5% dimethyl sulfoxide (DMSO) and pentastarch improves cryopreservation of cord blood cells over 10% DMSO.
BACKGROUND
Cell number and viability are important in cord blood (CB) transplantation. While 10% dimethyl sulfoxide (DMSO) is the standard medium, adding a starch to freezing medium is increasingly utilized as a cytoprotectant for the thawing process. Similar to hetastarch, pentastarch has the advantages of faster renal clearance and less effect on the coagulation system.


METHODS
We compared a lower DMSO concentration (5%) containing pentastarch with 10% DMSO and performed cell viability assay, colony-forming units (CFUs), and transplantation of CB cells in NOD/SCID IL2Rγ(null) mice.


RESULTS
CB cells in 5% DMSO/pentastarch had similar CD34+, CD3+, and CD19+ cell percentages after thawing as fresh CB cells. CB cells in 5% DMSO/pentastarch had higher viability (83.3±9.23%) than those frozen in 10% DMSO (75.3±11.0%, p<0.05). We monitored cell viability postthaw every 30 minutes. The mean loss in the first 30 minutes was less in the 5% DMSO/pentastarch group. At the end of 3 hours, the viability decreased by a mean of 7.75% for the 5% DMSO/pentastarch and 17.5% for the 10% DMSO groups. CFUs were similar between the two cryopreserved groups. Frozen CB cells engrafted equally well in IL2Rγ(null) mice compared to fresh CB cells up to 24 weeks, and CB cells frozen in 5% DMSO/pentastarch engrafted better than those in 10% DMSO.


CONCLUSIONS
Our data indicate that the lower DMSO concentration with pentastarch represents an improvement in the CB cryopreservation process and could have wider clinical application as an alternate freezing medium over 10% DMSO.
Hayakawa
Jun
J
Molecular and Clinical Hematology Branch (MCHB), National Institutes of Diabetes and Digestive and Kidney Disorders (NIDDK), National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health, Bethesda, Maryland, USA.
Joyal
Elizabeth G
EG
Gildner
Jean F
JF
Washington
Kareem N
KN
Phang
Oswald A
OA
Uchida
Naoya
N
Hsieh
Matthew M
MM
Tisdale
John F
JF
D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D001793:Blood Preservation / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000009:adverse effects; D004121:Dimethyl Sulfoxide / Q000009:adverse effects*; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000009:adverse effects; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000637:transplantation; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID
D018952:Antigens, CD34; D003451:Cryoprotective Agents; D006895:Hydroxyethyl Starch Derivatives; D004121:Dimethyl Sulfoxide