Table 4.

Summary of the cell-biological effects of all ZnO particles and zinc ions as control. NS nanospheres, SMS submicrospheres, MS microspheres, NR nanorods, MR microrods, Zn²⁺ zinc ions (zinc acetate)

Particle-cell contact	MR ≈ MS > SMS > NR ≈ NS
Intracellular zinc ion release	NS ≈ NR ≈ MS > SMS ≈ MR
cytotoxicity	Zn2+ ≈ NS ≈ NR > MR > SMS ≈ MS
Apoptosis induction	NS > MS ≈ NR ≈ MR > SMS ≈ Zn2+
Cell activation (ROS)	MR > SMS ≈ MS > NS ≈ NR ≈ Zn2+
Cytokine release	Zn2+ ≈ MR ≈ SMS ≈ MS ≈ NS ≈ NR
PICMA	Zn2+ > MR > NR > NS ≈ MS > SMS