WASHINGTON (Reuters) - A special gel enriched with enzymes and growth factors can help grow new blood vessels around a blocked artery in rats and might offer a way to make grow-your-own bypasses, US researchers reported on Monday. The gel appears to keep the necessary compounds in place until nearby blood vessels can sprout new branches into the desired area, the researchers reported in the Proceedings of the National Academy of Sciences. They have all the features of blood vessels, said Andres Garcia of the Georgia Institute of Technology, who led the study. The technology might also be used to provide a kind of nesting site for pancreas cells to treat patients with type-1 diabetes or those who have lost the insulin-secreting organ, Garcia said in a telephone interview. The polyethylene glycol hydrogel carries several compounds found naturally in the body, including enzymes called matrix metalloproteinases that break down materials and vascular endothelial growth factor or VEGF, which stimulates the growth of blood vessels. The enzymes break down the hydrogel, releasing the VEGF. Enough gel remains so that the VEGF is not carried away but stays in place to stimulate blood vessel growth, Garcia said. Cells from the blood can burrow into the implant and start dividing, creating vasculature, Garcia said. When the blood vessels of rats were cut and tied off, to simulate a blood clot in the leg, the enriched gel restored blood flow within two weeks, Garcias team reported. The researchers, funded by The National Institutes of Health, the Juvenile Diabetes Research Foundation, and the American Heart Association, are also working to use the gel to create a blood-enriched site to implant the islet cells from the pancreas that produce insulin. They are not yet working with a company but hope the technique could help millions of patients some day. Loss of blood supply from blocked or damaged arteries kills or puts into the hospital 8 million Americans with peripheral artery disease, which affects the legs mostly, and 16.8 million Americans with coronary heart disease.