Simultaneous quantification of antibiotic dyes in aquatic products and feeds by liquid chromatography–tandem mass spectrometry

AbstractA confirmatory and quantitative method based on liquid chromatography–tandem mass spectrometry (LC/MS/MS) has been developed for the determination of low-level residues of three antibiotic dyes and two metabolites in fish muscle and feed. The target compounds include methylene blue (MB), crystal violet (CV), leucocrystal violet (LCV), malachite green (MG), and leucomalachite green (LMG). The procedures involve solvent extraction by 50% McIlvaine’s buffer with acetonitrile, followed by solid phase extraction (SPE) with an MCX cartridge. High performance liquid chromatography (HPLC) and positive electrospray ionization (ESI) MS with multiple reaction monitoring of two transition reactions was applied for each compound. The detected ion ratios of MB, CV, LCV, MG, and LMG were 11.8, 34.9, 88.4, 25.6, and 42.0, respectively. The average fortification recoveries of the MB, CV, LCV, MG, and LMG of the level of 0.8 μg/kg tested in fish muscle and feed samples were 99.68, 98.93, 100.49, 100.01, and 100.00%, respectively. The precision of analysis of analytes in fish muscle and feed ranged from 4% to 14% and from 7% to 14%, respectively. The decision limits (CCα) were 0.28–0.54 μg/kg, and the detection capabilities (CCβ) were 0.35–0.67 μg/kg (n = 99)

Cancer nanomedicine meets immunotherapy: opportunities and challenges

Cancer nanomedicines have shown promise in combination immunotherapy, thus far mostly preclinically but also already in clinical trials. Combining nanomedicines with immunotherapy aims to reinforce the cancer-immunity cycle, via potentiating key steps in the immune reaction cascade, namely antigen release, antigen processing, antigen presentation, and immune cell-mediated killing. Combination nano-immunotherapy can be realized via three targeting strategies, i.e., by targeting cancer cells, targeting the tumor immune microenvironment, and targeting the peripheral immune system. The clinical potential of nano-immunotherapy has recently been demonstrated in a phase III trial in which nano-albumin paclitaxel (Abraxane®) was combined with atezolizumab (Tecentriq®) for the treatment of patients suffering from advanced triple-negative breast cancer. In the present paper, besides strategies and initial (pre)clinical success stories, we also discuss several key challenges in nano-immunotherapy. Taken together, nanomedicines combined with immunotherapy are gaining significant attention, and it is anticipated that they will play an increasingly important role in clinical cancer therapy

Advances in metal-mediated solid-phase synthesis of heterocyclic compounds

While heterocycles are a key feature frequently found in compounds with pharmaceutical or agrochemical interest, the combination between solidsupported synthesis and organometallic chemistry has demonstrated to be a helpful tool for the preparation of that class of biologically relevant structures. From the more disclosed Hüisgen 1,3-dipolar cycloaddition, the palladium-catalyzed synthesis of indoles and the ruthenium carbene-mediated preparation of heterocycles by ring-closing metathesis (RCM), to the less developed use of gold and iron in polymer-supported chemistry, this survey offers an overview of the solid-phase application of metal-mediated chemistry to the generation of libraries of a variety of heterocyclic systems.Fil: la Venia, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Delpiccolo, Carina Maria Lujan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Mata, Ernesto Gabino. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin