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Journal of Biomedicine and Biotechnology
Volume 2012 (2012), Article ID 649353, 10 pages
http://dx.doi.org/10.1155/2012/649353
Research Article

Evaluation of Distinct Freezing Methods and Cryoprotectants for Human Amniotic Fluid Stem Cells Cryopreservation

1Laboratory of Genetics and Molecular Hematology (LIM-31), University of São Paulo Medical School, 05403-000 São Paulo, SP, Brazil
2Fundação Pró-Sangue Hemocentro de São Paulo, 05403-000 São Paulo, SP, Brazil
3Department of Gynecology and Obstetrics, University of São Paulo Medical School, 05403-000 São Paulo, SP, Brazil
4Fetal Medicine, Department of Obstetrics, São Paulo Federal University Medical School, 04021-001 São Paulo, SP, Brazil

Received 29 December 2011; Accepted 6 March 2012

Academic Editor: Steve Winder

Copyright © 2012 Felipe de Lara Janz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Amniotic fluid (AF) was described as a potential source of mesenchymal stem cells (MSCs) for biomedicine purposes. Therefore, evaluation of alternative cryoprotectants and freezing protocols capable to maintain the viability and stemness of these cells after cooling is still needed. AF stem cells (AFSCs) were tested for different freezing methods and cryoprotectants. Cell viability, gene expression, surface markers, and plasticity were evaluated after thawing. AFSCs expressed undifferentiated genes Oct4 and Nanog; presented typical markers (CD29, CD44, CD90, and CD105) and were able to differentiate into mesenchymal lineages. All tested cryoprotectants preserved the features of AFSCs however, variations in cell viability were observed. In this concern, dimethyl sulfoxide (Me2SO) showed the best results. The freezing protocols tested did not promote significant changes in the AFSCs viability. Time programmed and nonprogrammed freezing methods could be used for successful AFSCs cryopreservation for 6 months. Although tested cryoprotectants maintained undifferentiated gene expression, typical markers, and plasticity of AFSCs, only Me2SO and glycerol presented workable viability ratios.