Chemotherapy is an effective way to treat cancer but it produces all sorts of unwanted side effects, including fatigue and nausea. One reason for this is that it kills cells indiscriminately, whether they're cancerous or not. But scientists may have found a solution, at least as far as cervical cancer is concerned. Sperm. 

Why sperm? First of all, it allows for a more targeted treatment. Chemo is usually administered orally or intravenously and, because of the negative side effects, has to be dealt in limited doses. The drugs are diluted by the patient's body fluids and broken down by enzymes in the body. Sperm, on the other hand, can be directed towards the cancerous cells in the cervix, minimizing side effects and allowing for a stronger dosage.

Second, sperm will not cause the patient's immune system to flare up thanks to the proteins and prostasomes in the cell membranes. This makes them "excellent candidates to operate in physiological environments" because "they do neither express pathogenic proteins nor proliferate to form undesirable colonies, unlike other cells or microorganisms," the study authors wrote.

Third and finally, there is the fact that "sperms are naturally optimized to efficiently swim in the female reproductive system.”

As of right now, medical tests are in the very early stages. Scientists from the Leibnitz Institute for Solid State and Materials Research in Germany investigated sperm's cancer-fighting potential by infusing the cells with doxorubicin hydrochloride (DOX-HCl), a drug frequently used in chemotherapy, and releasing them in a dish containing mini cervical cancer tumors.

The results were impressive – 87 percent of cancerous cells had been destroyed in just three days. The findings have been published in the journal ACS Nano.

Following the success of the initial experiments, the researchers introduced four-armed magnetic harnesses, which directed the sperm cells to the cancer. When the sperm-driven micromotor (or spermbot) hit a tumor cell, the magnetic harness opened and released the sperm cell. The sperm then swam into the cancer and spread the doxorubicin hydrochloride.

Unlike synthetic alternatives, the sperm will merge with the cervical cancer cells. This stops the drugs from becoming diluted and breaking down, making treatment more effective and comfortable for the patient. 

The technique is yet to be trialed in humans (or indeed any living creature), but the researchers hope that in the not-too-distant future it can be used to treat cervical cancer, as well as other conditions associated with the female reproductive system such as endometriosis.