Nanoparticle gel helps rebuild brain and bone matter in rats

It's always amazing to hear about advances like this. Articles like this always upset me a little as well though.<p>I don't think I'm overly sensitive (I'm a fighter, I enjoy a good steak and I'm happy to go hunting) but reading things like this make you realize how many of our medical advances come at the cost of intense discomfort for the animals that help pave the way...<p>I look forward to more advances, like the new methods that help us culture realistic skin samples independent of a human, that allow further advances to come at a reduced cost to the animals/people involved.

Anyone know enough to know if a similar approach has been tried for soft tissue repair (joints, tendons, ligaments, etc.)?<p>EG: injecting nanoparticles with suitable coatings as a way of promoting faster joint repair (hips, wrists, shoulders, etc.).

What are "nonoparticles"? Are they particles whose size is in the "nonometer" range?