Synthesis of chitosan-grafted-poly(N-vinylcaprolactam) coated on the thiolated gold nanoparticles surface for controlled release of cisplatin.

The gold nanoparticles surface was modified by thioglycolic acid ligand and their surface was coated by the chitosan-grafted-poly(N-vinylcaprolactam) (chitosan-g-PNVCL) copolymer. The cisplatin anticancer drug was loaded into the synthesized nanocarriers and its performance was investigated for the treatment of MCF-7 breast cancer cells in vitro. The synthesized nanoparticles were characterized using FTIR, DLS, TEM, SEM, EDX and TGA analysis. The lower critical solution temperature (LCST) of PNVCL/chitosan and PNVCL/chitosan coated gold nanoparticles were found to be 38 and 39 °C, respectively. The cisplatin loading efficiency, cisplatin release from nanoparticles at different temperatures and pH values as well as the pharmacokinetic studies were examined. The maximum cisplatin release from nanoparticles was achieved at T > LCST (42 °C) and pH of 5. The Korsemeyer-Peppas model was best described the cisplatin release from nanoparticles. The maximum MCF cell death was found to be 92% using cisplatin loaded-gold/TGA/chitosan-g-PNVCL nanoparticles under an induction heating system.

New anion-exchange solid-phase extraction support used for preconcentration and determination of lead in water samples by flame atomic absorption spectrometry.

A new chelating resin was prepared by coupling Amberlite XAD-2 with Brilliant Green through an azo spacer. The resulting resin has been characterized by FTIR spectrometry, elemental analysis, and thermogravimetric analysis and studied for the preconcentration and determination of trace Pb(II) ions from solution samples. The anionic complex of Pb(II) and iodide was retained on the resin by the formation of an ion associate with Brilliant Green on Amberlite XAD-2 in weak acidic medium. The optimum pH value for sorption of the metal ion was 5.5. The sorption capacity of the functionalized resin is 53.8 mg/g. The chelating resin can be reused for 20 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 103% was obtained for the metal ion with 0.1 M EDTA as the eluting agent. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The resin was subjected to evaluation through batch binding and column chromatography of Pb(II). The equilibrium adsorption data of Pb(II) on modified resin were analyzed by Langmuir, Freundlich, and Temkin models. Based on equilibrium adsorption data, the Langmuir, Freundlich, and Temkin constants were determined to be 0.192, 13.189, and 3.418 at pH 5.5 and 25 degrees C. The method was applied for lead ion determination in tap water samples.

Synthesis, characterization, and application of m-phenylendiamine-modified Amberlite XAD-4 resin for preconcentration and determination of metal ions in water samples.

A new chelating resin is prepared by coupling Amberlite XAD-4 (Serva, Heidelberg, New York) with m-phenylendiamine through an azo spacer, characterized (by elemental analysis, infrared, and thermogravimetric analysis) and studied for preconcentrating nickel(II), cobalt(II), zinc(II), copper(II), and chromium(III) using flame atomic absorption spectrometry for metal monitoring. The optimum pH values for sorption of the above-mentioned metal ions were 8.5, 8.5, 6.5, 6.5, and 5.5, respectively. The resin was subjected to evaluation through batch binding and column chromatography of the mentioned metal ions. Quantitative desorption occurred instantaneously with 0.5 M HNO3. Various flowrates of sorption and desorption of nickel(II) have been studied. The sorption capacity was found to be 3.89, 3.27, 2.96, and 3.44 mmol/g of resin for cobalt, copper, zinc, and nickel, respectively. The chelating resin can be reused for 10 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of >98% was obtained for all the metal ions, with 0.5 M HNO3 as the eluting agent. The method was applied for determination of metal ions from an industrial wastewater sample.