Highly Virulent Bactericidal Effects of Curcumin-based µ-Cages Fabricated by Two-Photon Polymerization.

A new antibacterial strategy is reported based on the two-photon fabrication of three-dimensional curcumin-embedded µ-cages. Such devices were designed to entrap and kill S. aureus bacteria upon visible light irradiation. The proposed concept mainly relies on the pivotal role of cur-cumin which is sequentially used as two-photon active free radical initiator and as photogenerator of reactive oxygen species within the cages µ-volumes. We show that these µ-cages exhibit extremely high antimicrobial properties lead-ing to 95 % bacteria mortality after only 10 min visible irra-diation. A pre-concentration mechanism of photogenerated oxygen species is proposed to account for this highly per-forming bactericidal effect whose virulence can be strikingly switched-on by increasing the light exposure time from 5 to 10 min.