Large-scale high-performance cell membrane perforation, with nanoimprinted mass producible perforator

The importance of developing methods in which certain materials can be introduced into a group of cells has been gaining considerable attention. However, owing to safety concerns accompanying the use of conventional viral-vector-based transfection and the low efficiency of plasmid-vector-based transfection, the development of a high performance nonbiological method has been expected. Currently available nonbiological methods such as electroporation generally have a low success rate and limited to low-molecular-weight molecules. For other methods that employ cellar uptake like phagocytosis, such as the cationic liposome method, these efficiencies largely depend on the nature of the target cells. In contrast, we found that submicron level cell membrane perforations could be made by inducing the local oxidations in the cell membrane while most of the treated cells were viable. We applied the perforation to the microinjection method and found that the injection of a functional dye, an antibody, and mRNA to the cells resulted in almost 100% survival as well as the successful manifestation of individual functions of these injected molecules. In the recent study, we extended the perforation process in a large number of cells. A nanobrush- shaped soft-polymer sheets formed by the nanoimprinting, which contained a photosensitizer, are used as the cell membrane perforator. We could automate the process by the robotics technology for the high-throughput operation. In future studies, we will extend the cell processing system for multi-purpose practical instruments for e.g. novel cell therapy, systematic cell differentiation.