Cord Blood Cryopreservation
There are three reasons for stem cell loss during processing and preservation stages, comments Coelho. First is poor volume-reduction techniques. UCB is collected in various volumes, but the storage volume has to be consistent. Traditional methods, such as via Ficoll density gradients, result, on average, in 25% loss of viable CD34+ cells. Next, incorrect rates and temperatures of sample freezing add 10% loss of cell viability. Finally, storage conditions at above -196°C combined with transient warming events lead to another 20% loss of viability.
At the end, you may end up with only 50% of viable cells from the original collection. A patient may die just because there were not enough viable cells for transplantation.
Thermogenesis solves these issues by automating every step of the process. Its AXP AutoExpress System provides an automated, one-step procedure that separates mononuclear cells from the plasma and red blood cells into a fixed 20-mL volume and transfers them directly into the freezing bag. With its enclosing metal storage canister, the whole unit is about the size of a Palm Pilot. 20% of the sample is directed into a detachable compartment for future in vitro stem cell expansion. Each bag and canister is bar coded for easy identification through Xpress TRAK software.
Since a freezing protocol has a dramatic effect on cell viability, Thermogenesis designed an automated controlled rate freezing method. The 20-minute freezing process takes place in liquid nitrogen vapors, after which the unit is transferred by a mechanical arm into one of the 3,626 slots, deep under the °C liquid nitrogen within the BioArchive System.
By monitoring the bag temperature via the external probes, the computer determines the actual temperatures inside the bag and derives a freezing curve to validate the process. Each BioArchive system is equipped with an autonomous power source and a manual retrieval system. In case of serious damage to the vacuum jacketing, the entire inventory could be swapped between two BioArchive dewars in less than 50 seconds. The post-thaw data provided by the company indicates that on average 96% of the cells are still viable.
Worldwide, BioArchive is installed in 76 blood banks in 29 countries. In October 2005, Thermogenesis signed the R&D and distribution agreement with GE Healthcare for the BioArchive and the AXP AutoExpress systems. Under the terms of the agreement, GE Healthcare will have exclusive global distribution rights for both systems and will also collaborate with Thermogenesis to develop new generations of the products.
The sales of its blood processing systems (including ThermoLine Freezing and Thawing systems and DAC System for semiautomated separation of blood) supports development of other blood-related products. The CryoSeal Fibrin Sealant System enables the production of autologous fibrin and thrombin from plasma in about 60 minutes. Thrombin Processing Device enables production of autologous thrombin in about 25 min, from only 11 mL of plasma. Fibrin sealants and topical thrombin are used in operating rooms to stop blood loss, promote blood clotting, and release growth factors from platelets.