Magnetic field controls sperm robots
German scientists have turned sperm cells into robots
German scientists have proposed using spermatozoa as the basis for microscopic "robots" whose movement can be controlled using a magnetic field. The description of the system is published in the journal Advanced Materials (Magdanz et al., Development of a Sperm-Flagella Driven Micro-Bio-Robot), New Scientist writes briefly about it (How do you control a spermbot? Try a magnetic field).
Biologists have learned to control the movement of spermatozoa through the use of microscopic hollow tubes made of iron and titanium nanoparticles. The length of the tubes was about 50 micrometers, and the diameter narrowed from 8 micrometers at one end to 5 micrometers at the other.
Image: Veronika Magdanz et al., Advanced Materials, 2013
The cone-shaped shape led to the fact that the spermatozoa, once in the tubes, could no longer get out and turned out to be fixed. At the same time, only the cell body was inside the tube, and the flagellum remained free and could continue to move. The direction of this movement was controlled by scientists using an external magnetic field. To create such "robots", it was enough for the authors to add a suspension of microtubules to bovine sperm.
Previously, biologists could control the movement of spermatozoa only by creating chemical gradients. However, this is a much less flexible method of control than a magnetic field, the direction of which can be changed almost instantly. A similar magnetic motion control system was previously tested on the example of bacteria with magnetic granules. The latter are also able to move in a viscous environment due to flagella, however, unlike spermatozoa, they usually cause an aggressive response of the immune system. Scientists believe that the use of controlled "spermobots" may be useful for the treatment of infertility and, in the future, for targeted drug delivery.
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13.12.2013