Enhancing cryopreservation of human iPSCs: Bottom-up vs Conventional freezing geometry

• Main Author: Teodoro Duarte Garcia Morais, Fernando Jorge
• Publication Date: 2024
• Other Authors: El-Guendouz, Soukaina, Neves, Rafaela, Duarte, Andreia, Rodrigues, Miguel A., Pinho Melo, Eduardo
• Format: Article
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10400.1/26786
• topic: Cryopreservation; Bottom-up freezing; Induced pluripotent stem cells; Scale- up

Induced pluripotent stem cells (iPSCs) hold large potential on regenerative medicine due to their pluripotency and unlimited self-renewal capacity without the ethical issues of embryonic stem cells. To provide quality-controlled iPSCs for clinical therapies, it is essential to develop safe cryopreservation protocols for long-term storage, preferable amenable for scale-up and automation. We have compared the impact of two different freezing geometries (bottom-up and conventional radial freezing) on the viability and differentiation capability of human iPSCs. Our results demonstrate that the bottom-up freezing under optimized conditions significantly increases iPSCs viability, up to 9% for the cell membrane integrity and up to 21% for the cell metabolic state, compared to conventional freezing. The improvement achieved for bottom-up versus conventional freezing was maintained after scale-up from cryogenic vials to 30 mL bags, highlighting the method’s potential for clinical applications. These findings show that bottom-up freezing can offer a more controlled and scalable cryopreservation strategy for iPSCs, promoting their future use in regenerative medicine.