Synthesis of porous γ-Fe2O3 from scorodite synthesized using ultrasound irradiation and evaluation of its battery performance

The effect of 200 kHz ultrasound on scorodite synthesis at 70 °C and 3 h reaction conditions was investigated using sulfuric acidic solutions of various pH (3.0, 2.0, 1.5, 1.0, and 0.0). In contrast to the case of only O2 gas flow without ultrasound irradiation, oxidizing radicals generated by ultrasound irradiation promote Fe(II) oxidation in solution and precursor, allowing scorodite to synthesize with high crystallinity (>99%), which relates to low solubility, even in strong acid solution at pH 1.0. During synthesis, particle shape was changed to polyhedral or spindle type depending on the pH of 0.0 to 3.0. The spindle-shaped scorodite was probably formed by the decrease of precursor amount produced in initial stage of the synthesis. Furthermore, porous maghemite obtained by alkali treatment of scorodite showed initial discharge capacities of 146 mAh/g (polyhedron) and 167 mAh/g (spindle), indicating that its potential use as a cathode material for lithium-ion batteries.

Ultrasound-assisted synthesis of β-enaminone derivatives via Tin(Ⅳ)-catalyzed addition reaction from β-dicarbonyl compounds with nitriles

An efficient and eco-friendly approach for the synthesis of β-enaminone derivatives is described, which is through the addition of nitriles with β-dicarbonyl compounds under ultrasound irradiation condition at room temperature. The scope and limitation of this strategy are also discussed. A variety of substituted amides can be obtained in moderate to good yields. We hope that this protocol for the efficient synthesis of β-enaminones will offer insights in further investigations.

An ultrasound-assisted solvent and catalyst-free synthesis of structurally diverse pyrazole centered 1,5-disubstituted tetrazoles via one-pot four-component reaction

1,5-Disubstituted tetrazoles are vital drug-like scaffold usually encountered as valuable bioisosteres of cis-amide bond. In this article, we reported synthesis of some novel medicinally relevant pyrazole centered 1,5-disubstituted tetrazoles using ultrasound irradiation via a one-pot 4-C reaction from various pyrazole originated aldehyde, amine, isocyanide, and sodium azide. All the synthesized derivatives were characterized by IR, 1H NMR, 13C NMR, spectroscopic techniques, and mass analysis. This ultrasound-assisted green protocol has several advantages like mild reaction condition, high yield, catalyst and solvent-free reaction protocol, 15 minutes reaction time and easy workup.

Acceleration of amyloid fibril formation by multichannel sonochemical reactor

Formation of amyloid fibrils of various amyloidogenic proteins is dramatically enhanced by ultrasound irradiation. For applying this phenomenon to the study of protein aggregation science and diagnosis of neurodegenerative diseases, a multichannel ultrasound irradiation system with individually adjustable ultrasound-irradiation conditions is necessary. Here, we develop a sonochemical reaction system, where an ultrasonic transducer is placed in each well of a 96-well microplate to perform ultrasonic irradiation of sample solutions under various conditions with high reproducibility, and applied it for studying amyloid-fibril formation of amyloid $\beta$, $\alpha$-synuclein, $\beta$2-microglobulin, and lysozyme. The results clearly show that our instrument is superior to conventional shaking method in terms of degree of acceleration and reproducibility of fibril formation reaction. The acceleration degree is controllable by controlling the driving voltage applied to each transducer. We have thus succeeded in developing a useful tool for the study of amyloid fibril formation in various proteins.

Ultrasound triggered topical delivery of Bmp7 mRNA for white fat browning induction via engineered smart exosomes

Background Efficient and topical delivery of drugs is essential for maximized efficacy and minimized toxicity. In this study, we aimed to design an exosome-based drug delivery platform endowed with the ability of escaping from phagocytosis at non-target organs and controllably releasing drugs at targeted location. Results The swtichable stealth coat CP05-TK-mPEG was synthesized and anchored onto exosomes through the interaction between peptide CP05 and exosomal surface marker CD63. Chlorin e6 (Ce6) was loaded into exosomes by direct incubation. Controllable removal of PEG could be achieved by breaking thioketal (TK) through reactive oxygen species (ROS), which was produced by Ce6 under ultrasound irradiation. The whole platform was called SmartExo. The stealth effects were analyzed in RAW264.7 cells and C57BL/6 mice via tracing the exosomes. To confirm the efficacy of the engineered smart exosomes, Bone morphogenetic protein 7 (Bmp7) mRNA was encapsulated into exosomes by transfection of overexpressing plasmid, followed by stealth coating, with the exosomes designated as SmartExo@Bmp7. Therapeutic advantages of SmartExo@Bmp7 were proved by targeted delivering Bmp7 mRNA to omental adipose tissue (OAT) of obese C57BL/6 mice for browning induction. SmartExo platform was successfully constructed without changing the basic characteristics of exosomes. The engineered exosomes effectively escaped from the phagocytosis by RAW264.7 and non-target organs. In addition, the SmartExo could be uptaken locally on-demand by ultrasound mediated removal of the stealth coat. Compared with control exosomes, SmartExo@Bmp7 effectively delivered Bmp7 mRNA into OAT upon ultrasound irradiation, and induced OAT browning, as evidenced by the histology of OAT and increased expression of uncoupling protein 1 (Ucp1). Conclusions The proposed SmartExo-based delivery platform, which minimizes side effects and maximizing drug efficacy, offers a novel safe and efficient approach for targeted drug delivery. As a proof, the SmartExo@Bmp7 induced local white adipose tissue browning, and it would be a promising strategy for anti-obesity therapy. Graphical Abstract