In short
In 2D culture, cells grow as a single layer on a flat flask. In 3D culture, they grow on microcarriers, in spheroids or along hollow fibers inside a bioreactor, which gives far more surface area per liter of media. Published studies report 7.5× to 20× more extracellular vesicles per production run from 3D culture than from matched 2D flasks.
2D flasks vs. 3D bioreactors
Conventional MSC expansion uses tissue-culture flasks or multilayer "cell factories": cells attach to a flat plastic surface and grow until the layer is full. Capacity scales by adding more flasks, so large lots mean many separate vessels, many open handling steps and more run-to-run variation.
A bioreactor changes the geometry. Cells attach to microscopic beads (microcarriers), form small aggregates (spheroids), or line the inside of hollow fibers while media flows past. Temperature, pH, dissolved oxygen and feeding are monitored and controlled for the whole vessel instead of flask by flask.
2D flask culture
- Single cell layer on flat plastic
- Scale-out by adding vessels
- Manual media changes per flask
- Environment checked per vessel
3D bioreactor culture
- Cells on microcarriers, spheroids or hollow fibers
- Scale-up within one closed vessel
- Continuous or programmed feeding
- pH, oxygen and temperature controlled throughout
Inside a bioreactor
The vessel in the illustration above is a stirred-tank design, one of several 3D formats. The parts that matter for consistency are the same across most systems:
| Component | What it does in manufacturing |
|---|---|
| Vessel | A closed, sterile container that holds cells and media for the whole run |
| Impeller or flow path | Keeps cells, microcarriers and nutrients evenly mixed without letting cells settle |
| Microcarriers | Small beads that give anchorage-dependent cells a large growth surface inside a small volume |
| Sensors | Continuous readings of pH, dissolved oxygen and temperature |
| Feed and harvest lines | Add fresh media and remove conditioned media without opening the vessel |
| Sampling port | Lets the team pull samples for cell counts and testing during the run |
Three common 3D formats
| Format | How cells grow | Notes |
|---|---|---|
| Stirred tank with microcarriers | Cells attach to beads kept in suspension by gentle mixing | Widely used for scale-up; Haraszti 2018 used microcarrier culture |
| Spheroid (aggregate) culture | Cells cluster into small 3D balls without a carrier | Simple format; aggregate size is controlled by seeding and mixing |
| Hollow-fiber bioreactor | Cells line the outside of porous fibers while media flows through them | Compact; Yan & Wu 2020 used a hollow-fiber system |
What the published yield data show
Several peer-reviewed studies compared extracellular vesicle (EV) output from MSCs grown in 3D systems with the same cells grown in 2D flasks. Each reported a multi-fold increase in EV yield from 3D culture.
Values are as reported by each study, which used different cell sources, culture systems and isolation methods. They describe manufacturing yield only and are not Stem Nova lot data.
Why yield matters to a buyer
Yield is a manufacturing metric, but it shapes what ends up in the vial. A process that produces more vesicles per run can reach a labeled particle count from fewer cells and fewer population doublings, and can make larger, more uniform lots. Fewer separate vessels also means fewer open handling steps.
Yield alone does not tell you a product is well made. It has to be paired with lot-level measurement: particle concentration and size by nanoparticle tracking analysis (NTA), sterility, endotoxin and mycoplasma testing, and a Certificate of Analysis that ties those numbers to a specific lot.
How Stem Nova applies it
Stem Nova's 3DEXO+ exosome products are produced from 3D bioreactor-cultured cells in an FDA-registered facility that is cGTP-compliant (21 CFR Part 1271). Each lot is NTA-verified and supported by Certificates of Analysis from two independent laboratories. Exosome products are topical cosmetic products only.
| Product | Labeled particles | Use category |
|---|---|---|
| 3DEXO+ 60B Exosome Matrix | 60 billion per vial (NTA) | Topical cosmetic |
| Nova Core Secretome Concentrate | 66 billion per 2 mL (NTA) | Topical cosmetic |
| Dermal Papillary Secretome Matrix+ 150B | 150 billion per 1.8 mL (NTA) | Topical cosmetic |
| 3DEXO+ 12B Exosome Matrix | 12 billion per 10 mL (NTA) | Topical cosmetic |
What to ask your supplier
- Is the product made from 2D flask culture or a 3D bioreactor system? Which format: microcarrier, spheroid or hollow fiber?
- What is the particle count per vial, and was it measured by NTA on this lot?
- Can I see the Certificate of Analysis, and is it from an independent laboratory?
- Which release tests are run on every lot: sterility, endotoxin, mycoplasma?
- Where is the product manufactured, and is the facility FDA-registered and cGTP-compliant (21 CFR Part 1271)?
Frequently asked questions
Does 3D culture change what the product is?
No. 3D culture changes the growth environment and scale of the manufacturing process. The product is still defined by its lot testing: particle count and size, sterility, endotoxin, mycoplasma and the documentation behind it.
What is a microcarrier?
A small bead, typically a few hundred micrometers across, that cells attach to and grow on while suspended in media. Thousands of beads give a very large growth surface inside a single vessel.
Why do the studies report different multiples?
Each study used different cells, bioreactor types and EV isolation methods, so the fold-increase varies (7.5× to 20× in the studies cited here). The consistent finding is direction, not a single number.
Are the yield figures Stem Nova product data?
No. They are published research results describing manufacturing yield. Stem Nova lot data is on each lot's Certificate of Analysis.
What is the regulatory status of 3D-cultured exosome products?
Stem Nova exosome products are topical cosmetic products; they are not drugs and are not FDA-approved. FDA registration of a manufacturing facility is not FDA approval of a product.
References
- Haraszti RA, Miller R, Stoppato M, et al. Mol Ther. 2018;26(12):2838-2847. doi:10.1016/j.ymthe.2018.09.015. Cited for: 3D microcarrier vs. 2D EV yield.
- Cao J, Wang B, Tang T, et al. Stem Cell Res Ther. 2020;11:206. doi:10.1186/s13287-020-01719-2. Cited for: 3D vs. 2D EV yield.
- Yan L, Wu X. Cell Biol Toxicol. 2020;36(2):165-178. doi:10.1007/s10565-019-09504-5. Cited for: hollow-fiber bioreactor vs. 2D EV yield.
- Welsh JA, Goberdhan DCI, O'Driscoll L, et al. J Extracell Vesicles. 2024;13(2):e12404 (MISEV2023). doi:10.1002/jev2.12404. Cited for: EV nomenclature and characterization guidance.
- Dragovic RA, Gardiner C, Brooks AS, et al. Nanomedicine. 2011;7(6):780-788. doi:10.1016/j.nano.2011.04.003. Cited for: nanoparticle tracking analysis of vesicles.
Citations support manufacturing, characterization and sourcing facts only. They are not claims about any Stem Nova product's effect in the body.