Recovering from bone grafts can be
a long and painful process in and of itself. These negative side effects can
easily be exacerbated and exaggerated if the materials used are not entirely
biodegradable which can lead to serious infection and possible fracture. Auto
grafting, or using bone from another part of the body in a graft, can be
problematic as well. While biodegradable, the types of bones that can be used
are severely limited based on the area being grafted and long-term impairment
of the source is quite possible.
Luckily,
scientists have discovered a material that may manage to solve all of these
problems and it comes from coral. Coral skeletons are made from calcium
carbonate. With a few tweaks, scientists have managed to turn this into
coralline hydroxyapatite/calcium carbonate, also known as CHACC. The finished
product is a calcium carbonate scaffold surrounded by a layer of
hydroxyapatite. Unlike the material it is derived from, coralline
hydroxyapatite (CHA), CHACC is biodegradable which is quite promising.
In
order to test CHACC’s effectiveness, scientists implanted small amounts of it
under the skin of mice and seeded it with human mesenchymal stem cells. The material
served as a scaffold for the new bone cells to grow and adhere to. Within 10
weeks the scaffolds were completely covered in new bone growth. Once they knew
it was safe, the scientists proceeded to use CHACC in an actual clinical trial.
The material was used in an actual graft to treat four different types of bone
deformities. Results showed that new bone had successfully grown around the
grafts after 4 months. In 18-24 months, the CHACC scaffolding had almost
completely biodegraded.
While this all seems like good
news, there is still some work to do. It is absolutely crucial that the timing
of the biodegradation matches up with body. If the material degrades too soon,
the new bone cells have no scaffolding to adhere too and the graft is essentially
useless. If the material degrades too late a whole host of problems could issue.
Also, the material does not induce new bone to grow, it simply supports it. A
perfect material would do both. While this is a good start, it could take years
before CHACC is completely up to par.
Works Cited:
Paddock, C. (2013, November 29). Bone
grafts may be better with new sea coral material. Retrieved from
http://www.medicalnewstoday.com/articles/269512.php
While this concept is awesome and allows increased faith in science, I still am left with some questions.
ReplyDeleteI find it difficult to believe that coral stemmed bone grafts would be strong enough in a human body, just imaging a femur derived from this material is a bit scary to me. How would they prevent degradation in a human body? Would elements from two different ecosystems be able to withstand rejection? I am no professional, and as you stated, there is more work to do, but as a patient, this concept would terrify me. I would much rather have a bone graft derived from stem cells, and for the sake of argument in ethics involving the matter, they would not even have to be embryonic.
The link below is a successful study indicating bones generated from stem cells, pretty fascinating! The study displayed stronger femur implantation with femurs derived from stem-cell growth.
Great post, this concept is very interesting: all science is terrifying initially, but someone every cure had to push the boundaries to get there.
http://onlinelibrary.wiley.com/doi/10.1002/jor.1100160202/full