Surface-Adaptive and Initiator-Loaded Graphene as a Light-Induced Generator with Free Radicals for Drug-Resistant Bacteria Eradication

Abstract

Since generating toxic reactive oxygen species is largely dependent on oxygen, bacteria-infected wounds' hypoxia significantly inhibits photodynamic therapy's antibacterial efficiency. Therefore, a novel therapeutic method for eradicating multidrug-resistant bacteria is developed based on the light-activated alkyl free-radical generation (that is oxygen independent). According to the polydopamine-coated carboxyl graphene (PDA@CG), an initiator-loaded and pH-sensitive heat-producible hybrid of bactericides was synthesized. According to fluorescence/thermal imaging, under the low pH of the bacterial infection sites, this platform turned positively charged, which allows their accumulation in local infection site. The plasmonic heating effects of PDA@CG can make the initiator decomposed to generate alkyl radical (R • ) under the followed near-infrared light irradiation. As a result, oxidative stress can be elevated, DNA damages in bacteria can be caused, and finally even multidrug-resistance death can be caused under different oxygen tensions. Moreover, our bactericidal could promote wound healing in vivo and negligible toxicity in vivo and in vitro and eliminate abscess. Accordingly, this study proves that combination of oxygen-independent free-radical-based therapy along with a stimulus-responsiveness moiety not only can be used as an effective treatment of multidrug-resistant bacteria infection, but also creates a use of a variety of free radicals for treatment of multidrug-resistant bacteria infection wounds.

A multifunctional platform with single-NIR-laser-triggered photothermal and NO release for synergistic therapy against multidrug-resistant Gram-negative bacteria and their biofilms

“…8i, j, TG-NO-B maintained accumulation at the infected site for at least 10 days. Besides accumulated in the infected wound, TG-NO-B also distributed in the liver and lung, which was consistent with previous studies [51], mainly as a result of the phagocytosis of the reticuloendothelial system [52]. At 10 days post-treatment, no detected fluorescent signals were observed in the major organs, demonstrating that TG-NO-B was excreted out of the body.…”

Bacteria responsive polyoxometalates nanocluster strategy to regulate biofilm microenvironments for enhanced synergetic antibiofilm activity and wound healing

“…However, the concentration of H 2 O 2 that is traditionally used is in the range of 166 mM to 1 M (volume ratio: 0.5-3 %) 38 - 40 , and this prevents wound healing and damages adjacent normal organs during bacterial sterilization. Currently, various novel types of peroxidase-like nanomaterials that have high peroxidase-mimic activity, such as carbon-based nanomaterials 41 - 44 , noble metals 45 - 51 , iron-based nanomaterials 52 - 55 , transitional metal dichalcogenides 56 , 57 , and polyoxometalates 58 , have been known to have obvious antibacterial effects. They can disrupt the integrity of bacterial cell membranes and cell wall permeability.…”

Recent Progress of Alkyl Radicals Generation‐Based Agents for Biomedical Applications

“…Reproduced with permission. [ 158 ] Copyright 2019, American Chemical Society.…”

“…j) Change in quantity of MRSA bacteria in normoxia and k) hypoxia. Reproduced with permission [158]. Copyright 2019, American Chemical Society.…”