Induced pluripotent stem cells (iPSCs) bear great potential for disease modeling, drug discovery, and regenerative medicine; however, the wide adoption of iPSC for clinically relevant applications has been hindered by the extremely low reprogramming efficiency. Here, we describe a high-efficiency cellular reprogramming strategy by puncturing cells with an array of diamond nanoneedles, which is applied to temporally disrupt the cell membrane in a reversible and minimally invasive format. This method enables high-efficiency cytoplasmic delivery of mini-intronic plasmid vectors to initiate the conversion of human fibroblast cells to either primed iPSCs or naı̈ve iPSCs. The nanopuncturing operation is directly performed on cells in adherent culture without any cell lift-off and is completed within just 5 min. The treated cells are then cultured in feeder-free medium to achieve a reprogramming efficiency of 1.17 ± 0.28%, which is more than 2 orders of magnitude higher than the typical results from common methods involving plasmid delivery.
Keywords: cell reprogramming; cell transfection; diamond nanoneedle; induced pluripotency; intracellular delivery; membrane disruption.