Near-Infrared Conjugated Oligomer for Effective Killing of Bacterial through Combination of Photodynamic and Photothermal Treatment

Abstract

In recent years, phototherapeutic strategies including photodynamic therapy (PDT) and photothermal treatment (PTT) have attracted extensive interest in biological and medical applications. To achieve high efficiency in therapy, it is crucial to develop promising agents possessing synergistic PDT and PTT effects, especially those triggered by single-wavelength near-infrared (NIR) light. Herein, a low-bandgap fluorene-based conjugated oligomer OF-Green-N with a donor−acceptor−donor (D−A−D) structure was synthesized, which had a broad absorption in both the visible and NIR range. Upon irradiation by 808 nm laser, the oligomer displayed a good photothermal capacity with a conversion efficiency of 37.7%, together with simultaneous photodynamic behavior which produced reactive oxygen species. By incubation with Escherichia coli, OF-Green-N was demonstrated to possess outstanding antibacterial activity owing to the synergistic effects of PDT/PTT. Moreover, its green fluorescence excited by 420 nm light also provides an opportunity for imaging-guided treatment.

Wide bandgap semiconductor-based novel nanohybrid for potential antibacterial activity: ultrafast spectroscopy and computational studies

“…8,9 In the last few years, photosensitizers (PS) have been broadly used in antibacterial photodynamic therapy (PDT) because of the high molar extinction coefficient, less toxicity, and good biocompatibility. 10,11 Some reports on their photocatalytic activity are also present. 12 They can generate reactive oxygen species (ROS) from neighboring water and oxygen molecules upon excitation.…”

Nanomaterials for the Photothermal Killing of Bacteria

“…In recent studies, the oligomer, OF GREEN N, has shown an enhanced photothermal efficiency of 37.7%. The OF GREEN N oligomer displayed enhanced antibacterial activity against S. aureus under NIR laser irradiation [ 113 ]. Pegylated and thiolated (PEG-SH) gold nanorods (AuNRs) conjugated with a phospholipid (DSPE-AuNR-PEG-SH) and cholesterol (Chol-AuNR-PEG-SH) exhibited an antibacterial effect.…”

Broad-spectrum Antimicrobial ZnMintPc Encapsulated in Magnetic-nanocomposites with Graphene Oxide/MWCNTs Based on Bimodal Action of Photodynamic and Photothermal Effect

“…In this regard, Romero et al, 2020 showed the ability of GO as an antimicrobial agent to eliminate E. coli and S. aureus bacteria through the combination of Photodynamic Therapy (PDT) and Photothermic Therapy (PTT) [9]. Peng et al, 2020 present a conjugated oligomer with antibacterial capacity to eliminate E. coli by PDT / PTT [10]. Xu et al, 2019 showed that nanocomposites based on Graphene and carbon nanotubes are capable of eliminating bacterial loads from Cyanobacteria, E. coli, S. aureus, Pseudomonas aeruginosa, Bacillus subtilis, Pseudomonas putida and Rhodococcus spp, based on the combination of PDT and PTT [11].…”