Photo-antimicrobial polymeric films releasing nitric oxide with fluorescence reporting under visible light

Abstract

A novel photoresponsive molecular hybrid has been embedded in poly(lactic-co-glycolic acid) (PLGA) to give an antibacterial polymeric film generating nitric oxide (NO) under visible light, with concomitant fluorescence reporting of NO release. The molecular hybrid integrates a nitroaniline NO photodonor and a coumarin latent fluorophore in the same molecular skeleton and results in quite homogeneous distribution in the polymer matrix where it preserves well the photobehavior exhibited in solution. The doped PLGA film shows an excellent optical transparency and can be excited by visible light leading to the production of NO and the parallel fluorescence revival of the coumarin fluorophore, which acts as an optical NO reporter. Photogenerated NO diffuses out of the polymer film, can be transferred to a biological milieu and induces remarkable antibacterial activity against Escherichia coli.