Study On The Application In Drug Delivery Of Surface Functionalized Magnetic Nanopaticles

A gene vector based on the nanoparticles with superparamagnetism (SPIONs@CA) modified with cation polymer polyethylenimine (PEI) was prepared in our study. In additional, cation functionalized magnetic nanoparticles coated with calcium phosphate were fabricated in order to improve the biocompatibility and multifunction. Subsequently FT-IR, XRD, AFM, TEM, DLS and VSM were performed to confirm the structure and morphologies of a series of magnetic nanoparticales.First of all, magnetic nanoparticales modified with citric acid (SPIONs@CA) were prepared by means of coprecipitation method, they can be dispersed in water well.Secondly, magnetic nanoparticales modified with polyethylene imine (SPIONs@PEI) were fabricated via acid amide reaction between the carboxyl on the surface of SPIONs@CA and the amino of PEI, it can be illustrated from the agargel electrophoresis that the SPIONs@PEI can bonding DNA and protect DNA from been broken down by the DNase I. Using the green fluorescent protein plasmid as the reporter gene, transfection efficiency in vitro of SPIONs@PEI/DNA was higher than that of PEI/DNA on the condition of magnetic field, meanwhile the cytotoxicity was lower for the groups treated with SPIONs@PEI/DNA.At last, cationic magnetic nanoparticales coated with calcium phosphate (SPIONs@PEI-CPs) were prepared by means of steeping the SPIONs@PEI into simulated body fluid (SBF), they possessed low cytotoxicity. When the doxorubicine (DOX) were loaded in the SPIONs@PEI-CPs, the DOX-loaded SPIONs@PEI-CPs showed high inhibiting rate for the tumor cells. At the same time, high transfection efficiency was shown used the SPIONs@PEI-CPs as the gene vector.