What do you think the leading cause of death in the USA is? Here’s a clue, it’s not cancer.
That dark accolade instead goes to heart diseases and cardiovascular problems, fueled by soft drinks and obesity. Over 26 million people suffer from heart failure worldwide, and 1 in 3 deaths is due to heart problems.
The problem is there are just not enough hearts. Transplant organs are usually taken from car crash victim donors, but there is still a sizable waiting list which can take months, or even years. Receiving a new heart doesn’t mean you’re out of the woods either; those who do often die within 10 years of the transplant; the body either rejects the new heart, or the anti-rejection drugs suppress the immune system, heightening rates of illnesses such as cancer.
If you find 3D bioprinting and 3D printed organs interesting, check out our full guide to 3D printed organs here.
- 1 3D Printed Hearts: The Solution
- 2 An Alternative: A 3D Printed Heart not made from cell tissue
3D Printed Hearts: The Solution
This is where 3D bioprinting may have a few ideas. Being able to create a heart of identical proportions to your own, and from your own cells, ticks off all the problems listed earlier.
But is this really possible? Can we just manufacture working human organs from thin air? This article involves extensive research into the area, and will seek to explain this in full detail. To do this, it is first necessary to explore the history of the 3D printed heart.
History of the 3D printed heart
The origins of of 3D bioprinting go back to the late 90s, but were solidified in 2003 when Dr Thomas Boland at Clemson University patented a way of inkjet printing of viable cells involving printing ‘a cellular composition containing cells onto a substrate.’
His work was then expanded the following year when 3D printed organ printing research begun at the University of Missouri, Columbia. This research was conducted on a $5M grant aimed to expand knowledge on the possibilities of organ printing, including a 3D printed heart.
A prominent company in the 3D printed heart and 3D printed organ space is Organovo. Founded in 2007 in San Diego, CA, Organovo design and create human tissues with 3D bioprinting and aim to create living human tissues that function identically to native tissues. The company has pioneered many of the bioprinting techniques known today.
Organovo’s first breakthrough came in 2009 when they created the first 3D bioprinted blood vessel. Since blood vessels are some of the main building blocks to creating organs (and therefore a successful 3D printed heart transplant), this was a tremendous achievement.
Organovo went on to develop 3D printed liver tissue, as well as partnering with L’Oreal to develop 3D printed skin tissue in 2015. They weren’t the only company trying to create 3D printed hearts and organs however, as companies such as Cellink, Biolife4D, EnvisionTEC, and more either build 3D bioprinters or research ways of printing organs.
3D Printed Heart Material: How to 3D Print a Heart
3D printing used to limited to a few plastics like PLA and ABS, but now you can 3D print metal, and even living cells.
To create the perfect 3D printed heart shape, you first need to know the exact dimensions of the patient’s heart. This can be done via MRI scan to create the digital 3D printed heart model. Once this is obtained, blood cells are taken from the patient. This is key so the body does not interpret the organ as foreign and reject it. They are then converted into 3D printed heart stem cells and infused within a bio-ink to be 3D bioprinted.
The most efficient way we currently know of to 3D print hearts is with a scaffold in place which defines the areas which the bio-ink and heart cells are to be printed in. Once the shape has been printed, this scaffold keeps the cells where they should be, allowing them to assemble into heart tissue. Miraculously, heart cells will just come together when in proximity, and will eventually start beating like a real heart does!
When the heart is mature enough to function without a scaffold, it is heated and melted off. This finished heart can then be transplanted into the patient with no chance of rejection and no need for anti-rejection drugs.
Companies such as BioLife4D and Cellink both follow this philosophy, believing that creating real 3D printed hearts from native tissue is the way forward. The treatment is not ready however, the above is still theoretical. We are currently able to create small tissues with a patient’s cells, and it does beat.
But there are problems on the very small scale. Capillaries are just one blood cell thick, and are plentiful inside the human body. No 3D printer on the planet can accurately print anywhere near that scale.
BioLife4D have a game plan for reaching a stage where 3D printed hearts will become a reality. They intend to make ‘mini’ hearts within a year that are entirely bioprinted. The belief is that pharmaceutical companies will use them to test new drugs and their effects. Once this preliminary stage has been completed, BioLife4D intend to move on to making small animal hearts. Then, they will gravitate toward large animals, before making the eventual leap to real 3D printed human hearts.
A conservative estimate for working 3D printed hearts is 30-50 years. This could all change if levels of investment change, or a sudden massive leap in progress occurs. It is handy that the heart is one of the simplest organs in the body however, as it fulfills no other role than to pump, pump, and pump some more.
There is another school of thought however. If a foreign object can fulfill the same role as a human heart does, do we really need a human heart at all? 3D printing can serve in this area too.
An Alternative: A 3D Printed Heart not made from cell tissue
We are better at manufacturing objects from materials such as plastics and metals than we are from living tissues; our cities and houses are evidence of that. Therefore, logic dictates that it would be simpler for us to build foreign structures that can pump blood round our bodies in the event that our heart fails.
The heart’s job doesn’t sound that difficult; it’s just pumping blood. This shouldn’t be hard to do artificially, right? We can build skyscrapers and racecars, surely we can build a glorified pump?
But alas no, it is not easy. Researchers at ETH Zurich found this out in July 2017.
ETH Zurich: 3D Printed Silicone Heart
Researchers at the Functional Materials Laboratory within ETH Zurich developed a silicone heart last year that beats almost like a human heart. There have been previous attempts to create artificial hearts that work, but this is the first entirely soft artificial heart.
What’s more, the pumping mechanism mimics a real heart, and required no assembling. It was 3D printed as one large, assembled structure and includes a left and right ventricle. Only the input and output parts need to be attached post-print, where the blood is pumped in and out.
This extraordinary heart was developed by doctoral student Nicholas Cohrs (with a surname eerily similar to the French word for heart – coeur), and was led by Professor Wendelin Stark of Functional Materials at ETH. The heart was made from silicone using Lost Wax Casting, which is often used in the mold making and 3D printed jewelry sectors. Weighing 390 grams, it is fairly similar to the weight of a real heart (310 grams), though this cloudy white contraption looks very alien.
3000 beats to heaven
When put under testing, ETH Zurich’s silicone heart lasted a few thousand beats before the material could no longer take the strain. Depending on your heart rate, this equates to between 30 and 45 minutes of human functioning. Therefore, it seems we still have a way to go before an artificial heart is possible.
We shouldn’t underestimate how dexterous our hearts are. They can work for a hundred years under the strain that our best alternatives cannot for an hour. Evolution is wonderful, and so is cardiac muscle.
This does mean however that we are some way from a 3D printed heart implant. ETH have shown that good progress has been made, so we have every reason to be positive. We must also however be humbled by the strength and power of our organs. They are temples, and we must treat them accordingly.
3D printed hearts offer an exciting alternative to current systems of organ donation. With self-driving cars promising to drop road accident deaths to a fraction of current levels, organs from donors is predicted to drop significantly. We need a new way to source organs, and 3D bioprinting them could be what saves us.
It’s too early to tell how feasible this is, as fully developed organs are still far from reality. Though don’t dismiss it as sci-fi either, 3D printing is an exponential technology and prone to huge discoveries. The future is always exciting, and we will have to see what it presents us.