Table 1 Comparison between different stem cells
ESCs | iPSCs | HSCs | MSCs | |
|---|---|---|---|---|
Potency | Totipotent: zygote – morula | Pluripotent | Pluripotent | Multipotent |
Pluripotent: inner cell mass of blastocyst | ||||
Major sources | Inner cell mass of blastocyst | Reprogramming of adult cells | Bone marrow, peripheral blood, umbilical cord blood | Bone marrow, adipose tissues, umbilical cord matrix |
Cell surface markers | hESC lines: SSEA-4, Tra 1-60, Tra 1-81 [273] | Cell surface antigenic markers expressed on ESCs, e.g. SSEA-3 in human, SSEA-1 in mouse [274] | CD70+, CD90+, CD105+ [277] | |
mESC lines: NANOG, OCT4, SOX2, SSEA-1 [274] | CD34– [278] | |||
Potential clinical application in cardiac regeneration | • Yield a variety of cardiomyocyte-atrial, ventricular and sinus-nodal like cells [279] • Isolation of pure ventricular cardiomyocyte population using adenovirus vectors [280] | Generation of cardiomyocyte sheet along with endothelial cells using angiogenic. factors (VEGF) [281] | No transdifferentiation into cardiac cells in ischaemic tissues [282] | • Improves heart function • Increase in augmented angiogenesis • Reduction in fibrosis [283] |
Advantages | Differentiates into three germ layers: ectoderm, mesoderm, endoderm | Produced using adult cells, hence avoids ethical issues | Proliferation and migration to site of injury | • Allogenic grafting possible without immunosuppressive agents • Limited inclination towards mutation |
Limitations | • Availability of cell lines for federally funded research • Risk of producing teratomas from transplanting undifferentiating stem cells | • Generation and safe delivery of iPSC-derived cardiomyocytes is strenuous [284] • Tumour formation possible [285] | • Insufficiency in the DNA repair system caused by ageing, thereby limiting the function of HSCs [286] • Insufficient information on signalling pathway [21] • Possibility of gonadal dysfunction and infertility [287] | • Insufficient information on which MSC source to be used for the therapeutic strategy concerning a disease [19] • Route of administration is uncertain for different diseases [19] |
Ethical concerns | • Involves human blastocyst • Consent for blastocyst/egg donation is required | None specifically | • Need for clinical parity • Consideration required for cure of children withess severe sickle cell disease [287] | None specifically |