Scientists create magnetic ‘mecha-sperm’ for drug delivery, fertilization

A team of scientists at the Institute for Integrative Nanosciences in Germany has used technology to create something so strange and fascinating that it sounds like it belongs in a Japanese manga: robotic sperm.

Using bull sperm and metal nanotubes, the scientists have designed biobots (‘biological robots’ —bacteria or cells programmed to behave in a specific manner) that can be controlled using magnets.

These ‘spermbots’ will be further improved for eventual use in a variety of medical purposes, such as for delivering drugs to certain parts of the body or for guiding sperm towards eggs for fertilization.

To create the sperm biobots, the researchers used iron and titanium nanoparticles to create 50-micron long nanotubes that had a diameter of five microns on one end and eight microns on the other. They then dropped the nanotubes into fluid containing thawed bull sperm. The sperm that swam into the wider ends of the nanotubes were trapped, leaving their tail-like flagella free to propel them. Additionally, external magnetic fields were set up to control the movement and orientation of the nanotubes.

Lead researcher Oliver Schmidt explained that sperm cells were an appealing choice for the experiment, as they cause no harm to the human body, are powerful enough to swim through viscous liquids, and are self-powered.

Schmidt and his colleagues’ research is the first of its kind to directly control a single cell’s movement. Previous experiments only involved the use of chemicals and magnetic fields to “persuade” or influence groups of cells. Eric Diller from the University of Toronto, Canada believes that this approach could serve as a pioneer in the field of robotic microsystems.

The scientists’ research can be found in the Wiley Online Library. — VC, GMA News