3-D printing has been rapidly growing from its roots as a rough prototyping tool into a now somewhat ubiquitous, chameleon-like technology; finding its way into everything from DIY toy making, to food production, to high-end fashion, to precision engineering. There’s even speculation about 3-D printing entire buildings in the future.
Accessibility of 3-D printing has vastly accelerated the development curve in many areas of the product development process. While many of the attractive aspects of 3D printing—quick turnaround, customizability, and intricacy—lend themselves nicely to challenges that are encountered in medicine, it has had largely been used for medical products that don’t rely heavily on complex physiological interactions and only require simple materials (like polymers, acrylics, or ceramics).
Increasingly, however, improvements in resolution, reduced costs, and new material capabilities are dramatically broadening the medical applications for 3-D printing and additive manufacturing (a term that often refers to 3-D printing when used for production-level parts). From 2008 to 2011, the number of scientific papers referencing bioprinting nearly tripled, and it seems inevitable that continued advances in this type of technology will find their place in medicine.
In May of this year, physicians and engineers at the University of Michigan requested special permission from the FDA to 3-D print and implant a trachea splint in an infant suffering from tracheomalacia, a condition that causes the trachea and bronchus to collapse. This customized device ultimately saved his life, and focused a lot of media attention on medical applications of 3-D printing.
While stories like this tend to be the exception in today’s medical practice, there are themes from the broader 3-D printing experience that point to an exciting future in medicine.
- Highly-customized, precision products. This isn’t a far leap from what is being done today with 3-D printing of prosthetic attachments, but companies like Bespoke Innovations (San Francisco) are making prosthetics “that perfectly mirror the sculptural symmetry and function of the wearer’s remaining limb,” becoming a point of pride and allowing the return to normalcy to people with limb loss. Advances in 3-D printing are also allowing for joint replacements to better match up with the patient’s native anatomy, requiring less tissue removal during implantation.
- Personalized medicine and training. In medicine, a faster method to developing individualized parts could mean advances in complex surgical planning or even the creation of medical devices “on-demand” in critical situations. There are several start-ups that are already 3-D printing patient-specific, ana-tomical models to practice and perfect implantation of novel medical devices to improve procedural outcomes.
- Ability to print complicated materials with increasing spacial accuracy. There are multiple research groups working on 3-D printing with a variety of cell types. While 3-D printing with cellular material is still in its nascency, there has been encouraging progress in areas like 3-D printing skin grafts. Researchers at the University of Toronto have developed a new technique to create large-area skin grafts by printing thin layers of polymer solutions that are preloaded with skin cells. These grafts could eliminate the need to remove large areas of transplant skin from otherwise healthy parts of the body, and might provide a more effective method of creating artificial grafts than seeded scaffold methods.
- Multi-material capabilities. New, cutting-edge 3-D printers (like Objet) allow for multi-material printing seamlessly within a single part, which means that mechanical properties can be tailored spatially. Highly ordered cellular architectures are essential to the function of complicated organs, and have been extraordinarily difficult to replicate. Advances in integrated multi-material capabilities could help to take a step closer to mimicking complex biomechanical properties of real human tissues, like the heart or cartilage. Researchers at MIT and Columbia have been working on a new scaffolding technique that allows them to form tissue that mimics the mechanical properties of cardiac tissues, which perform differently based on how they are stretched (called anisotrphy). While whole organ fabrication faces many challenges and is likely still years away, this represents interesting progress in the field.
Like any new technology, 3-D printing is not without its tradeoffs. While medical applications of additive manufacturing offer the potential to deliver previously unimaginable therapies and increasingly greater levels of personalization, they also bear their costs and risks. How will highly patient-specific devices be regulated? Will individually tailored prosthesis, implants, and training tools produce sufficient enhancement in outcomes to justify their greater cost? Could the holy grail of whole organ creation using this method ever make the leap from the lab to the operating room?
I look forward to discussing these and other interesting tech developments at MedtechVision 2013!
– Leslie Oley