Researchers at the McGill University, supported by funding from the National Institutes of Health (NIH), have created what is being called the smallest bioprinter reported to date—just 2.7 mm wide—that can accurately deliver hydrogels to vocal cords during surgery, helping prevent post-operative stiffness and improve patients’ ability to speak. The study was published in Cell Press journal Device.
“Our device is designed not only for accuracy and printing quality but also for surgeon usability,” said Swen Groen, first author and biomedical engineer at McGill University. “Its compact and flexible design integrates with standard surgical workflows and provides real-time manual control in a restricted work environment.”
Design and Function Inspired by Nature
According to a news report, voice disorders affect 3% to 9% of people, often caused by growths or lesions on the vocal cords. Surgical removal can lead to fibrosis, stiffening the vocal folds and making speech difficult. To improve hydrogel delivery, the team developed a miniature 3D printer that can operate through the patient’s mouth using a laryngoscope. “I thought this would not be feasible at first—it seemed like an impossible challenge to make a flexible robot less than 3 mm in size,” said Luc Mongeau, senior author and biomedical engineer at McGill University.
The device is inspired by elephant trunks: a flexible “trunk” ending in a nozzle, connected by tendon-like cables to a control module. Surgeons can manually guide the device in real time, applying a hyaluronic acid-based hydrogel in 1.2 mm lines, with precise and repeatable movements within a 20 mm working range.
Testing and Future Clinical Applications
To test its performance, the team manually drew shapes such as spirals, hearts, and letters on flat surfaces, then applied hydrogels to simulated vocal folds used for surgical training. The bioprinter accurately reconstructed tissue geometry, including cavities left after lesions and fully reconstructed vocal folds.
“Part of what makes this device so impressive is that it behaves predictably, even though it’s essentially a garden hose—and if you’ve ever seen a garden hose, you know that when you start running water through it, it goes crazy,” said Audrey Sedal, co-author and biomedical engineer at McGill University.
Currently, the device operates under manual control, but the team plans to integrate autonomous guidance. “We’re trying to translate this into the clinic,” said Mongeau. “The next step is testing these hydrogels in animals, and hopefully that will lead us to clinical trials in humans to test the accuracy, usability, and clinical outcomes of the bioprinter and hydrogel.”
Advances in Bioprinting
This research is part of a broader trends in bioprinting, where researchers and companies are developing advanced printing technologies to improve cell survival, precision, and clinical applicability across various tissues.
A team led by Riccardo Levato at Utrecht University and University Medical Center Utrecht (UMC Utrecht) in the Netherlands has created a 3D printer that combines computer vision with volumetric printing. Detailed in Nature, the system—named Generative, Adaptive, Context-Aware 3D printing (GRACE)—is designed to enhance cell survival and functionality in bioprinted tissues.
Elsewhere, Swiss biotech company TissueLabs introduced TissuePro, a next-generation bioprinter for advanced tissue applications. Building on its TissueStart platform, TissuePro offers higher precision in multi-material printing, improved automation, and expanded flexibility to support work in regenerative medicine, disease modeling, and even soft robotics.
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Featured photo shows Schematic overview of suspension laryngoscopy with the MIISB. Image via McGill University.
