Morphology of human cells from connective tissue (a, b, c, d) and A549 cells (e, f, g, h). The cells were untreated (a, e), exposed to free Selol (S) (b, f) or to Selol-PVM/MA nanocapsules (SPN) (c, g) for 72 h. Morphologic changes due to sodium selenite (SS) treatment for 24 h (d, h). Decrease in cell confluence by S and SPN treatments. Normal morphology of A549 (f, g) and SPN-treated connective tissue cells. Cytoplasmic retraction (arrows) on human cells from connective tissue after treatment with S (b). The bright, black-bordered spherical structures are free Selol microdroplets (b, f). Magnification: 20x.