Selenium-doped carbon dots inhibit ferroptosis by multi-hierarchy iron chelation and mitochondrial homeostasis regulation to control inflammation

Abstract

Ferroptosis has been identified as a prevalent pathological process in both infectious and non-infectious inflammation. Multiregional iron accumulation within extracellular, cytoplasmic, and subcellular compartments, particularly into mitochondria, can trigger lipid peroxidation and subsequent ferroptosis. Meanwhile, mitochondrial dysfunction, as a hallmark feature of ferroptosis, also exacerbates ferroptosis and inflammation. Here, a strategy of multi-hierarchy iron chelation coupled with mitochondrial homeostasis regulation is proposed to inhibit ferroptosis and relieve inflammation based on selenium-doped carbon dots (SeCDs). SeCDs with reactive oxygen species (ROS) scavenging capacity can be efficiently internalized into cells and enriched in mitochondria. Through the multi-hierarchy chelation for extracellular, cytoplasmic, and mitochondrial iron, iron overload is remarkably inhibited. Meanwhile, promoting glutathione peroxidase 4 (GPX4) expression and activating the AMPK pathway can restrain the metabolism of glycerophospholipids and polyunsaturated fatty acids and lipid peroxidation. Importantly, SeCDs restore mitochondrial homeostasis by chelating mitochondrial iron, scavenging mtROS, and increasing the level of GPX4, thereby enhancing ferroptosis suppression. Further, SeCDs rescue the osteogenic differentiation potential of stem cells, which is generally weakened by ferroptosis. In vivo experiments prove that SeCDs can significantly inhibit ferroptosis and inflammation, and facilitate tissue regeneration. Thus, this multifunctional nanosystem provides a promising therapeutic strategy to inhibit ferroptosis and ease inflammation.