Cellular uptake of PLA nanoparticles studied by light and electron microscopy: synthesis, characterization and biocompatibility studies using an iridium(III) complex as correlative label

We present the synthesis of polylactide by ring-opening polymerization using a luminescent iridium(III) complex acting as initiator. The polymer was formulated into nanoparticles, which were taken up by HEK-293cells.We could show that the particles provided an appropriate contrast in both superresolution fluorescence and electron microscopy, and, moreover, are non-toxic, in contrast to the free iridium complex.