Bioelectronic patch uses live bacteria to treat psoriasis in mice

A bioelectronic device containing live skin bacteria reduces inflammation and promotes healthy skin regeneration in mice suffering from psoriasis, a chronic autoimmune disease characterized by accelerated skin cell growth. A future version of this technology could help treat psoriasis in some of the 125 million people worldwide.

“For a mouse model, four days or almost a week should be enough for treatment,” says Bozhi Tian of the University of Chicago in Illinois, whose team developed the device. “If you are thinking about potential clinical use in humans, it will take more time, but it can be easily done.”

The top layer of the device contains electronic sensors that can measure the skin’s electrical impedance – which is a proxy for tracking skin thickness and dryness – as well as body temperature and humidity. The bottom layer consists of a soft hydrogel material containing life Staphylococcus epidermidis bacteria, a component of the normal human skin microbiome. These bacteria are mixed with starch and gelatin to mimic a “biofilm” in which the bacteria can grow.

The S. epidermis the bacteria naturally produce a metabolite capable of disrupting excessive skin cell growth. During treatment, this metabolite promoted normal skin growth. The researchers were able to track this process by monitoring the change in the skin’s electrical impedance and observing a reduction in clinical symptoms.

Such technology could ultimately lead to devices that use information from sensors to continuously adjust the therapeutic benefits of living bacteria, writes Peder Olofsson of the Karolinska Institute in Sweden in a perspective paper examining the implications of the new technology.

Preliminary work by Tian and his colleagues shows how to do this. Their latest study showed that the middle layer of the device could be used to deliver electrical stimulation after successful treatment, which kills S. epidermisbacteria and disinfects the skin. However, preliminary, unpublished results suggest that specific levels of electrical stimulation may actually enhance the therapeutic effects of skin bacteria, rather than kill them. This suggests that with careful control of electrical stimulation it would be possible to speed up or slow down the pace of treatment to meet the needs of the patient being treated.

“We are currently using electrical stimulation to further modulate microbial activity,” says Tian. “This allows you to still keep the cells alive, but with an enhanced therapeutic effect.”