Anti-tumor therapy through high ROS performance induced by Ag nanoenzyme from boron cluster with halloysite clay nanotubes.

The conventional silver nanoparticles (Ag NPs) are characterized with high loading rate and stacking phenomenon, leading to shedding caused biotoxicity and low catalytic efficiency. This seriously hinders their application in biomedicine. Here, we modified the highly dispersible Ag NPs and Ag single-atoms (SAs) synthesis by combining the halloysite clay nanotubes (HNTs) and dodecahydro-dodecaborate (closo-[B12H12]2-) to increase the biocompatible properties and decrease the loading rate. This novel Ag single-atom nanoenzyme alongside Ag NPs nanoenzyme avoid the elevated-temperature calcination while maintaining the exceptionally high-level efficiency of Ag utilization via the reducibility and coordination stabilization of closo-[B12H12]2- and HNTs. With theoretical calculation and electron paramagnetic resonance, we confirmed that both Ag SAzymes and Ag NPs in HNT@B12H12@Ag nanoenzyme are capable decompose the H2O2 into hydroxyl radical (·OH). For the application, we investigated the catalytic activity in the tumor cells and antitumor effects of HNT@B12H12@Ag nanoenzyme both in vitro and in vivo, and confirmed that it effectively suppressed melanoma growth through ·OH generation, with limited biotoxicity. This study provides a novel Ag nanoenzyme synthesis approach to increase the possibility of its clinical application.

Platinum group nanoparticles doped BCN matrix: Efficient catalysts for the electrocatalytic reduction of nitrate to ammonia.

The effective treatment of nitrate (NO3-) in water as a nitrogen source and electrocatalytic NO3- reduction to ammonia (NH3) (NRA) have become preferred methods for NO3--to-NH3 conversion. Achieving efficient NO3--to-NH3 conversion requires the design and development of electrode materials with high activity and efficiency for the electrocatalytic NRA reaction. Herein, based on the special properties of dodecahydro-closo-dodecaborate anions, a BCN matrix, loaded with platinum-group nanoparticles (namely, Pd/BCN, Pt/BCN, and Ru/BCN), was prepared using a simple method for the electrocatalytic NRA reaction. Results showed that Pd/BCN exerts the best catalytic effect on the NRA reaction. The NH3 production rate reached 12.71 mg h-1 mgcat.-1 at -1.0 V vs. RHE. Faraday efficiency reached 91.79 %, which can be attributed to the more uniform distribution of the nanoparticles. Furthermore, Pd/BCN exhibited high cycling stability and resistance to ionic interference. Moreover, the density functional theory calculations indicated that small and well-distributed Pd nanoclusters in the BCN matrix have a large active surface area and promote the catalytic process. This study provides a new strategy to design catalysts for green ammonia synthesis.

Applications of Boron Cluster Supramolecular Frameworks as Metal-Free Chemodynamic Therapy Agents for Melanoma.

Chemodynamic therapy (CDT) is a highly targeted approach to treat cancer since it converts hydrogen peroxide into harmful hydroxyl radicals (OH·) through Fenton or Fenton-like reactions. However, the systemic toxicity of metal-based CDT agents has limited their clinical applications. Herein, a metal-free CDT agent: 2,4,6-tri(4-pyridyl)-1,3,5-triazine (TPT)/ [closo-B12 H12 ]2- (TPT@ B12 H12 ) is reported. Compared to the traditional metal-based CDT agents, TPT@B12 H12 is free of metal avoiding cumulative toxicity during long-term therapy. Density functional theory (DFT) calculation revealed that TPT@B12 H12 decreased the activation barrier more than 3.5 times being a more effective catalyst than the Fe2+ ion (the Fenton reaction), which decreases the barrier about twice. Mechanismly, the theory calculation indicated that both [B12 H12 ]-· and [TPT-H]2+ have the capacity to decompose hydrogen into 1 O2 , OH·, and O2 -· . With electron paramagnetic resonance and fluorescent probes, it is confirmed that TPT@B12 H12 increases the levels of 1 O2 , OH·, and O2 -· . More importantly, TPT@B12 H12 effectively suppress the melanoma growth both in vitro and in vivo through 1 O2 , OH·, and O2 -· generation. This study specifically highlights the great clinical translational potential of TPT@B12 H12 as a CDT reagent.

Synthesis, Structure, and Properties of Complexes Based on 2,4-Bis-(triazol-1-yl)benzoic Acid as a Ligand.

Using 2,4-bis-(triazol-1-yl)-benzoic acid as the main ligand and terephthalic acid (TPA) as the auxiliary ligand, combined with Cd(NO3)2·4H2O and Zn(NO3)2·6H2O, self-assembly under solvothermal conditions gave three novel complexes: [Cd0.5(L)(H2O)] (1), [Cd(L)(TPA)0.5(H2O)]·H2O (2), and [Zn(L)(TPA)0.5]·H2O (3) (TPA = terephthalic acid). The crystal structure test showed that complex 1 belongs to the triclinic crystal system and the P1̅ space group and complexes 2 and 3 belong to the monoclinic crystal system and the P21/c space group. Solid-state fluorescence experiments show that complexes 1, 2, and 3 all have excellent optical properties: among them, complexes 1 and 3 can selectively detect MnO4 - with low detection limits (0.96 µM and 0.232 µM, respectively) and complex 2 can detect Cr2O7 2- [limit of detection (LOD) = 0.035 µM], and the most interesting thing is that all three complexes can be used as sensors for detecting Fe3+ (LOD = 0.76 µM, 0.657 µM, and 0.11 µM, respectively). In addition, the detection capabilities of these three complexes for different amino acids and antibiotics were also analyzed, and the results showed that all three complexes can effectively detect tetracycline hydrochloride through the quenching effect and 2 and 3 can selectively detect tryptophan via the fluorescence enhancement effect.