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3D-printed miniature human heart presents possibilities for future artificial transplants

Here's something straight out of science fiction: A company just successfully 3D-printed a miniature version of a human heart. BIOLIFE4D, a Chicago-based biotechnology company, announced that it was able to create a tiny model complete with all of the cellular structure that would be present in a full-sized, functioning heart. The development could mark a significant step forward in the search for a viable artificial heart that can be created for transplants.

According to the company, it was able to create the mini heart by taking a patient's own white blood cells and converting them into Induced Pluripotent Stem (iPS) cells, which returns them to an embryonic-like state that allows them to be made into just about anything. Then researchers then turn those malleable cells into different types of cardiac cells. Those cardiac cells are what enabled the company to be able to "bioprint" the components of the heart, including functioning valves, ventricles and blood vessels — a process the company first carried out in June 2018, when it successfully 3D-printed human cardiac tissue. That, combined with a bioink made from extracellular matrix compounds — three dimensional networks of things like collagen, enzymes and glycoproteins that provide support around cells — that replicate the properties of a mammalian heart, enabled the small heart to come together for the first time. It contains four internal chambers and accurately produces some functions of a full-sized heart.

“We are extremely proud of what we have accomplished, from the ability to 3D bioprint human cardiac tissue last summer to a mini heart with full structure now. These milestones are a testament to the hard work of our team and the proprietary process we have developed that enables this type of scientific achievement,” Dr. Ravi Birla, the chief science officer at BIOLIFE4D and biomedical engineering and cardiovascular expert, said in a statement.

While the model heart won't be making its way into a human body any time soon, the ultimate goal of BIOLIFE4D and a number of other companies and researchers is to one day create a viable, artificially created heart that can function just like a normal one. Heart transplants are complicated operations that require a lot of factors to come together in order to create a successful transplant. Columbia University reported that about 2,200 heart transplants take place in the United States each year, and about 3,800 worldwide. It's a process that requires a considerable amount of preparation, including intense screenings needed to determine associated health risks for the patient in need. According to the University of California, San Francisco, wait times for heart transplants are often long and can leave a person waiting for a matching donor for more than six months. For people suffering from severe heart disease and other disorders that can put them at risk, six months is sometimes too long to wait.

Columbia University noted that there is often a "tremendous gap" between the number of patients waiting for a new heart and the number of actual organs that are available. This shortage is often worsened by the fact that hearts and other organs deemed to be "less than perfect" are often discarded by hospitals, even if they present an opportunity for the sickest and most in need among us. The University of Michigan highlighted the fact that otherwise viable organs belonging to people who have succumbed to opioid addiction aren't being used despite the fact that they could save lives. Similarly, medical news publication STAT has reported on instances of hospitals simply tossing organs that could benefit sick patients because of strict and potentially misguided standards that minimize risk of failure instead of maximizing the opportunity for extending a person's life.

While it's extremely unfortunate that donated hearts go to waste, often at the expense of another person's livelihood, an artificial heart may mitigate the risks that make doctors hesitant to perform transplants with less than perfect organs. By using a patient's own tissues to create the heart, it also may limit the possibility of complications involved in the process, including the body rejecting the organ as a foreign object.

Luckily, BIOLIFE4D isn't the only team working toward this goal. Earlier this year, researchers at Tel Aviv University announced that they successfully 3D-printed a tiny heart — complete with working cells, blood vessels, ventricles and chambers — using cells and biological materials from a patient. Researchers at Rice University and the University of Washington worked together to 3D print complex vascular networks earlier this year as well, suggesting that it is possible to artificially create the incredibly details passageways required for the heart to function.

These potential solutions couldn't come at a better time. According to the Centers for Disease Control and Prevention, heart disease is the leading cause of death among both adult men and women in the U.S.