DEVELOPMENT OF A NOVEL METHOD FOR AMNIOTIC FLUID STEM CELL STORAGE

Background - Current procedures for collection of human Amniotic Fluid Stem Cells (hAFSCs) imply that amniotic fluid cells were cultured in flask for two weeks, than can be devoted to research purpose. However, hAFSCs could be retrieved directly from a small amount of amniotic fluid that can be obtained at the time of diagnostic amniocentesis. The aim of the study was to verify if a direct freezing of amniotic fluid cells is able to maintain and / or improve the potential of the sub-population of stem cells. Methods - We compared the potential of the hAFSCs depending on the moment in which they are frozen, cells obtained directly from amniotic fluid aspiration (D samples) and cells cultured in flask before freezing (C samples). Colony-forming-unit ability, proliferation, morphology, stemness-related marker expression, senescence, apoptosis, and differentiation potential of C and D samples were compared. Results - hAFSCs isolated from D samples expressed MSC markers until later passages, had a good proliferation rate, and exhibited differentiation capacity similar to hAFSCs of C samples. Interestingly, the direct freezing induce a higher concentration of cells positive for pluripotency stem cell markers, without teratoma formation in vivo. Conclusions - This study suggests that minimal processing may be adequate for the banking of amniotic fluid cells, avoiding in vitro passages before the storage and exposure to high oxygen concentration affecting stem cell properties. This technique might be a reasonable approach in terms of costs and for the process of accreditation in GMP for a stem cell bank.