Cryoprotection in Human Mesenchymal Stromal/Stem Cells: Synergistic Impact of Urea and Glucose

Standard freezing protocols of clinically relevant cell lines commonly employ agents such as fetal bovine serum and dimethyl sulfoxide, which are a potential concern from both a regulatory and a patient safety per-spective. The aim of this work was to develop formulations with safe and well tolerated excipients for the (cryo-) preservation of cell therapy products. We evaluated the cryoprotective capabilities of urea and glu-cose through measurements of cell metabolic activity. Freezing of clinically relevant human mesenchymal stromal/stem cells and human dermal fibroblasts at <= -65 degrees C at equimolar ratios of urea and glucose resulted in comparable viabilities to established dimethyl sulfoxide. Pre-incubation of human mesenchymal stromal/ stem cells in trehalose and addition of mannitol and sucrose to the formulation further enhanced cell viabil-ity after freeze-thaw stress. Other cell types assessed (A549 and SK-N-AS) could not satisfactorily be pre-served with urea and glucose, highlighting the need for tailored formulations to sustain acceptable cryopreservation.(c) 2023 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.

Automated summary

This study aims to develop safe and well tolerated formulations for the (cryo-) preservation of cell therapy products. The cryoprotective capabilities of urea and glucose were evaluated through measurements of cell metabolic activity. Freezing human mesenchymal stromal/stem cells and human dermal fibroblasts at -65°C with equimolar ratios of urea and glucose resulted in comparable viabilities to established dimethyl sulfoxide. Pre-incubation of human mesenchymal stromal/stem cells in trehalose and addition of mannitol and sucrose further enhanced cell viability after freeze-thaw stress. Other cell types assessed could not be satisfactorily preserved with urea and glucose, highlighting the need for tailored formulations.