Table 4 Urea concentration per HepG2 spheroid following both acute (24 h) and prolonged (120 h) exposure to increasing concentrations (0.2–10.0 µg/mL) of ENMs

0.690 (0.625–0.754)

0.937 (0.786–1.088)

0.455 (0.217–0.693)

0.394 (0.235–0.553)

0.675 (0.564–0.785)

1.021 (0.981–1.061)

0.744 (0.365–1.123)

0.389 (0.188–0.589)

0.292 (0.126–0.459)

0.927 (0.746–1.107)

0.813 (0.676–0.950)

1.245 (1.097–1.393)

0.520 (0.337–0.703)

0.498 (0.379–0.618)

0.724 (0.697–0.752)

1.108 (0.902–1.314)

0.832 (0.565–1.098)

0.523 (0.431–0.615)

0.402 (0.276–0.527)

0.968 (0.812–1.124)

0.889 (0.809–0.970)

1.036 (0.969–1.103)

0.550 (0.307–0.793)

0.505 (0.312–0.698)

0.762 (0.649–0.874)

1.273 (0.811–1.725)

0.769 (0.563–0.974)

0.563 (0.440–0.686)

0.409 (0.207–0.611)

0.920 (0.761–1.078)

0.859 (0.693–1.025)

1.145 (1.056–1.234)

0.539 (0.414–0.664)

0.638 (0.571–0.706)

0.775 (0.735–0.816)

1.213 (1.092–1.334)

0.794 (0.675–0.914)

0.490 (0.264–0.716)

0.549 (0.478–0.621)

0.940 (0.710–1.170)

0.930 (0.783–1.076)

1.120 (0.873–1.366)

0.567 (0.423–0.771)

0.573 (0.376–0.771)

0.717 (0.549–0.885)

1.197 (0.902–1.492)

0.795

(0.502–1.089)

0.521 (0.428–0.615)

0.481 (0.274–0.688)

0.971 (0.706–1.236)

0.699 (0.565–0.834)

0.793 (0.668–0.919)

0.596 (0.324–0.869)

0.643 (0.487–0.799)

0.782 (0.645–0.919)

0.805* (0.636–0.974)

0.832 (0.729–0.935)

0.703 (0.595–0.811)

0.781 (0.515–1.047)

0.955 (0.672–1.238)

0.628 (0.371–0.885)

0.728* (0.635–0.821)

0.571 (0.518–0.624)

0.618 (0.214–1.021)

0.792 (0.617–0.967)

0.846 (0.771–0.921)

0.737 (0.532–0.942)

0.726 (0.367–1.085)

0.899 (0.735–1.063)

0.909 (0.755–1.064)

0.773 (0.718–0.828)

0.881 (0.729–1.033)

0.515 (0.332–0.698)

0.423 (0.330–0.517)

0.755 (0.500–1.010)

0.846 (0.771–0.921)

0.488* (0.212–0.763)

0.516 (0.432–0.600)

0.323 (0.224–0.422)

0.953 (0.878–1.029)