An Immunomodulatory Biomimetic Single‐Atomic Nanozyme for Biofilm Wound Healing Management

Abstract

Nanozyme‐driven catalytic antibacterial therapy has become a promising modality for bacterial biofilm infections. However, current catalytic therapy of biofilm wounds is severely limited by insufficient catalytic efficiency, excessive inflammation, and deep tissue infection. Drawing from the homing mechanism of natural macrophages, herein, a hollow mesoporous biomimetic single‐atomic nanozyme (SAN) is fabricated to actively target inflamed parts, suppress inflammatory factors, and eliminate deeply organized bacteria for enhance biofilm eradication. In the formulation, this biomimetic nanozyme (Co@SAHSs@IL‐4@RCM) consists of IL‐4‐loaded cobalt SANs‐embedded hollow sphere encapsulate by RAW 264.7 cell membrane (RCM). Upon accumulation at the infected sites through the specific receptors of RCM, Co@SAHS catalyze the conversion of hydrogen peroxide into hydroxyl radicals and are further amplify by NIR‐II photothermal effect and glutathione depletion to permeate and destroy biofilm structure. This behavior subsequently causes the dissociation of RCM shell and the ensuing release of IL‐4 that can reprogram macrophages, enabling suppression of oxidative injury and tissue inflammation. The work paves the way to engineer alternative “all‐in‐one” SANs with an immunomodulatory ability and offers novel insights into the design of bioinspired materials.

Multifunctional Pd Single-Atom Nanozyme for Enhanced Cascade Chemodynamic Therapy of Chronic Wounds

“…The biofilm-induced inflammatory response exacerbates persistent infections and delays chronic wound healing. Therefore, the capacity to puncture and destroy biofilms is a significant indicator of the chronic wound-healing potential of antimicrobial agents. − The specific treatments of S. aureus biofilms were consistent with the six groups described above.…”

Recent Advances in the Bioactive Structure and Application of Single-atom Nanozymes

“…In vivo experiments revealed that FePN SAzyme treatment of wounds stimulated by exogenous nearinfrared (NIR) irradiation significantly reduced inflammatory cell infiltration and promoted epidermal regeneration, suggesting a synergistic therapeutic wound-healing effect of outstanding POD-mimic capacity-assisted CDT effect and localized photothermal efficacy. Similarly, Xu et al [107] also reported a Mn single-atom nanozymes for catalytic/photothermal treatment of bacteria-infected wound. The Mn single-atom nanozymes possessed NIR photothermal-induced enhanced POD-mimetic activity, which could catalyze the •OH-generation in the presence of H 2 O 2 .…”

Advanced nanozymes possess peroxidase-like catalytic activities in biomedical and antibacterial fields: review and progress

“…Inspired by this strategy, Zhang et al encapsulated IL-4 (a cytokine) within single-atom Co nanozymes (Co@SAHS) and then coated it with the RAW 264.7 cell membrane (RCM) to form Co@SAHSs@IL-4@RCM. 60 The RCM leverages its specific proteins to home inflammation site, helping Co@SAHSs@IL-4@RCM accumulation at the infection site. Subsequently, under the action of the nanozyme's POD-like catalytic effect, ˙OH is produced to kill bacteria and disrupt the RCM, releasing IL-4 and thus modulating macrophages towards an M2 phenotype to alleviate the inflammatory response (Fig.…”