Imagine someday \u201cprescribing\u201d a full-sized, adult, 3D printed heart as easily as you might prescribe Amoxicillin. If it sounds like we\u2019re cracking jokes about one of the body\u2019s heartiest muscles, we\u2019re not. And we\u2019re absolutely not making light of the good people who desperately need a heart transplant. We are, however, feeling a bit giddy about a recent, first-of-its-kind advancement in regenerative medicine \u2013 the place where biology meets technology. It\u2019s a breakthrough that\u2019s pumping up a remarkable world of possibilities.<\/p>\n\n\n\n
A FRESH Approach<\/strong><\/p>\n\n\n\n Let\u2019s stroll back to August 2019, when Carnegie Mellon University (CMU) researchers published a paper in Science magazine that presented a unique technique to 3D bioprint tissue scaffolds made out of collagen \u2013 the major structural protein in the human body. The technique, dubbed Freeform Reversible Embedding of Suspended Hydrogel (FRESH), takes the field of tissue engineering one mighty step closer to 3D printing a healthy, adult human heart.1, 2<\/p>\n\n\n\n The FRESH 3D bioprinting method opens the door to fabricating collagen scaffolds capable of replicating the structure and function of tissues and organs, which was previously impossible using traditional biofabrication methods.<\/p>\n\n\n\n \u201cWhat we\u2019ve 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,\u201d says Adam Feinberg, PhD, professor of biomedical engineering and materials science and engineering, whose lab performed this<\/p>\n\n\n\n work. \u201cBy using MRI data of a human heart, we were able to accurately reproduce patient-specific anatomical structure and 3D bioprint collagen and human heart cells.\u201d<\/p>\n\n\n\n The challenge to 3D print collagen, which makes up every single tissue in the body, turns out to be a sticky issue, explains Andrew Hudson, a BME PhD. student in Dr. Feinberg\u2019s lab and co-first author on the paper, explains what makes it so hard to 3D print collagen. \u201c(Collagen) starts out as a fluid \u2013 so if you try to print this in air it just forms a puddle on your build platform. So, we’ve developed a technique that prevents it from deforming.\u201d<\/p>\n\n\n\n The FRESH 3D bioprinting method allows collagen to be deposited layer-by-layer within a support bath of gel, giving the collagen a chance to solidify in place before it\u2019s removed from the support bath. With FRESH, the support gel can be easily melted away by heating the gel from room temperature to body temperature after the print is complete. This way, researchers can remove the support gel without damaging the printed structure made of collagen or cells.<\/p>\n\n\n\n GPS Set for Achievement<\/strong><\/p>\n\n\n\n While thought leaders in regenerative medicine continue to put FRESH in the same sentence with an ability to 3D print a full-sized, adult human heart, Dr. Feinberg remains cautiously optimistic on this goal. He\u2019s more of a step-by-step guy, working beside his team to fill reasonable and achievable \u201cbuckets\u201d before leaping to thoughts of fully functional organ replication.<\/p>\n\n\n\n \u201cFRESH may absolutely give us the ability to someday 3D print a human heart \u2013 but that\u2019s a good decade away, maybe two. For now, step one is focusing on regenerative medicine,\u201d Dr. Feinbergexplains. \u201cIn our lab, we\u2019re using the FRESH technique to 3D print a collagen scaffold that we could implant in the human body to augment or improve the body\u2019s own tissues\u2019 ability to regenerate. So, bucket number one is learning how to recruit the body\u2019s own cells to guide the regenerative process and repair tissue that would normally not have enough structure or the right growth factors to go it alone.\u201d<\/p>\n\n\n\n At present, Dr. Feinberg\u2019s team is developing a model to study volume metric muscle loss \u2013 and regenerative capabilities \u2013 in a large animal. \u201cWhen we progress to studying human applications, this could affect so many people. Think about how we could help soldiers, victims in a car crash \u2013anyone who loses a large piece of skeletal muscle that won\u2019t regenerate on its own,\u201d Dr. Feinberg says.<\/p>\n\n\n\n Guiding the body to repair damaged organ tissue or regions may even help reduce the growing need for new organs. \u201cOften an organ doesn\u2019t fail as a whole,\u201d Dr. Feinberg stresses. \u201cThere may be a damaged region that slowly progresses until a new organ is needed. But until we understand how to create new, functioning organs \u2013 so we can replace damaged organs \u2013 patching could stall or even stop damage progression in many instances.\u201d<\/p>\n\n\n\n