Light‐Driven Bacterial Inactivation Achieved with Thioglycerol‐Tuned Photosensitizers

This is the authors' abstract. We don't add key points for this paper.

Antimicrobial photoinactivation (PDI) is a therapeutic strategy for inactivating microorganisms. In this context, tetra‐thioglycerolporphyrin 1 (H 2 Por 1 , Φ Δ = 0.75), tetra‐thioglycerol chlorin 2 (H 2 Chl 2 , Φ Δ = 0.46), and octa‐thioglycerolphthalocyaninatozinc(II) 3 (ZnPc 3 , Φ Δ = 0.12) were applied in PDI of Staphylococcus aureus and Escherichia coli . The photonic properties of the photosensitizers (PSs) were correlated with in vitro bacterial studies without or with potassium iodide (KI). The PDI results of all derivatives were effective against S. aureus ( p < 0.05). H 2 Por 1 and H 2 Chl 2 were the most potent, lowering bacterial viability to the assay's detection threshold (8 Log CFU/mL) with 1.0 µM and 30 min of treatment (90 J/cm 2 ). In contrast, ZnPc 3 required higher concentration (10 µM) and longer exposure (90 min, 270 J/cm 2 ) to achieve the same effect. The KI addition enhanced the photodynamic effect, reducing inactivation times to 5, 15, and 30 min for 2 , 1 , and 3 (15–90 J/cm 2 ), respectively, at 1.0 µM. None of derivatives (10 µM) alone were effective against E. coli ( p > 0.05), however, when combined with KI, achieved bacterial viability reductions to the luminometer detection limit within 15–30 min (45–90 J/cm 2 ). Overall, these results demonstrate the PDI performance of PSs, indicating its potential to control pathogenic microorganisms.