A team of researchers is hoping to halt the progression from heart attack to heart failure with a small device called 'Therepi.' The device contains a reservoir that attaches directly to the damaged heart tissue. A refill line connects the reservoir to a port on or under the patient's skin where therapies can be injected either by the patient or a healthcare professional. A new study published in Nature Biomedical Engineering

A team of researchers is hoping to halt the progression from heart attack to heart failure with a small device called 'Therepi.' The device contains a reservoir that attaches directly to the damaged heart tissue. A refill line connects the reservoir to a port on or under the patient's skin where therapies can be injected either by the patient or a healthcare professional.

"From a pharmacological point-of-view, it's a big problem that you're injecting something that doesn't stay at the damaged tissue long enough to make a difference," says William Whyte, co-first author.

The alternative method involves an invasive procedure to directly inject therapies into the heart muscle. Since multiple doses are needed, this requires multiple invasive surgeries.

Therepi addresses the problems with current drug delivery methods by administering localized, non-invasive therapies as many times as needed. The device's reservoir can be implanted on the heart in just one surgical procedure.

Localized, bespoke therapies

The reservoir itself holds amazing potential for drug delivery. Constructed out of a gelatin-based polymer, the reservoir has a half-spherical shape with a flat bottom attached to the diseased tissue. The flat bottom consists of a semi-permeable membrane that can be adjusted to allow more drugs or larger materials to pass directly into the heart tissue.

In a rat model, the device was shown to be effective in improving cardiac function after a heart attack. The researchers administered multiple doses of cells to a damaged heart throughout a four-week period. They then analyzed the hemodynamic changes in the tissue using a pressure volume catheter and used echocardiography to compare functional changes over time.

Finding the Optimal Dose

Therepi's capabilities go beyond treating heart disease. Since it provides the opportunity for multiple, localized doses to be delivered, it could be used as a tool to identify the exact dosage appropriate for a host of conditions.

While the team has been focusing on how Therepi can mitigate the effects of heart disease, the device could be used in other parts of the body. By optimizing the design and adjusting the materials used to construct the reservoir, Therepi could be used for a wide range of diseases and health problems.

"The device is really a platform that can be tailored to different organ systems and different conditions," says Varela. "It's just a great example of how intersectional research looking at both devices and biological therapies can help us come up with new ways to treat disease."