Search

A novel short‐chain alcohol dehydrogenase from Tarenaya hassleriana labeled as putative tropinone reductase was heterologously expressed in Escherichia coli. Purified recombinant protein had molecular weight of approximately 30 kDa on 12% sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. T. hassleriana tropinone reductase‐like enzyme (ThTRL) had not detected oxidative activity. The optimum pH for enzyme activity of ThTRL was weakly acidic (pH 5.0). 50°C was the optimum temperature for ThTRL. The highest catalytic efficiency and substrate affinity for recombinant ThTRL were observed with (+)‐camphorquinone (kcat/Km = 814.3 s–1 mM–1, Km = 44.25 μM). ThTRL exhibited a broad substrate specificity and reduced various carbonyl compounds, including small lipophilic aldehydes and ketones, terpene ketones, and their structural analogs. [ABSTRACT FROM AUTHOR]

To optimize the extraction process of total saponins and polysaccharides of the jujube kernel and study its antioxidant effect, Box-behnken method was used to optimize the extraction process of total saponins and polysaccharides from semen ziziphi spinosae, and three antioxidant detection methods were used to study the antioxidant effects of different processed products of semen ziziphi spinosae. The results show that optimal extraction conditions of total saponins are as follows ultrasonic power 228.5 W, liquid-solid ratio 70:1,ethanol volume fraction 10%, and extraction time 21.1 min. The best extraction process of polysaccharides: ultrasonic power 200 W, liquid-solid ratio 70:1,ethanol volume fraction 21.2%, and extraction time 27.7 min. The total saponin content of stir-fried semen ziziphi spinosae is higher, and the polysaccharide content of raw-stir-fried semen ziziphi spinosae is higher. The total saponins and polysaccharides of semen ziziphi spinosae have certain antioxidant capacity. The optimized process can provide a basis for the development and application of jujube kernel. [ABSTRACT FROM AUTHOR]

We have investigated the focusing of the spoof surface acoustic waves (SSAWs) on a rigid surface engraved with array of cylindrical holes. To focus the SSAWs launched along x direction, the holes array, with a shape of rectangle as a whole, is fabricated to possess gradient index of refraction along both the +y and -y directions, which is achieved by varying linearly the radii of the holes along the corresponding directions. Good focusing performance has been demonstrated experimentally, which is in good agreement with the numerical simulations. This acoustic system is believed to have potential applications in acoustic field such as high resolution detecting. [ABSTRACT FROM AUTHOR]

Limited penetration of chemotherapeutic drugs through the blood brain barrier (BBB), and the increased chemo-resistance of glioma cells due to macroautophagy/autophagy, result in high tumor recurrence and extremely limited survival of glioma patients. Ultrasound-targeted microbubble destruction (UTMD) is a technique of transient and reversible BBB disruption, which greatly facilitates intracerebral drug delivery. In addition, sonodynamic therapy (SDT) based on ultrasound stimulation and a sonosensitizer, can be a safe and noninvasive strategy for treating glioma. We innovatively designed a smart "all-in-one" nanosensitizer platform by incorporating the sonoactive chlorin e6 (Ce6) and an autophagy inhibitor-hydroxychloroquine (HCQ) into angiopep-2 peptide-modified liposomes (designated as ACHL), which integrates multiple diagnostic and therapeutic functions. ACHL selectively accumulated in the brain tumors during the optimal time-window of transient UTMD-mediated BBB opening. The nanosensitizer then responded to a second ultrasonic stimulation, and simultaneously unloaded HCQ and generated ROS in the glioma cells. The sonotherapy triggered apoptosis as well as MAPK/p38-PINK1-PRKN-dependent mitophagy, in which the antioxidant relieved the sonotoxicity and MAPK/p38 activation, while the inhibition of MAPK/p38 attenuated the progression toward mitophagy by compromising redistribution of PRKN. Moreover, HCQ blocking autophagosome degradation, augmented intracellular ROS production and resulted in an oxidative-damage regenerative loop. ACHL-SDT treatment using this construct significantly inhibited the xenograft-tumor growth and prolonged the survival time of tumor-bearing mice, exhibiting an improved therapeutic efficiency. All together, we demonstrated a precision sonotherapy with simultaneous apoptosis induction and mitophagy inhibition, which served as an intelligently strategic sense of working alongside, providing new insights into the theranostics of brain tumors. ACHL: Angiopep-2-modified liposomes loaded with Ce6 and hydroxychloroquine; ACL: Angiopep-2-modified liposomes loaded with Ce6; BBB: blood brain barrier; Ce6: chlorin e6; CHL: liposomes loaded with Ce6 and hydroxychloroquine; CL: liposomes loaded with Ce6; CNS: central nervous system; DDS: drug delivery system; EB: Evans blue; FUS: focused ultrasound; HCQ: hydroxychloroquine; LRP1: low density lipoprotein receptor-related protein 1; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MBs: microbubbles; MTG: MitoTracker Green; MTR: MitoTracker Red; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; PBS: phosphate-buffered saline; PDI: polydispersity index; PINK1: PTEN induced kinase 1; PRKN/parkin: parkin RBR E3 ubiquitin protein ligase; ROS: reactive oxygen species; SDT: sonodynamic therapy; SQSTM1: sequestome 1; TA: terephthalic acid; TEM: transmission electron microscopy; TUNEL: terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling; US: ultrasound; UTMD: ultrasound-targeted microbubble destruction. [ABSTRACT FROM AUTHOR]