Mitochondria-targeted polydopamine nanoprobes for visualizing endogenous sulfur dioxide derivatives in a rat epilepsy model.

Epilepsy is the fourth most common neurological disorder, and aberrantly elevated sulfur dioxide derivatives (SO ₃ ^2- /HSO ₃ ^- ) are thought to underlie the hippocampal neuronal apoptosis in epilepsy. We have designed and synthesized a mitochondria-targeted polydopamine nanoprobe for visualizing endogenous SO ₃ ^2- /HSO ₃ ^- by the nucleophilic addition reaction. The nanoprobe was used for imaging SO ₂ derivatives both in the mitochondria of cultured cells and zebrafish, and successfully applied in the hippocampus of a rat model of epilepsy. The PDAD nanoprobe could be of great value for the elucidation of mechanisms of abnormal SO ₃ ^2- /HSO ₃ ^- involved in diseases such as epilepsy.