Eradication of Pathogenic Bacteria by Remote Delivery of NO via Light Triggering of Nitrosyl-Containing Materials

Although nitric oxide (NO) delivery systems have been fabricated with sol−gel-based materials, remote control of such systems with light has not been achieved. In this work, a fiber optic-based NO delivery system is described in which the photoactive metal-nitrosyl, [Mn(PaPy3)(NO)]ClO4 (1), has been employed in a sol−gel material. The material (1·FO) contains the manganese-nitrosyl, which releases NO upon illumination with visible light. The NO-releasing capacity of 1·FO has been measured with an NO-sensitive electrode, and the spatial diffusion of NO in solution has been visualized using the Griess reaction. The utility of 1·FO has been demonstrated in effective reduction of bacterial loads of Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and methicillin-resistant S. aureus. The results suggest that a device that releases NO via illumination by optical fiber may have clinical applications in combating infections with both Gram-positive, Gram-negative, and to some degree antibiotic-resistant bacteria.