Prize in Physiology or Medicine for their discoveries of the machinery and regulatory mechanisms underlying the exosomal transport system.

Distribution of Exosomes

Virtually all cell types can secrete exosomes, and they are widely present in various body fluids, including blood, tears, urine, saliva, and breast milk. For example, exosomes derived from mesenchymal stem cells (MSCs) have been shown in numerous studies to play important roles in immunomodulation, as well as in repairing and revitalizing damaged and senescent cells.

Exosomes are increasingly used in clinical diagnostics, food products, cosmetics, scientific research, and drug delivery, and hold considerable promise for future applications.

 Shenzhen Cell Valley Ultra-Pure Exosome Stock Solution

Shenzhen Cell Valley produces industrial-scale human mesenchymal stem cell-derived exosomes, with quality verified by third-party testing laboratories. Using Western blot analysis, exosome positive protein markers—including transmembrane proteins CD9, CD63, CD81, and the soluble protein TSG101—are all positive, while the negative exosome protein marker Calnexin (an endoplasmic reticulum protein) is negative, fully complying with the guidelines established by the International Society for Extracellular Vesicles (MISEV2023) for exosome identification [1].

In addition, nanoparticle flow cytometry is used to assess particle size and concentration, confirming uniform size distribution that meets the required standards.

Third-party Testing Report on Human Mesenchymal Stem Cell Exosomes from Shenzhen Cell Valley – Exosome Biomarkers

Third-party Testing Report on Human Mesenchymal Stem Cell Exosomes from Shenzhen Cell Valley – Particle Size and Concentration

Applications of Exosome Products

1. Diagnostics: Exosomes are present in virtually all biological fluids, making them attractive for multi-analyte profiling. Their lipid bilayer membrane provides sufficient stability to protect the biological information they carry from degradation during circulation, facilitating the capture of diagnostic signals. Consequently, exosomes have emerged as the newest and most promising biomarkers in cancer liquid biopsy. They can serve as auxiliary diagnostic tools for a wide range of cancers, including lung cancer, breast cancer, gastrointestinal cancers, hepatocellular carcinoma, pancreatic cancer, urological cancers, gynecological cancers, hematological malignancies, and melanoma [2].

2. Therapeutics: By combining the immunomodulatory functions of exosomes with their drug-carrier properties, they can initiate antitumor immune responses alongside chemotherapy, producing significant therapeutic effects. Natural killer cell-derived exosomes exhibit cytotoxicity against various human tumor cells. Dendritic cell-derived exosome-based vaccines have been developed and are in early-stage clinical trials, and are currently considered among the most promising carriers for tumor vaccines [3].

3. Drug Delivery: Because exosomes share a lipid bilayer structure similar to cell membranes, they can more easily deliver therapeutic agents into cells when used as drug carriers. By loading different proteins, nucleic acids, and lipids, exosomes can exert diverse therapeutic effects. An ideal exosome delivery vehicle should not only target different tissues and organs but also selectively enhance or inhibit the function of the targeted organ. Researchers have engineered various modified exosomes through multiple approaches to improve their drug-loading capacity [4].

4. Functional Medicine: Beyond the fields mentioned above, exosomes are gaining popularity in medical aesthetics for applications such as functional skincare, anti-aging, regenerative repair, and even hair management [5,6]. Some researchers believe that stem cell-derived exosomes are effective against skin aging. In one study, exosomes were collected from conditioned media of human induced pluripotent stem cells (iPSCs) and their effects on aged human dermal fibroblasts (HDFs) were investigated.

 The effect of iPSC-Exo on the proliferation of human dermal fibroblasts (HDFs)

The results showed that under normal conditions, iPSC-derived exosomes promoted proliferation and migration of both types of HDFs and increased the expression level of type I collagen. Moreover, they significantly reduced senescence-associated markers in HDFs, including the expression of senescence-associated β-galactosidase (SA-β-Gal) and matrix metalloproteinases (MMP-1/3). High SA-β-Gal expression is a hallmark of natural aging, while MMP-1/3 are key enzymes upregulated during cellular senescence. Pretreatment of HDFs with iPSC-derived exosomes also inhibited UVB-induced damage and MMP-1/3 overexpression. Taken together, these findings indicate that iPSC-derived exosomes hold therapeutic potential for treating skin aging [7].

References:

[1] Welsh JA, Goberdhan DCI, O'Driscoll L, et al. Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches. Journal of Extracellular Vesicles. 2024;13(2):e12404.

[2] Liang S, Qiu YF, Wang YY, et al. Advances in quantitative detection methods of exosomes as potential tumor markers. Progress in Pharmaceutical Sciences. 2023;47(11):837-848. [in Chinese]

[3] Zhu XX, Chen HZ, Cui KY, et al. Current status and prospects of exosomes in tumor diagnosis and treatment. China Medical Herald. 2023;20(09):41-45. [in Chinese]

[4] Cui J, Zhang Y, Zhang NK, et al. Advances in engineered exosomes for drug delivery. Progress in Pharmaceutical Sciences. 2024;48(08):633-640. [in Chinese]

[5] Park GH, Kwon HH, Seok J, et al. Efficacy of combined treatment with human adipose tissue stem cell-derived exosome-containing solution and microneedling for facial skin aging: A 12-week prospective, randomized, split-face study. J Cosmet Dermatol. 2023 Dec;22(12):3418-3426.

[6] Zheng SD, Wu JY, Zhang LP, et al. Research progress of stem cell-derived exosomes in cosmetic dermatology. Chinese Journal of Aesthetic and Plastic Surgery. 2023;34(04):246-248+259. [in Chinese]

[7] Myeongsik O, Jinhee L, Yu K, et al. Exosomes derived from human induced pluripotent stem cells ameliorate the aging of skin fibroblasts. Int J Mol Sci. 2018;19(6):1715.