Scientists use 3D printing and intelligent biomaterials to create implants

Bioengineers at Rice University are using 3D printing and smart biomaterials to create an insulin producing implant for patients with type 1 diabetes. This three-year project is a cooperative project between Omid Veiseh and Jordan Miller Laboratories, funded by JDRF, a global leading funder of diabetes research. Veiseh and Miller will use insulin secretion made from human stem cells β Cells create an implant to perceive and regulate blood sugar levels by responding to the correct amount of insulin at a specific time.

Assistant Professor Veiseh of Biotechnology has spent over a decade developing biomaterials to protect implanted cell therapies from the impact of the immune system. Associate Professor Miller of the Department of Biotechnology has spent over 15 years researching 3D printing techniques for tissues with blood vessels (or vascular networks).

Veiseh said, "If we really want to reproduce the normal function of the pancreas, we need the vascular system. That's the purpose of this funding collaboration with JDRF. The pancreas naturally has all these blood vessels, and cells are organized in a special way in the pancreas. Jordan and I want to print in the same direction as the natural world."

Type 1 diabetes is an autoimmune disease that causes the pancreas to stop producing insulin, the hormone that controls blood sugar levels. About 1.6 million Americans have type 1 diabetes, and more than 100 cases are diagnosed every day. Type 1 diabetes can be controlled by insulin injection. However, balancing insulin intake with diet, exercise, and other activities is difficult. The study estimated that in the United States, less than one third of patients with type 1 diabetes can continue to reach the target blood glucose level.

Veiseh and Miller's goal is to demonstrate that their implants can properly regulate blood sugar levels in diabetes mice for at least six months. To achieve this, they need to make their engineering β Cells have the ability to respond to rapid changes in blood sugar levels.

Miller said, "We must bring the implanted cells closer to the blood, so that..." β Cells can perceive and quickly respond to changes in blood sugar He said that under ideal circumstances, insulin producing cells should not be more than 100 micrometers away from blood vessels. Miller said, "We combine cutting-edge 3D bioprinting technology with host mediated vascular remodeling to give every implant the opportunity to bind to the host.".

Insulin producing cells will be protected by the hydrogel formula developed by Veiseh, who is also a scholar at the Texas Cancer Prevention and Research Institute. This hydrogel material has been proved to be effective in encapsulating cell therapy methods in bead sized spheres. The pores are small enough to prevent the cells inside from being attacked by the immune system, but large enough to allow nutrients and life sustaining insulin to pass through.

"Blood vessels can enter it," Veiseh said. "At the same time, we have our coating, our small molecules, to prevent the body from rejecting gel. Therefore, it should be very harmonious with the body."

If the implant's response to high or low blood sugar levels is too slow, this delay can have a roller coaster effect, with insulin levels repeatedly rising and falling to dangerous levels.

"Solving this delay is a huge problem in this field," Veiseh said. "When you give mice - and ultimately humans - a glucose challenge that mimics eating, how long does it take for this information to reach our cells, and how quickly does insulin come out?" By adding blood vessels to their implants, he and Miller hope to make their β The behavior of cellular tissues is closer to imitating the natural behavior of the pancreas.

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