Novel Strategies for the Improvement of Stem Cells’ Transplantation in Degenerative Retinal Diseases

Table 1

Embryonic versus adult versus induced pluripotent stem cells for cell-based therapy.

Cell type	Advantages	Disadvantages
Embryonic stem cell	(i) Pluripotent (can form all lineages of the body: ectoderm, mesoderm, endoderm); (ii) Grown relatively easily	(i) Likely to be rejected (if donor is allogeneic, unmatched); (ii) Harbors disease-causing genes of donor; Ethical problems; (iii) Chromosomal errors (aneuploidy), mitochondrion DNA defects, karyotype instability [40], and risk of teratoma formation following transplantation [10]
Adult stem cell	(i) Multipotent (can form multiple cell types of 1 lineage, e.g., retinal progenitor cell); (ii) Not rejected if transplanted into donor	(i) Relatively hard to harvest; (ii) Harbors disease-causing genes of donor
Induced pluripotent stem cell	(i) Pluripotent; (ii) Grown relatively easily; (iii) Probably not rejected if transplanted into donor	(i) May retain epigenetic features of cell type of origin; (ii) Harbors disease-causing genes of donor; (iii) Oncogenic potential of cells as a consequence of genetic manipulation [41]