Earth-Abundant CaCO_(3)-Based Photocatalyst for Enhanced ROS Production,Toxic By-Product Suppression,and Efficient NO Removal

Photoinduced reactive oxygen species(ROS)-based pollutant removal is one of the ideal solutions to achieve the conversion of solar energy into chemical energy and thus to address environmental pollution.Here,earthabundant CaCO_(3)-decorated g-C_(3)N_(4)(g-C_(3)N_(4)labeled as CN,CaCO_(3)-decorated g-C_(3)N_(4)sample labeled as CN-CCO)has been constructed by a facile thermal polymerization method for safe and efficient photocatalytic NO removal.The decorated CaCO_(3)as“transit hub”extends theπbonds of CN to deviate from the planes and steers the random charge carriers,which thus provides extra active sites and expedites spatial charge separation to facilitate adsorption/activation of reactants and promote formation of ROS participating in the removal of pollutant.Furthermore,boosted generation of ROS regulates the photocatalytic NO oxidation pathway and thus increases the selectivity of products.NO prefers to be directly oxidized into final product(nitrate)rather than toxic intermediates(NO_(2)),which is well demonstrated by theoretically simulated ROS-based reaction pathways and experimental characterization.The present work promotes the degradation of pollutant and simultaneously suppresses the formation of toxic by-product,which paves the way for ROS-based pollutant removal.

A Peroxidase Contributes to ROS Production during Arabidopsis Root Response to Potassium Deficiency

Reactive oxygen species （ROS） play an important role in root responses to potassium deprivation by regulating the expression of the high-affinity K＋ transporter gene AtHAK5 and other genes. Activation-tagged lines of Arabidopsis plants containing the AtHAK5 promoter driving luciferase were screened for bioluminescence under potassium- sufficient conditions. A member of the type Ill peroxidase family, RCI3, was isolated and when it was overexpressed by the activation tag, this led to the enhanced expression of luciferase and the endogenous AtHAKS. RCI3 was found to be up- regulated upon potassium deprivation. Plants overexpressing RCI3 （RCI3-ox） showed more ROS production and AtHAK5 expression whereas the ROS production and AtHAK5 expression were reduced in rci3-1 under K＋-deprived conditions. These results suggested that RCI3 is involved in the production of ROS under potassium deprivation and that RCI3- mediated ROS production affects the regulation of AtHAK5 expression. This peroxidase appears to be another component of the low-potassium signal transduction pathway in Arabidopsis roots.

A glutathione-triggered precision explosive system for improving tumor chemosensitivity

Stimuli-responsive delivery systems hold promise in cancer treatments.However,their application potential has been limited due to undesirable drug leaking during blood circulation and inefficient therapeutic efficacy in tumors,resulting in undesirable therapeutic outcomes.Herein,we have developed a novel redox-sensitive pegylated phospholipid,termed as DOPE-SS-PEG,which can form a glutathione(GSH)-triggered precision explosive system(GPS)for simultaneously improving circulation stability,tumor specificity,and chemosensitivity,leading to explosive anticancer effects.GPS is constructed of liposomal doxorubicin(DOX)functionalized with DOPE-SS-PEG and MnO_(2) nanoparticles,which can protect liposome structure in the presence of serum GSH(20μM),whereas converts to cationic liposome in response to intracellular GSH(10 mM),thereby enhancing circulation stability,tumor specificity,endosomal escape,and cytoplasmic delivery.Importantly,GPS can not only generate oxygen to relieve hypoxia and consequently enhance chemosensitivity,but quench GSH antioxidability to elevate the accruement of intracellular reactive oxygen species(ROS),leading to an explosion of oxidative stress induced cell injury.Particularly,in vivo studies show that GPS selectively accumulates in tumor tissues,effectively inhibits tumor growth,exhibits minimal systemic adverse effects,and consequently prolongs the survival time of tumor-bearing mice.Therefore,GPS is a unique stimuli-responsive treatment with programmed and on-demand drug delivery,as well as explosive therapeutic efficacy,and provides an intelligent anticancer treatment.