To apply laser pulses for printing of living cells and biomaterials is a promising technique for the realization of multicellular 3D constructs, for tissue engineering of 3D in vitro models, and for fabricating replacement tissue in regenerative medicine.
Our research group already demonstrated three-dimensional (3D) arrangements of single or two-dimensional (2D) patterning of different cell types. Cells can be printed with the laser-bioprinting technique without harm. We demonstrated the 3D arrangement of vital cells by laser-bioprinting as multicellular grafts analogous to native archetype. In one of our research projects, fibroblasts and keratinocytes embedded in collagen were printed in 3D as a simple example for skin. Thereby, we could observe (for the first time) the establishment of functional intercellular junctions, usually regarded as demonstration of tissue formation. Cell behavior after printing is highly affected by applied biomaterials. Thus, development and cell type specific optimization of biomaterials for printing (bio-ink) is a major task of our research. However, we also work on improving the laser-based technology and the application with cell type specific printing strategies.
The figure shows a schematic of the laser-bioprinting technique and a 2D pattern of printed hydrogel-droplets with embedded fluorescing cells. Besides the laser, the main element of the laser-bioprinting setup is a glass slide with two coatings on the lower side, first a thin laser absorbing layer and, subsequently, a layer of the biomaterial to be printed, usually a sol (the non-gelled precursor of a hydrogel) with embedded cells. The printing process is induced by a laser pulse focused from above through the glass slide into the absorption layer. The layer is evaporated in the focus and the expanding vapor bubble propels the biomaterial towards a substrate on which it deposits as a droplet with picoliter volume. Droplet-by-droplet and layer-by-layer predefined 2D and 3D patterns can be printed as a basis for generation of complex 3D tissue.
Dr. Lothar Koch
+ 49 511 532 1329