A severed mosquito proboscis can be turned into an extremely fine nozzle for 3D printing, and this could help create replacement tissues and organs for transplants.

at McGill University in Montreal, Canada, and his colleagues developed the technique, which they call 3D necroprinting, because they were unable to find nozzles thin enough for their work on manufacturing very fine structures. The narrowest commercially available nozzle they could find had an interior bore of 35 micrometres and also came with a hefty 拢60 ($80) price tag.

They experimented with techniques like glass-pulling, but found these nozzles also proved expensive and were very brittle.

鈥淭his made us think whether there is an alternative,鈥� says Cao. 鈥淚f Mother Nature can provide what we need with an affordable cost, why make it ourselves?鈥�

The researchers tasked a graduate student, , with finding a natural organ that could handle the task, considering everything from scorpion stingers to snake fangs. They eventually found that a mosquito proboscis 鈥� in particular, the stiffer version found in female Egyptian mosquitoes (Aedes aegypti) 鈥� allowed them to print structures as thin as 20 micrometres.

Cao says an experienced worker can make six nozzles an hour from mosquito mouthparts at a cost of less than a dollar each, making the process easy to scale up. The natural nozzles can be fitted to existing 3D printers and are relatively long-lasting considering their biological origin: after two weeks, around 30 per cent of them begin to fail, but they can be stored frozen for up to a year.

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The team tested the technique using a bio-ink called Pluronic F-127, which can build scaffolds for biological tissues including blood vessels 鈥� a potential method for creating replacement organs.

There have been several other examples of parts from small creatures being used in machines, including a moth antenna used in a smell-seeking drone and

at Swansea University, UK, says the work is another example of human engineers struggling to match the tools developed by nature.

鈥淵ou鈥檝e got a couple of million years of mosquito evolution: we鈥檙e trying to catch up with that,鈥� he says. 鈥淚 think that maybe they鈥檝e got the advantage on us there.鈥�

With slight modifications, hot glue guns commonly used in arts and crafts can repair damaged bones quickly and cheaply, researchers say.

Bones can repair themselves after small injuries, but if there is a void 鈥� because of serious trauma or tumour removal, for example 鈥� then that space needs to be filled with either a graft or an artificial plug made of a material that encourages bone cells to spread.

One solution is to use 3D printers to create perfectly-fitting scaffolds to fill such voids, but this requires scanning and remote fabrication 鈥� a process taking at least a week. That is fine for a pre-planned operation to fix a worn-out joint, for example, but not for emergency trauma surgery.

To solve this problem, at Sungkyunkwan University in South Korea and his colleagues have developed a system that can be applied instantly during a single surgery.

They modified a hot glue gun by reducing the temperature at which it operates from over 100掳C to around 60掳C. They also concocted a material that acts as a biological glue 鈥� a mixture of hydroxyapatite, which makes up 50 per cent of the volume of normal human bones, and a biodegradable thermoplastic called polycaprolactone.

Surgeons can use the hot glue gun to fill bone voids in a matter of minutes during surgery and bone cells are then able to span the gap and permanently repair the injury over time.

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鈥淚t is basically made of commercially available hot glue guns,鈥� says Lee. 鈥淲e can save time and cost.鈥�

Lee and his colleagues tested the glue gun by repairing centimetre-long gaps in rabbits鈥� femur bones. In samples taken after 12 weeks, there were no signs of medical problems or separation between the glue and the bone.聽 The bone volume was more than twice as high in the animals treated with the glue gun than in control animals where the repair was made with traditional bone cement.

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The researchers also found they could incorporate vancomycin and gentamicin, two antibacterial compounds, into the filament to reduce the potential for infection. The drugs are released slowly and diffuse directly onto the surgical site over several weeks.

at the University of Nottingham, UK, who is researching 3D-printed scaffolds for bone repair, is sceptical a hot glue gun will end up becoming a widely-used solution ahead of faster scanning and 3D-printing technology.

鈥淒o I think it鈥檚 an interesting concept? Yes. Could it feasibly work?鈥� Yes. Do I think it鈥檚 within the range of the plausible? 鈥℡es,鈥� he says. 鈥淏ut this might not be the thing.鈥�

Researchers have 3D printed devices made of insulin-producing cells. These devices could enable a long-term treatment for type 1 diabetes that would let people produce their own insulin 鈥� without requiring invasive surgery.

Because people with type 1 diabetes cannot make enough insulin to regulate their blood sugar, they must constantly manage their condition, usually with injections and dietary precautions. One longer-term treatment involves transplanting human islets 鈥� clusters of insulin-producing cells that typically grow in the pancreas 鈥� from donors. But like an organ transplant, this requires invasive surgery.

