Biomedical Engineering Reference
In-Depth Information
Chapter 13
Principles and Practice
of Stem Cell Cryopreservation
“Problems worthy of attack prove their worth
by fi ghting back.”
- Paul Erdos
Recent extensive application of various cell-mediated therapeutic approaches has
resulted in increased needs for both specific blood-derived cells and operating pro-
cedures to get minimized cell damages during their collection, processing, and stor-
age in liquid or frozen state. The aim of cryoinvestigations is to minimize cell
injuries during the freeze/thaw process (cryoinjury). Cryoinjuries may be the result
of extensive cell dehydration and/or intracellular ice crystallization. The basic goal
of cryopreservation is to maintain the cell viability—which may be defined as the
ability of cells to perform their normal or near-normal function when transfused or
transplanted. Generally, postthaw cell recovery is superior when the most appropri-
ate freezing procedure and the best cryoprotective agent (cryoprotectant) are used.
For blood progenitor or cell cryopreservation, glycerol, dimethyl sulfoxide (DMSO),
and hydroxyetilstarch (HES) are regularly used, although in different concentra-
tions. Despite the fact that cell freezing practice is already in routine use, some
questions related to the optimal living cell cryopreservation are still unresolved.
Basic Cell Preservation Techniques
Generally, cell preservation methods could be categorized as: (a) a liquid-state stor-
age at hypothermic temperatures, but > 0°C (usually 4 ± 2°C) for red blood cells and
leukocytes or seldom for hematopoietic stem cells (SCs) up to 48 h; (b) a frozen-
state storage (−80°C to −196°C), the so-called cryopreservation [
1
] .
In brief, cryobiology is a scientific discipline that estimates the effects of ultra-
low temperature on cell integrity and functionality in the “refrigerated biological
