Generation of human naive induced pluripotent stem cells in microfluidics

Induced pluripotent stem cells (iPSCs) are generated by expression of transcription factors OCT4, SOX2, KLF4 and cMYC (OSKM) in somatic cells. In contrast to murine naïve iPSCs, conventional human iPSCs are in a more developmentally advanced state called primed pluripotency. Here we report that human naïve iPSCs (niPSCs) can be generated directly from less than 1000 primary human somatic cells without stable genetic manipulation by delivery of modified messenger RNAs with microfluidics. Expression of OSKM in combination with NANOG for 12 days generates niPSCs free of transgenes, karyotypically normal, and display transcriptional, epigenetic and metabolic features indicative of the naïve state. Importantly, niPSCs efficiently differentiate into all three germ layers. While niPSCs could also be generated at low frequency under conventional conditions, our microfluidics approach will allow robust and cost-effective production of patient-specific niPSCs for regenerative medicine applications, including disease modelling and drug screening.