Cryopreservation of implantable human skeletal muscle-derived cell-microcarrier combinations for use in clinical regenerative medicine

Simitzi C, Zhang J, Marjsteiner R, Fuller B, Day RM.

Cytotherapy 12th September 2025.

Summary

This study looked at whether tiny, implantable beads carrying human muscle cells can be safely frozen and stored for later medical use. These beads (called microcarriers) are designed to deliver healthy cells to damaged tissues to help them repair themselves. Normally, these cell-carrying products must be made fresh, which makes them difficult to manufacture and distribute. The researchers tested different freezing and thawing methods and found that the muscle cells survived well, stayed attached to the beads, and still behaved normally after thawing. The beads themselves also remained structurally sound. This means that in the future, these cell-based treatments could be produced in advance, stored in a “cold chain” and delivered to hospitals when needed, making regenerative therapies much more practical and accessible.

Abstract

Background aims: Regenerative medicine therapies include tissue-engineered constructs to restore tissue and organ function. Among the different approaches, implantable polymeric microcarriers have been proposed for delivery of anchorage-dependent cells to target tissue locations. Cell-microcarrier combinations produced as fresh advanced therapy medicinal products face significant challenges in terms of manufacturing and time distribution. In the current study, we have explored the feasibility of cryopreservation for human skeletal muscle-derived cells (SMDC)—implantable microcarrier combinations.

Methods: Existing and novel cryoprotectant formulations combined with slow cooling were investigated, along with rapid and slow thawing regimens.

Results: Under specific conditions after cryopreservation and thawing, most SMDC cells were viable and remained attached to the microcarriers. Furthermore, the capacity of human SMDCs to differentiate into myotubes was unaffected. The cryopreservation process did not alter the physico-mechanical properties of the microcarriers enabling them to retain their primary function of an implantable cell substrate.

Conclusions: Overall, these findings pave the way to use cold-chain product supply for future clinical studies with the implantable cell-microcarrier technology.

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https://www.sciencedirect.com/science/article/pii/S1465324925008424