In diabetics, wounds tend to progress rapidly and heal slowly. Researchers have developed a way to use electricity to heal diabetic wounds three times faster, offering great potential for treating diseases that cause wounds to heal slowly.
People with diabetes are 15 times more likely to have an amputation due to foot wounds and ulcers. So even small cuts, scrapes, and scratches have the potential to develop into larger wounds, so it’s important to keep an eye out.
When diabetes is poorly controlled, blood sugar levels can be higher than normal. As a result, nutrients and oxygen fail to fuel cells, the immune system cannot function effectively, and there is widespread inflammation in the body. These things can slow down the wound healing process and increase the risk of infection. Older adults, people with poor circulation, and people with spinal injuries may also experience slower wound repair.
Researchers at Chalmers University of Technology in Sweden and the University of Freiburg in Germany have developed a way to use electricity to speed up the healing of chronic wounds, especially those in diabetic patients.
“Chronic wounds are a huge societal problem that we rarely hear about,” said Maria Asplund, corresponding author of the study. “We’ve discovered a way to make wounds heal three times faster, which could be a game-changer for people like diabetics and the elderly, who often suffer from wounds that don’t heal.”
Using electricity to stimulate healing is nothing new. In recent years, we’ve seen the development of smart bandages and bandages that tear open the wound before dissolving.
The rationale for using electricity to promote healing is that skin cells are electrotaxis, meaning that if an electric field is placed in a petri dish full of skin cells, the cells will migrate towards it. In the current study, the researchers investigated using this principle to electrically guide cells to heal wounds more quickly, especially in diabetic patients.
They focused on keratinocytes — the most dominant cell type in the skin — which play a vital role in skin repair. Keratinocytes migrate en masse as they undergo skin repair.
By combining laser-induced graphene (LIG) and integrated hydrogels, the researchers created a microfluidic platform capable of sustaining direct current (DC) electrical stimulation for hours. LIG is made by converting a polymer into a porous 3D graphene form. Using a tiny, engineered “wound-on-a-chip,” they evaluated electrically stimulated wound healing, first on healthy cells and then on cells that mimic diabetic keratinocytes.
“We were able to show that an old hypothesis about electrical stimulation can be used to make wounds heal faster,” Asplund said. “To study exactly what it does to wounds, we developed a biochip on which we grew skin cells and created tiny wounds in them. We then stimulated a wound with an electric field.”
Using a low electric field of around 200 mV/mm, they found that direct current stimulation accelerated wound closure in all cases without negatively affecting the cells. Wound healing was also stronger when the current was applied to only one side of the wound rather than both sides. Unidirectional stimulation resulted in complete wound closure within 10 hours, when only about 36% closed, compared to unstimulated wounds. This equates to a nearly three-fold increase in wound closure rates.
When the researchers applied electrical current to the “diabetic” cells, they found that after 12 hours of one-way stimulation, the cells shut down by about 34 percent, compared with about 12 percent in the unstimulated control group. The results were comparable to those observed in healthy cells, leading the researchers to conclude that electrical cell guidance resulted in faster wound closure, including in diabetic patients.
“We studied diabetic models of wounds and investigated whether our approach would work in these situations,” Asplund said. “We saw that when we simulated diabetes in cells, the wounds on the chip healed very slowly. However, with electrical stimulation, we were able to speed up the healing so that the cells affected by diabetes almost corresponded to healthy skin cells. “
Importantly, the researchers achieved these results without the use of a salt bridge, a tube containing an electrolyte that provides electrical contact between the two solutions. This should make it easier to translate the technology into 3D models, they say.
They plan to continue research to develop marketable wound healing products for individual use.
“We are now investigating how different skin cells interact during stimulation in order to more closely resemble real wounds,” Asplund said. “We wanted to develop a concept that would ‘scan’ wounds and tailor stimulation to individual wounds. We believe this is the key to effectively helping people with slow wound healing in the future.”
The study was published in the journal lab on a chip.