Abstract： Objective To prepare a novel folate-targeted magnetic nanocomposites loaded with tissue facor pathway inhibitor 2 (TFPI-2) and cisplatin (CDDP) and to investigate its targeting ability and anti-tumor effect on nasopharyngeal carcinoma HNE-1 cells in vitro.Methods The copolymer folic acidpolyethylene glycol-polyethyleneimine (FA-PEG-PEI) was synthesized through amidation reaction,and then FA-PEG-PEI/ magnetic nanoparticles-CDDP/TFPI-2 (MNP-CDDP/TFPI-2) nanocomposites was obtained by electrostatic adsorption between TFPI-2 plasmid and magnetic nanoparticles loaded with CDDP (MNP-CDDP) with vortex FA-PEG-PEI.1H Nuclear Magnetic Resonance (1H NMR) was used to determine if FA-PEG-PEI was synthesized.The particle size,zeta potential and morphology were detected by dynamic light scattering (DLS) and transmission electron microscope (TEM).The content of Fe and CDDP was measured by phenanthroline and o-phenylenediamine (OPDA) colourimetry.Agarose gel electrophoresis was used to analyze the binding ability of FA-PEG-PEI/MNP-CDDP to TFPI-2 plasmid.Molecular targeted uptake of FA-PEG-PEI/MNP-CDDP/TFPI-2 coupling with green fluorescent protein (GFP) in NPC cells were observed by Prussian-blue iron staining and fluorescence microscope.The levels of TFPI-2 protein expression after transfection were evaluated by Western blot.The effects of nanocomposites on HNE-1 cells proliferation and apoptosis were measured with Cell Counting Kit-8 (CCK-8) and flow cytometry.Results Special peak value of FA,PEG and PEI were showed on 1H NMR spectrogram.The mean size and zeta potential of FA-PEG-PEI/MNP-CDDP/TFPI-2 were 141.1 nm and 21.5 mV.The nanocomposites showed a good monodispersity and an insufficient size uniformity under TEM.The content of Fe and CDDP were 116.2 μg/ml and 92.88 μg/ml,respectively.Agarose gel electrophoresis showed TFPI-2 could be encapsulated completely and protected from digestion of DNA enzyme as the mass ratio of FA-PEG-PEI/MNP-CDDP and TFPI-2 plasmid was equal or higher than 1:1.More blue-stained magnetic granulars and green fluorescence were seen in folate receptor (FR)-positive HNE-1 cells than in FR-negative CNE-2 (P ＜0.05) under microscope and fluorescence microscope.The level of TFPI-2 protein expression in HNE-1cells increased significantly after transfection by FA-PEG-PEI/MNP-CDDP/TFPI-2,compared with other control groups (FA-PEG-PEI/MNP-CDDP group and TFPI-2 group),all P ＜ 0.05.The nanocomposites inhibitory effect on HNE-1 including cell growth inhibition rate (64.00％) and apoptosis rate (49.61％) were significantly higher than that in FA-PEG-PEI/MNP group (8.19％,9.26％),FA-PEG-PEI/TFPI-2 group (40.35％,19.85％) and FA-PEG-PEI/MNP-CDDP group(56.15％,36.46％) (P ＜ 0.05).Conclusion FA-PEG-PEI/MNP-CDDP/TFPI-2 nanocomposites was successfully synthesized using amidation and electrostatic adsorption technology and has a good molecular targeting and inhibitory effect on FR-positive HNE-1cells in vitro.