1 - ArticleMagnetic nanorods were successfully prepared in water by a simple and fast method through microwave (MW) assisted reduction using akaganeite beta-FeOOH nanorods and hydrazine as precursors and reductor, respectively. Elongated paramagnetic akaganeite precursors are synthesized for the first time using dopamine as green chemical shape-control agent. The nature and the growth mechanism are identified by XRD, Raman spectroscopy and HRTEM analysis. Fast MW reduction process induces a structural and magnetic change depending on MW irradiation cycles. After 2 min, MW reduction leads to iron oxide nanorods with aspect ratio 3.2. XRD and Raman spectroscopy indicate a heterogeneous composition with high proportion of maghemite. The FMR spectrum is characteristic of shape anisotropy and weak ferromagnetic behavior is observed from SQUID measurements

A bone targeting nanosystem is reported here which combined magnetic contrast agent for Magnetic Resonance Imaging (MRI) and a therapeutic agent (bisphosphonates) into one drug delivery system. This new targeting nanoplatform consists of superparamagnetic γFe2O3 nanoparticles conjugated to 1,5-dihydroxy-1,5,5-tris-phosphono-pentyl-phosphonic acid (di-HMBPs) molecules with a bisphosphonate function at the outer of the nanoparticle surface for bone targeting. The as-synthesized nanoparticles were evaluated as a specific MRI contrast agent by adsorption study onto hydroxyapatite and MRI measurment. The strong adsorption of the bisphosphonates nanoparticles to hydroxyapatite and their use as MRI T2∗ contrast agent were demonstrated. Cellular tests performed on human osteosarcoma cells (MG63) show that γFe2O3@di-HMBP hybrid nanomaterial has no citoxity effect in cell viability and may act as a diagnostic and therapeutic system.

Thanks to their magnetic properties, superparamagnetic iron oxide nanoparticles are considered as a good delivery vehicle after grafting a therapeutical drug on their surface. For additional "stealth" characteristics, PEGylation of surfaces is necessary. The presence of PEG chains divert nanoparticles from their preferred target, the liver macrophages and increased the particle time circulation. In this work, PEG chain is added to an anticancer drug Alendronate. This molecule is grafted on iron oxide nanoparticle surface in one step surface functionalization method. The in vitro cytotoxic efficiency of γ-Fe 2 O 3-Alendronate-PEG nanocrystals is compared with that of free Alendronate, Alendronate-PEG and γ-Fe 2 O 3-Alendronate nanocrystals.