Researchers in Germany have investigated the possibility of using sperm cells to deliver drugs to cancerous tumors in female patients. In a paper uploaded to the preprint server arXiv, the group describes how such a technique might work, their initial test results, and what they learned from their experiments.
In recent years, medical researchers have been focusing on developing carrier systems for the delivery of chemicals to targets inside the body to treat diseases such as cancer, but so far, it has been slow going because of a variety of issues, such as the body responding in unhelpful ways or targets such as tumors putting up tough resistance.
In the new effort, the researchers looked into the idea of using a natural carrier to deliver helpful drugs to specified targets—in this case, sperm cells delivering drugs guided to tumors and other problem sites in the female reproductive tract.
While it is known that sperm cells will swim around in the vagina searching for an egg to fertilize, and in some cases, have been known to swim up and fertilize eggs still in the fallopian tube, the randomness of their behavior was deemed too untenable for drug delivery.
The German team wanted to be able to steer individual sperm cells. To accomplish that feat, they coaxed sperm cells to swim into a very tiny helmet coated with iron that would adhere to its head. The sperm could then be steered using an external magnet. The helmet was designed with a quick-release mechanism that allowed it to dislodge from the sperm when it ran head first into something, such as a tumor cell, allowing the sperm cell to penetrate the tumor cell the same way it would an egg, delivering the drug. The researchers also found that they could cause a sperm cell to absorb a cancer drug simply by soaking it in a solution containing the drug.
The researchers tested their idea using bull sperm on a tiny track in their lab. They were able to successfully move sperm cells to stand-ins for tumor cells. They report that the helmet caused the sperm to swim 43% more slowly than normal.
Although the test results were encouraging, many hurdles need to be overcome before such a technique could be used in humans—first and foremost, preventing accidental pregnancies, the researchers say. There is also the issue of what happens to the abandoned helmets (thousands would be left behind) and whether a sperm cell could be steered around inside the human body.
Source: Phys.org; April 14, 2017.