Self-adaptive carbon nanozyme regulation of ROS balance for bacteria-infected wound therapy

Abstract

Nanozymes sterilizing drug-resistant (DR) bacteria by generating reactive oxygen species (ROS) have emerged as a promising approach for treating infected wounds. However, designing biocompatible adaptive ROS balance therapeutic platform for DR bacteria-infected wounds remains a great challenge. Herein, biocompatible lignin-based carbon dot nanomaterials (LCDs-OA) with more CO and COOH functional groups on the surface were prepared by hydrothermal organic acid co-processing and used as a dual enzyme-like active nanozyme for the therapy of wounds infected by DR bacteria. Experimental and theoretical calculations demonstrated that the CO and COOH functional groups in LCDs-OA have site-switching roles in the dual enzyme-like activity, which can balance reactive oxygen species (ROS) according to the changes in microenvironmental pH at the wound site, and realize the adaptive regulation of ROS generation for bactericidal and ROS scavenging for healing. Furthermore, the performance differences between different organic acid treatments were investigated and an adaptive ROS balance therapeutic platform (LCDs-OA@CaO2) was constructed to overcome the major limitation in treating DR bacterial infected wounds. The system achieved >99.6 % in vitro antimicrobial efficiency against DR bacteria and was highly biocompatible while effectively reducing oxidative damage to normal tissues, resulting in satisfactory therapeutic results in repairing wounds infected with DR bacteria.