When applied to neurons, a magnetic field can reduce the cells' pain signals, suggests a new study.
In the United States, chronic pain is "the most common cause of long-term disability."
According to the National Institutes of Health (NIH), over 76 million people in the U.S. — that is, approximately 1 in 4 people — have had an episode of pain that lasted for more than 24 hours.
In this context, the search for new, more effective pain management therapies is ongoing and of vital importance. Now, bioengineers from the University of California, Los Angeles (UCLA) have designed an innovative method that may succeed where other pain therapies have previously failed.
Researchers led by senior investigator Dino Di Carlo, a professor of bioengineering at UCLA, set out to investigate how magnetic force could be used to relieve pain.
The first author of the paper is Andy Kah Ping Tay, a postdoctoral researcher at Stanford University in California. The researchers published their findings in the journal Advanced Materials.
Magnetic force reduces neuronal pain signals
Tay and his colleagues designed a hydrogel using hyaluronic acid, which is a molecule uniquely capable of retaining water and that has key roles in skin moisture and skin aging. Additionally, hyaluronic acid can be found between the cells in the brain and in the spinal cord.
After creating this hyaluronic hydrogel, the scientists filled it with small magnetic particles. Then, they grew a type of brain cell — called dorsal root ganglion neurons — inside the gel.
Next, Tay and team applied magnetic force on the particles, which enabled the transmission of the magnetic field through the hydrogel and to the neural cells. By measuring the calcium ions in the neurons, the scientists were able to tell whether the cells responded to the magnetic pull — and they did.
Finally, the researchers steadily increased the magnetic force and found that doing so reduced the neurons' pain signaling. In an attempt to return to a stable state, the brain cells adapted to the magnetic stimulation by decreasing their pain signals.
"Our results show that through exploiting 'neural network homeostasis,' which is the idea of returning a biological system to a stable state, it is possible to lessen the signals of pain through the nervous system [...] Ultimately, this could lead to new ways to provide therapeutic pain relief."
Andy Kah Ping Tay
Prof. Di Carlo also comments on the results, saying, "Much of mainstream modern medicine centers on using pharmaceuticals to make chemical or molecular changes inside the body to treat disease."
"However," he adds, "recent breakthroughs in the control of forces at small scales have opened up a new treatment idea — using physical force to kick-start helpful changes inside cells. There's a long way to go, but this early work shows this path toward so-called 'mechanoceuticals' is a promising one."