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