Universal “Three-in-One” Matrix to Maximize Reactive Oxygen Species Generation from Food and Drug Administration-Approved Photosensitizers for Photodynamic Inactivation of Biofilms

Abstract

Biofilms, an accumulation of microorganisms, cause persistent bacterial infection and low cure rate due to the remarkable drug resistance. Photodynamic inactivation (PDI) is a promising treatment modality for bacterial infections, but the formation of biofilms raises new challenges for photosensitizers (PSs), particularly the reactive oxygen species (ROS) generation efficiency. Herein, through targeting the Jablonski energy diagram, we proposed a universal "three-in-one" matrix of Gd 3+ -ADP assembly for encapsulation and fixing of PSs to inhibit nonradiative transitions and promoting intersystem crossing (ISC) by the heavy atom and paramagnetic effects of Gd 3+ , eventually resulted in boosted ROS generation from the existing PSs (1.5−9.0-fold). Particularly, photophysical studies indicated that the matrix resulted in simultaneous ISC promotion and triplet-state lifetime lengthening, which is essential for ROS boosting. The PDI performance of the matrix was confirmed through fast and effective elimination of bacterial biofilms in 10−30 min. Moreover, successful therapy of a Pseudomonas aeruginosa biofilm-infected all-thickness third-degree burn wound was achieved within 11 days with Ce 6@CNs (matrix) but not feasible for matrix-free PSs (Ce 6 only), which highlighted the role of "three-in-one" matrix in ROS boosting.

Selective Heavy Atom Effect-Promoted Photosensitization Colorimetric Detection of Ag+ in Silver Ore Samples

“…As indicated by IUPAC, HAE is the enhancement of the rate of a spin-forbidden process by the presence of an atom of high atomic number to the excited molecular entity, leading to spin–orbit coupling enhancement. Typically, HAE results in simultaneous fluorescence quenching and phosphorescence enhancement. − But for EB, binding with dsDNA (base pair intercalation) would also turn on its fluorescence due to the isolation of EB from surrounding water molecules to alleviate the fluorescence quenching from excited state proton transfer, , as well as movement restriction upon intercalation into the DNA double strand. Accordingly, there would be a competition between HAE-induced fluorescence quenching and dsDNA-induced fluorescence enhancement (Figure A).…”

Precise ligand engineering of Ir(III)‐based photosensitizer with aggregation‐induced emission for image‐guided photodynamic therapy

“…In recent decades, photodynamic therapy (PDT) has received considerable attention for cancer treatment due to its ability to enhance cancer treatment through the generation of reactive oxygen species (ROS) upon light irradiation [1][2][3][4][5]. The photosensitizers (PSs) that are closely related to the effectiveness of PDT are especially critical [6][7][8][9]. When exposed to white light or laser, PSs can undergo type-II photochemical reactions to generate singlet oxygens ( 1 O 2 , energy transfer) or type-I reactions to generate toxic radicals (O 2…”

Polythiophene as a near full pH photo-antimicrobial

“…Herein, a photosensitizer polythiophene was explored as a near full pH molecule for photodynamic antibacterial therapy (PDAT). PDAT is an appealing approach for the treatment of bacteria infections, 15 but full pH photosensitizers are seldom reported. Polythiophene is a well-known electroluminescent polymer and has been extensively used in photovoltaic cells, chemical sensors, rechargeable batteries, and microwave absorption.…”