Scientists have developed a non-invasive cosmetic surgery technique that uses tiny needles and electric current to quickly reshape cartilage in the nose or ears, without the need for making incisions. Traditional surgery to reshape a nose or ear entails cutting and suturing, sometimes followed by long recovery times and scars. “We envision this new technique as a low-cost office procedure done under local anaesthesia,” said Michael Hill, one of the project’s principal investigators at Occidental College in the US.
“The whole process would take about five minutes,” Hill said. A non-invasive technique to reshape cartilage would be useful for cosmetic surgery procedures, such as making a nose more attractive. However, the method also could help fix problems, such as a deviated septum, or conditions for which no good treatments exist, such as joint contractures caused by stroke or cerebral palsy.
The team began experimenting with passing current through cartilage to heat it up. The method indeed allowed them to reshape tissue, but, curiously, not by warming it. Cartilage is made up of tiny rigid fibres of collagen loosely woven together by biopolymers. It also contains negatively charged proteins and positively charged sodium ions. Cartilage with a greater density of these charged particles is stiffer than cartilage with a lower charge density.
Researchers discovered that passing current through cartilage electrolyses water in the tissue, converting the water into oxygen and hydrogen ions, or protons. The positive charge of the protons cancels out the negative charge on the proteins, reducing charge density and making the cartilage more malleable. The team tested the method on a rabbit whose ears normally stand upright. They used a mold to hold one ear bent over in the desired new shape.
By inserting microneedle electrodes into the ear at the bend and pulsing current through them with the mold in place, they briefly softened the cartilage at the bend site without damage. Turning off the current than allowed the cartilage to harden in its new shape, after which the mold was removed. To achieve this outcome with traditional methods, a surgeon would have to cut through the skin and cartilage and then stick the pieces back together. That can lead to the formation of scar tissue at the joint.
The scar tissue must sometimes be removed in subsequent operations, Hill said. By avoiding mechanical damage to the cartilage, the molecular surgery technique causes no scarring and no pain. The researchers are exploring licensing options for the cartilage technique with medical device companies.