光化学原位制备PDEA-磁性纳米凝胶用于DNA 固定及缓释研究

应用光化学原位聚合法合成了聚(甲基丙烯酸二乙氨基乙酯)包覆的磁性纳米凝胶 (PDEA-磁性纳米凝胶). 应用傅里叶变换红外光谱(FTIR)、热重分析仪(TGA)、振动样品磁强计 (VSM)、光子相关光谱(PCS)等对PDEA-磁性纳米凝胶的结构、形貌、磁学性质、粒径及表面 ζ-电位等进行了表征. 结果表明, PDEA-磁性纳米凝胶形状较规则, 为“核-壳”结构, 表面PDEA高分子层约为26%, 平均水合粒径为43 nm, 具有超顺磁性. 该磁性纳米凝胶具有明显的pH敏感性, 在室温、 pH 5.0时可结合DNA分子, 最大结合量为51 μg/mg, 在pH 7.4条件下能够将DNA高效释放出来, 且呈现出明显的缓释效应, 加之良好的磁响应性能, 使其可作为一种新型磁靶向转基因载体应用于生物医学研究.

Photochemical preparation of polyDEA-coated magnetic nanoparticles for DNA capture and release

Poly(2-(diethylamino)ethyl methacrylate) coated magnetic nanoparticles (PDEA-MNPs) were prepared via photochemical method in aqueous system. Transmission electron microscopy (TEM) and photo correlation spectroscopy (PCS) results indicate that the PDEA-MNPs are nearly spherical in shape and have a uniform hydrodynamic particle size of 43 nm. The successful coat-ing of PDEA on the MNPs was ascertained by Fourier transform infrared spectroscopy (FTIR) analysis, and the weight of PDEA polymer was calculated by thermogravimetric analyzer (TGA), accounting for 26%. The PDEA-MNPs behave superparamagnetically with a saturated magnetization of 52 emu/g. The PDEA-MNPs have pH-sensitive properties. They can capture DNA on their surface with a capture capability of 51 μg/mg at pH 5.0 and efficient release DNA at pH 7.4. The slow-release characters, efficient release behavior and strong magnetic response make the PDEA-MNPs become an ideal candidate carrier in target gene delivery systems.