August New research prevents build-up of scar tissue around medical devices

Breakthrough study follows collaboration between NUI Galway and Massachusetts Institute of Technology

A team of researchers from NUI Galway and Massachusetts Institute of Technology (MIT) has devised a new design that prevents the build-up of scar tissue and extends the therapeutic lifespan of an implanted medical device. 

The breakthrough device/development, which does not rely on immunosuppressing drugs, may assist efforts to develop an artificial pancreas to treat diabetes.

The study was published in the international journal Nature Communications.

Implantable drug delivery devices that release insulin into the body over long periods of time hold promise as an alternative way to treat diabetes without insulin injections or cannula insertions. 

However, one obstacle that has prevented their use so far is that the immune system attacks them after implantation, forming a thick layer of scar tissue that blocks insulin release. This cascade of events, known as the foreign body response, can also interfere with many other types of implantable medical devices which leads to premature failure. 

The NUI Galway-MIT research team incorporated mechanical actuation in their design which enabled small and regular movements of the implanted device. The research showed that just by moving the device every 12 hours, the device remained functional after eight weeks of implantation and was as good as a freshly implanted device. It also showed that this type of motion modulates how immune cells respond to the implanted device, which extends its lifetime and efficacy.

NUI Galway’s Assistant Professor in Biomedical Engineer Dr Eimear Dolan said: “We are very excited about the results of this study. We believe our approach holds promise to improve the performance of a range of implantable drug delivery devices - from insulin to cancer therapy delivery. It is a privilege to work with such a talented multi-disciplinary team and I look forward to continuing working together.”

Professor Garry Duffy, Professor of Anatomy and Regenerative Medicine, NUI Galway, said: “This is a continuation of our efforts to thwart the foreign body response to allow long term lifespan of implantable drug delivery devices with a specific focus on improving the lives of people living with Type 1 diabetes. Soft robotics allow us to make the implants active and to influence how the immune system perceives medical device implants. We will continue to translate this technology through to the clinic in the coming years.”

Professor Ellen Roche from MIT said: “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. I think any sort of implantable drug delivery device could benefit.”

In this study published in Nature Communications, the team applied their design to diabetes to see if that immunomodulatory effect could help improve drug delivery over eight weeks. The team built a two-chambered device where one of the chambers acts as a drug reservoir, and the other acts as a soft, inflatable actuator. Using an external controller, the researchers can stimulate the actuator to inflate and deflate on a specific schedule. 

They found that mechanical actuation clears away immune cells called neutrophils, the cells that initiate the process that leads to scar tissue formation, and it took much longer for scar tissue to develop around these devices. The research showed scar tissue did eventually form, but its structure was unusual - instead of the tangled collagen fibres that built up around static devices, collagen fibres surrounding actuated devices were more highly aligned, which the researchers believe may help drug molecules to pass through the tissue.

The researchers evaluated the effectiveness of the insulin release by measuring subsequent changes in blood glucose levels and found with the actuated device, effective insulin delivery was maintained throughout the eight weeks of the study. 

Co-Founded by Professor Duffy, Professor Roche and Dr Dolan and led by CEO Robert Wylie, Fada Medical is developing fully implantable and partially implantable versions of this technology that will improve insulin delivery for people with diabetes. This venture will be supported by the unique NUI Galway innovation ecosystem drawing expertise from CÚRAM, the HRB Clinical Research Facility and leading clinicians. 

The research was funded in part by Science Foundation Ireland, Juvenile Diabetes Research Foundation, and the National Institutes of Health.

The study builds on a strong collaboration between NUI Galway’s Dr Eimear Dolan and Professor Garry Duffy, and Professor Ellen Roche from MIT. 

MIT postdocs William Whyte and Debkalpa Goswami, and visiting scholar Sophie Wang, are the lead authors of the paper, with contributions from NUI Galway researchers Niamh Ward, Dr Ruth Levey, Rachel Beatty, Dr Scott Robinson, Dr Declan Sheppard, Raymond O’Connor, Dr David Monahan, Lesley Trask, Robert Wylie, Dr Joanne O’Dwyer and Daniel Domingo.

The full study is available in Nature Communications at https://www.nature.com/articles/s41467-022-32147-w 

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