Researchers at McGill University have developed a technique using severed mosquito proboscises as ultra-fine nozzles for 3D printing, enabling the creation of structures as thin as 20 micrometres. This innovation, dubbed 3D necroprinting, addresses the limitations of commercial nozzles and could aid in producing replacement tissues and organs. The approach draws inspiration from nature to achieve affordable, precise bioprinting.
Engineers often face challenges in fabricating nozzles narrow enough for high-resolution 3D printing, particularly in biomedical applications. Changhong Cao at McGill University in Montreal, Canada, and his colleagues encountered this issue while working on fine structures. The narrowest commercially available nozzle they found had an interior bore of 35 micrometres and cost £60 ($80). Alternatives like glass-pulling techniques proved expensive and brittle.
"This made us think whether there is an alternative," says Cao. "If Mother Nature can provide what we need with an affordable cost, why make it ourselves?"
The team tasked graduate student Justin Puma with exploring natural options, from scorpion stingers to snake fangs. They settled on the proboscis of female Egyptian mosquitoes (Aedes aegypti), which is notably stiff and allows printing of structures as thin as 20 micrometres. An experienced worker can produce six such nozzles per hour from mosquito mouthparts, each costing less than a dollar.
These biological nozzles fit existing 3D printers and demonstrate surprising durability: about 30 per cent begin to fail after two weeks, but they can be frozen for storage up to a year. The researchers tested the method with bio-ink Pluronic F-127, suitable for building scaffolds like blood vessels, potentially advancing organ transplants.
This work joins other bio-inspired engineering feats, such as moth antennae in smell-detecting drones and dead spiders as mechanical grippers. Christian Griffiths at Swansea University, UK, praises the approach: "You’ve got a couple of million years of mosquito evolution: we’re trying to catch up with that. I think that maybe they’ve got the advantage on us there."
The study appears in Science Advances (DOI: 10.1126/sciadv.adw9953).