Doxorubicin Loaded Silica Nanoparticles with Dual Modification as a Tumor-Targeted Drug Delivery System for Colon Cancer Therapy.

In the following study, we describe the preparation and characterization of poly(ethylene glycol) (PEG) and biotin modified, doxorubicin (DOX) loaded silica nanoparticles (Dox/SLN-PEG-Biotin), which was employed as a drug delivery system for colon cancer therapy. The DOX/SLN-PEG-Biotin exhibited small particle size and low cytotoxicity in vitro. Moreover, the Dox releases from DOX/SLN-PEG-Biotin followed a redox-sensitive behavior. Biotin functionalized Dox/SLN-PEG-Biotin demonstrated tumor-targeted delivery of their payload, resulting in enhanced cellular uptake in HCT116 tumor cells and potentiated tumor accumulation in HCT116 tumor-bearing mice. In particular, in vivo anti-cancer assay confirmed that DOX/SLN-PEG-Biotin as a tumor-targeted delivery system exerted strong anti-cancer efficacy. Altogether, DOX chemotherapy using DOX/SLN-PEG-Biotin might be an effective strategy for improved treatment in colon cancer.

Determination of nitrobenzene by differential pulse voltammetry and its application in wastewater analysis.

A new method for the determination of nitrobenzene (NB) by differential pulse voltammetry (DPV) based on an adsorptive stripping technique was developed. Cyclic voltammetry (CV) was used in a comparative investigation into the electrochemical reduction of NB at a glassy carbon electrode (GCE). With this electrode, the sharp peak of NB appeared at -0.71 V (vs. Ag/AgCl). The experimental parameters were optimized. Studies on the effect of pH on the peak height and peak potential were carried out over the pH range ca. 9.0-11.5 with sodium carbonate/sodium hydrogen carbonate buffer solution. A solution of pH 9.9 was chosen as analytical medium. Cathodic peak currents were found to be linearly related to the concentration of NB over the range ca. 12.3-1.23 x 10(4) microg L(-1) with relative standard deviations of ca. 3.26-6.75%. The detection limit of NB in water was 5.42 microg L(-1). The interference of organic and inorganic species on the voltammetric response was also studied. The proposed method was applied to the determination of NB in wastewater samples with an average recovery of ca. 95.9-102.4%.