title: Surface-modified superparamagnetic nanoparticles for drug delivery: preparation, characterization, and cytotoxicity studies.
abstract: Superparamagnetic iron oxide nanoparticles have been used for many years as magnetic resonance imaging (MRI) contrast agents or in drug delivery applications. In this study, a novel approach to prepare magnetic polymeric nanoparticles with magnetic core and polymeric shell using inverse microemulsion polymerization process is reported. Poly(ethyleneglycol) (PEG)-modified superparamagnetic iron oxide nanoparticles with specific shape and size have been prepared inside the aqueous cores of AOT/n-Hexane reverse micelles and characterized by various physicochemical means such as transmission electron microscopy (TEM), infrared spectroscopy, atomic force microscopy (AFM), vibrating sample magnetometry (VSM), and ultraviolet/visible spectroscopy. The inverse microemulsion polymerization of a polymerizable derivative of PEG and a cross-linking agent resulted in a stable hydrophilic polymeric shell of the nanoparticles. The results taken together from TEM and AFM studies showed that the particles are spherical in shape with core-shell structure. The average size of the PEG-modified nanoparticles was found to be around 40-50 nm with narrow size distribution. The magnetic measurement studies revealed the superparamagnetic behavior of the nanoparticles with saturation magnetization values between 45-50 electromagnetic units per gram. The cytotoxicity profile of the nanoparticles on human dermal fibroblasts as measured by standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that the particles are nontoxic and may be useful for various in vivo and in vitro biomedical applications.
authors.affiliation: Centre for Cell Engineering, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK. akgupta25@hotmail.com
authors.forename: Ajay Kumar
authors.initials: AK
authors.lastname: Gupta
authors.forename: Stephen
authors.initials: S
authors.lastname: Wells
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured; D016503:Drug Delivery Systems; D004355:Drug Stability; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D008280:Magnetics; D008823:Micelles; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D008823:Micelles; D013501:Surface-Active Agents; C000499:ferric oxide; D011092:Polyethylene Glycols