3D printing has opened new avenues for manufacturers and processes. The medical field is always on the lookout of new techniques and technologies that helps them improve treatment, and 3D printing fits the bill to a ‘T’. More and more medical professionals (doctors, dentists and pharmaceutical manufacturers) are turning to 3D printing for personalized healthcare solutions and improved quality of substitute organs. There are quite a few areas in medical field where 3D printing proves to be beneficial. For the purpose of this article, we will take a bird’s eye view of the utility of 3D printers in this field. We will cover each topic in detail in subsequent articles.
3D Printing in Surgery
Surgical models allow surgeons to replicate human body parts. This is important for treatment planning as they allow a surgeon to visualize pre operative and post operative positions of that organ. Before 3D printing became popular, surgeons had to make do with models that were inelastic and hard. It was difficult to accurately estimate the underlying soft tissue, structure of the bone and location of the blood supply. 3D printed medical models have changed all that. The present day CAD based 3D printing technology assists in fabrication of 3D templates that replicate all the underlying structure accurately. While dentists predominantly use 3D printing for surgical templates (there are 3D printers developed especially for dental surgeons - like the Stratasys dental printers), even cardiovascular surgeons find use for 3D prototypes. Data for the organ (heart, bones, tooth, etc.) is created using magnetic resonance imaging (MRI) or computed tomography (CT) scan. This data is then converted to a STL file using appropriate software, and a 3D printed prototype of the body part is created. Cardiovascular surgeons find it extremely useful to practice on this prototype, especially for complicated heart surgeries. Likewise, dentists use 3D printing for graft implantation, precision drilling and to estimate proper angulations of the replacement tooth.
3D Printed Body Parts
Apart from 3D models mentioned above, implantation of 3D body parts has also been conducted successfully. Typical parts that have been 3D printed include bone scaffolds, which allow for healthy bone tissue to grow around it. One 3D printing raw material that has been successfully evaluated for this purpose is Polylactic acid. It is a linear aliphatic polyester which is biodegradable filament used for bone tissue engineering.
3D Printed Modelling of Organs
With the availability of a wide choice of printing materials, 3D printing offers excellent options for replicating human organs. Human anatomy consists of various tissues, cellular material and bones. They are both hard (bones, teeth, etc.) and soft (tissues, organs). Because they can be composed of different materials – from hard to soft - 3D printed medical models are more realistic than their traditional counterparts. 3D printing makes it possible to emulate the human body structure better than the traditional models that use some sort of plastic. Not only are 3D printed models useful for learning the human anatomy for aspiring doctors; they are extremely useful for surgeons as well in customizing an operation. 3D printed models provide the advantage of haptic feedback as well, along with direct manipulation, and enhanced understanding of cardiovascular anatomy and underlying pathology.
Bioprinting
There is an increasing demand for organ transplant in India and rest of the world. One of the most exciting applications of 3D printing in the domain of medicine is bioprinting, which allows cells and biomaterials to be combined and deposited layer by layer. The required cells for bioprinting are taken from the patient. It is then cultivated until there are enough to create a bio-ink, which is nothing but a liquid like gel that allows doctors to 'print' in order to achieve the desired shape. Most 3D bio-printers also deliver organic or synthetic dissolvable gel, which acts as a support to which cells can attach to and grow. Of course, bioprinting is in a nascent stage as of 2020, but it has tremendous potential in the way organ transplant will work in the future. This is one field in medical science where there is a lot of research going on, and 3D printing has a very important role to play in this domain.
Prosthetics
The human body is not only precious, it is very complex. Researchers and innovators have been trying for centuries to replace lost limbs. Evidences from ancient times suggest that humans have been trying to replace lost limbs. However, the movement of limbs, especially of the hands, is a truly complex phenomenon that cannot be replicated easily. 3D-printed materials now allow medical doctors to take advantage of detailed scans by using them to fabricate models of patients' bodies for practising procedures or teaching purposes. They can build accurate frames on which to construct titanium parts for reconstructive surgery, as well as surgical guides, knives and other tools to support specific medical interventions. 3D-printing technology, coupled with advanced imaging techniques, can deliver prosthetic body parts that are highly tailored to the individual patient and may offer better results than 'off-the-shelf' solutions. As a side note, earing-aid manufacturers were one of the early adopters of 3D-printing technology.
Pharmaceutical Products
Current pharmaceutical manufacturing processes are designed only for mass production. While this reduces the manufacturing cost, it is not possible to alter the dosage suited to each patient. Can you imagine tablets that are custom made? Say, a patient needs a dose of exactly 325 mg of Ibuprofen (a class of drugs called non-steroidal anti-inflammatory drugs) to control his or her pain. Currently, this drug is available in standardized quantity like 200 mg, 400 mg, and so on. 3D printing will make it possible in the near future to custom create capsules that contain a precise dose of 325 mg. What is more, it will not be very expensive to manufacture either. Custom formulations, custom mixtures of drugs will also be possible at very little additional cost as 3D printing technology is adopted by the pharmaceutical sector. A revolution indeed!
Advantages of 3D Printing
As we have seen, 3D printing technology offers significant advantages for tissue engineering and biomedical domain because of its ability to fabricate low volume or distinct parts on demand based on specific patient needs. Traditionally, body parts that require surgical grafts are manufactured by making a mould and then casting, forging and machining that part. With different machines performing these operations, it becomes an expensive proposition for the patient who needs a graft. 3D printers reduce this cost significantly as it minimises the number of operations that need to be carried out for a graft.
One more advantage 3D printing provides in medicine is when it comes to manufacturing a customized, critical implants. They provide structural freedom to designers without manufacturing restraints. Using 3D printing techniques, medical designers can create lightweight prosthetic and graft designs.
We are just scratching the surface when it comes to harnessing the power of 3D printing technology for medical purpose. Dentists, doctors and medical professionals are finding new ways of improving healthcare and medical services every day with the help of 3D printing. When bioprinting techniques advance in the near future, 3D printing will really prove to be disruptive technology in the medical field.
Dentistry is one specialized branch of medicine that has made excellent use of 3D printers. Implants, crowns and bridges, orthodontic devices, etc. are regularly made using speciality 3D dental printers like those from Stratasys.
Constraints
While the future of 3D printing is indeed bright, current 3D printing technology has some limitations that need to be overcome. First and foremost, processing speed and printer resolution is still less than needed for many medical applications. But with rapid advances in technology, this limitation is vanishing fast. Secondly, there still is a dearth of bioprintable material that perfectly mimics human tissue. Human organs and tissues are really complicated, and it will still take some research before we are able to produce raw material that exactly emulates the corresponding human organ.
Medical 3D Printing in India
The medical facilities offered in India are at par with the best in the world. Indian doctors are innovative and progressive doctors who are aware of the benefits offered by 3D printing. Availability of quality 3D printers, coupled with good 3D printing software augurs well for the future of this sector in India.