Achievement

Trainees Shawn Fisher (Brownawell Lab), Shavonne Hylton (Schoonen and Tsirka labs), Kelly Morgan (Grey Lab) work together to determine the production of hydroxyl (OH) radicals in slurries of Mn oxides with different Mn oxidation states. Moreover, trainee Hylton determined the production of reactive oxygen species (ROS) in a human lung cell line after exposure to the Mn oxides. Synchrotron analysis determined the oxidation state of Mn in the materials. OH radical production in slurries was measured by a newly developed phenylalanine probe and a standard molecular OH radical probe. The results show that Mn oxide with all or some fraction of Mn in the trivalent form generate the highest amount of OH radical. These materials also elicit the highest upregulation of ROS in lung epithelium cells. The work suggests that the presence of Mn(III) is critical and that this form of Mn facilitates the Fenton reaction, that produces OH radical via a reaction between a transition metal and H2O2.