Intelligent anticancer drug delivery performances of two poly(N-isopropylacrylamide)-based magnetite nanohydrogels.

This article evaluates the anticancer drug delivery performances of two nanohydrogels composed of poly(N-isopropylacrylamide-co-itaconic anhydride) [P(NIPAAm-co-IA)], poly(ethylene glycol) (PEG), and Fe3O4 nanoparticles. For this purpose, the magnetite nanohydrogels (MNHGs) were loaded with doxorubicin hydrochloride (DOX) as a universal anticancer drug. The morphologies and magnetic properties of the DOX-loaded MNHGs were investigated using transmission electron microscopy (TEM) and vibrating-sample magnetometer (VSM), respectively. The sizes and zeta potentials (ξ) of the MNHGs and their corresponding DOX-loaded nanosystems were also investigated. The DOX-loaded MNHGs showed the highest drug release values at condition of 41 °C and pH 5.3. The drug-loaded MNHGs at physiological condition (pH 7.4 and 37 °C) exhibited negligible drug release values. In vitro cytotoxic effects of the DOX-loaded MNHGs were extensively evaluated through the assessing survival rate of HeLa cells using the MTT assay, and there in vitro cellular uptake into the mentioned cell line were examined using fluorescent microscopy and fluorescence-activated cell sorting (FACS) flow cytometry analyses. As the results, the DOX-loaded MNHG1 exhibited higher anticancer drug delivery performance in the terms of cytotoxic effect and in vitro cellular uptake. Thus, the developed MNHG1 can be considered as a promising de novo drug delivery system, in part due to its pH and thermal responsive drug release behavior as well as proper magnetite character toward targeted drug delivery.

A novel starch-based stimuli-responsive nanosystem for theranostic applications.

The aim of this study was to synthesis and characterization of a novel stimuli-responsive polymeric nanosystem for theranostic applications. For this purpose, starch was modified by itaconic anhydride to afford an itaconat-functionalized starch macromonomer (starch-IA). This macromonomer with carboxylic functional groups was subsequently adsorbed onto the surface of iron oxide nanoparticles (Fe3O4 NPs), and then copolymerized with N-isopropylacrylamide (NIPAAm) monomer via a 'free' radical initiated polymerization technique to produce a temperature-responsive magnetic nanohydrogel (MNHG). The chemical structures of all samples as representatives were characterized by means of Fourier transform infrared (FTIR) spectroscopy. The lower critical solution temperature (LCST), thermal responsibility, morphology, elemental composition, thermal stability, and magnetic properties of the synthesized MNHG were investigated. In addition, the methotrexate (MTX)-loading capacity (∼74%) and stimuli-responsive drug release ability of the synthesized MNHG were also evaluated. As results, we envision that the synthesized starch-g-PNIPAAm/Fe3O4 MNHG may be find theranostic applications, in part due to its smart physicochemical properties.