Preparation and characterization of magnetic nanoparticles containing Fe3O4-dextran- anti-β-human chorionic gonadotropin, a new generation choriocarcinoma-specific gene vector

Abstract

Cai Jingting1,2, Liu Huining1, Zhang Yi11Department of Obstetrics and Gynecology, Xiangya Hospital, Central South University, Changsha, Hunan, People’s Republic of China; 2Department of Gynecological Oncology, Hunan Tumor Hospital, Changsha, Hunan, People’s Republic of ChinaObjective: To evaluate the feasibility of using magnetic iron oxide (Fe3O4)-dextran-anti-β-human chorionic gonadotropin (HCG) nanoparticles as a gene vector for cellular transfections.Study design: Fe3O4-dextran-anti-β-HCG nanoparticles were synthesized by chemical coprecipitation. The configuration, diameter, and iron content of the nanoparticles were detected by transmission electron microscopy (TEM), light scatter, and atomic absorption spectrophotometry. A3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide assay was used to evaluate the cytotoxicity of Fe3O4-dextran-anti-β-HCG nanoparticles. Enzyme-linked immunosorbent assay and indirect immunofluorescence were used to evaluate immunoreactivity. The efficiency of absorbing DNA and resisting deoxyribonuclease I (DNase I) digestion when bound to Fe3O4-dextran-anti-β-HCG nanoparticles was examined by agarose gel electrophoresis. The ability of Fe3O4-dextran-anti-β-HCG nanoparticles to absorb heparanase antisense oligodeoxynucleotides (AS-ODN) nanoparticles in different cell lines was evaluated by flow cytometry. The tissue distribution of heparanase AS-ODN magnetic nanoparticles in choriocarcinoma tumors transplanted in nude mice was detected by atomic absorption spectrophotometry.Results: TEM demonstrated that the shape of nanoparticles is irregular. Light scatter revealed nanoparticles with a mean diameter of 75.5 nm and an iron content of 37.5 µg/mL. No cytotoxicity was observed when the concentration of Fe3O4-dextran-anti-β-HCG nanoparticles was <37.5 µg/mL. Fe3O4-dextran nanoparticles have a satisfactory potential to combine with β-HCG antibody. Agarose gel electrophoresis analysis of binding experiments showed that after treatment with sodium periodate, Fe3O4-dextran-anti-β-HCG nanoparticles have a satisfactory potential to absorb DNA, and the protection experiment showed that nanoparticles can effectively protect DNA from DNase I digestion. Aldehyde Fe3O4-dextran-anti-β-HCG nanoparticles can transfect reporter genes, and the transfection efficiency of these nanoparticles is greater than that of liposomes (P <0.05). Fe3O4-dextran-anti-β-HCG nanoparticles can concentrate in choriocarcinoma cells and in transplanted choriocarcinoma tumors.Conclusions: The results confirm that Fe3O4-dextran-anti-β-HCG nanoparticles have potential as a secure, effective, and choriocarcinoma-specific targeting gene vector.Keywords: magnetic nanoparticles, Fe3O4-dextran-anti-β-HCG, choriocarcinoma, targeting vector, gene vector