One of the most overlooked aspects of stem cell therapy happens after the cells leave the laboratory but before they reach the patient.
Unlike conventional medications, Umbilical Cord Derived Mesenchymal Stem Cells, or UC-MSCs, are living biological products. After cells leave their controlled laboratory culture environment, transportation, temperature, storage solution, concentration, preparation time, and delays before administration can influence their condition.
Research consistently shows that MSC viability and function can change during this period. However, there is no universal number of hours that applies to every UC-MSC product. The appropriate administration window should be based on the manufacturer’s validated preparation and storage protocol
Why Transportation Matters
Transportation is part of the cell therapy process, not simply a delivery service.
MSCs may need to travel from a manufacturing laboratory to the clinic where treatment takes place. During that journey, they are removed from the controlled environment in which they were grown and maintained in a transport formulation designed to preserve them until administration.
Research examining cell transport has identified several variables that can influence cell quality, including the suspension solution, temperature, transportation time, cell concentration, and even the container being used. Although individual studies have used different stem cell sources, the broader principle is consistent: living cells are sensitive to their environment during the period between laboratory preparation and clinical administration.
This is why transportation protocols should specify storage temperature, preparation method, acceptable transportation time, and handling conditions rather than simply sending the cells from one location to another.
What Happens Once Stem Cells Are Mixed Into an Infusion Bag?
Normal saline is commonly used as a clinically compatible solution for preparing cells for administration. However, saline is not the same environment as the nutrient-rich culture medium used to expand cells in a laboratory.
Once UC-MSCs are transferred into an administration solution, their viability does not suddenly disappear. Instead, cellular condition can gradually change with time.
A study specifically evaluating human UC-MSCs stored in several clinically used solutions, including 0.9% saline, found progressive deterioration in viability and cell attachment during storage. After six hours, viability differed depending on the solution and temperature, showing that both formulation and storage conditions influence how well the cells are preserved. This does not mean all UC-MSCs must be administered within a particular number of hours. Other studies using different preservation formulations have maintained UC-MSC viability for considerably longer periods. The important point is that the stability window is product specific.
Do Stem Cells Start Dying Immediately After Preparation?
Not immediately. Stem cells are living cells, and their viability generally declines gradually over time rather than suddenly dropping at a specific hour.
How quickly this happens depends on several factors, including the cell source, storage solution, temperature, concentration, handling conditions, and how long the cells remain outside their controlled laboratory environment.
This is why timing and transport matter. The goal is to preserve the highest possible number of healthy, functional cells until administration.
It is also important to remember that viability is only one measure of cell quality. A cell can still be counted as alive while some aspects of its biological function may already be changing, which is why validated storage and administration protocols are important.
Can UC-MSCs Remain Viable for Longer Periods?
Yes, under appropriately validated preservation conditions.
More recent research comparing preservation strategies for MSCs from umbilical cord, adipose tissue, and bone marrow found that UC-MSCs could maintain considerably better viability over longer periods when stored under specific temperature and carrier conditions.
These findings explain why it is inaccurate to say that all MSCs “die after a few hours.” The carrier solution and validated manufacturing process can dramatically change the stability window.
Why Does Cell Viability Matter?
Cell viability represents the percentage of cells in a preparation that are alive at the time of testing.
For cellular therapy products, the FDA recommends establishing a minimum viability specification. Its guidance states that the minimum acceptable viability specification for somatic cellular therapies is generally set at 70%, while products using a lower threshold require supporting justification.
That 70% figure should not be interpreted as the ideal target for every treatment. It is a regulatory reference point for product release specifications, and individual manufacturers may establish substantially higher internal standards.
There is also an important difference between viability and potency.
A viability test primarily tells us whether cells are alive. It does not fully determine whether they retain their expected biological activity. Research has demonstrated situations where MSC viability remained relatively high while proliferation or differentiation capacity had already declined. This is why evaluating a cell product requires more than looking at a single viability percentage.
