Abstract
MSCs can be isolated from adult sources such as bone marrow and adipose tissue. In contrast to these adult tissue sources, harvesting MSCs from cord tissue is a non-invasive procedure and poses no risk to the donor. Stem cell banks offer the opportunity to cryopreserve cord tissue as a source of MSCs for future autologous or allogeneic stem cell based regenerative medicine applications. There is little published data however, characterizing MSCs isolated from cryopreserved cord tissue. The goal of this study was to determine if MSCs isolated from cryopreserved cord tissue are functionally equivalent to MSCs isolated from fresh cord tissue. Umbilical cords were collected from 10 donors. Cords were segmented into 4-6 inch pieces and either cryopreserved or used immediately. Fresh and thawed cord segments were cultured in 7-14 days for outgrowth of MSCs. MSCs were analyzed by FACS for CD45, CD73, CD90 and CD105 expression. FACs analysis confirmed cells isolated from both fresh and frozen tissue expressed MSC markers. Adherent cells were obtained from both fresh and cryopreserved cord tissue segments at a similar plating efficiency. There was no difference in either the number or time of population doublings. MSCs isolated from fresh and frozen tissue were capable of differentiating along adipogenic, chondrogenic, osteogenic and neurogenic pathways, as confirmed by histology and RT-PCR analysis of tissue specific mRNAs. No significant functional differences were observed between MSCs from frozen cord tissue as compared to fresh cord tissue. Cryopreserving cord tissue allows for isolation of MSCs at the point of care when the specific clinical application is known. This may be advantageous as MSC isolation protocols continue to be optimized dependent on intended use.
Keywords: Cord tissue, cryopreservation, mesenchymal stem cells, regenerative medicine, stem cells, tissue engineering.
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