Chitosan derived nitrogen-doped carbon dots suppresses osteoclastic ostelysis via downregulating ROS
Osteoclasts are the main cells of normal bone remodeling and pathological bone destruction in vivo. Overactivation of osteoclasts can lead to osteolytic diseases including breast cancer bone tumors, arthritis, aseptic loosening of orthopedic implants and Peget's disease. Excessive reactive oxygen species is the main cause of osteoclast overactivation. Our first synthesis of nano-fluorescent carbon quantum dots (N-CDs) with high yield and high ability to scavenge reactive oxygen species. N-CDs effectively abrogated RANKL-induced elevation in ROS generation and therefore impaired the activation of NF-κB and MAPK pathways. Osteoclastogenesis and bone resorption was effectively attenuated in vitro. Further in vivo mice administered with N-CDs protected them against lipopolysaccharide (LPS)-induced calvarial bone destruction and breast cancer cell-induced tibial bone loss. Based on the good biocompatibility of N-CDs and the ability to efficiently remove reactive oxygen species, the nanomaterial treatment scheme was provided for the first time for the clinical treatment of osteolytic diseases.