What is Tissue Engineering?
Tissue engineering is exactly what it sounds like; doctors create tissues in the lab to aid the body in healing damaged areas. Tissue engineering can aid injection therapies like stem cell treatments and platelet-rich-plasma treatment. Injection treatments simply inject cells into the damaged tissue to spur the creation of growth factors at the site, which result in healing. Tissue engineering, on the other hand, includes delivering actual scaffolding to the area, which directs the cells more effectively and aids them at rebuilding and repairing damaged tissues. Basically, it’s often a way to optimize regenerative injection therapies. But another part of tissue engineering is the creation of biocompatible tissues meant to replace tissues destroyed by illness or injury. Tissue engineering has amazing implications for eliminating immune rejection of organ transplants.
How has Tissue Engineering Developed in the Last Two Decades?
Tissue engineering emerged as a field of medicine in the ‘90’s. Its intention was to use cells, growth factors and scaffolding in tandem to spur tissue healing and regeneration. The first way tissue engineering was used in a clinical setting was for skin grafts. Researchers used collagen-gel scaffolding, keratinocytes and fibroblasts to encourage skin regrowth. The ultimate goal of all tissue engineering is to source the biological material from the patient, because the body won’t reject it. But elderly people or people whose bodies have been ravaged by disease may not have the biological resources necessary for autologous tissue engineering.
The scaffolding portion of tissue engineering is really where the development of this field is focused. How is scaffolding best designed? What features does it need to have to be effective? If we think of cells as seeds, well-designed scaffolding will have thousands of holes to plant the seeds in. These small holes are called micropores. Scaffolding also needs a good supply of blood and nutrients. Scaffolding should also absorb, much the way that when constructing a building, eventually you take all the scaffolds down. Scaffolding that stays too long at the site of treatment may weaken tissue. In skin grafting, scaffolding should stick around for about a month.
We keep using the word “scaffolding”; but what is it made of? Ideally, it would be natural tissues lab-grown from the patient’s own cells. Currently, though, biocompatible, absorbable polymers are often used. The issue with these polymer-based scaffolds is that some types absorb too quickly, and some too slowly. It’s a constant struggle to utilize them effectively with consistency.
Implications of Tissue Engineering in Regenerative Medicine
Development of tissue engineering has promising implications for regenerating tissues in cases where there is no other option than replacing an organ, such as kidneys and livers. Effectively creating scaffolding and organoids in a lab setting can greatly lessen the burden on the organ donation field. Instead of sitting on a list for a new liver for months or possibly years, scientists could grow you a new kidney and implant that. Not only is this faster, it’s safer. Ideally, it would eliminate the need for an immunosuppressant regiment post-surgery.
Another interesting thing to note is that tissue engineering has made first-hand research of cancerous tumors possible. Everyone knows that treatments for cancers are… middling, at best. And they often include poisoning the patient in order to kill the tumors. Tissue engineering allows researchers to observe metastatic tumors in a neutral setting (read: not in a patient) – observing their environment and their behavior. They can compare how cells shouldbe acting vs. how they act in tumor development. This includes the abnormal blood supply metastatic tumors build so they can keep growing and spreading. The implications of furthering tissue engineering research in this way is exciting on many levels.
So, you see, regenerative medicine is proliferating at a quick rate, both in research and in clinical applications. And tissue engineering is much more than growing human ears on the backs of mice. It has real potential to prevent hundreds of thousands of deaths from treatment-resistant ailments.
