Cryopreservation as a Key Element in the Successful Delivery of Cell-Based Therapies—A Review

Abstract

Cryopreservation is a key enabling technology in regenerative medicine that provides stable and secure extended cell storage for primary tissue isolates and constructs and prepared cell preparations. The essential detail of the process as it can be applied to cell-based therapies is set out in this review, covering tissue and cell isolation, cryoprotection, cooling and freezing, frozen storage and transport, thawing, and recovery. The aim is to provide clinical scientists with an overview of the benefits and difficulties associated with cryopreservation to assist them with problem resolution in their routine work, or to enable them to consider future involvement in cryopreservative procedures. It is also intended to facilitate networking between clinicians and cryo-researchers to review difficulties and problems to advance protocol optimization and innovative design.

Formulation Considerations for Autologous T Cell Drug Products

“…Bags may be over-wrapped and placed into metal cassettes to ensure that their thickness is uniform during freezing. Metal is also an excellent heat conductor and facilitates uniform cooling on freezing and thawing across the cassette and bag [ 21 ]. In a closed, automated fill–finish process, the TNC/mL value for the drug substance calculates the cell concentration and dilution steps to meet a target TNC/mL for the drug product [ 20 ].…”

“…Electronic temperature recording and tracking systems are available for the latter devices and can support the required Chain-of-Custody strategy (cf. [ 21 ]). Thawing of typical T cell drug product volumes ( Table 1 ) using a water bath is generally complete in approx.…”

Brief Overview of Ice Nucleation

“…The nucleation of ice is vital in cloud physics and impacts on a broad range of matters, from the cryopreservation of food, tissues, organs, and stem cells [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] to the prevention of icing on aircraft wings, bridge cables, wind turbines, and other structures [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Ice nucleation thus has broad implications in medicine, food engineering, mineralogy, biology, and other fields.…”

The transfer temperature from slow cooling to cryogenic storage is critical for optimal recovery of cryopreserved mammalian cells

“…The lethal injuries that are acquired during controlled rate cryopreservation are primarily dependant on intracellular ice formation (IIF) and solute toxicity [ 1 , 2 ]. Freezing of the extracellular medium effectively removes water from the solution as ice crystals, leaving a residual, more concentrated and as yet unfrozen, extracellular solution.…”