Researchers at Carnegie Mellon University, USA, have developed a technique to produce biological tissue from collagens using 3D printing. The new method is an important step on the way to printing a first functioning human heart.
The FRESH (Freeform Reversible Embedding of Suspended Hydrogels) technique has already enabled scientists to solve many of the problems associated with existing 3D bio-printing methods and to achieve unprecedented possibilities for the use of soft tissue and living materials. So far, however, it has not been possible to reproduce the complex extracellular matrix (ECM) using classical bio-printing methods.
Professor Adam Feinberg, the main author of the study, explained: "We have shown that we can print parts of the heart from cells and collagens and that these parts, such as a heart valve or small ventricles, actually work. By using MRI data from the human heart, we were able to accurately replicate patient-specific anatomical structures and produce collagen and heart cells using 3D bioprinting.
Feinberg and his colleagues are working to address the problem of urgently needed organs with a new generation of artificially made organs, which are a more detailed replica of natural organ structures. "Collagens are extremely useful biomaterials for 3D printing because they can actually reproduce every single tissue in the body," explains Andrew Hudson, co-author of the study. "What makes it more difficult to use in 3D printing, however, is the fact that collagens are first made with a liquid. So if you try to print it simply in the air, nothing but a puddle remains on the printer. That's why we've developed a technique that prevents the material from deforming."
The FRESH 3D-Bioprint method developed by Professor Feinberg's research team makes it possible to immerse the collagen layer by layer in a gel bath, where the material can initially solidify. The FRESH method makes it easy to remove the gel afterward by heating it from room temperature to body temperature. The printed structure of collagens or cells is not damaged.
However, other soft gels such as fibrin, algin or hyaluronic acid can also be used for the new 3D bio-print method. In addition, the researchers have developed open license blueprints so that as many people as possible in the field of research have access to low-cost, high-performance 3D bioprinters.
Regarding the potential of the FRESH technology, Feinberg says: "We are talking about the convergence of different technologies. It's not just about what we do in our laboratory, but also about the work of other laboratories and small companies in the field of stem cells, machine learning and computer simulations, as well as 3D bioprinting, hardware, and software.” He adds: "It is important to understand that many years of research lie ahead. Nevertheless, it is exciting that we are making real progress in the artificial production of human tissues and organs".
A. Lee, A. R. Hudson, D. J. Shiwarski, J. W. Tashman, T. J. Hinton, S. Yerneni, J. M. Bliley, P. G. Campbell, A. W. Feinberg. 3D bioprinting of collagen to rebuild components of the human heart. Science, 2019; 365 (6452): 482 DOI: 10,1126/science.aav9051