writer：Gu Jun-heng, Zhang Qing-yun, Zhang Wei, Yang Xin-lin
keywords：tumor; molecular targeted therapy; metal nanoparticles; folic acid
source：期刊
specific source：Chin J Tissue Eng Res (中国组织工程) 18 (30), 4823-4830 (2014). doi:10.3969/j.issn.2095-4344.
Issue time：2014年

he Pluronic F127-folic acid conjugates were prepared via esterification reaction. Then Fe₃O₄ NPs were wrapped with Pluronic F127-folic acid to result in the superparamagnetic composite particles with well dispersion and biocompatibility. The size of most superparamagnetic composite particles was less than 200 nm and the size of Fe₃O₄ core was 10-20 nm from the observation of transmission electron microscopy. The results from the Fourier transform infrared-spectra and UV-vis absorption spectra confirmed that folic acid molecules were modified on the surface of the superparamagnetic composite particles successfully. The mass ratio of Pluronic F127-folic acid conjugate was determined by thermal gravimetric analysis as 27.2 wt% in the resultant Pluronic F127-folic acid-Fe₃O₄ composite particles. The saturated magnetic intensity of the superparamagnetic composite particles was 47.35 emu/g by vibrating sample magnetometer and the relaxation rate was 0.025×10⁶/mol/s from MRI. The WST assay showed the negligible cell cytotoxicity of Pluronic F127-folic acid-Fe₃O₄. The superparamagnetic composite particles have potential application as the MRI contrast agents with tumor targeting, and the Pluronic F127-folic acid-Fe₃O₄ composite particles is expected to be used as a MRI contrast agent for tumor targeting.