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Injectable Artificial Bone Developed
An anonymous reader writes in with the news that British scientists have invented artificial "injectable bone" that flows like toothpaste and hardens in the body. This new regenerative medicine technology provides a scaffold for the formation of blood vessels and bone tissue, then biodegrades. The injectable bone can also deliver stem cells directly to the site of bone repair, the researchers say. "Not only does the technique reduce the need for dangerous surgery, it also avoids damaging neighboring areas, said [the inventor]. The technology's superiority over existing alternatives is the novel hardening process and strength of the bond... Older products heat up as they harden, killing surrounding cells, whereas 'injectable bone' hardens at body temperature — without generating heat — making a very porous, biodegradable structure."
I just wonder what it 'biodegrades' into... and if you really want that in your bloodstream.
It would be my guess that if it is considered to be "biodegradable" in the human body, they mean that it is fully and wholly metabolized by the human body without generating any inflammatory or toxic reaction. There are several polymers which fit this scenario, such as one based on glycolic acid and lactic acid. The cool thing about this stuff is its rigidity and lack of tissue damage. /me isn't close to a medical student, but google can make me sound like I am.
Not no surgery, less surgery.
Instead of opening someone up, pulling out the hammer and power tools and doing some serious repair work you just make a little hole or two, yank everything around to where you want it, squirt in some bone juice to bond everything, and you're done.
Similar techniques are being tried also to regrow damaged or missing cartilage.
http://www.sciencedaily.com/releases/2007/09/070906104136.htm
It looks like the current trend is to use stem cells from within a patient's own body. That way there are no ethical issues and no worries about tissue rejection. Researchers are figuring out ways to extract stem cells from a patient's own blood.
http://www.bio-medicine.org/biology-news/Breakthrough-isolating-embryo-quality-stem-cells-from-blood-669-1/
steveha
lf(1): it's like ls(1) but sorts filenames by extension, tersely
Bones are continuously maintained in a way quite different from most of a tooth. This is a trick to give the normal process to replenish bone and repair broken bones to a headstart and some basic structure to get the final layout right. Triggering the growth of a new tooth in situ is a quite different thing, especially to get the outer layers right, without which it would indeed be quite biodegradeable in any mouth.
You're probably not far off.
I studied this exact kind of stuff (well, very obsolete versions of it) in grad school, early 1990's. A class presentation that I gave once made the point that the three main surgical instruments used in joint-replacement surgeries were:
A saw.
A drill.
A hammer.
And these surgeries are violent.
This injectable bone idea, while not brand new, is very interesting, and I have to appreciate that a non-exothermic hardening process is a significant part of that. Some polymers used as fixatives in implants, like (very possibly obsolete) poly-methyl methacrylate, are *very* exothermic as they set, and extreme care has to be taken to use only the minimal required amount; picture a thicker-than-necessary glob of the stuff sitting in an unevenly-drilled femur as the shaft of a hip replacement is put into place, and that glob heating up as it sets, weakening or destroying the bone, and at least (I'd imagine) causing incomprehensible pain.
So, this non-exothermic stuff is way cool.
The biodegradable aspect (calling to mind poly-lactic acid artery/vein grafts, which degrade into plain ol' lactic acid, which the body knows how to deal with) is a serious bonus.
My wife had this "grout" injected on an experimental basis to fill in for a a couple crushed disks. She was in constant severe pain before, but after the surgery she has found her back get better and better. Her middle aged back will never be as strong or pain free as a 19 year old's, but at least she has a back that if she does not do any lifting over 25 pounds and is careful she is pain free. The surgery also used some tubular "spacer" to keep the joints apart until things fused. The x-rays showed her back joints fused just as planed in a matter of weeks. I don't if she had the same stuff or if we would have had the same outcome with the same good surgeon, but it has been a wonderful outcome that has vastly improved both our lives.