The body is expert at re-growing bone, but it doesn't always manage to get the right shape. Now, a team from Rice University has developed a hydrogel that could let clinicians grow bone right where they need to.

The researchers have created a hydrogel that's liquid at room temperature but stiffens to a semi-solid at body temperature. Unlike other gels, it maintains its original size when it stiffens, providing a predictably sized scaffold on which bone could grow.

By doping the gel with stem cells, the researchers should be able encourage bone growth in well-defined regions. What's neat, though, is that the phosphate ester bonds that hold the scaffold together are naturally eroded by alkaline phosphatase—and enzyme given off as bone grows.

So, as the body's naturally produces new bone to grow where the scaffold is placed, it also causes it to disappear. The rate of decay could even be tuned to the rate of growth of different types of bone, meaning that it need never disappear too soon.

The researchers hope to try the new gel out on the face and skull first. Why? Well, it's a common scene of bone damage and, since they're not load-bearing bones, the new bone needn't be at peak strength once it's grown. The thin covering of skin also makes surgery to complete the process straightforward, making repair of damage—or even cosmetic surgery—a more structurally rigorous process than ever before. [Rice University via Geek]