Stabilizing Enzymes in Plasmonic Silk Film for Synergistic Therapy of In Situ SERS Identified Bacteria

Abstract

Increasing antibiotic resistance becomes a serious threat to public health. Photothermal therapy (PTT) and antibacterial enzyme‐based therapy are promising nonresistant strategies for efficiently killing drug‐resistant bacteria. However, the poor thermostability of enzymes in PTT hinders their synergistic therapy. Herein, antibacterial glucose oxidase (GOx) is embedded in a Ag graphitic nanocapsule (Ag@G) arrayed silk film to fabricate a GOx‐synergistic PTT system (named silk‐GOx‐Ag@G, SGA). The SGA system can stabilize GOx by a vitrification process through the restriction of hydrogen bond and rigid β‐sheet, and keep the antibacterial activity in the hyperthermal PTT environment. Moreover, the arrayed Ag@G possesses excellent chemical stability due to the protection of graphitic shell, providing stable plasmonic effect for integrating PTT and surface enhanced Raman scattering (SERS) analysis even in the GOx‐produced H2O2 environment. With in situ SERS identification of bacterial intrinsic signals in the mouse wound model, such SGA realizes superior synergistic antibacterial effect on the infected Escherichia coli, Staphylococcus aureus, and methicillin‐resistant Staphylococcus aureus in vivo, while without causing significant biotoxicity. This system provides a therapeutic method with low resistance and in situ diagnosis capability for efficiently eliminating bacteria.

Metal Graphitic Nanocapsules for Theranostics in Harsh Conditions

“…(E) AuNR@G-P-aspirin for enhanced NIRmediated PTT of solid tumor and simultaneously inhibit PTT-induced inflammatory response (Dong et al, 2018). (F) Thermostable Ag@G-GOx synergistic PTT platform for bacterial elimination (Liu et al, 2022). of protecting Ag NPs from oxidation, Song et al (2014) prepared a highly surface enhanced Raman scattering (SERS)-active AgCu graphitic nanocapsules (AgCu@G).…”

“…Based on the superior thermostability and photothermal property of AuNR@G, Xu et al (2019) reported a AuNR@G-doped hydrogel system for highly efficient photothermal antibacterial therapy for both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Recently, Liu et al (2022) reported a GOx and Ag graphitic nanocapsules (Ag@G) co-loaded silk membrane theranostic system, the silk membrane enabled GOx to maintain good antibacterial activity during the photothermal antibacterial therapy process, the inert graphitic shell enabled Ag@G to keep excellent SERS performance and photothermal performance under high temperature and GOx-catalyzed production of large amounts of H 2 O 2 , SERS identification of bacteria in the bacteria-infected wound model and efficient synergistic treatment of bacteria were eventually achieved (Figure 1F).…”

Recent Progress of Surface-Enhanced Raman Spectroscopy for Bacteria Detection

“…SERS applied for bacteria detection has great advantages, such as a fast detection speed and high sensitivity without using labeling agents such as antibodies, and, in particular, it has simultaneous detection capabilities for multiple types of bacteria [ 35 , 36 ]. In addition, SERS is considered a promising tool to detect bacteria in infected wounds or blood tissue without damaging the actual sample structure [ 37 , 38 ].…”

Silver Nanoparticle-Assisted Photodynamic Therapy for Biofilm Eradication

“…doped the AgNPs onto the surface of a black phosphorus nanosheet to achieve a photocatalytic disinfectant to produce ROS and Ag species for bacterial killing . Recently, Liu et al reported a photothermal/enzymatic combined antibacterial treatment using the silk film decorated with graphite-encapsulated AgNPs and glucose oxidase . In silver therapy, the released silver ions (Ag + ) from the AgNPs is the main bactericide .…”