Feasibility of defined, animal component free, protein free, salt base freezing solution composed of 5% DMSO for cryopreservation of HMSC toward clinical applications

Abstract

Background & Aim hMSC are a critical raw material for cell-based therapies and usually a large number of cells are required for clinical applications. Cryopreservation is currently the only method to preserve cells with maintained functional properties and genetic stability for long term storage. To date, a common practice is use of homebrew cryo-medium that is composed of animal-derived raw materials and low Mw Cryoprotective agents (CPAs), usually 10-20% DMSO. Alternatively, animal component free (ACF) freezing solutions were developed for clinical applications, but they are still based on culture medium and are composed of 10% DMSO (e.g. NutriFreez™ D10). In addition, a few products were developed with a reduced concentration of DMSO or even without DMSO. However, these products appear not to be optimal for hMSC. Moreover, most of the commercially available DMSO-free products are actually composed of other potentially toxic permeable CPAs (e.g. Ethylene Glycol, EG). Exposure of cells to these materials can impact the quality, safety and efficacy of cell-based therapeutic product. Facing strict regulatory requirements, the development of defined, ACF, salt base freezing solution with reduced concentration of DMSO is essential. Methods, Results & Conclusion The current study presents the feasibility of a novel defined, ACF, protein free, salt base freezing solution composed of 5% DMSO for cryopreservation of hMSC from various sources. Results show that the novel cryopreservation solution efficiently maintains high cell yield and viability, and supports the recovery of hMSC while maintaining the normal hMSC features: typical fibroblast-like cell morphology, phenotypic surface marker profile, differentiation capability as well as self-renewal potential. Clinically accepted, cryopreservation solution for hMSC holds a unique opportunity to facilitate the translation of these cells to cellular therapy applications.