German researchers have developed a new chemotherapy drug delivery system that arms sperm with powerful drugs to attack cervical cancer tumours.

Scientists, from the Leibniz Institute for Solid State and Materials Research, report that they have exploited the swimming power of sperms to ferry a cancer drug directly to a cervical tumour in lab tests.

In the study, the team led by Mariana Medina-Sanchez from the varsity, packaged a common cancer drug, doxorubicin, into bovine sperm cells and outfitted them with tiny magnetic harnesses.

Using a magnetic field, a sperm-hybrid motor was guided to a lab-grown tumour of cervical cancer cells. When the harness arms pressed against a tumour, the arms opened up, releasing the sperm.

The sperm then swam into a tumour, fused its membrane with that of a cancer cell, and released the drug.

When unleashed by the thousands, the drug-loaded sperm killed more than 80 per cent of a cancerous ball while leaking very little of their payload in the process.

The new findings, detailed in the journal ACS Nano, could pave the way for applications outside of chemo delivery for cervical cancer patients.

However, further work is needed to ensure the system could work in animals and eventually humans, but researchers say the sperm motors have the potential to one day treat cancer and other diseases in the female reproductive tract, such as the endometriosis or ectopic pregnancies.