Magnetosomes isolated from magnetic bacteria.

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 optimised 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 carrier in magnetic drug delivery applications.

Figure 1: The ear is a portal of entry for nanoparticles via the external auditory canal. The connection of ear to inner ear offers an entrance to the most central parts for the particles. Nanoparticles go through the tympanic membrane to enter via the tympanic cavity all other parts of the inner ear and can even delocalize via the vestibular nerve, the cochlear nerve and the blood to the entire body, especially the brain. The particles can be from lead oxide, lead acetate and lead acetate coated solarium dioxide nanoparticles.

The Beethoven’s deafness and its development are a riddle. In a previous article the authors (Luthe and Bischoff, 2020) suggested poisoning by ultrafine particles through lead corrosion of e.g. organ pipes. In the present article, they propose that Beethoven’s health problems, especially his deafness, were caused by a combination of exposure to lead-containing micro- and nanoparticles. In addition, high alcohol consumption weakened the defense against radical oxidative stress. The authors further hypothesize that the ear is a major portal of entry for nanoparticles, in this case causing lead poisoning of the inner ear. 

Figure 1: (A) Distribution of the particular matter into the follicles in a schematic presentation. (B) Particle size determines deposition in lung and penetration depth in hair follicle. In hair follicles penetration is highest for particles of a size ~ 643 nm with a depth of ~ 1200 µm.
 

In this article the authors (Luthe and Bischoff, 2020) connect recent findings in nano-toxicology with the investigations in Ludwig van Beethoven’s supposed saturnism. Namely, contradicting measurements of lead concentration in Beethoven’s hair and bone cannot be explained by the current hypothesis discussed among scientists. This mismatch may be called the key to the conundrum. It is also of broader interest to toxicologists, as the circumstances of Beethoven’s poisoning elucidate a general issue of particle uptake and resulting effects, which is quite neglected until now. They suggest that lead containing micro- and nanoparticles, i.e. lead oxides and acetate are the basis for the contradicting lead levels. The different portal of entry discriminates the concentrations in the bones when compared to the hair follicles. The authors also consider the source for these ultrafine lead-containing particles in Beethoven’s environment, and propose a complete explanation for his saturnism. 

Dr. Sergey Korchak, Dr. Stefan Glöggler, and Dr. Anil Jagtap (from left) with their home-made portable MRI unit. Frederik Köpper. Max Planck Institute for Biophysical Chemistry

Magnetic resonance imaging (MRI) is indispensable in medical diagnostics. However, MRI units are large and expensive to acquire and operate. With smaller and cost-efficient systems, MRI would be more flexible and more people could benefit from the technique. Such mini MRI units generate a much weaker signal that is difficult to analyze, though. Researchers at the Max Planck Institute (MPI) for Biophysical Chemistry and the Center for Biostructural Imaging of Neurodegeneration have now developed a method amplifying the signal so much that they could monitor a metabolic reaction in real time with a miniature MRI. This is an important contribution to making flexible small MRI devices usable.