This extracellular matrix stuff is quite exciting. They've actually managed to reconstitute entire organs (but are of course still a long way from doing it reliably for humans):
There was noise about trials of regrowing fingers on amputees using extracellular. I have yet to hear anything, which makes me think it may not have gone well.
http://www1.umn.edu/umnnews/Feature_Stories/Researchers_crea...