The effects of cryopreservation on cells isolated from adipose, bone marrow and dental pulp tissues.

The effects of cryopreservation on mesenchymal stem cell (MSC) phenotype are not well documented; however this process is of increasing importance for regenerative therapies. This study examined the effect of cryopreservation (10% dimethyl-sulfoxide) on the morphology, viability, gene-expression and relative proportion of MSC surface-markers on cells derived from rat adipose, bone marrow and dental pulp. Cryopreservation significantly reduced the number of viable cells in bone marrow and dental pulp cell populations but had no observable effect on adipose cells. Flow cytometry analysis demonstrated significant increases in the relative expression of MSC surface-markers, CD90 and CD29/CD90 following cryopreservation. sqRT-PCR analysis of MSC gene-expression demonstrated increases in pluripotent markers for adipose and dental pulp, together with significant tissue-specific increases in CD44, CD73-CD105 following cryopreservation. Cells isolated from different tissue sources did not respond equally to cryopreservation with adipose tissue representing a more robust source of MSCs.