With the emergence of induced pluripotent stem cell (iPSC) technology, the somatic cells
can be reprogrammed to pluripotent state, and thus the new paradigm to generate patient-specific
pluripotent stem cells for disease pathogenesis and cell therapy. These iPSCs produced from a variety
of somatic cell sources are found to be very similar if not identical to embryonic stem cells. Currently
the most efficient way to produce such cells is by viral transduction with a combination of
transcriptional factors and as such that renders these cells unfit for therapeutic purposes. However,
recently there is further development in methods for generating iPSCs with minimal or no genetic
modifications via excisable lentiviral and transposon vectors or through repeated application of
transient plasmid, episomal, and adenovirus vectors and very recently the use of small molecules,
synthetic mRNA and microRNAs. However, as it is becoming evident now that the cell type of origin
influences the molecular and functional properties of derived iPSC. The indications that reprogramming
may erase the cell memory also raises the question if the disease phenotype may not be correctly
represented or also erased in iPSC unless coaxed by further perturbation in vitro culture conditions.
Similarly other tissue-derived stem cells and hESC-derived lineages offer an unprecedented opportunity
in biomedical research, cell therapy and regenerative medicine. However, to harness the full potential of
these technologies, a number of issues need to be resolved pertaining to their safety, stability, culture
variability, and better ways to direct a specific reprogramming process including lineage specifications.
Both hESC and iPSC fields offer phenomenal opportunities to study the basic molecular mechanistic of
human development, their use in disease modelling, regenerative medicine and drug discovery. A
steady progress in transitional and translational research particularly in various disease animal models
and very recently some human trials with these cells are very encouraging. This chapter briefly
summarises (not review) the recent developments in stem cell therapy, pitfalls and development.
Keywords: Cell therapy, stem cells, induced pluripotency, transplantation, graft rejection, regulation.
