Open Access

Louise Breideband, Kaja N. Wächtershäuser, Levin Hafa, Konstantin Wieland, Achilleas S. Frangakis, Ernst H. K. Stelzer, Francesco Pampaloni

• A widespread application of 3D bioprinting in basic and translational research requires accessibility to affordable printers able to produce physiologically relevant tissue models. To facilitate the use of bioprinting as a standard technique in biology, an open-source device based on a consumer-grade 3D stereolithography apparatus (SLA) printer is developed. This SLA bioprinter can produce complex constructs that preserve cell viability and recapitulate the physiology of tissues. The detailed documentation of the modifications apported to the printer as well as a throughout performance analysis allow for a straightforward adoption of the device in other labs and its customization for specific applications. Given the low cost, several modified bioprinters could be simultaneously operated for a parallelized tissue production. To showcase the capability of the bioprinter, constructs consisting of patient-derived cholangiocarcinoma organoids encapsulated in a gelatin methacrylate (GelMA)/polyethylene glycol diacrylate (PEGDA) hydrogel are produced. A thorough characterization of different GelMA/PEGDA ratios reveals that the mechanical properties of the bioprinted tumor model can be accurately fine-tuned to mimic a specific tumor micro-environment. Immunofluorescence and gene expression analyses of tumor markers confirm that the bioprinted synthetic hydrogel provides a flexible and adequate replacement of animal-derived reconstituted extracellular matrix.