Laser light-scattering analysis of protoplasmic streaming in the slime mold Physarum polycephalum

On the Internalisation, Intraplasmodial Carriage and Excretion of Metallic Nanoparticles in the Slime Mould, Physarum Polycephalum

The plasmodium of Physarum polycephalum is a large single cell visible with the naked eye. When inoculated on a substrate with attractants and repellents the plasmodium develops optimal networks of protoplasmic tubes which span sites of attractants (i.e. nutrients) yet avoid domains with a high nutrient concentration. It should therefore be possible to program the plasmodium towards deterministic adaptive transformation of internalised nano- and micro-scale materials. In laboratory experiments with magnetite nanoparticles and glass micro-spheres coated with silver metal the authors demonstrate that the plasmodium of P. polycephalum can propagate the nano-scale objects using a number of distinct mechanisms including endocytosis, transcytosis and dragging. The results of the authors’ experiments could be used in the development of novel techniques targeted towards the growth of metallised biological wires and hybrid nano- and micro-circuits.

Single cell laser light scattering spectroscopy in a flow cell: repeated sickling of sickle red blood cells

We performed dynamic laser light scattering measurements of hemoglobin aggregates in single, sickle erythrocytes. Sickle erythrocytes were attached to the poly-(L-lysine)-coated surface of a flow cell. They were exposed to several oxygenation-deoxygenation cycles by repeatedly changing the flowing solution. The rate of cycling was found to be a determining factor for the formation of irreversible morphologic alterations as well as irreversible hemoglobin aggregates. In slow cycling, the sickle erythrocytes took an irreversible, irregular, rounded shape, and hemoglobin aggregates were observed even in the oxygenated state after 20 cycles. In the fast cycling, however, these changes did not take place even after 60 cycles.