High-throughput continuous flow femtosecond laser-assisted cell optoporation and transfection

We present a femtosecond-laser based nanoprocessing system for transient optical cell membrane poration to allow the introduction of foreign molecules into the interior of a cell with very high throughput. In the setup, cells flow through a micro-flow tube for spatial confinement and are simultaneously targeted by fs laser radiation. Beam-shaping generates a focal geometry along a line which is scanned across the micro-flow cell to increase the number of reachable cells. Successful cell membrane poration was observed indirectly by cell transfection even with cell-light interaction times in the millisecond range. The system was characterized by experiments with Chinese hamster ovary cells regarding cell viability, the uptake of extrinsic molecules and cell transfection efficiency. The continuous flow of cells enables a tremendous increase of cell throughput compared to previous nonflow approaches by treating millions of cells, although with only limited efficiency. The setup opens the possibility to realize a completely automated high-throughput laser-assisted cell-poration system which could be integrated in lab-on-a-chip devices.