Fig. 2

COC expansion in the presence of increasing concentrations of TiO₂ NPs. COCs cultured in increasing concentrations of TiO₂ NPs were evaluated in comparison to the control culture (CTRL), in which COCs were not exposed to NPs. In all samples, the extent of COC expansion was assessed at the end of the culture time (16 h) and expressed as expansion index (E_i)