Bioprinting of human tissue is still a technology that is undergoing development, but it is already paving the way for some really exciting possibilities, including the ability of 3D printing complete human organs. This particular scientific objective is becoming more and more achievable with each passing day, and a team of researchers at Carnegie Mellon University has reported a breakthrough as well. According to the report, the team was able to 3D print full-scale heart components that were even able to function like the real thing.
The particular cells that are responsible for creating different organs in the human body are held together using extracellular matrix (ECM). It not just a web of proteins that is keeping everything together but also gives the biochemical signaling that is required for a regular and healthy function of the organ. Collagen is a protein that is pivotal to this structural integrity; however, when it comes to bioprinting; it also offers some really noteworthy challenges.
Andrew Hudson, the co-first author of the new paper, said, ‘Collagen is an extremely desirable biomaterial to 3D print with because it makes up literally every single tissue in your body. What makes it so hard to 3D print, however, is that it starts out as a fluid – so if you try to print this in the air, it just forms a puddle on your build platform. So we’ve developed a technique that prevents it from deforming.’
The technique that Hudson talked about focuses on a specially developed hydrogel. The team was successful to use it as a temporary support structure for stopping the collagen from ending up like a heap. The gel basically serves as a bath and enables collagen to be deposited layer after layer for forming a solid structure within it. The support-gel can then be removed by heating it until it reaches room temperature, thus leaving the 3D printed structure in place.
The team made use of this technique for the construction of a variety of amazing proof-of-concept heart components. These components were full-scaled and were not just based on collagen. In fact, they used cardiomyocytes along with heart imaging data for creating blood vessels, heart valves that were capable of opening and closing, and ventricles that could contract.
Adam Feinberg, a professor of biomedical engineering and materials science and engineering, whose lab had performed this work, said, ‘What we’ve shown is that we can print pieces of the heart out of cells and collagen into parts that truly function, like a heart valve or a small beating ventricle. By using MRI data of a human heart, we were able to accurately reproduce the patient-specific anatomical structure and 3D bioprint collagen and human heart cells.’
Feinberg further added, ‘It is important to understand that there are many years of research yet to be done. But there should still be excitement that we’re making real progress towards engineering functional human tissues and organs, and this paper is one step along that path.’ The research of the team was published in the journal Science.