ABSTRACT
The enormous potential of hESCs and iPSCs to treat human diseases has energized the scientifi c community and the lay public alike. These cells hold great promise in regenerative biology, but many key barriers will need to be overcome before these cells can be safely and effectively be put into clinical practice. One fundamental challenge is the reproducible isolation of pure cell populations for transplantation. Despite the rapidily evolving area of differentiation of both from hESCs and iPSCs to different cell types, it is still very diffi cult to isolate homogeneous populations of the specifi c cell type required. In addition, the incomplete differentiation of pluripotent stem cells may lead to unwanted teratoma formation in the donor (Wu and Hochedlinger 2011). The issue of survival and proper migration of donor cells in recipients raises another big question mark. Thus, the optimization and innovation in transplantation methods are the immediate research direction for fulfi llment of the cellular regenerative medicine. Issues with low cell survival, poor migration and integration of stem cells upon transplantations will need to be addressed, as well as immunological complications surrounding the use of non-autologous stem cells. In this respect, iPSCs may be a better alternative and can be used to develop individual-specifi c stem cell lines with their own set of unique genetic material.
