Ultrastructural morphology of human connective tissue cells: control (a, b), treated with free Selol (S) (c, d) or treated with Selol-PVM/MA nanocapsules (SPN) (e, f). Note the integrity of the control cells, as expected. In c, a Selol vesicle being taken up by a cell exposed to free Selol is shown by an arrow. In d, the arrow points to an endosome. In e and f, the ultrastructural morphology is unchanged by SPN treatment. N, M, ER, GC, PM, and V: nucleus, mitochondria, endoplasmic reticulum, Golgi complex, plasma membrane and vesicle, respectively.