Treating Lupus with Light

About 1.5 million Americans and at least five million people worldwide have a form of lupus, according to the Lupus Foundation of America. An autoimmune disease, lupus occurs when the body’s immune system attacks its own tissues and organs. It can impact many different body systems, including the joints, skin, kidneys, blood cells, brain, heart, and lungs.

Light sensitivity is a common symptom in people with lupus, with 40% to 70% of people experiencing worsening of their disease due to exposure to sunlight or even artificial indoor light.

In response to this debilitating symptom, a team of University of Minnesota Twin Cities engineers and doctors designed a novel 3D-printed light-sensing medical device placed on the skin that generates real-time feedback to correlate light exposure with flare-ups of the disease. The researchers hope to help the millions worldwide with lupus as well as other light-sensitive diseases via access to more personalized treatments and data to determine what is causing their symptoms.

Wearable devices or those that interface with the skin that continuously monitor environmental signals in-situ can become useful real-time, health-profiling strategies and may potentially mitigate the severity of environmentally sensitive health ailments.

“I treat a lot of patients with lupus or related diseases, and clinically, it is challenging to predict when patients’ symptoms are going to flare,” University of Minnesota Medical School dermatologist Dr. David Pearson said to the press. “We know that ultraviolet light and, in some cases visible light, can cause flares of symptoms—both on their skin, as well as internally—but we don’t always know what combinations of light wavelengths are contributing to the symptoms.”

The research, for which Dr. Pearson was a study co-author, was recently published in the journal Advanced Science. The team has also filed a patent on the new device and stated that the technology is available for licensing.

Also on the team was University of Minnesota mechanical engineering professor Michael McAlpine. Professor McAlpine and his team had made strides in customized 3D-printing of wearable devices, and Dr. Pearson reached out to him to work together for a solution for his problem.

The result was a first-of-its kind, fully 3D-printed device containing a flexible UV-light detector that could be put on the skin. The device also contains a custom-built portable console for continuous monitoring and correlations of light exposure to symptoms. The device is composed of multiple material layers—which include electrodes and optical filters—printed on a biocompatible silicone base. Filters can be swapped out depending on the particular wavelength needing to be evaluated.

“This research builds upon our previous work where we developed a fully 3D printed light-emitting device, but this time instead of emitting light, it is receiving light,” said McAlpine. “The light is converted to electrical signals to measure it, which in the future can then be correlated with the patient’s symptoms flare ups.”

The team also used zinc oxide to gather the UV light and convert it into electrical signals. The custom-built console is attached to the device mounted on the skin in order to capture and store data.

The fully 3D printed flexible hybrid UV-visible photodetector array—as it’s referred to in the Advanced Science article—was fabricated on a stretchable substrate. The flexible photodetectors were printed on a PDMS (polydimethylsiloxane) substrate, which is commonly used for this type of elastic substrate for biointerfaced compliance. The 3D-printed, eight channel photodetector array is composed of eight UV-vis broadband photodetectors with different optical bandpass filters that define the spectral ranges of the photodetectors. The flexible photodetectors, according to the researchers, showed reliable performance stability during both optical and mechanical tests.

The signal processing board is a single board that houses the microprocessor, as well as an uninterruptable power supply module.

The team has gained approval to start testing the device on humans and will soon enroll participants in the study.

“We know these devices work in the lab, but our next step is really to put them into the hands of patients to see how they work in real life,” Pearson said. “We can give them to participants and track what light they were exposed to and determine how we can predict symptoms. We will also continue testing in the lab to improve the device.”

The 3D-printing process is relatively low-cost and may someday allow expedited access to the new device without the expensive manufacturing and fabricating processes of traditional medical devices.

“There is no other device like this right now with this potential for personalization and such easy fabrication,” Pearson said. “The dream would be to have one of these 3D printers right in my office. I could see a patient and assess what light wavelengths we want to evaluate. Then I could just print it off for the patient and give it to them. It could be 100% personalized to their needs. That’s where the future of medicine is going.”