Re(I)-BODIPY Photosensitizer for Infected Wound Healing in the Rat Model under Green Light

Herein, we report a BODIPY-appended Re(CO)3 complex (Re2) for green light-mediated inhibition of various Gram-negative (E. coli) and Gram-positive (Staphylococcus aureus, Bacillus subtilis) bacteria, together with its non-BODIPY analogue (Re1) as a control. Re2 exhibited green-light absorption (λmax = 505 nm) and potent photodynamic activity in aqua-rich conditions under green-light (525 nm, 50.4 J cm-2) irradiation, including efficient singlet oxygen generation (Φ1O2 = 0.14), rapid NADH photo-oxidation (TOF = 38.6 h-1), and H2O2 generation, facilitating multiple oxidative stress pathways. TD-DFT studies supported its absorption/emission behaviour, light-triggered 1O2 generation, and triplet excited-state characteristics. Re2 demonstrated rapid bacterial internalization, elevating intracellular ROS levels upon light exposure, resulting in potent antibacterial activity and effective disruption of mature E. coli biofilms. Furthermore, Re2 displayed good cyto/hemo-compatibility and promoted wound healing in E. coli-infected rats. Nevertheless, Re2 is limited by the shallow tissue penetration of green light, necessitating red/NIR activation for deep-seated infection treatment.