To overcome the urgency of zirconium and hafnium separation, a novel mesoporous silica sorbent (PS-G1.0-MSNs) modified with phosphorous-functionalized G1.0 PAMAM dendrimers was prepared. The adsorption and separation behaviors of PS-G1.0-MSNs adsorbent on Zr(IV) and Hf(IV) were perfromed as a function of acidity, contact time, temperature, and ion concentrations by batch sorption methods. The maximum adsorption capacities for Zr(IV) and Hf(IV) were 25.7 mg g−1 and 5.36 mg g−1 under optimal experimental conditions, respectively, and the separation factor βHf/Zr = 2.0 > 1 demonstrated that the prepared sorbent had preferential selectivity for Hf(IV) in rich Zr(IV) solution. Moreover, kinetic data indicated that the sorption process on Zr(IV) and Hf(IV) achieved equilibrium within 120 min, and followed the pseudo-first-order model with a rate-determining step. The adsorption amount increased as temperature raised from 283 K to 303 K and the isothermal data plotted with the Langmuir model was better than the Freundlich model with monolayer behavior. Thermodynamic data analysis indicated that the sorption process was spontaneous and endothermic. Furthermore, XPS analysis revealed that the metal ion adsorption was mainly induced by the chemical coordination of Zr(IV) and Hf(IV) ions with N, O, P atoms of amide and phosphate groups. The present work provides good guidelines on the design of high efficient sorbent for the separation of Hf(IV) from Zr(IV) solutions.
Wenjing Jiang,Linni Wu,Junling Duan,Huanshun Yin,Shiyun Ai
An ultrasensitive sandwiched electrochemiluminescence (ECL) immunosensor was developed for 5-hydroxymethylcytosine (5hmC) detection in genomic DNA by using Fe 3 O 4 @SiO 2 core–shell magnetic nanomaterial as a immobilization matrix for anti-5hmC antibody, PAMAM conjugated avidin and Ru(bpy) 2 (phen-5-NH 2 )(PF 6 ) 2 as signal amplification unit. Importantly, Fe 3 O 4 @SiO 2 nanoparticles were verified to not only possess enormous surface for loading antibody by amido link, but also exhibit excellent bioactivity . With the dual signal amplification strategy, the ECL immunosensor showed wide detection range from 0.1 to 30 nM with low detection limit of 0.047 nM (S/N = 3). Based on the specific immunoreaction, the developed method also illustrated excellent detection selectivity . The fabricated immunosensor was also applied to detect the 5hmC in genomic DNA of cancer tissue, which indicated that the immunosensor possess potential applications in clinical detection.
Nanomaterial-based drug delivery systems have demonstrated powerful applications in tumor therapy. PAMAM dendrimers by virtue of multivalent modification and biocompatible components were widely used to construction multifunctional targeted chemotherapeutics. In this report, we present a PAMAM dendrimer-based nano-prodrug delivery system for targeted tumor therapy. The RGDyC-PEG-PAMAM-PBA-Res (RPPPR) nano-prodrug was characterized by 1 H NMR, zetasizer, and TEM, the drug loading and pH-sensitive drug release behaviors were investigated. In vitro cell viability assay revealed that the group treated with the nano-prodrug exhibited lower cell viability compared to the control group as concentration increased, confirming the nano-prodrug’s effectiveness in treating tumors. In vitro studies on cellular uptake of the nano-prodrug demonstrated that RPPPR had a high targeting ability, primarily attributed to the RGD-mediated target effect. Relevant data from our hemolysis assay indicated that the nano-prodrug maintained good blood compatibility within the concentration range of 0.1 to 0.3 mg/mL. In vivo experiments focusing on tumor therapy showed that RPPPR suppressed tumor growth and promoted tumor apoptosis. H&E staining, TUNEL assay, and immunohistochemistry results further validated the enhanced therapeutic effect. Importantly, no toxicity was observed in the vital organs such as the heart, liver, lung, kidneys, or spleen. These results suggest the superior antitumor efficacy of RPPPR compared to Resveratrol alone, and thus may be useful for tumor therapy. It is expected to explore new directions to establish a general strategy with dendritic prodrugs for synergistic tumor targeting therapy.
危险品化学品经营许可证（带存储）