Page 15 - Orthofeed 2022_issue1_June

Amazing discovery 14

Amazing discovery

Piezoelectricity to

heal joints - a bioengineering
breakthrough

The worsening of cartilage deterioration in arthritis can make simple body movements like

walking, extremely painful. The most suitable treatment strategy is to regrow a healthy cartilage
1, 2
in the damaged joint itself. 1, 2

A recent study showed that cartilage regeneration can be critically regulated by electrical signals. A tissue
2
scaffold designed out of nanofibers of poly-L lactic acid (PLLA), a biodegradable polymer has a neat property
called piezo-electricity. Weak electric current is generated when the scaffolding is squeezed or any mechanical
2
force is applied to it. The regular movement of a joints during such as during walking, can cause the PLLA
1, 2
scaffold to generate a weak but steady electrical field that facilitates cells to colonize the scaffold and grow into

cartilage. The PLLA scaffolding is dissolved and completely replaced by the cells forming a fully grown
1, 2
biological tissue. This scaffold was tested in the knee of an injured rabbit. The study stated that external
2
growth factors or stem cells were not required, and the newly formed cartilage was mechanically robust. 1, 2

Following implantation of the scaffold, the rabbit was allowed to exercise on a treadmill, and the cartilage grew
back normally. 1, 2 This novel approach warrants further validation in larger and aged animals to confirm the
long-term effectiveness and durability of the cartilage. Arthritis is highly prevalent among older population, and
2
if this model based on piezo-electic stimulation shows similar positive outcomes in aged and large animals to

regrow injured cartilage, it would prove to be a bioengineering breakthrough. 1, 2

References

1) Claire Wilson. Electric knee implants could help treat pain of osteoarthritis. New Scientist. Published January 12, 2022.
https://www.newscientist.com/article/2304357-electric-knee-implants-could-help-treat-pain-of-osteoarthritis/
2) Liu Y, Dzidotor G, Le TT, et al. Exercise-induced piezoelectric stimulation for cartilage regeneration in rabbits. Sci Transl Med.
2022;14(627):eabi7282. doi:10.1126/scitranslmed.abi7282