Table 4.

iPSC reprogramming and type of gene transfection.

Type	Advantages	Disadvantages	Transgene expression	Efficiency	Ref.
Virus
Adenovirus	Nonintegrative; infects dividing and nondividing cells	Low efficiency	No	0.0001~0.01%	[84, 85]
Lenti/retrovirus	Ease of handling with experience; medium–high efficacy	Integration of foreign DNA into genome; residual expression of reprogramming factors; controversy regarding tumor formation	Yes	0.1~1%	[73, 125]
Sendai virus	Medium–high efficiency; nonintegrating; robust protein-expressing property; wide host range	Involve viral transduction	No	0.5~1.0%	[88, 89]
Plasmid vector
Episomal	Nonintegrative; simple to implement to laboratory setup; less time-consuming	Very low efficiency; the use of potent viral oncoprotein (SV40LT antigen)	No	3–6 × 10 − 6	[87, 126]
Minicircle	More persistent transgene expression; lack bacterial origin	Very low efficiency	No	0.01%	[127]
miRNA	Relative high efficiency; nonintegration; easily automated, making it an exciting candidate for routine biomanufacture.	Requires high gene dosages and multiple transfections; daily transfection; controversy in reproducibility and mitigating cost effectiveness	No	1.4~2%	[128, 129]
PiggyBac transposons	Elimination of insertional mutagenesis; no footprint upon excision; higher genome integration efficiency	Inefficient excision, potential for genomic toxicity	Excision with transposase	0.1~1%	[80]
Protein	Free of genetic materials; direct delivery of reprogramming factor proteins	Slow kinetics, low efficiency; difficulties in generation and purification of reprogramming protein	No	0.005~0.001%	[130]
Small molecules	Ease of handling; no requirements for reprogramming factors	More than one target, toxicity	No	0.3~0.5%	[86]