Three-dimensional decellularized amnion membrane scaffold promotes the efficiency of male germ cells generation from human induced pluripotent stem cells.

Cells grow differently in conventional 2D cell culture than when they grow in the physiological microenvironment. In this study, we developed a 3D cell culture model for generating male germ cells from human iPSCs using a human decellularized amnion membrane (DAM) scaffold. To this end, human iPSCs were generated using retroviral vectors and characterized for pluripotency properties by immunofluorescence assay, flow cytometry, ALP staining, cytogenetic assay, and differentiation capacity. The iPSCs were used for investigating male germ cells differentiation efficiency in both conventional 2D culture and 3D-DAM scaffold. The expression of male germ cell markers was evaluated at day 21 of differentiation using immunofluorescence assay, flow-cytometry, and RT-qPCR. The results indicated a successful reprogramming of human foreskin fibroblast cells into pluripotent iPSCs. The reprogrammed cells were positive for pluripotency markers and differentiated into the three germ layers. During male germ cell differentiation, the cells tend to aggregate and form colony-like structures in both 2D and 3D conditions. However, significant expression of VASA, DAZL, PLZF, STELLA, and NANOS3 markers and more efficient haploid male germ cell production were observed in the 3D condition when compared to the 2D model. Considering the effect of the 3D-DAM scaffold in prompting male germ cell-specific markers and increased efficiency of germ cell differentiation in 3D culture, it appears that DAM scaffold is a useful tool for in vitro studies of human germ cell development and ultimately future clinical application.