June 2018 Tech Acute
These days, 3D printers are used to make all sorts of toys and doodads. 3D-printed jewellry and other fashion items are becoming a hot new trend. All of this is exciting and innovative, but what if the technology could be put to more meaningful use? The possibilities are only being explored a fraction of what they might be in the near future. Science is close to finding ways to get around the lack of organs available for transplants and grafts. Although there have been bioprinters in the past, many challenges continue to exist. The inability to keep cells alive long enough to transplant them has hindered the progress of the concept.
Thus far, medical advances include 3D-printed organs such as artificial hearts, ears, and even bone tissue. So why not eye parts? There are millions of people worldwide suffering from vision loss caused by eye-related illnesses. Impoverished countries commonly have viral infections that cause corneal damage, and if not treated, blindness. Could we possibly use the technology offered by 3D printing to create replica corneas? The probability of this happening sooner than later is high. This type of printer needs ink matter to function. Currently, researchers are combining alginate (a gelling agent extracted from seaweed) with collagen proteins to create a bio-ink. The ink needs to be ‘alive’ in order to fuse with a human’s cells. It would need to allow connective tissues to proliferate for the human body to accept and integrate the prosthetic materials. Stem cells seem to be the answer concerning fabricating this type of ‘living’ material.
Cell expansion has already been proven in other types of prosthetics. However, without a consistent blood vessel supply, these cells can only live a limited amount of time. Researchers are looking for ways to ensure cell life through the printing process and then some. For now, the bio gels and replacement ‘parts’ have shown a remarkable way to produce an artificial chassis. The living cells in this chassis begin to form their own bio ‘mesh’ and hold themselves together. In time, the artificial matter (often forms of silicone and medical grade plastics) fades or dissipates, leaving only biological matter in its place. Though the 3D-printed object provides the initial structure of the implant, the cells themselves form a sort of matrix capable of maintaining its shape.
New tissue or even cartilage and bone cell generation could eventually mimic the rest of the human body. In tests with lab mice, implanted skull fragments showed they were able to grow their own bone tissue, complete with blood supply. And with 3D-printed muscle implants, mice developed nerve tissues. This new growth only took two weeks to form. Although the tests have yet to be conducted on human subjects, it does show the possibility to do so with further research.
Corneal implants would work in the same manner. But would muscle or sturdy bone mass be easier to concoct than tissues that need to ‘perceive’? An ocular structure needs to not only move and keep its shape but also help the individual to see. Will the brain reconnect to a corneal implant to provide functional sight? If engineers can perfect the 3D printing ink, the reproductive tissues would likely be able to ‘think’ for themselves with the help of the human brain. Much in the way that a cochlear implant learns to reconnect to the brain to interpret sounds, the eye structure would probably be able to do similar.
Soon, 3D-printed corneas could solve the problem of waiting for a compatible human donor. From computer to printing nozzle to eye, science is creating medical solutions we once only thought possible in science-fiction movies. How long will it be until so-called cyborgs walk among us? Only time will tell.