Hybrid Conjugated Polymer Nanoparticles as a Dual‐Mode Photodynamic–Photothermal Platform for Antibacterial Inactivation
Hygor Chaves, Cynthia S. A. Caires, Laís F. Aguilera, Regiane G. Lima, Priscila S. Cavalheri, Montcharles S. Pontes, Samuel L. Oliveira, Anderson R. L. CairesABSTRACT
This study explores a light‐activated antimicrobial strategy by developing hybrid nanoparticles (Cn‐TBT‐NPs) composed of the conjugated polymers Cn‐PPV and PCPDTBT, which combine photodynamic and photothermal effects to inactivate Staphylococcus aureus and Escherichia coli . Cn‑TBT‑NPs, produced by nanoprecipitation and exhibiting an average diameter of 157 nm, showed sufficient spectral overlap between the polymers to support efficient Förster resonance energy transfer (FRET), thereby enhancing reactive oxygen species (ROS) generation and light‑to‑heat conversion. Under visible light irradiation (RGB LED), the hybrid NPs promoted a population reduction of over 4 logs (99.99%) for S. aureus and over 3 logs (99.94%) for E. coli . Furthermore, they exhibited a photothermal effect, raising the temperature by 20°C in 20 min under 806 nm irradiation. Electron microscopy images confirmed lethal damage to the bacterial cell structure. These results demonstrate promising photodynamic and photothermal effects, positioning these hybrid polymeric NPs as a highly effective platform for combating bacterial infections.