Qi Zhang,Zhe Zheng,Yiting Zhao,Qing Wu,Chu Wu,Xiuli Wang,Xia Wang,Qigang Wang,Peiru Wang
The transformation of O 2 is primarily facilitated by the catalytic action of redox enzymes, which play a pivotal role in sustaining cellular energy metabolism and redox balance. Bioinspired by O 2 distribution and ROS regulation related to cascade biocatalytic process, a D-peptide NapG D F D F D Y engineered hydrogel has been constructed with encapsulated dual-enzyme superoxide (SOD) and chloroperoxidase (CPO) cascade catalytic circuit and co-assembled photosensitizer of 5-aminolevulinic acid molecules (ALA). Multimodal oxygen modulation has been conducted by the concurrent oxygen generation via SOD-catalyzed ⋅O 2 − dismutation and oxygen consumption for 1 O 2 production by CPO and ALA, achieving self-sustaining enzymatic dynamic therapy (EDT)-photodynamic therapy (PDT) (EDT-PDT) synergy. The endogenous cascade-amplified EDT not only enhances the 1 O 2 efficacy in exogenous PDT therapy, but the intermediate O 2 can also alleviate local neuropathic pain caused by hypoxia for safe PDT treatment. This work pioneers enzyme-mediated dynamic control of tumor redox homeostasis, establishing a new therapeutic axis between biocatalytic amplification and photodynamic processes.
Total antioxidant capacity (TAC) is a significant indicator for evaluating nutritional value of fruit and beverage industries, in the aspects of their reactive oxygen species (ROS) scavenging activity. The sensitivity and selectivity of the TAC assay based on the peroxidase (POD) assay is restricted by their poor catalytic activity. Herein, a simple and sensitive strategy for assessing TAC in fruits based on light (808 nm) boosted POD like activity of Au 25 nanoclusters (NCs) have been reported. The absorption bands of mercaptohexanoic acid (MHA)-protected Au 25 NCs could be extended into the near-infrared region (∼770 nm) by introducing neutrally charged ligands or 2,2’(ethylene dioxy) diethyl thiol (EDT)) as bi-thiol ligands, which may contribute to more obvious light enhanced POD activity. The most intense absorption at 770 nm can be obtained by the ratio of MHA/EDT=1.7:0.3 (denoted as MEA-17). Since we have confirmed that ROS is involved in the light enhanced POD like activity, the concentration of various antioxidants AA, GSH and L-Cys, can be analyzed by their inhibitory effect to the oxidation of TMB. More importantly, light enhanced POD like activity of MEA-17 have been successfully utilized to analysis TAC value in various fresh fruits. This work not only provide novel direction for the rational development of near-infrared light-enhanced POD-like nanozyme, but also further expands the prospect of the application of Au 25 NCs protected with thiols for TAC analysis.
危险品化学品经营许可证（带存储）