At the University of California Berkeley researchers are refining a technique to use self assembling artificial viruses to create biological scaffolds. The goal is to create a tool with which to rebuild spinal cord tissue around damaged nerve cells.
From MIT Tech Review:
Some biological engineers are using scaffolds made of polymers to try to mimic the supportive matrix of real tissue. Seung-Wuk Lee, a bioengineer at the University of California, Berkeley, has turned to viruses instead. "Viruses are smart materials," he says. "Once you construct the genome, you can make billions of phages, and they're self-replicating materials." The phage that Lee is working with, called M13, is long and thin like the protein fibers that make up the cellular matrices inside the body.
http://www.medgadget.com/archives/2009/01/engineered_viruses_may_serve_as_neurosurgeons_of_the_future.html