Cell Poration of Fixed and Live Cells by Phase Shaped Femtosecond Pulses

In femtosecond optical transfection and nanosurgery, cell survival critically depends on phototoxicity. It is therefore of primary importance to optimize the laser-cell interaction in order to increase the membrane poration efficiency while reducing collateral cell damage. Baumert group studied the impact of spectral phase modulation of femtosecond for machining on glass substrate. They demonstrated that the use of third order phase pulses (Airy pulses) could modulate the photon-interaction leading to holes of higher aspect ratio, compared to those produced by femtosecond bandwidth limited pulses. Following this approach, we showed that optimally shaped temporal Airy pulses display better performances also on fixed biological samples. In fact, Airy pulses can increase the cell membrane poration efficiency for a lower peak intensity and a similar energy per pulse than bandwith limited femtosecond pulses. We also discuss results from a live cell experiment. We set up a protocol where we investigate cells poration efficiency and cell viability as a function of pulse spectral phase. Hence, we present a protocol based on the use of three fluorophores to assess cells viability at different time points after poration.