We’ve all seen 3D medical models in doctors’ offices, operating rooms and surgical centres, but now 3D printing technology is being used to treat diseases, medical conditions, and injuries. From surgical implants to prosthetics, 3D bioprinting (a form of personalised medicine) is transforming the field of medicine. Doctors can create customised, patient-specific implants to save more lives, and researchers can use 3D printers to grow tissue and human organs in order to understand the human body better.
How 3D printed medical models are made
It’s basically a combination of modern medicine and technology, where doctors and surgeons scan a patient’s internal organs into a computer using a CT scanner or magnetic resonance imaging (MRI). Then they take the data and make a 3D rendered model (including colour, size, and texture) before converting it into a file format that a 3D printer will use to create an accurate and synthetic 3D model of that organ, layer by layer.
The printer uses the organ’s cells to create the model, as well as binding agents to ensure that it doesn’t fall apart. It can take a few hours to a whole day to produce a model. Once it’s finished printing, it gets washed and cleaned, and then you have a completely accurate representation of a person’s insides but available for physical study.
Uses of 3D printing technology in medicine
There are many great uses for 3D printing in medicine, from education and training to replacing body parts.
Medical education and training
3D printed anatomical models can be used to further educate and train medical students and health professionals. They can also be useful in countries where obtaining and working with cadavers, as well as storing them, is both problematic and costly.
A 3D printed anatomy series has been created by researchers from Monash University in Victoria, which doesn’t contain human tissue and includes the major parts of the body (e.g. limbs, chest, abdomen, head and neck). These models have muscles, tendons, ligaments and blood vessels, which means that students and professionals can now better understand the human anatomy. And unlike cadavers, these 3D printed body parts don’t smell, won’t deteriorate, and are more cost-effective. Moreover, they can be developed quickly, cheaply and easily.
Planning out medical procedures before performing surgery
Doctors at the Children’s National Medical Centre in Washington, DC, are using 3D printers to make hearts that look and feel like the real thing. They use these models to solve complex heart problems like congenital heart disease, and then plan out medical procedures prior to performing surgery on patients with this condition.
For example, paediatric cardiologist Laura Olivieri said that a heart model enabled her to make connections that she couldn’t when looking at the heart on the computer screen. She also used the model of a patient’s heart that she took apart to analyse and perform practice runs on before the actual surgery. With 3D bioprinting, patients with congenital heart disease now have a much higher chance of surviving.
Replacing body parts
3D printing technology can also be used to develop and replace body parts. For example:
- In Australia, a man’s heel bone was replaced with a 3D printed titanium heel.
- In China, a boy’s vertebra was replaced with a customised 3D printed vertebra (it’s made of porous titanium so that natural bone can grow through it).
- In Holland, a woman’s skull was replaced with a 3D printed one.
- In Britain, part of a man’s face was replaced with a 3D printed version.
- In Belgium, a woman’s jaw was replaced with a 3D printed titanium jaw.
- In the US, a woman’s hip was replaced with a 3D printed hip joint.
Ethical issues raised by 3D bioprinting
Although 3D bioprinting offers many benefits, it also raises a few ethical issues, which are outlined below.
Access to healthcare: Where’s the justice?
As with all advancements, both medical and otherwise, there will be a period where the cost is prohibitive for some. Personalised medicine is often expensive, so patients without a lot of money will miss out on receiving treatment that could in fact be effective for their condition. For example, the cost and time needed to provide customised and different-sized prostheses for a child who lost their leg to cancer has prevented those without the money and time from accessing this treatment.
3D bioprinting can, however, reduce the cost and time for the customisation and production of prosthetic legs. It can also decrease the cost of orthopaedic surgery, in which lost bone structures are restored. On the whole, this means that personalised medicine can now be accessible to many patients, allowing them to receive the treatment they deserve.
And as the technology advances and becomes cheaper to manufacture, it will become available to an ever-increasing number of the population.
Is it safe and effective?
Generally, new types of treatments are tested for safety and effectiveness and then approved by a medical authority before they can be provided as a clinical treatment. When it comes to 3D bioprinting, the titanium that is generally used to replace bone is already being used for orthopaedic surgery and so has proven to be compatible with human tissue and bone. It has also been tested for safety and efficacy over a long period of time on many patients, which means that it’s highly unlikely it will pose any new risk.
Furthermore, 3D printing could be combined with personalised stem cell therapies in the future, leading to the development of 3D printed functioning organs. These can then be used to replace a damaged organ without the risk of rejection that comes with donor organs, as it uses the patient’s own cells as the origin. This treatment is considered safe because it’s tailored to the patient and therefore can’t be tested on anyone else. As for testing its safety and effectiveness, new models may need to be developed.
Should it be used to enhance human capacities?
3D printing technology can be used to create organs and bones in order to replace injured or damaged ones, so this means that it can also be used to enhance human capacities beyond what is considered normal. For example, bones can be replaced with artificial ones that are stronger, more flexible and less breakable, and muscle tissue can be made more resilient and less likely to get worn out.
However, human enhancement can be both a disadvantage and dangerous thing, especially when it comes to sport and military use of the technology. Technology-enhanced athletes will surely win over their competitors and is considered to be cheating, while enhanced soldiers will have an advantage in battle as they would be less vulnerable to wounds, exhaustion and harm. This could lengthen a war, which is not a good thing for soldiers and civilians alike.
There will never be a definitive end to this debate, and ultimately it will be up to governments and scientific communities to impose laws and regulations which will decide the answers to these questions.
Why 3D printed medical models are not readily available yet
The reasons why we haven’t yet seen widespread use of 3D printed medical models is because they’re expensive to make, they take many hours to create, and people are still getting used to the new technology.
As for 3D printing functional human organs, it can be difficult to find materials that can be used to create them and to let them grow effectively outside of the body. Most importantly, once an organ is printed, it needs to go into an incubator so that the cells can fuse and work together like the real thing. If it doesn’t, it can’t be used in patients.
Many researchers have also found it hard to make 3D printed blood vessels because they’re too long, too thin and tube-shaped, which is difficult to print. But organs need them to function properly. The good news is that a team from Brigham and Women’s Hospital in Boston, Massachusetts, have used agarose (a sugar-based molecule) as a template for developing blood vessels.
The future of 3D bioprinting
As mentioned above, 3D printing technology could be used together with stem cell therapy in the future, where a patient’s own cells are used to print living bone cells or functioning organs for transplants (e.g. kidneys, hearts, livers and the pancreas). Doctors and researchers are also working on 3D printing noses, eyes, ears, and even the skin. Printing soft tissue is underway as well, which can allow printed veins and arteries to be used in surgeries.
3D printed medical implants will start saving more lives and improve people’s quality of life. 3D bioprinting could also enable custom medicines and decrease or even eliminate the shortage of organ donors. While 3D bioprinting promises better and more personalised treatments for a range of conditions, it’ll also challenge people to address the ethical issues raised by the technology.
Whether it’s the 3D printing of tumours and surrounding tissue to help surgeons remove cancer from a patient’s body without damaging healthy tissue, or the better understanding of body parts using 3D printed models, 3D bioprinting will definitely see greater use in the future.