[conflict_unresolved] Are there independent studies directly comparing episomal and Sendai reprogramming in the same human somatic cell type while matching the reprogramming-factor cocktail, culture substrate and media, starting-cell denominator, colony-counting endpoint and time point, and replicate design?

Answer

No verified study in this corpus fully satisfies the task's matching criteria -- same human cell type, identical reprogramming-factor cocktail, matched culture substrate/media, the same starting-cell denominator, the same colony-counting endpoint/time point, and a stated replicate design -- for an episomal-versus-Sendai comparison, so the specific gap this task names remains open. The two closest independent, same-cell-type comparisons disagree with each other. Okur et al. (2019) compared Sendai virus and Epi5 episomal reprogramming on the same bone-marrow mesenchymal stromal-cell samples from osteopetrosis patients and found Sendai about three-fold more efficient -- 0.3 +/- 0.11% AP-positive colonies versus 0.1 +/- 0.02% for Epi5 at roughly day 24-28 -- though the two arms used different factor cocktails 90ca7aae. Trevisan et al. (2017) instead compared episomal and Sendai reprogramming of the same batch of human neonatal foreskin BJ fibroblasts, using identical media, feeders, reagents and operator, and identical TRA-1-60-positive colony counting at the same time points, and found no meaningful efficiency difference between the two methods, about 0.05% for both, again with differing factor cocktails 92d5ee92. A third source, Manzini et al. (2015), compared Sendai against three plasmid-transfection techniques -- Nucleofector, Neon electroporation, and Lipofectamine -- in the same primary human dermal fibroblast donors, but used different cell-input denominators between the Sendai and plasmid arms (roughly 150,000 versus 600,000 cells) and did not isolate a clean episomal-versus-Sendai comparison 9009180d.

Summary

The corpus contains partially matched, independent episomal-versus-Sendai comparisons, but none matches every dimension the question requires, and the two best-matched studies point in opposite directions -- one favors Sendai, the other finds no difference. The all-dimensions-matched study this gap calls for has not yet been verified in this corpus.

Evidence

• Okur et al., 2019 (Stem Cell Research & Therapy) -- same-patient bone-marrow MSC comparison; Sendai 0.3 +/- 0.11% vs. episomal (Epi5) 0.1 +/- 0.02% AP-positive colony efficiency at day ~24-28; factor cocktails differ between arms. 90ca7aae
• Trevisan et al., 2017 (International Journal of Molecular Sciences) -- same-batch, same-operator comparison in BJ fibroblasts; episomal and Sendai both ~0.05% TRA-1-60-positive colony efficiency, versus 0.01% for retroviral; culture substrate, media, denominator and counting endpoint matched, factor cocktails differ. 92d5ee92
• Manzini et al., 2015 (Stem Cell Reviews and Reports) -- same-donor primary human dermal fibroblasts; Sendai efficiencies 0.0026%, 0.04%, 0.0173% across three patients versus plasmid-transfection methods at differing cell-input denominators; not a clean episomal-vs-Sendai isolate. 9009180d

Methodology

I excluded the chemical-reprogramming induction-time submission because it does not address episomal-versus-Sendai delivery at all. I treated the remaining three sources as partial matches rather than pooling their percentages, since each isolates a different subset of the required matching dimensions -- patient/cell-type match without factor-cocktail match for Okur and Trevisan; cell-donor match without denominator match for Manzini -- and none reports a formal cross-lab replicate design. Because Okur and Trevisan disagree on direction while both are only partially matched, I did not average their efficiency values or declare a winner.

Limitations

• No verified source in this corpus matches all five required dimensions -- factor cocktail, culture substrate/media, starting-cell denominator, colony-counting endpoint/time point, and replicate design -- in a single episomal-vs-Sendai comparison.
• Okur et al. (2019) and Trevisan et al. (2017) are both partially matched but disagree on which delivery method is more efficient, so combining them does not resolve the question either.
• Manzini et al. (2015) uses mismatched cell-input denominators between its Sendai and plasmid arms, so its percentages cannot be compared directly to the other two studies.