C-1010: Low temperature cell pausing: An alternative short-term preservation method for use in cell therapies

Abstract

Background: Advancements in cell therapies have produced a requirement for an effective short-term cell preservation method, enabling time for quality testing and transport to their clinical destination. We aim to ‘pause’ cells at ambient temperature whilst maintaining cell viability and quality post preservation. Storage at ambient temperature effectively bypasses cell damage from freezing and will greatly reduce costs and reliability of specialist machinery. Methodology: Initially, a human osteosarcoma cell line (HOS TE85) was paused at ambient temperatures (no atmospheric control) for up to 48 h. Cell assessments were performed immediately after cell pausing and following 24 h recovery at 37 °C, 5% CO 2 ,95% humidity. Results: Viability (propidium iodide) remained above 98% and 91% for cells paused at 24 and 48 h respectively and significantly lower reductive metabolism (PrestoBlue) was observed during pausing compared with non-paused controls ( p ⩽ 0.01). Following recovery, metabolic activity became similar to the control and alkaline phosphatase activity (typically secreted by osteoblasts) remained unchanged. Conclusion: HOS TE85 cells effectively recover following 48 h pausing in standard media and show evidence of ‘pausing’ with regards to lower reductive metabolism at ambient temperature exposure. Current experiments are investigating the effects of prolonged pausing (144 h), pausing in suspension and application to mesenchymal stem cells. Successful cell pausing will create a simpler, cost effective short-term preservation method for cell therapies.