Carnosine-Modified Fullerene as a Highly Enhanced ROS Scavenger for Mitigating Acute Oxidative Stress

Fullerenes are known as highly efficient scavengers for reactive oxygen species (ROSs). In this study, a carnosinemodified fullerene derivative (C-60-Car) was synthesized via a one-step nucleophilic addition reaction. C-60-Car forms nanoparticles (NPs) readily in water at neutral pH and room temperature through self-assembly. The C-60-Car NPs were found to possess good water solubility, biocompatibility, and excellent ROSs scavenging capability. The scavenging efficiency of ROSs is as high as 92.49% and significantly better than that of hydroxyfullerene (C-60-OH NPs, 70.92%) and L-carnosine. Furthermore, C-60-Car NPs showed strong cytoprotective ability against H2O2-induced damage to the normal human fetal hepatocyte cells (L-02) and human epidermal keratinocytes-adult (HEK-a) cells at a lower concentration of 2.5 mu M. In contrast, C-60-OH NPs showed a minor cytoprotective effect on cells at a high concentration of 10 mu M. The excellent properties of such a fullerene derivative, C-60-Car, can be attributed largely to the involvement of L-carnosine with biological activity and antioxidant property, which make it better for biomedicine, and it may provide a new strategy for mitigating acute oxidative stress based on fullerene materials.