Dr. Jeff Hersh
Q: Is 3D printing being used for medical treatments?
A: Most manufactured objects start out more or less as block-like structures, and parts of them are then removed by cutting, drilling, etc. to create their detailed three-dimensional (3D) shape, like a sculpture being chiseled from a block of marble. Of course, more complex objects may be made by putting simpler objects together, whether by gluing, welding, using fasteners (such as a screw) or by other means.
A 3D printer creates objects by laying down (“printing”) successive layers; it is sometimes called “additive manufacturing.” You can think of this like taking pieces of paper cut to precise designs and then laying them one on top of another to create a full three-dimensional object; however, actual 3D printing technology is much more advanced than this. So, 3D printing allows a very specific (in shape, size, etc.) three-dimensional object to be digitally designed and then produced.
Almost a decade ago I wrote a column about possible use of 3D printing in medicine. I noted “This allows the potential for a medical device to be specifically designed for a patient.” Examples include 3D printing of dental crowns, bridges and implants, artificial limbs, splints, replacement bones, a scaffolding to support a baby’s trachea (for a baby born with a weakened trachea, a condition called tracheobronchomalacia, causing their breathing pipe to have insufficient strength) and others. At that time I posited: “imagine using a patient’s own body cells themselves as the 3D printer’s ‘ink’ to print a new body organ replacement.”
So where are we now?
3D technology has definitely taken a big step forward over the last decade. Recently, a company has taken cells from a person born with a smaller incompletely or improperly formed external ear and used these cells to 3D print a new external ear for them. The congenital condition, called microtia and affecting 1 of every 2,000 to 10,000 babies, creates a cosmetic issue and sometimes compromises the patient’s hearing. Old techniques would take cartilage from the baby’s ribs and attempt to fashion a new ear, and although this is overall beneficial, the cosmetic and functional results may be somewhat limited. In this new, first-of-a-kind technique, body cells that create cartilage called chondrocytes were taken from the patient, then “expanded” to create cartilage which was then mixed with the company’s “bio-ink” formula. This mixture was then used to 3D print a new ear for the patient, using a mirror image of the patient’s other ear as the model. This new ear was then surgically placed under the patient’s skin to correct their malformed ear. The result was a matching ear made of the patient’s own living tissue, optimizing the cosmetic and functional result.
Other active 3D printing research includes:
- Creating patient-specific replacement heart valves.
- Using a patient’s own cells to create new blood vessels to use as vasculature grafts (for example for use in bypass surgeries).
- Other futuristic work using a patient’s own cells to print certain body organs such as a replacement liver, kidney, and even a heart. In the future this will hopefully address the huge issue of limited organ availability for patient’s requiring an organ transplant.
There is still a long way to go to realize the full potential of 3D printing, specifically using a patient’s own cells, as a treatment modality. However, the progress that has been made over the last decade is encouraging, and I am very hopeful for what future research will create!
Jeff Hersh, Ph.D., M.D., can be reached at [email protected].