A Single‐Atom Nanozyme for Wound Disinfection Applications

Abstract

Single‐atom catalysts (SACs), as homogeneous catalysts, have been widely explored for chemical catalysis. However, few studies focus on the applications of SACs in enzymatic catalysis. Herein, we report that a zinc‐based zeolitic‐imidazolate‐framework (ZIF‐8)‐derived carbon nanomaterial containing atomically dispersed zinc atoms can serve as a highly efficient single‐atom peroxidase mimic. To reveal its structure–activity relationship, the structural evolution of the single‐atom nanozyme (SAzyme) was systematically investigated. Furthermore, the coordinatively unsaturated active zinc sites and catalytic mechanism of the SAzyme are disclosed using density functional theory (DFT) calculations. The SAzyme, with high therapeutic effect and biosafety, shows great promises for wound antibacterial applications.

When Nanozymes Meet Single‐Atom Catalysis

“…Chemie growth of Pseudomonas aeruginosa with high antibacterial effect in vitro ( Figure 7A)a nd they displayed great promise as disinfectants of the wounds of mice ( Figure 7B). [90] They found that coordinatively unsaturated zinc atoms play ak ey role in mimicking peroxidase and could thus be employed in bioapplications.Areasonable catalytic mechanism was disclosed with the help of DFT calculations.F irst, the H 2 O 2 molecule was adsorbed on the ZnN 4 active site and activated swiftly,f ollowed by homolysis to generate two adsorbed hydroxide species (OH*). One of the two OH* moieties desorbed from the single zinc site and became an active COH radical that could cause oxidative damage to bacteria and promote wound healing.…”

“…However,i nan eutral catalytic milieu, OH* species poison the FeN 4 active sites after the dissociation of H 2 O 2 into COH, leading to am ajor decline of the catalytic activity.Inthe whole process, COH was the active species,which contrasts with the findings of Li et al [87] Apart from tumor therapy,S ACsa lso possess considerable potential as antibacterials. [81,90] Liu and colleagues prepared ZIF-8-derived carbon nanospheres containing atomically dispersed zinc atoms (ZnÀNÀC), which behaved as photosensitizers and possessed excellent peroxidase-like activity.T he ZnÀNÀCS Azymes were found to inhibit the…”

Single‐Atom Catalysts in Catalytic Biomedicine

“…Inspired by high catalytic activity of natural metalloenzymes, M‐N‐C SACs with similar structure of natural metalloenzymes were exploited as single‐atom nanozymes to mimic the catalytic activities of natural enzymes . Atomically dispersed single zinc atoms supported on carbon spheres (denoted as PMCS) were fabricated as single‐atom nanozyme (SAzyme) with predominant peroxidase‐mimicking activity for suppressing the bacteria proliferation and facilitating the wound regeneration ( Figure a) . The unsaturated coordination structure of the SAzyme is of critical significance to the excellent performance in mimicking peroxidase, leading to the rapid decomposition of H 2 O 2 into abundant •OH.…”

“…SACs, as novel, stable, and efficient antibacterial materials, presented high catalytic performance in promoting the generation of •OH due to their highest atomic utilization and well‐established geometric structure. Furthermore, SACs exhibited high biocompatibility with negligible leakage of metal ions owing to the intense interaction between single metal atoms and support materials, guaranteeing SACs with high potential in wound disinfection …”

An Enzyme‐Mimicking Single‐Atom Catalyst as an Efficient Multiple Reactive Oxygen and Nitrogen Species Scavenger for Sepsis Management

“…[24][25][26][27][28] Recently, owing to their similar CUS active sites compared to metalloenzymes,S ACsh ave successfully mimicked horseradish peroxidase (HRP), SOD,C AT,a nd oxidase for efficient biosensors,a ntibacterial agents,a nd cytoprotection. [29][30][31][32][33][34][35] These enzyme-mimicking single-atom catalysts (SAzyme) have excellent catalytic activity,and are promising in replacing low-activity nanozymes.O nt he other hand, it has been demonstrated that CNO tend to react fast with the unoccupied coordination position of metalloproteins to form metalnitrosyl complexes. [36] Inspired by this,weenvision that SACs could remove CNO competently and simultaneously mimicked antioxidative enzymes to efficiently scavenge RONS,w hich remains af ormidable challenge for currently nanozymes.…”