Researchers Find Novel Target for Controlling Immune Response to Implanted Materials

Researchers at MIT and Boston Children's Hospital have published a report in the journal Nature Materials that provides a better understanding of the body's immune responses to the materials used in implanted medical devices. Funding for this study is made possible through collaboration between JDRF and The Leona M. and Harry B. Helmsley Charitable Trust.

The report, "Colony stimulating factor-1 receptor is a central component of the foreign body response to biomaterial implants in rodents and non-human primates," could have a significant impact on our future ability to prevent immune rejection of devices that treat type 1 diabetes (T1D), including infusion sets, sensors for continuous glucose monitors (CGMs), and in particular, cell encapsulation and transplantation devices. The study, conducted in rodents and non-human primates, found a significant increase in immune response from colony stimulating factor-1 binding its receptor (CSF1R) following implantation of multiple biomaterial classes such as ceramic, polymer and hydrogel. It also found that specifically targeting CSF1R improved biocompatibility and reduced the thickening and scarring of connective tissue known as fibrosis without the need for broad immunosuppression that would inhibit necessary immune functions like wound healing.

Currently, devices like CGMs and infusion sets for insulin pumps must be changed regularly because the body's immune response causes what's known as a fibrotic cascade, preventing the device from interacting with the surrounding microenvironment - making it impossible for the devices to sense glucose levels or effectively deliver insulin. In addition, non-biodegradable microcapsules and macrodevices are being tested to immunoisolate transplanted islet cells in people with T1D, however immune and fibrosis responses directed at the encapsulation material contribute to the failure of the device.