科学美国人60秒:Goo Keeps Bones Strong but Supple

New news is goo news—when it’s inside our bones, anyway. Because a combination of imaging techniques and modeling has revealed that our bones are filled with a natural chemical goo that’s key to the bones’ function as support structures. The finding is in the Proceedings of the National Academy of Sciences. [Erika Davie et al, Citrate bridges between mineral platelets in bone]
And it could inform research into the prevention and treatment of osteoporosis.
 
Bone actually largely consists of tiny crystals of calcium phosphate, and the goo is in fact a combination of the compound citrate and water. The viscous mixture surrounds the crystals, letting them slide and slip past each other.
 
The resulting flexibility lets bones bend but not break under normal pressure. Most of that flexibility had been attributed to the presence of the protein collagen, but the citrate goo appears to play a big role too.  
 
Unfortunately, as people age, the goo may begin to seep out. The remaining mineral crystals then can fuse together, according to lead researcher Melinda Duer at the University of Cambridge, and the bones become brittle.
 
Keeping the goo in its proper place between the mineral crystals might thus help ward off osteoporosis. Which would be a bona fide breakthrough.
 
—Dina Fine Maron
 
[The above text is a transcript of this podcast]