Article controlled study 43 chemistry 39 nanoparticle 38 nonhuman 32 human 31 Nanoparticles 30 Humans 25 unclassified drug 24 particle size 23 drug delivery system 21 procedures 18 transmission electron microscopy 18 Animals 17 animal 17 animal experiment 17 drug effect 16 in vitro study 16 mouse 16 priority journal 16 human cell 14 male 14 metabolism 14 pH 14 Mice 13 female 13 scanning electron microscopy 13 zeta potential 13 X ray diffraction 12 Fourier transform infrared spectroscopy 11