Xiao-Cheng Liu,Chuan-Shu He,Zi-Yang Shen,Wen-Qiang Li,Ning Chen,Jun-Sheng Song,Xiao-Guo Zhou,Yang Mu
Fe(III) chelate reduction is of great importance in the homogeneous neutral electro-Fenton (EF) process, but its reduction mechanisms with different reductive species remain unclear. In this study, the reduction mechanisms of several typical Fe(III) chelates through electron and atomic H* were investigated using experiments and density functional theory calculations. The results indicated that the electron reduction efficiencies for [Fe(III)-EDTA] − and [Fe(III)-EDDS] − chelates were 16.23 and 8.31 times higher compared to [Fe(H 2 O) 6 ] 3+ , which was featured by low E LUMO - HOMO and concentrated LUMO distribution around Fe atom. In contrast, the atomic H* reduction efficiency for [Fe(III)-HA] 3+ chelate was 10 times higher than that of electron, attributed to high chelation ability of HA and negative energy barrier of [Fe(III)-HA] 3+ reduction in the atomic H*-dominated system. Additionally, phthalocyanine (Pc) had insignificant effect on pollutant degradation efficiency in the neutral EF systems due to the lower chelate ability of Pc with Fe(III) compared to H 2 O.
Ming Teng,Xiaomin Luo,Fen Ao,Liuying Li,Jianyan Feng,Peng Zhang,Xiaomeng Zhang,Xudan Liu,Chen Yang,Lufeng Ji,Xuechuan Wang,Haiyan Ju,Xinhua Liu
Bacteria‐infected skin wounds are an immense public health challenge for high mortality-rate and enormous financial burden worldwide. Emerging living bacterial therapy promises the desired therapeutic efficacy for wound healing, however, its indiscriminate negative effects on the bioactivity of beneficial bacteria remain enormous challenges for clinical far-ranging applications. Herein, silk fibroin-based nanofibrous scaffolds equipped with nano-engineered tannic acid (TA)-Fe(III) chelate-encapsulated Lactobacillus reuteri (denoted as Mbr/ L @FeTA) were proposed for antibiotic-free accelerated bacteria‐infected wound healing. Mbr/ L @FeTA exhibited excellent antimicrobial properties (99.03% and 98.60% bactericidal efficiency against Escherichia coli and Staphylococcus aureus , respectively), gratifying mechanical properties and biocompatibility. Furthermore, due to on-demand TA-Fe(III) chelate-encapsulated bacterial tactics, Mbr/ L @FeTA demonstrates exceptional environmental resistance and maintains satisfactory biological-activity even when administered with antibiotics. Additionally, Mbr/ L @FeTA enables the stable release of organic acids and other metabolites that significantly improve the wound microenvironment and modulate inflammatory reactions. In vivo and in vitro experiments confirmed that Mbr/ L @FeTA strongly promoted cell growth and proliferation, inhibited bacteria growth at the wound-site, and further accelerated the healing process in bacteria-infected wounds. These findings suggest that Mbr/ L @FeTA exhibits great potential for applications in antibiotic-free infected wound therapy and simultaneously represents a useful approach for clinical applications of living bacterial therapy.
The self-healing property based on metal-ligand physical coordination is particularly interesting in bio-hydrogel science due to its allowance for multiple local healing events to process. As the most abundant renewable green resource in nature, Gleditsia sinensis galactomannan has great potential as a starting material for functional materials. In this study, the biocompatible Gleditsia sinensis galactomannan and cellulose were firstly chemically modified and then taken as the main constituent for constructing the metal-ligand coordination through an enzyme-regulated strategy. The hydrogel could quickly gelatinize in the surrounding environment, corresponding to the violent exothermic phenomenon, and exhibit extraordinary self-healing behavior. The molecular dynamics simulation of the hydrogel confirmed the more stable coordinated configuration from Fe(III)-chelates than Fe(II)-chelates. The morphology, mechanical property, antibacterial, and cytotoxicity of the prepared hydrogel were also studied. Our results indicated that galactomannan hydrogel based on the metal-ligand networks could balance the kinetic stability and intrinsic healability through the enzyme-induced route, which provide a new perspective in the field of biomaterial applications.
危险品化学品经营许可证（带存储）