Georges Kyrillos / Alamy

There’s a new use for sperm – delivering cancer drugs.
Standard chemotherapy is toxic to both cancer cells and normal cells, leading to symptoms like nausea, and limiting the dose a person can receive. But if chemotherapy drugs specifically targeted tumours, we could avoid this.
Haifeng Xu at the Leibniz Institute for Solid State and Materials Research in Germany and his team are experimenting with using sperm cells to take drugs to cancers in the female reproductive tract. When they loaded sperm cells with doxorubicin, a common chemo agent, and released them in a dish containing mini cervical cancer tumours, the sperm swam towards the tumours, killing 87 per cent of their cells within three days.
The team then fitted sperm with tiny four-armed magnetic harnesses that allowed them to be guided by magnets. When the sperm hit a solid tumour, the arms sprung open, releasing the sperm and allowing them to swim into the tumour.
As well as cancer, spermbots might be useful for treating other conditions affecting the female reproductive tract such as endometriosis or ectopic pregnancies, says Xu.