Endoplasmic reticulum-targetable selenium-doped carbon nanodots with redox-responsive fluorescence for in situ free-radical scavenging in cells and mice

Endoplasmic reticulum, the largest cellular organelle where protein synthesis, folding, transportation, and the maintenance of Ca2+ homeostasis occurred, is sensitive to the imbalance of its inner environment. Particularly, overproduction of reactive oxygen species in endoplasmic reticulum region can initiate endoplasmic reticulum stress and is tightly related to many metabolic diseases. In this respect, to retain normal function of endoplasmic reticulum, it is highly important to synthesize antioxidants with endoplasmic reticulum-targeting capability for precisely clearing excessively generated reactive oxygen species in endoplasmic reticulum. Herein, we demonstrate the preparation of endoplasmic reticulum-targeting Se-doped carbon nanodots and assays with HeLa cells as well as in vivo tests with mice have shown that the prepared carbon nanodots can significantly eliminate both •OH and O2•−. Experimental results declared that the fabricated carbon nanodots with powerful scavenging capabilities toward •OH and O2•-, low cytotoxicity and endoplasmic reticulum targetability can be utilized to protect cells against raised levels of reactive oxygen species in endoplasmic reticulum. What’s more, the fabricated carbon nanodots effectively alleviated phorbol 12-myristate 13-acetate induced ear inflammation in live mice.