The Boston Globe looks at a good example of present day research and development at the tissue engineering side of regenerative medicine. Pervasis Therapeutics is working to "fix arteries and veins not with tools, but by wrapping them in a gelatinous sheath of living, healthy cells. ... a 'cellular Band-aid' - a soft wrapper lined with a healthy colony of living blood-vessel cells. ... surprisingly, he found that they didn't need to be stuffed inside injured blood vessels to help them heal properly. Even wrapped around the outside of the artery, the cells appear to spur healing on the inner surface. In essence, the wrap fixes arteries by rebuilding them inside-out. ... If his idea works in humans, he said, it would show that you don't need to fully rebuild an organ to replace it. ... It could very well be that you could get 95 percent of the functionality that you wish, without getting anywhere close to 100 percent of the structure."

Link: http://www.boston.com/business/healthcare/articles/2006/10/02/cells_not_tools_may_help_fix_arteries?mode=PF