Technion researchers have built pancreatic tissue with insulin-secreting cells, surrounded by a three-dimensional network of blood vessels. The engineered tissue could pave the way for improved tissue transplants to treat diabetes.
The tissue created by Professor Shulamit Levenberg of the Technion-Israel Institute of Technology and her colleagues has some significant advantages over traditional transplant material that has been harvested from healthy pancreatic tissue.
The insulin-producing cells survive longer in the engineered tissue, and produce more insulin and other essential hormones, Levenberg and colleagues said. When they transplanted the tissue into diabetic mice, the cells began functioning well enough to lower blood sugar levels in the mice.
Transplantation of islets, the pancreatic tissue that contains hormone-producing cells, is one therapy considered for people with type 1 diabetes, who produce little or no insulin because their islets are destroyed by their own immune systems. But as with many tissue and organ transplants, donors are scarce, and there is a strong possibility that the transplantation will fail.
The well-developed blood vessel network built into the engineered tissue is key to its success, the researchers concluded. The blood vessels encourage cell-to-cell communication, by secreting growth hormones and other molecules, that significantly improve the odds that transplanted tissue will survive and function normally.
The findings confirm that the blood vessel network "provides key survival signals to pancreatic, hormone-producing cells even in the absence of blood flow," Levenberg and colleagues concluded in their study published in the journal PLoS One.
One reason transplants fail, Levenberg said, "is that the islets are usually transplanted without any accompanying blood vessels." Until the islets begin to connect with a person's own vascular system, they are vulnerable to starvation.