鈥淐urrent practice is to inject these human islets through the portal vein into the liver,鈥� says at the Wake Forest Institute for Regenerative Medicine in North Carolina. However, about half of the implanted islets quickly lose their functionality, which means people must undergo several transplantations to make the treatment effective.

If islets could be placed directly under the skin, surgery would not only be less invasive, but it would also produce less of the stress and inflammation that shortens the cells鈥� functional life.

鈥淭he higher the density [of islets], the smaller the size of the device you would need to plant in the patient,鈥� says at Carnegie Mellon University in Pennsylvania and the biotech company FluidForm Bio in Massachusetts.

To achieve that high density, Perrier and his colleagues 3D printed islets from a 鈥渂ioink鈥� made of human pancreatic tissue and alginate, a type of carbohydrate derived from seaweed. Live insulin-producing cells were mixed into this material.

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鈥淲e put this bioink with the [human] islet into a syringe, and we print a special motif [with it],鈥� says Perrier. This porous grid is designed to allow new blood vessels to grow around and through the structure.

In the lab, this technique 鈥渨orks very well鈥�, says Perrier, noting that about 90 per cent of the islets鈥� cells survived and functioned for up to three weeks. 鈥淭he next challenge is really to validate this finding in vivo.鈥� Perrier and his colleagues presented their research at the European Society for Organ Transplantation (ESOT) 2025 meeting in London on 29 June.

Feinberg and his colleagues have also 3D printed their own islets. Their technique is to make a framework by printing cells and collagen directly into a hydrogel polymer 鈥� 鈥渒ind of like 3D printing inside of hair gel鈥�, he says. It was presented at the International Pancreas & Islet Transplant Association 2025 meeting in Pisa, Italy on 16 June. In diabetic lab mice, the islets restored normal glucose control for up to six months.

Feinberg says Perrier鈥檚 work is 鈥渄efinitely promising鈥� but that the inherent variability of the human tissue used to make the islets could pose challenges in a living body. 鈥淚t鈥檚 like getting a transplant organ,鈥� he says. 鈥淥n one side, the material may work better. On the flip side, it鈥檚 variable and hard to get, and that鈥檚 a really hard problem to solve.鈥�

To avoid such transplantation issues, both Feinberg and Perrier say stem cell therapies represent the future of type 1 diabetes treatment. Using stem cells in the 3D printing process 鈥� instead of the cells they are currently using 鈥� could solve a lot of issues at once, they say.

Fighter jets that first flew in the 1970s can be transformed into a fine powder and used to 3D print components for the next generation of aircraft in the UK鈥檚 Royal Air Force (RAF). Experts say this is a more efficient way to make aircraft 鈥� it鈥檚 less environmentally damaging and also solves the problem of sourcing materials from countries that are under sanctions, like Russia.

at Additive Manufacturing Solutions has developed a technique to recycle crucial materials like Ti64 鈥� which is titanium with 6 per cent aluminium and 4 per cent vanadium. The UK Ministry of Defence has large quantities of expensive and hard-to-source materials like Ti64, but they are tied up in obsolete or broken aircraft and in stored components.

The company was able to take turbine blades from a Panavia Tornado 鈥� an aircraft in service with the RAF from 1980 to 2019 鈥� and recycle them into a nose cone for a prototype engine that will power the RAF鈥檚 next generation of fighter jet.

鈥淭he world is more expensive than it used to be. It鈥檚 more complex and more expensive to make products,鈥� says Higham. 鈥淲e can make them as cost effectively as possible.鈥�

Higham says that creating spherical particles from the old parts is key to printing quality new parts, as jagged particles can get stuck in the 3D printer. Simply grinding the metal down won鈥檛 do, so the recycled components are melted and then sprayed into a high-pressure jet of argon, where they break up into raindrop-shaped droplets. These droplets spin in the gas, become spherical then drop out and solidify. 鈥淚t鈥檚 a very similar process to the way that rain becomes hailstones,鈥� says Higham.

The resulting powder聽can then be fed into 3D printers. These machines essentially weld the powder into layers half the thickness of a human hair and set down each layer, one by one, to build the new part. 鈥淚t鈥檚 a very straightforward microscopic welding process. It isn鈥檛 really anything more complex than that,鈥� says Higham.

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In this first case, the powder was used to 3D print a nose cone for an Orpheus jet engine, which Rolls Royce is currently developing for the (FCAS). The FCAS includes a range of aircraft with modular components, including the BAE Systems Tempest 鈥� a proposed sixth-generation fighter jet destined for the RAF.