I tripped over this while I was looking for something entirely
different:
http://www.sciam.com/article.cfm?id=new-nanomaterial-fuses-sp
Basically it's a method of fusing spider silk and diatoms' silica-
making proteins, generating silica coatings on the silk. This makes a
biological equivalent of fiberglass, at low temps and without weird
chemistry.
The researchers are very proud of doing it in the "nanoscale" range
(two microns) but I see no reason it won't work for "macroscale" stuff
like femurs.
It works for silk fibers and sheets meaning it isn't restricted to
roughly tubular shapes.
Mark L. Fergerson
