Back at it again with the 3D printing. As we have mentioned in previous articles on additive manufacturing, 3D printing will go on to impact just about every major industry across the world including healthcare. We have already seen how 3D printing could benefit the healthcare industry with the recent coronavirus pandemic.
Leading 3D printing companies like Carbon, Prusa Research and Formlabs are printing face shields, masks, and crucial hospital tools for healthcare professionals. The overall 3D printing community has been hard at work to ease the pressure on supply chains and governments.
3D printing holds the promise of changing the healthcare industry for the better offering patients things like smarter drugs and hyper customized prosthetics. However, like something out of the 1990 film Dark Man, it might become commonplace for doctors to print organs to treat patients. In fact, it is already happening. Researchers from various leading universities have 3D printed major functioning human organs. Currently, around the world, and especially in the United States organ shortages are a major growing health concern.
3D Printed Organs could save people’s lives
Due to the tremendous demand for organs, it has been estimated that 900,000 deaths each year could be prevented using engineered organs. Currently, in the United States, there are 113,000 men, women, and children on the national transplant waiting list as of July 2019. Sadly, on average, 20 people die each day waiting for a transplant, while every 10 minutes a new person is added to the waiting list. 3D printed organs are a viable solution. Even more so, these engineered organs go far beyond its practical benefits as these new engineered organs are very cost-effective.
For example, according to the National Foundation for Transplants, a standard kidney transplant can on average costs upwards of $300,000, whereas a 3D bioprinter, the printer used to create 3D printed organs, can cost as little as $10,000 with costs expected to drop as the technology evolves over the next couple of years. Medical professionals and researchers are excited about the coming age of 3D printed organs.
Today we are going to further explore the implications of 3D bioprinting, the challenges, benefits and potential issues of this revolutionary new product. Over the next couple of years, the demand for bioprinting is only expected to increase.
The basics: What is 3D Bioprinting?
You may hear the process of 3D printed organs described as 3D bioprinting, with the final products (organs) being called engineered organs. In short, the process of Bioprinting is similar to many of the additive manufacturing processes you are familiar with. However, in this case, additive manufacturing, the process involves combining cells and growth factors to create tissue-like structure and eventually organs. Think of your standard FDM printer. Chances are, you have one on your desktop right now, or have seen one in action. The process is very similar.
When you want to 3D print something, the first thing you have to do is create a digital model, which is then in turn printed into a physical 3D object using thermoplastic, layer by layer. Bioprinting works similarly, with researchers creating a model of the tissue they want to create followed by the process of printing which is the final object layer by layer. However, because printers are using sterile cells, the resolution of the print (layer height), and matrix structure need to be properly prepared for the print.
Breaking it down further, closely resembling the pre and post-production of SLA printing, there are specific steps researchers take to ensure that organs are properly printed. First and foremost, during the preproduction phase, medical professionals create the digital model for their print using technologies like computed tomography scans and magnetic resonance imaging scans. Printers are then prepared and sterilized before printing as a means to optimize cell viability.
Next, the model is sent to the printer. Rather than use a thermoplastic, researchers use bioink to print their structures. Bioink ink is extruded layer by layer with an average thickness of about 0.5 mm or less. Yet, just like a filament, the bioink is placed in a printer cartridge and is used to create the physical 3D model. Finally, during the post-production phase, after the print is completed, researchers mechanically and chemically stimulate the part to ensure the creation of stable structures. The process of solidifying the organ is usually aided by UV light, specific chemicals, or even occasionally heat.
Bioink is the “filament” used in bioprinters
As mentioned above, Bioink is used to create the artificial tissues modeled during the 3D bioprinting process. Multiple different properties make Bioink uniquely perfect for the precise task at hand. Upon further inspection, you would realize that this bioink is made up of cells and a carrier material, which is usually a biopolymer gel.
Though bioinks can be completely made from cells, this biopolymer gel is needed to hold the cells in place, allowing them to grow, spread, and even multiply, protecting the cells during the 3D printing process. Without this biopolymer gel, the process of 3D printing tissue would be much more difficult.
When printed using an FDM printer, the nozzle used for the printing process is heated to high temperatures to melt the plastic and create the intended part. When using the 3D bioprinter, the process is the same and again highlights the importance of the polymer. As bioink passes through the nozzle of a printer the heat mustn't “cook” the cell.
The biopolymer gel keeps the cells from getting too hot during the printing process. Even more so during this same process, the viscoelastic properties of the gel help prevent the cells from being damaged during the process of extrusion out of the nozzle during printing.
Now, if you are wondering what else you might find in the mini cellular soup of bioinks, today you are in luck. As stated by the team at All3DP, “...bioinks rely on a combination of several polymers to achieve some sort of middle ground where chemical, physical, and biological constraints are respected.” Typically, Bioink might include anything from hyaluronic acid to collagen, alginate, cellulose, and even silk.
Have people 3D printed organs yet?
The short answer, yes. Back in 2017, a team of engineers from the Pohang University of Science and Technology developed and 3D printed what they dubbed as “bio-blood-vessels” by utilizing materials from the human body as a template for the process. The blood vessel functioned beautifully with no issues at all. While researchers from Harvard University, just a year earlier developed a new type of bioink specifically for kidneys, allowing the team of researchers to create crucial functional parts of the kidney.
While a team from the bioprinting startup Organovo, in San Diego, has already gone on to demonstrate that it can print human liver patches and implant them into mice. However, the goals of the Organovo team does not stop there. As mentioned on their website, “We are pioneering a unique set of therapeutic and drug profiling capabilities based on our revolutionary ability to 3D sd bioprint tissues that mimic key aspects of human biology and disease. We are striving to change the face of medicine through clinical development of regenerative medicine therapies for treating disease and by enabling translational drug discovery.”
Human trials for the liver transplants could start as early as this year. The idea of bioprinting human organs is no longer some far off science fiction idea. Researchers from private companies and leading universities have printed ears, lungs, and even a heart.
Bioprinting technology is far from perfect
Yes, there have been multiple successful efforts in creating engineered tissues and organs. However, the technology still has a ways to go before it is fully adapted in hospitals near you. There are some obvious hurdles we need to overcome.
First, bioprinting needs to become faster as well as be able to produce tissues at a higher resolution. Being able 3D print an organ in a matter of hours or minutes could make 3D bioprinting far more commercially appealing. While the higher resolution would allow for better interaction and control in the 3D microenvironment.
Secondly, we need more biomaterial. At the moment, it is like printing with only a few filaments. Just like with an FDM or even SLA printer, you use different printing materials to tackle different jobs.
The same goes for the world of bioink and the complex and various types of medical tissue treatments that humans may need. Nevertheless, the technology is exciting and as mentioned above, could save millions of lives shortly. Growing competition in the private sector could help spawn the quick innovation needed to make 3D printing viable.
What do you think about the world of 3D bioprinting? Will this technology revolutionize the healthcare industry?