Automated nanotube stamping system for direct delivery of liquid substances into adherent cells

Abstract Nanotube (NT) stamping has the advantage of delivering substances to a large number of cells in a shorter time. However, because it was controlled manually, the results varied depending on the individual performing the procedure. Here we propose an automated NT stamping system that enhances the accuracy and reproducibility of delivering liquid substances into cells by combining stepper motor control and image processing with a conventional inverted microscope. The automated system inserts NTs into adherent cells by sequential two-step focusing of the objective lens on the target cells and the NT membrane. We show that the automated system achieves submicron precision in controlling the vertical position of the NTs relative to the adherent cells by the two-step focusing while maintaining a high delivery rate of 72% and high cell viability of more than 90%. The target substances can be delivered into the nuclei of HeLa cells preferentially by our stamping system.