Magnetic painkiller technique could revolutionise treatment

For most of the history of medicine, the best way to treat many disorders is through drugs: chemical compounds that influence biology, whether they are derived from plants and animals or from laboratories and chemical plants. Researchers at the University California Los Angeles are now investigating a different technique which involves no drugs but uses magnetic fields to manipulate the microscopic activity of the human body.

A team of bioengineers led by Professor Dino Di Carlo has developed a gel -like material containing microscopic magnetic particles that can be injected into a site where a patient is experiencing pain, either from disease or injury. They used these particles to control proteins in cell membranes that, in turn, control the flow of ions which are involved in mediating and transmitting the sensations of pain.

The lead author of a study in Advanced Materials describing the research, Andy Kah Ping Tay of the Samueli School of Engineering, explained that the technique exploits a phenomenon known as neural network homeostasis, which describes returning a biological system to a stable state. This, he said, lessens the signals of pain through the nervous system. Ultimately, this could lead to new ways to provide therapeutic pain relief.

Treating pain has been one of the biggest issues facing medicine for centuries. Despite much research, we still do not have any painkillers more powerful than opiates, which pose the risk of addiction and other dangerous physiological effects.

The magnetised gel is based on hyaluronic acid, a polymer which provides structural support in the spiral cord and the brain, and which is increasingly used in moisturising cosmetics. The team mixed magnetic microparticles into the gel, and then used it as a culture medium to grow a type of primary nerve cell – dorsal root ganglion neurons – through the gel mixture.

In laboratory tests in vitro, they used magnetic fields to manipulate the microparticles and found that the forces induced by the fields were associated with an increase of calcium ions in the neurons, indicating that the cells are responding to the mechanical forces. By increasing the force steadily and observing the calcium level, they deduced that the neurons were adapting to the continuous stimulation by reducing the signals for pain.

The team suggests that the magnetic gel could be tailored with different biomaterials to make it suitable for treating cardiac and muscle disorder pain. It could also be used in studies to emulate concussion or other traumatic events where the body's cells are impacted by physical forces. “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," commented Prof Di Carlo. "There's a long way to go, but this early work shows this path toward so-called 'mechanoceuticals' is a promising one."