Medical researchers have come up with a novel way to stiffen the spider silk – using glass. The discovery could make it easier to grow replacement parts for human bodies by improving the silk scaffolds on which human cells are grown. Spider silk is stiffened by reinforcing it with the same microscopic glass beads that single-celled marine algae (called diatoms) use to reinforce their protein shells. To fuse silk and glass, the engineers combined a silk gene from the golden orb-weaver spider (Nephila clavipes) with a gene for a peptide called R5 that encourages the formation of silica beads in the shells of diatoms.
The engineers inserted the resulting combination gene into bacterial cells, which then produced a "chimeric" protein that had the properties of silk married with the unique chemistry of R5.
Now the team is trying to fuse silk genes with genes for proteins that capture other minerals, such as hydroxyaptite, which is found in human bone.