Discovering the Best Size and Shape for Beta Cell Replacement

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Watch this: To learn more from MIT’s Dr. Anderson.

Smaller Is Not Always Stealthier

In a recent Nature Materials’ publication, Daniel Anderson, Ph.D., of the Massachusetts Institute of Technology (MIT) detailed how the immune system responds to implanted material depending on its size and shape. In this short video, you can learn about the future of beta cell replacement technology discussed by Dr. Anderson and his research collaborator Gordon Weir, M.D., Diabetes Research and Wellness Foundation Chair at Joslin Diabetes Center and Professor of Medicine at Harvard Medical School.

According to Dr. Weir, “There are two major hurdles with beta cell replacement, one is the supply of beta cells and the other is the need to protect these cells from being killed by the immune system. We are interested in creating a membrane for nutrients and oxygen to flow in and insulin to get out and small enough for t-cells not to get to the beta cells.”

The research examined how animal models reacted to various materials including natural materials such as seaweed and synthetic materials like hydrogels and ceramics when implanted and tested, and specifically, if scarring occurred where the encapsulation materials were implanted. “Traditionally, spheres smaller than 0.5 mm were believed to be the best way to facilitate the diffusion of nutrients and oxygen to the cells,” said Anderson. “The smaller spheres however are not as biocompatible as the larger spheres.”

Researchers implanted a diabetic mouse model with 0.5 mm and 1.5 mm encapsulation capsules filled with insulin-producing islets taken from rats and discovered that the animals with the smaller implants maintained normal blood glucose levels for roughly 30 days while those with the larger implants maintained normal levels significantly longer and for up to 180 days. When the capsules were retrieved, researchers found scarring around the smaller implants, but not around the larger ones, suggesting the scarring had affected the islets’ viability and function. In summary, the larger spheres triggered fewer immune responses with less scarring. “In the next couple of years, I hope that we have a device that we can take forward into patients,” said Anderson.
For more information or to support JDRF’s Encapsulation research program, please click here.

Why it Matters
If functioning beta cells thrive after implantation, we can eliminate type 1 diabetes; so perfecting the delivery of beta cells is necessary to know what is best tolerated by the body. The JDRF-supported researchers’ goal is to create a successful islet encapsulation system which allows cells to sense change in blood glucose while protecting them from the immune system.


By Emily Howell