Intracellular transport of nanodiamond particles in human endothelial and epithelial cells

During the recent years nanodiamonds have been the subject of interest as possible means of targeted delivery of anticancer substances. Detonation nanodiamonds are attractive candidates for intracellular studies due to their synthesis methods, low cost, good biocompatibility and facile surface functionalizability. Our previous study, in which we used nanoparticles obtained by different methods showed the significance of size and way of production of nanodiamonds in their cellular effects. The aim of this study was to check the ability of surface-modified detonation nanodiamonds to reach intracellular compartments without degradation of the surface-conjugated drug or fluorescent marker. In this study we examined the penetration HUVEC-ST and A549 cells by detonation nanodiamonds (grain size <20 nm) modified by adding to, employing four pharmacological inhibitors of endocytosis, using optical, confocal and transmission electron microscopy We discuss the possibilities, the challenges of studying the endocytic pathways involved in cellular uptake of nanoparticles. Our results suggest that fluorescent nanomaterials are very promising for monitoring the intracellular fate of nanodiamonds.