May 9, 2014
Have you ever broken your tailbone? I have. It hurts. I mean, it really hurts. Not so much the actual breaking, as I did not even realize I had injured myself at the time. No, what really hurts is having to sit down afterward. I was in Junior High and it was time for Physical Ed. The teachers were having one of their “we do not care days” (one of many) and so we were just allowed to run around a play basketball. Oh how fun for the short, plump kid that I was. Even so, not playing meant… well, I honestly do not know. Failing? Can you fail P.E.? Detention, maybe. They were very fond of that option. Anyway, I ended up playing and where I went to school, when we played anything we played it pretty rough. No one was acting as referee, so why not? We were teenagers, which roughly translates to “young and dumb.” I took a pretty bad body block from an opposing player and ended up landing hard right on my rump. I head a loud pop, there was a quick stabbing of pain, but I shook it off, got up, and got back into the game. It was only when P.E. was over and I made my way to whatever my next class was and sat down did I realize that something was actually wrong.
Now, the biggest problem with something like a broken tailbone is that there is not really anything you can do about it. It is not like fingers, an arm, or other extremities that can just be put in a cast. I was told that I would just have to bare with it and hope for a speedy recovery. Ow. Not pleasant.
Now, thanks to the work of Brendan Watson, Rice University graduate student, that problem may be a thing of the past. Watson has developed a hydrogel that not only can instantly turn from its liquid form to a semisolid when at close to body temperatures, it also degrades at almost exactly the same pace as the healing of bone. This new gel holds great potential as a bioscaffold, supporting the regrowth of bone and other three-dimensional tissues within the body of a patient while using the patient’s own cells to help seed the process along. When injected into the sight of an injury, the gel would fill and stabilize the space while natural tissues could grow in to replace it at its own pace.
[ Watch the Video: New Hydrogel Serves As Bioscaffold To Regrow Bones ]
Until now, a major problem facing thermogelling polymers is that once they harden, they start to collapse and force water out of the patient’s body through a process called syneresis, which defeats the purpose of defining the space that doctors hope to be filled with new tissue. According to Watson, “If the transition gellation temperature is one or two degrees below body temperature, these polymers slowly start to expel water and shrink down until they’re one-half or one-third the size. Then the defect-filling goal is no longer accomplished.” This issue was solved by adding in a chemical cross-link to the gel’s molecules. “It’s a secondary mechanism that, after the initial thermogellation, begins to stabilize the gel.” While the links begin to form at the same rate as the gel, the cross-linking takes a bit longer.
Finally, the final cherry on top of this wondrous process is that the gel will self-destruct in a way that will not harm the body, breaking down once its task is done. The chemical cross-links are attached by phosphate ester bonds, which are degraded by alkaline phosphatase, which is naturally produced by bone tissue and in significantly higher amounts around areas of newly formed bone. What this means is that we are given a “semi-smart” material that knows when its job is done. When the new bone is formed, the gel degrades more quickly in that area when then allows even more space for the bone to grow.
An amazing new innovation that should help heal those hard-to-treat areas of the human body.