A needle that softens and becomes flexible when it enters the body could reduce inflammation and damage during injections, while also reducing the risk of accidental pricks.听
Needles and plastic catheters frequently cause inflammation and complications when injected, partly because they are not as flexible as the body鈥檚 soft tissue and veins. Used needles can also risk spreading disease if a medical professional is accidentally pricked with one after use.听
As an alternative, at the Korea Advanced Institute of Science and Technology in South Korea and her colleagues developed a needle made with gallium, which has a melting point above room temperature but below body temperature, allowing it to soften and bend within a minute of entering the body, and also allowing it to be used as a longer-term catheter.听
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鈥淚f the patient now moves then the needle inside will not hinder the mobility of the patient,鈥� says Agno. This softening also acts as a safety feature, she says. 鈥淲hen the softened needle is removed, it stays soft and will not be rigid and sharp enough to accidentally stab another person or use for another injection.鈥�听
Agno and her team tested the needle in live mice and measured the tissue damage and inflammation compared to both a stainless steel needle and a commercial plastic catheter. They found that the flexible needle caused less inflammation than the steel one and comparable amounts of inflammation to the plastic catheter. They also added a temperature and fluid sensor to the needle, and showed it could be used to measure body temperature and accidental drug leakage during injection, in mice and pig tissue.听
It is unclear whether the gallium needle would be safer or less irritating than plastic catheters, which already have a safety mechanism to prevent reuse, says at the University of Queensland, Australia. They could have an advantage over short-term stainless steel needles, but more work is needed to show they are cost-effective and safe first, says Rickard. 听
The flexible needle could also be tricky to transport, given the temperature sensitivity, while the ability to detect leaking fluids and temperature differences could be useful, as few hospitals monitor this in real time at present, she says.
Nature Biomedical Engineering
