What if you could print your own bandages? Or skin grafts? How about a new liver? Living in the future is a strange and interesting place, and it grows more interesting by the year. Scientists at Germany’s Fraunhofer Institute for Interfacial Engineering and Biotechnology are advancing the field of tissue engineering—developing biologically-derived tissue replacements—by automating tissue replication through the use of inkjet printers.
Fraunhofer scientists have developed biological inks, which consist largely of various biomolecules suspended in gelatin. Gelatin is derived from collagen, a common material in biological extracellular matrices that link cells together to form tissues. By combining various inks and irradiating them with UV light, scientists can adjust the properties of the printed mixture to imitate various living tissues by forcing the gelatin to cross-link into hydrogels, which are polymers containing high amounts of water that are stable in biologically-relevant aqueous conditions at 37 Co. Since a variety of bio-inks can be used with varying degrees of UV exposure, it’s possible to populate the gels with living cells and substitute the hydrogels for repair of natural tissues.
The printers themselves are very similar to standard inkjet printers: the ink reservoirs and inkjets are functionally the same. However, each well contains a heater that adjusts the ink to a correct temperature for a given temperature assignment. Additionally, due to current laboratory limitations, the number of jets and wells are both smaller than traditional printers; increasing these values is a current work in progress that should increase the range and specificity of bio-ink-derived structures.