Preparation Of Magnetic Iron Oxide Nanoparticles Research Articles

Magnetic gelatin nanoparticles as a biocompatible carrier system for small interfering RNA in human colorectal cancer: Synthesis, optimization, characterization, and cell viability studies

Iron oxide-based nanoparticles have gained tremendous attention in developing next-generation personalized medicine modalities. Gelatin can be a good alternative for encapsulating iron oxide nanoparticles with its biocompatibility, biodegradability, low immunogenicity, and richness of functional groups. Herein, magnetic iron oxide nanoparticles (MNPs) were synthesized, coated with gelatin (Gel-MNPs), and loaded with mammalian target of rapamycin (mTOR)-silencing siRNA to induce the in vitro therapeutic effect in colorectal cancer (CRC) cells. To the best of our knowledge, this study is the first report using Gel-MNPs as siRNA carriers. We first optimized several experimental conditions for the preparation of MNPs and Gel-MNPs and the resulting optimized nanoparticles showed a narrow size and size distribution. Gelatin-coating increased the storage stability by preventing the aggregation of MNPs and did not alter the magnetic characteristics of MNPs significantly. siRNA encapsulation abilities of Gel-MNPs were determined in the range of 18.4 and 41.5% in varying siRNA amounts. Bare Gel-MNPs were highly cytocompatible against CRC cells, Caco-2, while Gel-MNPs-mTOR-siRNA exhibited a significant anticancer effect to kill these cells. Comparison with HiPerFect, a commercial siRNA transfection reagent, demonstrated that Gel-MNPs-mTOR-siRNA inhibited cell viability almost similar to or better than HiPerFect-mTOR-siRNA. Taken together, our data indicated that Gel-MNPs could potentially be used in further gene silencing approaches as a safe and multifunctional siRNA carrier candidate.

Preparation of magnetic iron-oxide nanoparticles by successive reduction–oxidation in reverse micelles: Effects of reducing agent and atmosphere

The chemical reduction of ferrous or ferric ions to metallic iron by a reducing agent such as sodium borohydride (NaBH4), hydrazine (N2H4), or sodium phosphonate (NaH2PO2) and its subsequent oxidation were investigated for the preparation of iron-oxide nanoparticles in reverse micelles. The crystal structure and crystallinity of the oxide nanoparticles were found to depend on the oxidation potential of the reducing agent and the catalytic activity of the surface of deposited iron. In addition, it was demonstrated that the process used for oxidizing the metallic iron was critical for the formation of oxide nanoparticles, and that the enhancement of magnetic properties was achieved by providing a flow of oxygen during the oxidation process.