A team of researchers from the U.S. and Ireland have developed a device that can be used to deliver drugs directly to a damaged region of the heart. The capability has the potential to provide a direct therapeutic option to guide how the heart recovers following a heart attack, leading to improved cardiac function. As Ellen Roche, one of the authors of the paper appearing in Nature Biomedical Engineering, explains, “After a heart attack we could use this device to deliver therapy to prevent a patient from getting heart failure. If the patient already has some degree of heart failure, we can use the device to attenuate the progression.”
Currently, drugs meant for the heart that are delivered via injection into the blood stream end up affecting the whole of the body and have to be administered in small doses to minimize the impact. Direct, repeat injections into the heart have a host of other possible complications. The new device, called Therepi, can be implanted in a single procedure and used repeatedly to push drugs right into the targeted tissue.
One end of the Therapi is attached to cardiac tissue and has a membrane that allows the release of a drug, while at the other end is an injection port penetrating the skin at the abdomen. A syringe is simply pushed into the port and the drug is injected, a process that can be done by a clinician or even by the patient at home.
The membrane that sits between the drug reservoir and the heart’s tissue can be selected from a variety of pore sizes that are designed for different drugs, depending on their molecular sizes and how much needs to be released. “The material we used to construct the reservoir was crucial. We needed it to act like a sponge so it could retain the therapy exactly where you need it,” said William Whyte, another author of the paper. “That is difficult to accomplish since the heart is constantly squeezing and moving.”
So far the technology has been tried in lab rats and the results are quite splendid, including moderately improved cardiac function after a four week trial, compared to controls. The researchers believe that the results can be drastically improved once dosages are figured out, the device optimized, and its usage is perfected.