title: 5% dimethyl sulfoxide (DMSO) and pentastarch improves cryopreservation of cord blood cells over 10% DMSO.
abstract: 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.
authors.affiliation: 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.
authors.forename: Jun
authors.initials: J
authors.lastname: Hayakawa
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Joyal
authors.forename: Jean F
authors.initials: JF
authors.lastname: Gildner
authors.forename: Kareem N
authors.initials: KN
authors.lastname: Washington
authors.forename: Oswald A
authors.initials: OA
authors.lastname: Phang
authors.forename: Naoya
authors.initials: N
authors.lastname: Uchida
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Hsieh
authors.forename: John F
authors.initials: JF
authors.lastname: Tisdale
mesh_terms: 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
chemical_list: D018952:Antigens, CD34; D003451:Cryoprotective Agents; D006895:Hydroxyethyl Starch Derivatives; D004121:Dimethyl Sulfoxide