A team of MIT engineers and collaborators has designed an implantable device that prevents the buildup of scar tissue around medical implants. Implantable devices can be used to treat diabetes without insulin injections or cannula insertions by releasing insulin into the system. However, implantable devices can often trigger a foreign body response, a formation of a thick layer of scar tissue that prevents insulin release within weeks or months. As a result, the majority of patients with type 1 diabetes prefer to receive insulin through daily injections. These can be provided through wearable insulin pumps or insulin patches.
The researchers at MIT sought to develop a method to inhibit the formation of scar tissue. Researchers initially injected immunosuppressants to combat tissue growth. However, the MIT team instead devised a device to regulate immune cells. The device operates by regularly inflating and deflating for five minutes once every 12 hours. The mechanical deflection inhibits immune cells from gathering around the device. The MIT engineers tested the device with mice and discovered that the time required for scar tissue to form around the devices was substantially longer. Scar tissue did ultimately form, but it had an odd composition. The fibers were more highly aligned, which the researchers believe may allow insulin molecules to pass through the tissue.
The team at MIT have developed a 120 millimeter by 80 millimeter human-sized version of the device and demonstrated it was capable of being successfully implanted in the stomach of a human corpse. Researchers at the Washington University School of Medicine hope to adapt the device to deliver stem-cell pancreatic cells to detect glucose levels and release insulin to prevent excessive amounts of glucose. Researchers also hope to utilize the device to treat ovarian cancer and to prevent heart failure in patients who have suffered heart attacks.
“You can imagine that we can apply this technology to anything that is hindered by a foreign body response or fibrous capsule, and have a long-term effect,” says Ellen Roche, Co-author of the study and the Latham Family Career Development Associate Professor of Mechanical Engineering. “I think any sort of implantable drug delivery device could benefit.”