Scientists at Penn State have developed soft, stretchy electronic implants that could help treat people with dangerous high blood pressure that does not respond to medication.
The new devices gently stimulate a major artery in the neck using tiny electrical signals. In animal tests, the implants lowered blood pressure while causing much less tissue damage than traditional devices.
The researchers described their work in the journal Device.
High blood pressure, also called hypertension, affects nearly half of adults in the United States and is a major cause of heart disease and stroke. While many people can manage the condition with medicine, healthier diets, and exercise, some patients have drug-resistant hypertension. This means their blood pressure stays dangerously high even after taking several medications.
According to Tao Zhou, the lead researcher on the project, these patients may benefit from a different approach that uses bioelectronics instead of drugs.
The new implant, called CaroFlex, works by interacting with the body’s natural blood pressure control system, known as the baroreflex.
Inside the walls of major arteries are tiny sensors called baroreceptors. These sensors detect changes in blood pressure and send signals to the nervous system to help the body adjust. Many of these receptors are found in the carotid sinus, an important area where the carotid artery branches near the neck.
By placing bioelectronic devices on this area, scientists can stimulate the baroreceptors with gentle electrical pulses. This can help lower blood pressure by calming the body’s response systems.
Some existing devices already use this method, but they are often made from rigid metals and plastics. Because arteries constantly stretch and move as blood flows through them, stiff devices can irritate or damage nearby tissue over time. They are also usually attached with stitches, which may create additional problems.
To solve these issues, the Penn State team designed CaroFlex using soft hydrogel materials. Hydrogels are jelly-like substances that are flexible and more similar to natural body tissue.
The implant contains conductive hydrogel electrodes that carry electrical signals, along with adhesive hydrogels that allow the device to stick gently to tissue without stitches.
Laboratory testing showed that the device could stretch to more than twice its original size before breaking. The adhesive also remained strong and stable even after being stored for six months.
The researchers then implanted CaroFlex into rats and monitored their blood pressure. Out of five electrical settings tested, four successfully lowered blood pressure, reducing readings by more than 15% on average during the experiments.
After two weeks, the tissues around the implants appeared healthy, with little sign of damage or immune reaction.
The researchers believe this is an important step toward safer and more comfortable bioelectronic treatments for hypertension. The next stage will involve improving the device further and eventually testing it in humans.
The team also says the same 3D-printing methods could help create future bioelectronic devices for other parts of the body, potentially leading to new treatments for a wide range of medical conditions.
