Delivery of reprogramming factors into fibroblasts for generation of non-genetic induced pluripotent stem cells using a cationic bolaamphiphile as a non-viral vector

Protein delivery allows a clinical effect to be directly realized without genetic modification of the host cells. We have developed a cationic bolaamphiphile as a non-viral vector for protein delivery application. The relatively low toxicity and efficient protein delivery by the cationic bolaamphiphile prompted us to test the system for the generation of induced pluripotent stem cells (iPSCs) as an alternative to the conventional vector-based genetic approach. Studies on the kinetics and cytotoxicity of the protein delivery system led us to use an optimized cationic bolaamphiphile-protein complex ratio of 7:1 (wt/wt) and a 3 h period of incubation with human fibroblasts, to ensure complete and non-toxic protein delivery of the reprogramming proteins. The reprogrammed cells were shown to exhibit the characteristics of embryonic stem cells, including expression of pluripotent markers, teratoma formation in SCID mice, and ability to be differentiated into a specific lineage, as exemplified by neuronal differentiation.