Techniques of Human Embryonic Stem Cell and Induced Pluripotent Stem Cell Derivation

Developing procedures for the derivation of human pluripotent stem cells (PSCs) gave rise to novel pathways into regenerative medicine research. For many years, stem cells have attracted attention as a potentially unlimited cell source for cellular therapy in neurodegenerative disorders, cardiovascular diseases, and spinal cord injuries, for example. In these studies, adult stem cells were insufficient; therefore, many attempts were made to obtain PSCs by other means. This review discusses key issues concerning the techniques of pluripotent cell acquisition. Technical and ethical issues hindered the medical use of somatic cell nuclear transfer and embryonic stem cells. Therefore, induced PSCs (iPSCs) emerged as a powerful technique with great potential for clinical applications, patient-specific disease modelling and pharmaceutical studies. The replacement of viral vectors or the administration of analogous proteins or chemical compounds during cell reprogramming are modifications designed to reduce tumorigenesis risk and to augment the procedure efficiency. Intensified analysis of new PSC lines revealed other barriers to overcome, such as epigenetic memory, disparity between human and mouse pluripotency, and variable response to differentiation of some iPSC lines. Thus, multidimensional verification must be conducted to fulfil strict clinical-grade requirements. Nevertheless, the first clinical trials in patients with spinal cord injury and macular dystrophy were recently carried out with differentiated iPSCs, encouraging alternative strategies for potential autologous cellular therapies.