A recent investigation by scholars from the University of Galway and the University of Limerick indicates that electrical stimulation may play a crucial role in maintaining the health of tendons, paving the way for new opportunities in tendon repair and regeneration.
This study was conducted at the CÚRAM Research Centre for Medical Devices, which is supported by Taighde Éireann — Research Ireland, previously known as Science Foundation Ireland.
Tendons are designed to withstand significant mechanical stress while allowing the transfer of force from muscles to bones. They are also capable of generating electric fields when stretched, a characteristic believed to be vital for regulating the function of tendon cells. Unfortunately, tendons have a limited ability to heal after injury, often resulting in chronic pain and disability that can diminish a patient’s productivity.
In 2023, severe tears or traumatic injuries affecting tendons, ligaments, and muscles impacted nearly half a million individuals in full-time jobs across the United States.
The recovery process for tendon injuries is lengthy and often necessitates extensive rehabilitation, leading to almost two months of lost workdays for each injury. Current regenerative medicine techniques for tendon repair have so far struggled to recreate the natural environment of tendon cells, which diminishes their effectiveness.
Dr. Marc Fernandez-Yague, who earned his PhD while researching with CÚRAM at the University of Galway, led the research team in exploring how electrical and mechanical signals work together to influence tendon cell behavior. Traditionally, it has been incredibly challenging to culture tendon cells in a laboratory setting, as they quickly and irreversibly lose their tendon-like characteristics once removed from the body.
To tackle these issues, the team created an innovative cell culture device called a “tympanic piezoelectric bioreactor.” This device operates similarly to the human eardrum, providing mechanical vibrations and electrical stimulation to the tendon cells.
This combination of stimuli helped the cells maintain their healthy, tendon-specific traits while being cultivated in the lab, making them suitable for use in tissue repair and regenerative methods.
Dr. Fernandez-Yague stated: “Our research is based on a comprehensive understanding of how cells perceive and interact with their surroundings. Until now, tendon cells have been grown in specialized devices that stretch them to mimic body movement effects. However, this method fails to consider that tendon tissues are piezoelectric—producing electrical signals under mechanical stress. Our project developed dynamic electrical-mechanical stimulation systems, which offer the cells the precise signals required to properly direct their growth, thereby mimicking crucial environmental conditions seen during typical tissue formation and healing.”
Dr. Manus Biggs, Associate Professor at the University of Galway and principal investigator of the study, discussed some broader implications of the findings: “Our methodology not only shows substantial promise for the potential to grow tendon tissues in a lab setting, but it also holds important implications for generating other tissues influenced by dual electrical and mechanical stimuli, such as cartilage, bone, and even cardiovascular tissues. This research opens new avenues for developing treatments that encourage tissue reinforcement and provide alternative or complementary strategies to existing physical rehabilitation practices.
“We recognize that conventional musculoskeletal therapies often depend on physical therapy to deliver mechanical signals to the cells of regenerating tissues. By integrating electrical stimulation, we can achieve improved precision in controlling cellular responses, thus offering a more effective approach for applications in regenerative medicine. Importantly, the piezoelectric properties of tendons have long been thought to have physiological roles. This study is one of the pioneering efforts demonstrating that piezoelectric signals can influence cell differentiation and development.”
