Synthesis and characterization of new fluorescent polyimides bearing 1,2,4-triazole and 1,2-diaryl quinoxaline: Study properties and application to the extraction/elimination of metallic ions from aqueous media

In this article, synthesis and characterization of triazole-based polyimides for solid-phase extraction of metal cations is described. For this purpose, new aromatic diamines containing 1,2,4-triazole and substituted 1,2-diaryl quinoxaline units were synthesized and used in polycondensation reaction with aromatic dianhydrates to yield poly(triazole-imide)s (PTAI)s. These polymers had inherent viscosities in the range of 0.58-0.62 dL/g and were readily soluble in a variety of organic solvents; they formed low-colored and tough thin films via solution casting. The PTAIs exhibited Tg between 280 and 338 \ub0C, and their 10% weight loss temperatures were in excess of 540 \ub0C with up to 76% char yield at 700 \ub0C in N2. These polymers emitted green or blue fluorescence in dilute NMP solution and in the solid state. The triazole groups in the polymer chain were efficient chelating/host units for heavy metal ions. One of these polymers, PTAI(1b), was investigated for its extraction capability for environmentally deleterious metal ions such as CrVI, CrIII, CoII, Zn II, PbII, CdII, HgII and Mn II from aqueous solutions either individually or in the mixture and at different pH values. \ua9 2012 Elsevier Ltd. All rights reserved

Engineering red-emitting multi-functional nanocapsules for magnetic tumour targeting and imaging

In this work we describe the formulation and characterisation of red-emitting polymeric nanocapsules (NCs) incorporating superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic tumour targeting. The self-fluorescent oligomers were synthesised and chemically conjugated to PLGA which was confirmed by NMR spectroscopy, FT-IR spectroscopy and mass spectrometry. Hydrophobic SPIONs were synthesised through thermal decomposition and their magnetic and heating properties were assessed by SQUID magnetometry and calorimetric measurements, respectively. Magnetic nanocapsules (m-NCs) were prepared by a single emulsification/solvent evaporation method. Their in vitro cytotoxicity was examined in CT26 colon cancer cells. The formulated fluorescent m-NCs showed good stability and biocompatibility both in vitro and in vivo in CT 26 colon cancer models. Following intravenous injection, accumulation of m-NCs in tumours was observed by optical imaging. A higher iron content in the tumours exposed to a magnetic field, compared to the contralateral tumours without magnetic exposure in the same animal, further confirmed the magnetic tumour targeting in vivo. The overall results show that the engineered red-emitting m-NCs have great potential as multifunctional nanocarriers for multi-model bioimaging and magnetic-targeted drug delivery