Self-Sterilizing 3D-Printed Polylactic Acid Surfaces Coated with a BODIPY Photosensitizer

Herein, we report the use of polylactic acid coated with a halogenated BODIPY photosensitizer (PS) as a novel self-sterilizing, low-cost, and eco-friendly material activated with visible light. In this article, polymeric surfaces were 3D-printed and treated with the PS using three simple methodologies: spin coating, aerosolization, and brush dispersion. Our studies showed that the polymeric matrix remains unaffected upon addition of the PS, as observed by dynamic mechanical analysis, Fourier transform infrared, scanning electron microscopy (SEM), and fluorescence microscopy. Furthermore, the photophysical and photodynamic properties of the dye remained intact after being adsorbed on the polymer. This photoactive material can be reused and was successfully inactivating methicillin-resistant Staphylococcus aureus and Escherichia coli in planktonic media for at least three inactivation cycles after short-time light exposure. A real-time experiment using a fluorescence microscope showed how bacteria anchored to the antimicrobial surface were inactivated within 30 min using visible light and low energy. Moreover, the material effectively eradicated these two bacterial strains on the first stage of biofilm formation, as elucidated by SEM. Unlike other antimicrobial approaches that implement a dissolved PS or non-sustainable materials, we offer an accessible green and economic alternative to acquire self-sterilizing surfaces with any desired shape.