The major damaging factors associated with freeze-drying liposomes are lipid-phase transition (LPT) and fusion. Jennings said “most investigators have at times overlooked the importance of the freezing process…while simple in concept, the freezing process will be shown to be perhaps the most complex and least understood step in the lyophilization process”. Overcoming these obstacles is not simple. In order to freeze-dry the cells, we first had to develop a method that would enable freezing in the absence of permeating cryoprotectant agents (CPAs) such as DMSO, glycerol or ethylene glycol, to name a few, and would enable the use of additives that have a high glass transition temperature (Tg) and that are solid at room temperature. In addition, freeze-drying does not involve the thawing process to which cell damage is attributed, particularly at large volumes (e.g. These advantages are especially important when long-term preservation is required, e.g. lyophilization) of the cells should theoretically substantially decrease the risks associated with storage at ultra-low temperatures, thus simplifying the procedure, reducing costs and allowing for better management of sample storage and transport.

This conventional mode of cryopreservation is prone to transient warming events and various other hazards, such as cross-contamination, , and results in cell losses of 20 to 30%. Hematopoietic as well as other somatic cells are currently cryopreserved and stored in liquid nitrogen (LN) tanks, in nitrogen vapor phase or in −80☌ freezers. Moreover, in haplo-identical transplants, the donor undergoes multiple stem cell mobilization and harvesting, which necessitates cryopreservation of the graft.

WO05/072523 - Biological Material and Methods and Solutions for Preservation ThereofĬryopreservation of hematopoietic stem cells (HSC) is the backbone of clinical stem cell transplantation (SCT), and this technique is an essential part of autologous SCT, cord blood transplantation (CBT) and in many cases, allogeneic SCT, particularly when the donor is elderly and the stem cells are not readily available.

WO07/015252 - Somatic Cells for Use in Cell Therapy.

WO03/020874 - Improved Method for Freezing Viable Cells.

The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptĬompeting interests: I am a co-inventor of the following patent applications in the field of UCB cryopreservation, which are licensed to Core Dynamics.

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.įunding: Core Dynamics has funded this study. Received: SeptemAccepted: FebruPublished: April 21, 2009Ĭopyright: © 2009 Natan et al. Schnur, Geroge Mason University, United States of America Citation: Natan D, Nagler A, Arav A (2009) Freeze-Drying of Mononuclear Cells Derived from Umbilical Cord Blood Followed by Colony Formation.

Second life freeze dry