Summary: It is known that tendons have piezoelectric properties. That means tendon cells make a weak electric current when stretched. Now a first-of-its-kind study shows that this current plays a key role in tissue regeneration (regrowth of tissue).
Electrical stimulation therapies have long been used in sports medicine. Studies show that this therapy helps. But how it works is still poorly understood. Now a new lab study seems to give sound evidence supporting electrical stimulation in sports injuries. This is true most of all for tendons and ligaments.
In the US, about half a million adults report tendon injuries each year. These injuries are hard to treat. It usually takes months for people to fully recover.
Tendon injuries cause major disability, because tendons are slow to heal. A partial tear may take a few weeks to even months to fully recover. A complete tear is hard to repair and needs surgery. Even after surgical repair, it takes months to heal. So we need ways to speed up healing.
This new study by the University of Galway and the University of Limerick suggests that electrical stimulation may be quite helpful. Just as important, this study could shed some light, explaining how electrical stimulation may help.
Tendons are very tough. They are built to resist massive physical stress. Tendons are a kind of fibrous tissue that ties muscles to bones. New studies show that tendons are not just piezoelectric. These currents also play a vital role in how the tissue works. When tendons are squeezed or stretched, they make electricity. This weak current plays a vital role in how tendons work. It also means tendons need this weak current to regenerate.
Researchers have tested human tendon-derived cells (hTDCs) in the lab. But they found that hTDCs are hard to grow. In this new study, researchers built a special device called a tympanic bioreactor. It shakes the lab-grown cells with a vibrating force and also gives them a mild electric current. Researchers found that this physical stress plus a weak current could greatly boost the growth of hTDCs.
Researchers say these findings matter a great deal, because this tool and this insight can grow other tissues like tendons. For example, it could be tested for growing cartilage cells, bones, and even heart and blood vessel tissues.
Science has long known that physical force helps muscles, bones, and joints heal. That is why physical therapy works so well for these conditions. Now this new study shows that applying electrical stimulation may add more benefit for these conditions.
Finally, these new insights must be used to build new ways to manage chronic pain and grow different tissues. They can be used to create new methods in regenerative medicine.
Science has long known that tendons have piezoelectric properties. But this is the first study to show that these signals play a vital role in cell differentiation (cells taking on their final job), tissue regeneration, and healing.
Frequently asked questions
Will a damaged tendon ever heal?
Yes, but slowly. Tendons are slow to heal. That is why tendon injuries cause so much disability. A partial tear can take a few weeks to several months to fully recover. A complete tear is much harder. It usually needs surgery, and even after surgery it takes months to heal.
What does it mean that tendons are piezoelectric?
It means tendons make electricity. When a tendon is stretched or squeezed, its cells make a weak electric current. Scientists have known this for a long time. This study is the first to show that the current plays a vital role in cell differentiation, tissue regeneration and healing. So tendons need that current to regenerate.
Does electrical stimulation help tendons heal?
Electrical stimulation has long been used in sports medicine. But how it works was poorly understood. This study came from the University of Galway and the University of Limerick. A device that used vibration plus a mild electric current greatly boosted the growth of human tendon-derived cells in the lab. That points to why electrical stimulation can help injured tendons and ligaments.
What helps tendons heal faster?
Physical force has long been known to help muscles, bones, and joints heal. That is why physical therapy works so well for these conditions. This study adds electrical stimulation to that picture. Pairing physical stress with a weak current may give injured tendons an added benefit. The same method could also be tested for growing cartilage, bone and even heart and blood vessel tissue.
Source:
Fernandez-Yague, M. A., Palma, M., Tofail, S. A. M., Duffy, M., Quinlan, L. R., Dalby, M. J., Pandit, A., & Biggs, M. J. (2024). A Tympanic Piezo-Bioreactor Modulates Ion Channel-Associated Mechanosignaling to Stabilize Phenotype and Promote Tenogenesis in Human Tendon-Derived Cells. Advanced Science, 11(45), 2405711. https://doi.org/10.1002/advs.202405711
Dr. Gurpreet Singh Padda, MD, MBA, MHP
