Abstract
We have successfully synthesized iron and gamma ferric oxide magnetic nanoparticles with particle sizes of 4±0.8 nm through a high-yield chemical thermal reflux method. Polyethyleneimine (PEI) was used to enhance biologically compatibility and monodispersion of nanoparticles. The PEI coated magnetic nanoparticles have sizes between 100 to 200 nm. More importantly, we formed magnetic retroviral vectors through combining Moloney leukemia virus based retroviral vectors with the particles. An external magnetic field can bring the magnetic retroviral vectors to the targeted cells and significantly raised the gene transduction efficiency. We present physical properties and biological activities of magnetic nanoparticles associated with retroviral vectors. © 2003 Advanced Study Center Co. Ltd.