Frequently Asked Questions
- How long do stem cells survive in a saline bag?
There is no universal timeframe. UC-MSC viability in saline changes with temperature, concentration, formulation, manufacturing method, and other factors. Studies have demonstrated progressive declines during storage, so administration should follow the manufacturer’s validated stability window rather than a universal rule.
- Are UC-MSCs still alive after several hours?
They can be. Research has demonstrated viable UC-MSCs after several hours of storage, although viability may gradually decrease. The proportion remaining viable depends heavily on how the product is formulated and stored
- Do stem cells die immediately after being mixed with saline?
No. Stem cells remain alive after suspension in saline, but they are no longer in their ideal growth environment. Their viability gradually declines over time rather than disappearing suddenly.
- Why can’t cells simply stay in saline indefinitely?
Saline is a clinically compatible carrier but does not reproduce the nutrient-rich environment in which MSCs are cultured. Over time, cellular stress can affect survival and biological function.
- Why is transportation important for stem cell therapy?
Stem cells are living products. Proper temperature control, validated packaging, careful handling, and minimizing transport time all help preserve cell quality before treatment.
- Does higher cell viability guarantee better treatment?
Not necessarily. Viability is only one measure of quality. Cell identity, sterility, potency, manufacturing consistency, and physician expertise are also important.
- Should clinics prepare stem cells immediately before treatment?
Many clinics aim to prepare stem cells as close to administration as practical to minimize unnecessary time outside their validated storage conditions. However, the exact handling procedures depend on the manufacturer’s validated protocol.
About EDNA Wellness
EDNA Wellness is a surgeon-led regenerative medicine center in Bangkok, specializing in orthopedic and neurological conditions using Umbilical Cord Derived Mesenchymal Stem Cells (UC-MSCs).
All cases are reviewed by orthopedic surgeons and neurosurgeons, with a focus on clinical indication, patient safety, and realistic treatment expectations. Stem cell therapy is recommended selectively, and alternative treatments are considered when more appropriate.
For more information or to book a consultation:
LINE: @ednawellness
WhatsApp: +66 (0) 64 505 5599
Website: www.ednawellness.com
References
- Chen Y, Yu B, Xue G, et al. Effects of Storage Solutions on the Viability of Human Umbilical Cord Mesenchymal Stem Cells for Transplantation. Cell Transplantation. 2013.
https://pubmed.ncbi.nlm.nih.gov/23043973/ - Sohn HS, Heo JS, Kim HS, Choi Y, Kim HO. Duration of in vitro storage affects the key stem cell features of human bone marrow-derived mesenchymal stromal cells for clinical transplantation. Cytotherapy. 2013.
https://pubmed.ncbi.nlm.nih.gov/23318345/ - Ngo ATL, Le HM, Trinh NTH, et al. Clinically relevant preservation conditions for mesenchymal stem/stromal cells derived from perinatal and adult tissue sources. Journal of Cellular and Molecular Medicine. 2021.
https://pubmed.ncbi.nlm.nih.gov/34708529/ - Yu NH, Chun SY, Ha YS, et al. Optimal Stem Cell Transporting Conditions to Maintain Cell Viability and Characteristics. Tissue Engineering and Regenerative Medicine. 2018.
https://pubmed.ncbi.nlm.nih.gov/30603585/ - Mohyeddin Bonab M, Talebian F, Borzabadi A, et al. A novel method for maintaining the stability of freshly cultured Mesenchymal stem cells in clinical grade injection ready state without cryopreservation. Translational Medicine Communications. 2021.
https://link.springer.com/article/10.1186/s41231-021-00103-3 - U.S. Food and Drug Administration. Guidance for FDA Reviewers and Sponsors: Content and Review of Chemistry, Manufacturing, and Control (CMC) Information for Human Somatic Cell Therapy Investigational New Drug Applications (INDs).
https://www.fda.gov/media/73624/download