Let’s begin with a few specific examples from the not-too-distant past.
In 2006, a team at Wake Forest University removed muscle and bladder cells from a young woman and cultured those cells in their lab before seeding them onto a bladder-shaped scaffold. Those cells grew into a new bladder which surgeons successfully implanted, restoring normal function.
Five years later, regenerative medicine researchers at the Karolinska Institute in Stockholm used bone marrow stem cells to grow the world’s first synthetic trachea, which they implanted in a patient whose natural trachea had become cancerous.
Three years ago, surgeons at Hasselt University Hospital in Belgium implanted a 3-D printed lower jawbone, made from titanium powder, into an 83 year old woman’s mouth. Later she had false teeth set into her new jaw, but already by then, dental scientists at King’s College London were making progress toward growing human teeth with natural root structures from adult human gingival epithelial cells of the gum.
And quite recently, bioengineers at London’s Queen Mary University announced their findings that a solution of proteins and peptides, upon touching each other, self-assembled into shapes that can be guided into forming blood vessels.
This list could go on and on, as news in 2015 alone included announcements of bionic eye implants, regenerated taste buds, 3-D printed eardrums, lab gown contracting muscle, and insulin-producing mini-organs that can be transplanted into the omentum of severe diabetics.
Innovation is speeding up, as everything seems to stimulate everything else.
The technologies that drive biomedical engineering today—stem cell culture, 3-D printing with living cells, protein chemistry for biomaterials, and neuroprosthetics—have surprisingly long histories.
As a whimsy, MIT alumnus Arthur Little denatured hog collagen and spun it into a smooth fiber to make “a silk purse from a sow’s ear” in 1921. His purse is in the Smithsonian, but collagen is used today to make artificial organ scaffolds.
James Till and Ernest McCullock, at the Ontario Cancer Institute, proved the existence of stem cells in 1961, but it wasn’t until 2007 that Shinya Yamanaka and James Thomson independently demonstrated how fully differentiated cells could be reverted to what’s called “induced pluripotent stem cells.”
With stem cells at hand, engineers at Heriot-Watt University in Edinburgh (UK) created a 3-D cell printer in 2013 for living tissue fabrication, though rapid prototype printing began a generation earlier.
Neuroprosthetics derive from the first pacemaker in 1950, and first cochlear implant in 1972, but now devices that affix to the surface of the brain can free “locked in” patients from the most severe paralysis.
It is conceivable that the future will bring a 3-D printed novel-fabric patch, made of stem cells, that literally is a living prosthetic. And, we should notice that all the technologies of biomedical engineering are becoming automated.