How we handled the dextran shortage: an alternative washing or dilution solution for cord blood infusions

Abstract

Dextran 40 is the main component of the solution used to wash or dilute thawed cord blood unit (CBU) products for stem cell transplant. Dextran 40 became unavailable in the United States as of April 2014. Like many other cellular therapy laboratories in the United States, we found ourselves with limited dextran 40 inventory, a growing CBU transplant requirement, and no alternative solution. Since there are no published alternative washing solutions for cryopreserved CBU we had to develop and validate a new solution rapidly. We chose to validate hydroxyethyl starch (HES) due to its similar ability to stabilize red blood cells and reduce sudden changes in osmolality that occur during thawing. For the validation we used 3 CBUs and thawed and washed each unit with both dextran 40- and HES-based solutions; thus, each CBU served as its own control. We observed no significant differences between the two wash solutions for all the monitored variables including cell viability, cell recovery, or potency measured by colony-forming cell assay. Based on this initial validation we began using HES-albumin for CBU washing after our supply was exhausted. Our initial experience with the first 16 CBU transplants after validation indicates safe infusion and preliminary cord engraftment.

An alternative to dextran for the thawing of cord blood units

“…17,18 It has been recently suggested that a solution of PA supplemented with HSA and HES gave results similar to the dextran 40 solution in terms of TNC recovery, CD341 and CD451 cell viability and recovery, and CFUs. 8,9 Our results also point to this conclusion. However, in this study, PA/HSA supplemented with Hespan was compared only to dextran 40 and not compared to the base solution alone (PA).…”

“…Besides, Hespan had already been proposed as a substitute for dextran 40 shortage, 8 and PA 16 is used for thawing peripheral blood mobilized stem cells. Based on these results, these solutions were further analyzed according to clonogenic potential.…”

“…Saline, Plasma-lyte A (PA), Plasma-lyte 148, and Plasma-lyte 148/dextrose were from Baxter Health Corp. The 25% HSA solution (Alburex) was from CSL Behring AG and Hespan was from Braun Medical, Inc. Because of the injectable-grade dextran 40 shortage, 8 we had to use powdered dextran 40 (US Biologicals) reconstituted in saline and supplemented with 5% HSA. Tubes were removed from the liquid nitrogen storage and thawed for 90 seconds in a 378C water bath.…”

“…While some centers are proactive in finding a solution, 8,9 most centers could find themselves in a critical situation shortly. Consequently, we undertook the search for a valid alternative to dextran 40 for the dilution or washing of thawed CBUs.…”

Dual‐Functional Dextran‐PEG Hydrogel as an Antimicrobial Biomedical Material

“…PEG is the most widely investigated synthetic polymer used in hydrogel preparation due to its unique properties, such as high hydrophilicity, nontoxicity, low protein adhesion, and nonimmunogenicity. In addition, both dextran and PEG, have been approved by the United States Food and Drug Administration (FDA) as biocompatible materials for various biomedical applications …”