L. Koch
A. Deiwick
B. N. Chichkov

Laser Cell Printing for Tissue Engineering

Macromolecular Colloquium Freiburg
24.-26. Februar
Type: Konferenzbeitrag
Currently, different 3D printing techniques are investigated for printing biomaterials and living cells. An ambitious aim is the printing of fully functional tissue or organs; but also for manifold applications in biomedical research and in testing of pharmaceuticals or cosmetics, printed tissue could offer new approaches. One of these techniques is laser-assisted bioprinting (LaBP) based on the so-called laser-induced forward transfer. For printing cells, the cells are embedded in hydrogel precursors, so-called sols, hydrogels, or compositions of different sols/hydrogels and deposited (printed) as droplets. For printing 3D cell patterns or tissue, often a sol is printed with embedded cells and then gelled with a cross-linker to yield appropriate stiffness for a 3D structure. A schematic sketch of the printing setup is shown in figure 1. In principle, a laser-transparent glass slide is coated with a thin layer of a laser absorbing material. A layer of the cell-containing sol is blade coated on top of the absorbing layer. Then, the glass slide is mounted upside-down above the item onto which the cells shall be printed. Through the glass slide, the laser pulses are focused into the absorption layer, which is rapidly evaporated in the focus. A vapor bubble expands and propels the subjacent sol downwards, which deposits as a small droplet. By moving the laser beam and the glass slide, droplets are deposited in two-dimensional patterns (figure 1); three-dimensional patterns can be generated layer-by-layer.