Examination of Optimal Transport Conditions for Adipose-Derived MSCs for Clinical Cell Transport

Background: Efficient transport of mesenchymal stem cell (MSC) products represents a major practical barrier to the clinical implementation of regenerative medicine. Many intravenous preservation fluids that are approved for clinical use are not optimised for MSC preservation, and many commonly used hypothermic preservation solutions are not approved for direct injection. Such solutions therefore require an additional washing step prior to administration, which is impractical at the bedside. Methods: Human adipose-derived MSCs were suspended in normal saline, dextran L (a Japanese-approved injectable formulation) at 5%, and Lactated Ringer’s solution. Samples were stored at refrigerated (4°C), room temperature (25°C) and body temperature (37°C) conditions. Viability was determined by trypan blue exclusion using an automated cell counter. Results: Viability was measured hourly from 1 to 4 hours after suspension. When cells were stored after suspension, viability was not markedly affected across solutions and temperatures up to 2 hours; however, viability declined from 3 hours onwards. In particular, storage at 37°C had a pronounced detrimental effect on viability. Conclusions: Although clinically approved solutions for intravenous administration were used to suspend the cells, cell death begins within 2 hours following suspension, indicating that transport conditions are critically important to maintain cell viability until patient administration. Dextran L, which obviates the need for a post-storage washing step, may be a practical transport medium for MSCs under clinical ambient conditions. These findings support the potential to simplify clinical workflows and reduce operational risk associated with inter-facility MSC handling. Furthermore, as viability declines markedly by 4 hours regardless of temperature and solution composition, short transport times are paramount for safety management.