Human amniotic epithelial cells:culture technology optimization and biological characteristics / 中国组织工程研究

ABSTRACT

BACKGROUND:As current studies on isolation, culture andcryopreservation of human amniotic epithelial cells (hAECs) are relatively scattered, it is difficult to form a comprehensive and effective solution to meet the clinical needs of stem cells for transplantation in future.OBJECTIVE:To establish the technology of isolation, culture and cryopreservation of hAECs, and to study the biological characteristics of hAECs.METHODS:Orthogonal method was used to study the effects of different factors on the separation, culture and cryopreservation, and range method was adopted to analyze the data to optimize the separation, culture and cryopreservation. We performed cell primary and passage cultures, morphology observed by microscope, drawn cell growth curve and flow cytometry assay, immunofluorescence staining, hepatocyte like cell differentiation to study the biological characteristics of hAECs.RESULTS AND CONCLUSION:(1) The optimal hAECs separation conditions were as followstrypsin digestions were conducted at a concentration of 0.25%, four times, once for 20 minutes digestion; optimal conditions of culture were 4×108/L cell seeding density, 10 μg/L epidermal growth factor, 5% serum; optimal conditions of cryopreservation were 1×1010/L cell cryopreservation density, 10% dimethyl sulfoxide, 80% serum. (2) The primary cells were adhered to the wall in 2-3 days, exhibiting irregular polygon, paving stone-like growth. Cell adherence and growth rate were accelerated after subculture, and the growth and proliferation ability of passage 2 cells were not significantly decreased after cryopreservation and resuscitation. (3) Immunofluorescence staining showed that the primary cells strongly expressed SSEA-4 and CK19, but did not express Vimentin, CD45 and HLA-DR. The immunophenotype statistics of the primary and passage 4 cells showed the epithelial mesenchymal transition of hAECs in culture process. (4) Immunofluorescence staining showed that the liver cell marker expression of ALB, CK18 was significantly increased after hAECs were induced to differentiate into hepatocyte-like cells. Glycogen staining revealed glycogen synthesis in hAECs after 3 weeks of induction. To conclude, hAECs are easy to obtain and have strong proliferation ability in vitro, and express surface markers for undifferentiated embryonic stem cells.