Femtosecond laser printing of living human cells

Laser-induced forward transfer (LIFT) has been used in recent years for the flexible and gentle 3D-bioprinting of cells with superior cell survival rates relative to other methods [1]. One drawback of the current state-of-the-art nanosecond laser based cell printing is the fact that material from an inorganic sacrificial layer, which is required for laser energy absorption, is transferred to the printed target structure, where it contaminates the printed construct [2]. Therefore, alternative approaches using deep UV laser sources and protein based acceptor films for energy absorption, have been introduced. Nevertheless, deep UV radiation can introduce DNA double strand breaks, thereby imposing the risk of carcinogenesis [3].