Why can we not regenerate cartilage in our ear and nose, while bones and flesh can heal?
What makes it so resistant to regeneration. Can we artificially create it in the lab?
The reason that cartilage rarely is able to regenerate is that it is poorly vascularized and innervated. It doesn't have its own blood supply to deliver signaling molecules that promote regeneration and repair after injury.
There has been some recent progress on getting the body to repair and replace cartilage with lab created biogels detailed here.