Dimethyl fumarate (DMF) has an antioxidant effect by activating the nuclear factor erythroid 2-related transcription factor 2 (Nrf2). Cisplatin (CIS) has nephrotoxicity as a frequently associated side effect that is mainly mediated by oxidative stress. In this study, we investigated whether the DMF-mediated antioxidative mechanism activated by Nrf2 can ameliorate CIS-induced renal tubulointerstitial lesions in rats. In Experiments 1 and 2, 25 five-week-old male Wistar rats were divided into five groups: control, CIS, and 3 CIS+DMF groups (300, 1,500, and 7,500 ppm in Experiment 1; 2,000, 4,000, and 6,000 ppm in Experiment 2). Rats were fed their respective DMF-containing diet for 5 weeks. CIS was injected 1 week after starting DMF administration, and the same volume of saline was injected into the control group. CIS-induced severe tubular injury, such as necrosis and degeneration in the outer segment of the outer medulla, was inhibited in the 7,500 ppm DMF group and ameliorated in all DMF groups in Experiment 2. Increased interstitial mononuclear cell infiltration and increased Sirius red-positive areas were also observed in CIS-administered groups, and these increases tended to be dose-dependently inhibited by DMF co-administration in Experiments 1 and 2. The numbers of α-smooth muscle actin (SMA)-positive myofibroblasts, CD68-positive macrophages, and CD3-positive lymphocytes observed in the peritubular area also increased with CIS administration, and these increases were dose-dependently inhibited by DMF co-administration. Moreover, renal cortical mRNA expression of Nrf2-related genes such as NQO1 increased in DMF groups. This investigation showed that DMF ameliorates CIS-induced renal tubular injury via NQO1-mediated antioxidant mechanisms and reduces the consequent tubulointerstitial fibrosis.

For most nanoparticle applications, understanding the "strength" of anchoring events at the surface is necessary to design effective ligand exchange processes. The present report demonstrates the ability to direct the ordering of phosphonic acid, catechol, and carboxylic acid as anchoring groups for iron oxide nanoparticles, enabled by a stepwise phase-transfer strategy. A key feature was the use of a cyclohexane-based thermomorphic system that provided a unique homogeneous field for ligand-exchange processes, where hydrophobic nanoparticles and a hydrophilic ligand, or hydrophilic nanoparticles and a hydrophobic ligand, effectively mixed together within a moderate temperature range.Iron oxide nanoparticles are powerful platforms capable of producing novel functional materials, and can impart useful magnetic responses to molecules anchored onto their surface. [1] These responses can be exploited to develop contrast agents for magnetic resonance imaging (MRI), probes for in vitro diagnostics, and devices to induce hyperthermia. The low toxicity and low cost of iron oxide nanoparticles have resulted in the development of numerous creative applications, especially in biomedicine as magnetic carriers. Although a one-step process to produce iron oxide nanoparticles capped with organic molecules is possible, [2] biomolecules should be designed and pre-synthesized prior to anchoring onto the surface of the nanoparticles because nanoparticle production conditions generally are too harsh for biomolecules and can damage them. Therefore, the iron oxide nanoparticles and biomolecules should be prepared separately and attached during the final step. Separate preparation of the biomolecules is also important for their characterization, because one-dimensional solution 1 H nuclear magnetic resonance (NMR) spectroscopy, a fundamental organic analytical technique, is much less effective after anchoring due to the magnetic response.To obtain stable colloidal iron oxide nanoparticles, the surface must be capped with suitable ligands to prevent nanoparticle aggregation. In general, the ligands are designed with an anchoring group of specific organic chain(s) selected for affinity toward the solvent. Oleic acid (1) is a standard ligand and one of the most useful for iron oxide nanoparticles because it promotes nanoparticle stability in low-polarity solvents. [3] A carboxylic acid is used as an anchoring group for various oxide surfaces, [4] because it forms relatively weak reversible bonds with the surface. This weak and reversible bonding is important for ligand exchange processes, [5] through which biomolecules equipped with another anchoring group can be loaded onto the oxide surface. The driving force for these ligand exchange processes is based on equilibrium; the ligand anchored onto the surface can be exchanged by the addition of a large excess of another ligand. In addition, anchoring reversibility is key to understanding the driving force for the ligand exchange processes. A ligand forming a reversible bond, such as a c...

No abstract

The cover feature shows a schematic impression of our study on the dispersibility of TiO2 nanoparticles in less polar solvents. For ligand tail structures, there is a huge gap between saturated stearyl groups (depicted as waxes) and unsaturated oleyl groups (depicted as olives), even though there is very little difference in their molecular structures. In this study, we have synthesized two different ligands to bridge shores that are close yet far apart. More information can be found in the Research Article by Y. Okada and co‐workers (DOI: 10.1002/chem.202203608).

Nanoparticles (NPs) are inherently prone to aggregation and loss of their size‐derived properties, thus it is essential to enhance their dispersibility for applications. In less polar solvents, organic ligands containing oleyl groups are known as good dispersants due to their inefficient shell packing and inhibition of chain–chain crystallization as well as interdigitation between adjacent NPs. However, reagents with oleyl structures, such as oleic acid and oleylamine, can contain trans double bonds and saturated impurities, which might affect the chemical and/or physical properties of the NPs. Nevertheless, the effect of slight differences in surface ligand structure, including isomers, on the dispersibility of NPs has been little studied. We have synthesized five phosphonic acid ligands to investigate the structure–dispersibility relationship in detail. Dynamic light scattering and visible light transmittance revealed that not only regio‐ but also the stereochemistries of the C=C double bond in the ligand molecule, as well as the choice of solvent, are key factors in enhancing dispersibility.