An optimized process to isolate and purify magnetic nanoparticles Magnetic nanoparticles biosynthesized by bacteria might soon play an important role in biomedicine and biotechnology. Researchers of the University of Bayreuth have now developed and optimized a process for the isolation and purification of these particles from bacterial cells. In initial tests, magnetosomes showed good biocompatibility when incubated with human cell lines. The results presented in the journal "Acta Biomaterialia" are therefore a promising step towards the biomedical use of magnetosomes in diagnostic imaging techniques or as carriers in magnetic drug delivery applications. The magnetotactic bacterium Magnetospirillum gryphiswaldense produces intracellular magnetic nanoparticles, so-called magnetosomes. These are arranged in a chain-like manner similar to a string of pearls, thereby forming a kind of magnetic compass needle that allows the bacteria to navigate along the Earth's magnetic field.