In the recent breakthrough of stem cell researches, somatic cells can be reprogrammed to pluripotent states or be converted to other cell lineages by delivery of transcription factors, RNA or small molecules. The first challenge to overcome is to deliver molecules cross cell membrane. Several delivery methods, such as viral infections, lipid-mediated transfections and electroporations, are widely applied due to their robustness and large-scale operation. However, the spatial and temporal controls are hard to achieve due to stochastic nature of bulk processes. Here we developed a method, called nano-plasmonic poration, which allows large scale light-patterned molecular delivery at single-cell level resolution. Plasmonic gold nanorods (GNRs) have high efficiency of light harvesting and photothermal conversion, which makes them an ideal vector for melting cell membranes locally. The energy required to generate nanopores is extremely low, and therefore can be provided by a low magnification air objective with large field of excitation. Nanopores have long lifetime and exhibit two distributions in their diameter. Time dependent multi-molecules delivery and RNA induced gene silencing are demonstrated. By simply extending the expose area, light-patterned delivery can be scaled up to tissue-level. The flexible light-patterning, together with the capability of in situ and multi-delivery, makes nanoplasmonic poration a promising approach for studying cellular interactions during nuclear programming.
Project end date: 08/14/12