Here are several references for articles describing
polyvinyl alcohol-hydrogel (PVA-H).
This material is used for the replacement of cartilage.

1)http://www.sciencedirect.com/science?_ob=Article
2)www.nuigalway.ie/ncbes/news/pdf/paper118.pdf
3)http://pubs.acs.org/cgi-bin/abstract.cgi/bipret/2006/22/i05/abs/bp060181u.html