Researchers want to use sperm cells to help deliver cancer treatment to patients.

A team from the Leibniz Institute for Solid State and Material Research in Dresden, Germany have successfully used bull sperm to deliver chemotherapy (in bulls, not humans). The group found that when sperm was soaked with a particular drug, it could reduce the amount of cancer cells by 90% in just three days.

The biggest benefit of using sperm is that it does not cause immune responses from cells such as bacteria. This allows the chemotherapy to have an impact without killing healthy cells. Sperm is also more naturally mobile, Engadget reports.

The sperm cells were also fitted with iron "hats" to help control the medicine through magnetism. Instead of bathing the tumor in chemotherapy, the sperm cells were able to break through the walls of the tumor and and attack the cells directly.

Still confused? Watch the video at the top for a quick explanation.

Cancer treatments are at the cutting edge of microbiology and just last month it was reported that tiny springs controlled by magnets could one day be used to fight the disease.

A team of scientists at the Chinese University of Hong Kong, led by Professor Li Zhang, are using a biodegradable substance called spirulina algae. Covered in an iron coating, the nanobots are controlled by magnetic fields. The coil shape of the nanobot allows it to move easily with the help of magnetic waves.

"Rather than fabricate a functional microbot from scratch using intricate laboratory techniques and process, we set out to directly engineer smart materials in nature, which are endowed with favourable functionalities for medical applications owing to their intrinsic chemical composition," Zhang said.

"For instance, because these biohybrid bots have a naturally fluorescent biological interior and magnetic iron-oxide exterior, we can track and actuate a swarm of those agents inside the body quite easily using fluorescence imaging and magnetic resonance imaging."

Not relying on a fuel source (most of which are toxic to humans) allows the nanobots to biodegrade naturally over hours or days (depending on the thickness of the iron coating). When cancer cells are exposed to the nanobots, only about 10% (of the cancer cells) manage to survive. It is harmless to other cells in the body, making it a viable solution for fighting cancer.