Evaluations of bioantioxidants in cryopreservation of umbilical cord blood using natural cryoprotectants and low concentrations of dimethylsulfoxide.
Transplantation using hematopoietic stem cells from umbilical cord blood (UCB) is a life-saving treatment option for patients with select oncologic diseases, immunologic diseases, bone marrow failure, and others. Often this transplant modality requires cryopreservation and storage of hematopoietic stem cells (HSC), which need to remain cryopreserved in UCB banks for possible future use. The most widely used cryoprotectant is dimethylsulfoxide (Me(2)SO), but at 37 degrees C, it is toxic to cells and for patients, infusion of cryopreserved HSC with Me(2)SO has been associated with side effects. Freezing of cells leads to chemical change of cellular components, which results in physical disruption. Reactive oxygen species (ROS) generation also has been implicated as cause of damage to cells during freezing. We assessed the ability of two bioantioxidants and two disaccharides, to enhance the cryopreservation of UCB. UCB was processed and subjected to cryopreservation in solutions containing different concentrations of Me(2)SO, bioantioxidants and disaccharides. Samples were thawed, and then analysed by: flow cytometry analysis, CFU assay and MTT viability assay. In this study, our analyses showed that antioxidants, principally catalase, performed greater preservation of: CD34+ cells, CD123+ cells, colony-forming units and cell viability, all post-thawed, compared with the standard solution of cryopreservation. Our present studies show that the addition of catalase improved the cryopreservation outcome. Catalase may act on reducing levels of ROS, further indicating that accumulation of free radicals indeed leads to death in cryopreserved hematopoietic cells.
Histocompatibility and Cryopreservation Laboratory, Department of Histology and Embryology, Institute of Biology Roberto Alcantara Gomes, Rio de Janeiro State University, 20950-003 Rio de Janeiro, Brazil.
J P R
JP
Motta
B E
BE
Gomes
L F
LF
Bouzas
F H
FH
Paraguassú-Braga
L C
LC
Porto
D000975:Antioxidants / Q000494:pharmacology*; D001793:Blood Preservation / Q000379:methods*; D002374:Catalase / Q000494:pharmacology; D002469:Cell Separation; D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004187:Disaccharides / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology / Q000187:drug effects; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D006801:Humans; D013234:Stem Cells / Q000187:drug effects; D013395:Sucrose / Q000494:pharmacology; D014199:Trehalose / Q000494:pharmacology
D000975:Antioxidants; D003451:Cryoprotective Agents; D004187:Disaccharides; D013395:Sucrose; D014199:Trehalose; D002374:Catalase; D004121:Dimethyl Sulfoxide