The new method developed by Professor Adam W. Feinberg and his colleagues is called FRESH (Freeform Reversible Embedding of Suspended Hydrogels). It allows printing collagen scaffolds from fibers only 25 micrometers thick as well as cell-loaded organ parts. The collagen is printed in a bath of a tough hydrogel, which keeps the collagen in shape and is later melted away. Even the finest ramifications and pores can be considered with the print. In addition to collagen, they printed myocardial stem cells which were able to beat synchronously after seven days.
However, there are still a few years further research are needed before a complete, functional heart can be printed.
Lee, A., Hudson, A. R., Shiwarski, D. J., Tashman, J. W., Hinton, T. J., Yerneni, S., Bliley, J. M., Campbell, P. G. & Feinberg, A. W. (2019). 3D bioprinting of collagen to rebuild components of the human heart. Science 365/6452: 482-487. DOI: 10,1126/science.aav9051
Source:
https://www.scinexx.de/news/medizin/schlagende-herzkammer-aus-dem-3d-drucker/