Supramolecular Radical Anions Triggered by Bacteria In Situ for Selective Photothermal Therapy

Abstract

A supramolecular complex that can be selectively reduced to radical anions in situ by facultative anaerobic bacteria is reported. To this end, a water-soluble bifunctional monomer bearing perylene diimide was synthesized, and its supramolecular complex with cucurbit[7]uril was fabricated on the basis of host-guest complexation, which could be reduced to forming radical anions in the presence of E. coli. It was found that this supramolecular complex could display different ability of generating radical anions by facultative anaerobic and aerobic bacteria in terms of their various reductive abilities. The selective antibacterial activity of the supramolecular complex could be realized by the photothermal performance of the radical anions under near-infrared irradiation. It is anticipated that this method may lead to a novel bacteria-responsive photothermal therapy to regulate balance of bacterial flora.

Light‐Activated Rapid Disinfection by Accelerated Charge Transfer in Red Phosphorus/ZnO Heterointerface

“…The related mechanism is depicted in Figure A. The locally increased temperature (more than 50 °C) generated by the solar light‐activated photothermal reaction can provide lethality through hyperthermia and irreversible bacterial destruction, eventually killing bacteria . Additionally, the direct thermalization in fibrous RP can consume the photon energy, and the rest of the band edge energy located in the infrared region may also result in the generation of heat and be thermally absorbed by the vibration of the crystal lattice .…”

Supramolecular Antibacterial Materials for Combatting Antibiotic Resistance

“…Another type of a PTT system that has selective bacterial recognition properties is the CB[7] protected supramolecular complex CPPDI ( Figure ), which is triggered by a chemical reductive response. Xu and Zhang et al reported that PDI group in the complex are selectively reduced by facultative bacteria like E. coli to form radical anions, while aerobic bacteria like B. subtilis do not . As mentioned above, PDI radical anions exhibit the capacity of photothermal conversion under NIR irradiation.…”

“…These key interactions can arise from unique surface properties of pathogenic bacteria, including pH, shapes and chemical reductive responses. By utilizing supramolecular strategies and accurate recognition systems, more effective photothermal systems have been designed for PTT of bacteria.…”

“…b) Schematic illustration of photothermal therapy for CPPDI with high selectivity towards E. coli over B. subtilis . Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

Phthalocyanine‐Assembled Nanodots as Photosensitizers for Highly Efficient Type I Photoreactions in Photodynamic Therapy

“…Recently,Zhang et al reported that hydrogenases,which are present in abundance on membranes of facultative anaerobic bacteria, promote reduction of as upramolecular complex (CPPDI) to form radical anions,w hich then induce antibacterial effects. [23] Inspired by this interesting report, we reasoned that if hydrogenases facilitate the type Ip hotoreaction promoted by irradiation of NanoPcA, then ahigher level of photoinactivation would be occur against facultative anaerobic bacteria compared to aerobic bacteria (Figure S11a). To assess this proposal, ap reliminary study was conducted to compare the relative PDT growth inhibitory effects of NanoPcA against P. aeruginosa (aerobic,G ramnegative) and E. coli (facultative anaerobic, Gram-negative).…”