Professor Bozhi Tian, a pioneer of bioelectronics, has just lit a spark of hope in the hearts of millions of people together with his research group. His intuition led to the creation of a revolutionary pacemaker, a masterpiece of miniaturization and biocompatibility that challenges the limits of medical technology. A device that dissolves in the body, like a whisper of light that restores the vital rhythm. And it is powered by light.
A pacemaker “in the light”
Tian and his team created a prototype pacemaker made of a specially engineered membrane, weighing less than one-fiftieth of a gram. Its thickness? Smaller than that of a human hair. This feature makes the device extremely light and capable of being implanted with minimally invasive surgery, without moving parts inside.
Millions of people around the world they depend on pacemakers, small but critical devices that regulate the heart's electrical impulses to maintain a regular beat. Solutions like this can reduce all the complications related to the use of these devices.
Preliminary experiments have been very promising, and we have high hopes for the future of this translational technology.
Pengju Li, doctoral student at the Pritzker School of Molecular Engineering at the University of Chicago. You are part of the research team that worked on the pacemaker.
A photovoltaic technology for the human body?
Professor Bozhi Tian's laboratory has focused for years on developing devices that can use solar cell-like technologies to stimulate the body. PV is particularly attractive for this purpose because it has no moving parts or wires that can break or become intrusive, which is especially useful in delicate fabrics such as heart.
Instead of a battery, the researchers simply implant a tiny optical fiber next to the device to provide power. The results? As reported in the magazine Nature (I'll link it all here) are really important.
A “targeted” design
To achieve the best results, scientists had to modify the system to adapt it for biological purposes, unlike the usual design of solar cells. “In a solar cell, the goal is to collect as much sunlight as possible and transfer that energy along the cell, regardless of which part of the panel is affected,” explains Li. “For this application, however, we want to be able to illuminate a very localized area and activate only that.”
The final pacemaker design is made up of two layers of a silicone material known as P-type, which responds to light by creating an electrical charge. The result is a tiny, flexible membrane, which can be inserted into the body via a tube together with an optical fiber, in a minimally invasive operation. To be clear, current pacemakers weigh at least 250 times more.
Disposable
This particular version of the pacemaker device is intended for temporary use. At the end of its "mission" another operation will not be necessary to remove it: it will dissolve on its own into a non-toxic compound known as silicic acid. However, researchers indicate that the devices could be designed to last even longer, depending on the desired duration of cardiac stimulation.
This advancement represents a turning point in cardiac resynchronization therapy. We are at the dawn of a new frontier where bioelectronics can integrate seamlessly with the body's natural functions.
Narutoshi Hibino, professor of surgery at the University of Chicago Medicine and co-corresponding author of the study.
Applications: beyond the heart
Although the first tests were conducted on heart tissue, the approach could also be used for neuromodulation, for example by stimulating nerves in movement disorders such as Parkinson's, or to treat chronic pain and other disorders. Li coined the term “photoelectroceuticals” for this field.
The day they first tested the pacemaker on pig hearts, very similar to human ones, remains vivid in Tian's memory: “I remember that day because it worked on the first try. It is both a miracle and the fruit of our extensive efforts.”
An open heart miracle.
