The long-range goal of this research is to development novel carbon nanodots as a new avenue of nanopharmacology for treatment of vascular diseases. Vascular inflammation and its subsequent endothelial dysfunction play a fundamental role in the initiation and progression of atherosclerotic vascular disease. It is believed that tumor necrosis factor (TNF)-alpha is critically involved in the pathogenesis of atherosclerosis. Carbon nanodots (C-dots) are fascinating newcomers to the world of nanoparticles with sizes below 10 nm. C-dots have drawn considerable attentions and become a rising star in the nanocarbon family due to their lower toxicity, versatile surface modification, green synthetic method, optical stability, and good bio-compatibility. Our recent preliminary data for the first time showed that C-dots significantly reduced TNF-alpha-induced adhesion of monocytes to human primary umbilical vein endothelial cells (HUVECs) suggesting a potential anti-inflammatory action of C-dots against vascular dysfunction. Overproduction of reactive oxygen species (ROS) is known to cause endothelial dysfunction. Our preliminary data further showed that C-dots decreased ROS production and the treatment is nontoxic. These results suggest a new avenue of nanopharmacology for more effective treatment of inflammatory disorders such as atherosclerosis. Extensive studies demonstrated that the activation of NF-?B is essential for the transcriptional regulation of IL-8 and MCP-1. Our preliminary data further showed that TNF-alpha significantly increased NF-?B binding activity indicating that activation of the transcription factor NF-?B might be critical for the TNF-alpha-induced inflammatory response. Based on these data, we therefore hypothesize that C-dots with respect to antioxidant properties suppress TNF-alpha-induced adhesion of monocytes to endothelial cells via inhibition of NF-?B signaling that subsequently regulates chemokine and adhesion molecular expression. Thus, the specific aims of this R15 proposal are: 1): to determine whether carbon nanodots inhibit TNF-alpha-induced expression of adhesion molecules, markers of vascular inflammation and nuclear translocation of NF-?B, and whether the mechanism is through NF-?B signaling in HUVECs; 2) to carry out the Bio-distribution, safe studies of carbon nanodots and the protective effects of carbon nanodots on vascular oxidative stress, inflammation and atherosclerosis in Apo E-/- mice. Based on our pilot studies, we believe that C-dots may provide a new avenue of nanopharmacology for more effective treatment of inflammatory disorders such as atherosclerosis and the proposed studies will also provide valuable training opportunities to undergraduate and graduate students interested in basic science research. Fulfillment of this research project is expected to provide new information on the potential application of novel carbon nanodots to the treatment of vascular diseases.
Atherosclerotic vascular disease is a major cause of morbidity and mortality in the industrial world. Our preliminary data indicate carbon nanodots (C-dots), fascinating newcomers to the world of nanoparticles, is a promising agent to protect against vascular dysfunction caused by the proinflammatory cytokine tumor necrosis factor (TNF)-alpha. The elucidation of the molecular mechanism(s) of C-dots will provide a new avenue of 'nanopharmacology' for more effective treatment of inflammatory disorders such as atherosclerosis.
