Scheme 1

Schematic diagram of the experiments done in vitro and in vivo to evaluate the corneal toxicity induced by montmorillonite (Mt) with different properties. HCEC-B4G12 cells were treated with Na-Mt, H-Na-Mt, C-H-Na-Mt, Ca-Mt, and MMt to assess cytotoxicity, cell morphological changes, cell uptake, ROS production, and the expression of MAPK signaling proteins. Ocular irritation tests were performed on rats to monitor the area of corneal injury, corneal apoptosis, ROS generation in the cornea, and the expression of MAPK signaling proteins in the cornea of rats. Both in vitro and in vivo, the Mt types showed distinct corneal toxicity