Polylactic Acid Filament Containing Boron-Dipyrromethene (BODIPY) for Singlet Oxygen Generation in Photoactivatable Antimicrobial Objects

Antimicrobial materials are required to diminish the propagation of infectious diseases. Exploiting photosensitization of cytotoxic singlet oxygen (1O2), we report a strategy for manufacturing an antimicrobial filament by combining a halogenated boron-dipyrromethene (BODIPY) photosensitizer (PS) with polylactic acid (PLA). The filament (PLAPS) was then used to three-dimensional (3D)-print square-shaped objects and meshes, facilitating material characterization and testing. The results demonstrate that the spectroscopic characteristics of the PS entrapped in the polymeric matrix are preserved, including its photostability. These properties were maintained after two cycles of recycling, proving the reusability of PLAPS. Irradiation of the material with green light triggers 1O2, as evidenced by oxidation of a water-soluble anthracene derivative and direct detection of 1O2 luminescence experiments. Fluorescence microscopy studies, assessing real-time bacterial inactivation on the material’s surface, indicate complete elimination of Pseudomonas aeruginosa in the imaging region after 40 min of irradiation with a low light dose (1.6 J/cm2). Furthermore, a prototype of a water treatment apparatus was assembled and successfully inactivated 99.9% of Shigella dysenteriae, a typical waterborne pathogen. This sets the stage and opens diverse avenues for a cost-effective and straightforward design of sustainable 3D materials for light-mediated microbial deactivation.