ANDRZEJ KRAUZE
A sperm’s job is simple: Swim to an egg, and inject genetic material. The structure of a mammalian sperm cell reflects those basic functions, consisting primarily of a DNA-containing head and a rapidly beating tail. Recently, scientists at the Leibniz Institute for Solid State and Materials Research (IFW) Dresden in Germany decided to exploit this structure, plus these cells’ natural inclination to travel through the female reproductive tract, for an unusual project. “We [thought], why not use these sperm cells as drug carriers?” says Mariana Medina-Sánchez, group leader of micro- and nanobiomedical engineering at IFW Dresden. The idea is less outlandish than it may sound. After all, “in the community [of researchers working on] micromotors or microswimmers, there were others using stem cells or bacteria ...
