TABLE 3.
Reprogramming Strategies Developed to Generate Induced PSCs
| Reprogramming Methods | Advantages | Drawbacks | Induced PSC Generation (%) | Example of Somatic Cell Types Used | ||
|---|---|---|---|---|---|---|
| Integrative | Viral | Retrovirus | Highly efficient, stable, easy to use, efficient on a large number of cell types | Genomic integration (Cre/Lox system possible) | ≈0.1 | Fibroblasts, urine cells, MSCs, hepatocytes, GECs, NPCs |
| Lentivirus | Efficient, stable, easy to use, efficient on a large number of cell types | Genomic integration | ≈0.1 | Fibroblasts, PBMCs, adipose stem cells | ||
| Excisable lentiviral vectors | Excisable, relatively efficient | Genomic integration | ND | Fibroblasts | ||
| Inducible lentiviral systems | Controlled expression of reprogramming factors | Genomic integration | ND | Fibroblasts, melanocytes | ||
| Nonviral | PiggyBac | Excisable, relatively efficient | Genomic integration, efficiency? | ND | Fibroblasts | |
| Zinc finger nucleases | Targeted integration, excisable | Genomic integration | ND | Fibroblasts | ||
| Nonintegrative | Recombinant virus | Adenovirus | Very low genomic integration, easy‐to‐use | Time‐consuming, low efficiency, only in permissive cell types | ≈0.0002 | Fibroblasts, fetal liver cells |
| Sendai | No genomic integration, efficient on a large number of cell types, easily eliminated | Viral elimination not immediate (several passages required) | ≈0.1 | Fibroblasts, T cells, CD34+ cells | ||
| Episomal | Episomal vectors | Low risk of integration, easy to perform, controllably removable | Very low efficiency, time‐consuming | ≈0.0003‐0.0006 | Fibroblasts, CD34+ cells, dental pulp cells, PBMCs | |
| Others | mRNA | No genomic integration, very safe for clinical application | Daily transfection, efficiency dependent on cell type | ≈0.001‐2 | Fibroblasts, ADSCs, keratinocytes | |
| Proteins | No genomic integration, very safe for clinical application | Difficult to perform, low efficiency | ≈0.0005‐0.001 | Fibroblasts | ||
| Plasmids | Low risk of integration, easy to perform | Transient expression factors | ≈0.002‐0.01 | Fibroblasts, ADSCs, CD34+ cells, PBMCs | ||
| Small molecules | Highly efficient | Long to perform | ≈0.2 | Fibroblasts | ||
| miRNA | No genomic integration, very safe for clinical application | Can be time‐consuming, efficiency dependent on cell type | ≈0.03‐10 | Fibroblasts, hair follicle cells, ASCs | ||
Additional data are available in Supporting Table S3.
Abbreviations: ADSC, adipose‐derived stem cell; ASC, adipose stromal cell; CD34, cluster of differentiation 34; GEC, gastric epithelial cell; NPC, neural progenitor cell; PBMC, peripheral blood mononuclear cell.