Using electrical fields to heal wounds
Electrical fields (EF) play a role in various processes within the body, including as cues for the development and life cycle of tissues, and embryonal development. When the skin is injured, exchanges of ions between the wound and intact skin generate EFs naturally. Yet new tools and methods for exploring EF stimulation directly in human tissue could help develop novel clinical applications. In the SPEEDER project, which was funded by the European Research Council, a team of researchers sought to fill this knowledge gap, by testing whether EFs can be used to heal complex wounds. “We were really happy to find that at least in our wound-healing-on-a-chip model, epithelial wounds closed up to three times faster when stimulation was applied,” says Maria Asplund, professor of Electronics Material and Systems at Chalmers University of Technology in Sweden and SPEEDER project coordinator.
Honing in on electrotaxis
SPEEDER focused on a specific interaction some cells possessed called electrotaxis, which means these cells align their migration along EFs. “We believe that EF guidance of skin cell migration could be quite a powerful way to influence how cells infiltrate wounds, which may increase chances that epithelium grows back to cover the open wound faster,” explains Asplund. Using EF to boost wound healing would be particularly helpful for older people – particularly those with comorbidities such as diabetes or spinal cord injuries – who tend to have impaired wound healing abilities. Even small wounds can develop into chronic wounds, with profound impacts for both patient and society: care of chronic wounds takes up around 2 % of Sweden’s healthcare budget, for example.
Developing fluidic chips
The SPEEDER team developed a new electrode concept able to apply EF stimulation to human tissue directly in a biocompatible and robust way, while keeping the system cost-effective. To test their materials and the concept, the researchers built sophisticated microfluidic environments (fluidic chips) in labs, where they could stimulate different skin cells and cells that form epithelial layers. “We have not yet moved to human tissues, but an interesting spin-off was to build similar environments for stimulation of brain tissue,” adds Asplund. “This way we were able to study how the type of stimulation that is used for transcranial brain stimulation acts on a complete slice of brain tissue.” The results of these experiments were recently published in the journal ‘Lab on a Chip’. The team are now working to translate these findings for use on human skin. The team also found that stimulation could compensate for impaired wound healing in diabetic cells, a finding also published in ‘Lab on a Chip’ earlier this year.
Collaboration on spinal cord repair research
“On a more general level, we now understand much more about direct current (DC) stimulation, and how different materials can interplay to make this biocompatible,” Asplund notes. “We are currently exploring this for wound healing but also for other regenerative processes, such as DC stimulation to regenerate the spinal cord.” This work is being pursued in collaboration with a team in New Zealand, using the materials concepts developed in SPEEDER. “We are excited to see if there is also a benefit of DC-guided regeneration here,” says Asplund. “This is often explored in culture but we now have the capability to do this in real tissue which is very exciting for us.”
Keywords
SPEEDER, wound, healing, electrical, fields, tissue, fluidic chips, spinal, cord, repair