[Photo by Logan Voss on Unsplash]
October 31, 2025 (Friday) – By Jaewon Jayden Lee
A research team at McGill University in Canada has developed the world’s smallest 3D bioprinter—a 2.7-millimeter-wide flexible device capable of printing healing hydrogels directly onto vocal cords during surgery. The achievement, published October 29, 2025, in Device, marks a significant milestone for regenerative medicine and may one day help restore the voices of patients who lose speech following throat operations.
The innovation began with a practical question: how can surgeons reach narrow spaces inside the body without losing visibility? Traditional vocal cord surgeries, often used to remove cysts or cancerous growths, carry a high risk of leaving scarred and stiff vocal folds that no longer vibrate normally. Vocal cord surgeries, often required to remove cysts or cancerous growths, carry a high risk of leaving scarred and stiff vocal folds that no longer vibrate normally, which can severely impact a person’s ability to produce sound. The vocal folds must open and close rapidly to create the vibrations that generate the human voice, so even small scars can cause hoarseness or permanent voice loss.
Existing methods rely on hydrogel injections to prevent scarring, but the process is often imprecise and difficult to control. The new McGill bioprinter directly addresses this limitation by enabling in-situ tissue reconstruction inside the throat with sub-millimeter precision.
The printer’s design was inspired by the flexibility of an elephant’s trunk. Its soft robotic arm can bend, twist, and extend through a surgical scope, carrying a nozzle that deposits thin layers of hydrogel with extraordinary accuracy. Unlike standard injection tools, it gives surgeons real-time manual control over where and how the gel is placed.
Unlike standard injection tools, it gives surgeons real-time manual control over where and how the hyaluronic acid-based hydrogel is placed, the same biocompatible material used to cushion and regenerate damaged vocal tissue.
This control allows the operator to recreate the natural curvature and texture of healthy vocal folds. Researchers note that the system combines precision, visibility, and minimal invasiveness, making it compatible with current surgical setups.
The printer extrudes a hyaluronic acid-based hydrogel, a material already used in tissue engineering. Mounted on a surgical microscope, the printhead operates within a workspace of about two centimeters while maintaining both stability and accuracy.
Early laboratory tests on artificial vocal cords yielded promising results. The printer successfully filled small lesions and gaps, reconstructing the natural geometry of the folds’ with unprecedented detail. Researchers believe this level of accuracy could revolutionize how surgeons perform delicate procedures on the throat and other internal organs.
The next step for the McGill team is testing the device on live animal models to observe how printed hydrogels integrate with natural tissue. If successful, human clinical trials will follow to evaluate safety, usability, and long-term outcomes.
Beyond vocal cord repair, scientists envision the same approach being adapted for organs like the colon or esophagus, where precise, minimally invasive reconstruction remains a challenge.
The achievement reflects a broader transformation in modern surgery, from cutting and suturing to printing and regenerating. By shrinking bioprinting technology to fit inside the human body, McGill researchers have opened new possibilities for personalized healing.
For patients who have lost their voices, this elephant-inspired robot may one day help them speak again, not through machines, but with living tissue rebuilt, layer by layer, from within.
