An oligomeric semiconducting nanozyme with ultrafast electron transfers alleviates acute brain injury

Abstract

An oligomeric nanozyme with ultrafast electron transfer can achieve high catalytic activity and alleviate acute brain injury.

Single-atom nanozymes catalytically surpassing naturally occurring enzymes as sustained stitching for brain trauma

“…Other unresolved and high-profile questions are the underlying reaction mechanisms and detailed atomic coordination structures during biocatalytic reactions to endow catalytic selectivity 13 , 31 – 33 . Unlike the well-defined structures of single-atom catalysts 16 , 34 , 35 , traditional nanostructures without elucidated atomic structures on the surface cannot provide sufficient structure-function correlation to study the electron transfers at atomic levels 36 . For example, Pt and Fe 3 O 4 exhibit peroxidase-like (POD-like) activities 6 , 37 ; Au and V 2 O 5 are more selective for the glutathione peroxidase-like (GPx-like) activity 38 – 40 ; Cu demonstrates a superior superoxide dismutase-like (SOD-like) activity 41 .…”

A GPx-mimetic copper vanadate nanozyme mediates the release of nitric oxide fromS-nitrosothiols

“…Furthermore , the K M value reported for the GPx enzyme was 25 μM in the case of H 2 O 2 as a substrate, which was comparable to CuV’s K M value for H 2 O 2 , which was 23.83 μM. 67–69 These values are low and they indicate that the affinities of CuV and the GPx enzyme toward H 2 O 2 are high, although there is a huge difference between the native enzyme and the nanozyme in terms of the structure and mechanism. The higher GPx-like activity (∼140 μM min −1 ) of CuV is also attributed to its higher affinity towards H 2 O 2 , leading to the broad coverage of the surface of CuV with H 2 O 2 molecules, transforming GSH to GSSH and exhibiting steady state kinetics.…”

Engineering Antioxidative Cascade Metal-Phenolic Nanozymes for Alleviating Oxidative Stress during Extracorporeal Blood Purification

“…In the past decades, for mimicking the endogenous enzymes and overcoming their drawbacks (easily affected antioxidative properties by redox microenvironments and pH changes, and specific reactive nitrogen and oxygen species (RNOS) scavenging activity), 16 artificial enzymes (also termed as nanozymes) have aroused great interest and enthusiasm in oxidative stress treatment due to their high stability and versatile enzyme simulation selectivity. 17−21 Until now, various nanozymes, including metal nanoparticles such as platinum, 22 metal oxides such as CeO 2 , 23,24 Mn 3 O 4 , 25,26 and Fe 3 O 4 , 27 transition metal dichalcogenides, 28,29 prussian blue nanoparticles, 18,30,31 quantum dots, 32,33 single atom catalysts, 8 and metal-phenolic nanozymes, 27,34 have been developed for antioxidative applications. For example, the cascade nanozymes have exhibited superior therapeutic efficacy for in vivo inflammatory treatment.…”

“…In the past decades, for mimicking the endogenous enzymes and overcoming their drawbacks (easily affected antioxidative properties by redox microenvironments and pH changes, and specific reactive nitrogen and oxygen species (RNOS) scavenging activity), artificial enzymes (also termed as nanozymes) have aroused great interest and enthusiasm in oxidative stress treatment due to their high stability and versatile enzyme simulation selectivity. − Until now, various nanozymes, including metal nanoparticles such as platinum, metal oxides such as CeO 2 , , Mn 3 O 4 , , and Fe 3 O 4 , transition metal dichalcogenides, , prussian blue nanoparticles, ,, quantum dots, , single atom catalysts, and metal-phenolic nanozymes, , have been developed for antioxidative applications. For example, the cascade nanozymes have exhibited superior therapeutic efficacy for in vivo inflammatory treatment. − However, the application of artificial enzymes in blood purification is almost nonexistent, which could be ascribed to the following reasons: (1) most reported nanozymes are single components, which hardly prevent oxidative damage completely because the multiple pathways that produce ROS are activated for the CKD patients with maintenance blood purification; , (2) determining the kinds and accurate dosages of nanozymes is complicated due to the inter-patient variability and varied disease states for these patients; (3) once the antioxidative nanozymes with poor biocompatibility enter the blood directly, they will cause blood clots and blockage of blood vessels. − Therefore, an ideal strategy to achieve the oxidative stress treatment in the extracorporeal circulation of blood purification should meet these two requirements: (1) the developed antioxidative nanozymes should effectively scavenge multiple ROS, and (2) the antioxidative process should be temporary and localized, which could prevent the nanozymes going into the bloodstream to induce some potential side effects.…”