Delivering Drugs,
Providing Relief


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Early prototypes of the LiRIS device. Image: Patrick Gillooly / MIT

There are few things more uncomfortable than a bladder issue. Repairing it isn’t always comfortable either. MIT professor of engineering Michael Cima is part of a team trying to do something about interstitial cystitis – a chronic condition in which the patient experiences constant bladder pressure and pain – among other bladder-related illnesses.

“I went to a meeting and I found out about the common practice of instilling drugs into the bladders of patients for a whole variety of diseases,” he says. “I thought if a disease is confined to a single compartment then why not confine that drug to that compartment? After the conversation, it was about looking into whether others had worked on this basic need and what was tried really didn’t work. I did see validation that this was an important thing to do.”

Defining the Product

His team realized there were basic requirements that had to be met to make a workable product for delivering drugs. “First, we had to get an efficient drug to the urothelium for any of these diseases we were interested in,” he says. “It had to provide a pharmacological advantage. Next, it had to be there for a long enough time. That was a big problem with installations. The last thing is we had to make it comfortable so that the patient couldn’t tell really that this device was in them. That told us a lot about what it had to look like.”

MIT Professor Michael Michael Cima (left) and alumnus Heejin Lee display early prototypes of the LiRIS device. Image: Patrick Gillooly / MIT

Comfort had been an issue partly because they found that sometimes the devices used would irritate the tissue. “We knew we needed something small that could move around and had to stay in the bladder and not come out accidentally,” he says. “We learned that unless you design it right it comes out after inserting it.”

What they came up with used medical-grade silicone, which could change shape as needed. “The tubing was a dual lumen silicone tube and the two lumens were two different sizes," Cima says. "One is small and within it goes nitinol wire that’s heat-treated to provide the [device’s] pretzel shape, and then the other lumen has pellets of the drug that have been placed in it.” The device’s ability to turn into a pretzel shape is what actually prevents it from coming out of the body.

The silicon is important because it’s permeable to water. Water is actually diffused through the silicon, dissolves salt, and then osmotic pressure forces the drug solution out through an orifice and the drug is delivered for two weeks.

Doing an open-label study with interstitial cystitis patients with doses of 200 mg and 650 mg, they found 400 mg was sustainable, according to Cima.

They believe the product could assist in bladder cancer that isn’t muscle invasive and possibly be helpful with urinary tract infections. “People with bladder issues sometimes find it so difficult that it gets in the way of their work and their relationships,” he says. “Providing relief can make a difference.”

Eric Butterman is an independent writer.

Learn more about the study of biology and treatment of disease at ASME 2015 4th Global Congress on NanoEngineering for Medicine and Biology

People with bladder issues sometimes find it so difficult that it gets in the way of their work and their relationships. Providing relief can make a difference.

Dr. Michael Cima,
MIT

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January 2015

by Eric Butterman, ASME.org