Nitric oxide (NO) is a biological free radical, associated with many physiological and pathological processes that include neuronal signaling, immune response and inflammatory response. In mammalian organisms, NO is produced from L-arginine in an NADPH-dependent reaction catalyzed by a family of nitric oxide synthase (NOS) enzymes. Fluctuations in NO levels generally accompany a number of inflammatory diseases. Cystic Fibrosis (CF) is an autosomal recessive genetic disease that chronically affects the lungs. It has been found that exhaled NO levels remains unchanged or reduced in cystic fibrosis patients unlike other inflammatory lung diseases like asthma where it increases. However it is not clear whether the lower NO levels in cystic fibrosis correlate with lowered production of this metabolite in the bronchial epithelium. Also, it has been proposed recently that nitric oxide can be used as a potent antimicrobial molecule to treat bacterial infection of CF tissue. Nitric oxide’s role in CF is mutlifaceted. In this work, we want to establish a basic system to understand how nitric oxide interacts with CF cells versus normal cells by monitoring levels of nitric oxide released from NOS-loaded liposomes on normal cells and CF cells.

We will present work establishing the performance of combined reference/working electrodes modified with ruthenium oxide and poly(3,4-ethylenedioxythiophene) (PEDOT) for catalytic detection of nitric oxide. We will then show how we can use this nitric oxide sensitive probe to measure levels of nitric oxide from NOS-loaded liposomes. In this case, nitric oxide is triggered exogenously both in proximity of normal cells and near a CF cell line model. We will compare and contrast the observed amperometric levels of nitric oxide and discuss the results in light of potential biological implication of nitric oxide with the two cell models.