Fol. Biol. 2024, 70, 209-218
Effect of Cryoprotectants on Long-Term Storage of Oral Mucosal Epithelial Cells: Implications for Stem Cell Preservation and Proliferation Status
In this study, we tested a method for long-term storage of oral mucosal epithelial cells (OMECs) so that the cells could be expanded in vitro after cryopreservation and used for the treatment of bilateral limbal stem cell deficiency. The ability of suspended primary OMECs to proliferate in vitro after cryopreservation was compared to that of OMEC cultures that had undergone the same process. Both were preserved in standard complex medium (COM) with or without cryoprotective agents (CPAs) (glycerol at 5 % or 10 % or dimethyl sulphoxide at 10 %). We found that after cryopreservation, primary OMECs could form a confluent cell sheet only in a few samples after 22 ± 2.9 (mean ± SD) days of cultivation with 72.4 % ± 12.9 % overall viability. Instead, all ex vivo OMEC cultures could re-expand after cryopreservation with a comparable viability of 78.6 ± 13.8 %, like primary OMECs, but with significantly faster growth rate (adj. P < 001), forming a confluent cell sheet at 13.7 ± 3.9 days. Gene expression analyses of the ex vivo expansion of OMEC cultures showed that the stemness, proliferation and differentiation-related gene expression was similar before and after cryopreservation, except for KRT13 expression, which significantly decreased after the second passage (adj. P < 0.05). The addition of CPAs had no effect on these outcomes. In conclusion, the optimal strategy for OMEC preservation is to freeze the cells that have been previously cultured, in order to maintain cell viability and the capacity to create a sizable graft even without CPAs.
Supplementary materials: Tables S1-S5 (pdf file)
Contribution of authors: Joao Victor Cabral, Natálie Smorodinová, and Eleni Voukali contributed equally to this work.
Keywords
oral mucosal epithelial cells, limbal stem cell deficiency, cryopreservation, cryoprotectives, cell culture, stemness.
Funding
This study was supported by the Norway Grants and Technology Agency of the Czech Republic within the KAPPA Programme (project TO01000099), by research project BBMRI_CZ LM2023033, and the institutional support (Charles University, Prague) was provided by programmes Progres-Q25 and Cooperatio: Medical Diagnostics and Basic Medical Sciences.
References
Copyright
This is an open-access article distributed under the terms of the Creative Commons Attribution License.