Effect of Long-Term Cryopreservation on the Stemness of Stem Cells of Apical Papilla.

Stem cells of apical papilla (SCAPs) are considered a subpopulation of dental stem cells with unique properties. They originate from a developing tissue, the apical papilla of developing teeth, a characteristic that enhances their stemness. Banking of these stem cells can offer a source of dental stem cells for future regenerative therapies. Until now, only the effect of six months' cryopreservation on SCAPs has been studied. In this study, the long-term (19 months) effect of cryopreservation on SCAPs was examined by means of estimation of their differentiation's capacity, flow cytometry immunophenotypical characterization, and molecular characterization of the main transcriptional factors that coincide with pluripotency. As was indicated from our results, 19-month cryopreservation of SCAPs did not affect negatively their stemness; since no significant difference was observed on their typical fibroblast-like morphology, they retained their differentiation capacity, and no discrepancies were found either on immunophenotypical level or molecular level.