磁性金纳米基因载体的制备及结合DNA研究

Preparation of magnetic gold nano-particles gene vector and its DNA binding test

目的制备1种高分子材料聚乙烯亚胺（PEI）修饰的磁性金纳米粒子作为新型基因载体，观察其表征及结合DNA的能力。方法应用原位合成法合成稳定的复合磁性金纳米微粒（Au-MP-PEI）,将适量FeCl3和FeS04制备纳米磁颗粒（MP-CA）分散液，加人适量PEI溶液及氯金酸（AU-C14 ·3H20）溶液沸腾制得Au-MP-PEI;通过透射电镜观察磁性金纳米粒形态，并检测该纳米粒的粒径及电位分析;采用原液及稀释1 倍的纳米载体进行磁性金纳米载体-DNA的结合实验。结果对PEI包敷的纳米磁颗粒（MP-PEI）做磷钨酸染色后电镜扫描可见每1个团聚体都有数个纳米颗粒构成,笼罩在薄薄一层灰黑色分子下，大小在90 nm左右，而在磁性金纳米颗粒电镜照片中磁颗粒表面可见较多黑色点状颗粒，此即为合成的胶体金。通过不同浓度的金磁纳米载体凝胶阻滞电泳证明磁性金纳米原液能将DNA完全结合。结论成功制备粒径均一的磁性金纳米粒子作为新型基因载体，并且凝胶电泳实验证明该基因载体对DNA具有完全结合的能力。

Objective To synthesize macromolecule materials polyethyleneimine （ PEI） modifiedmagnetic gold nano-particles,then study their characteristics and DNA binding ability. Methods The sta-ble magnetic gold nano-particles （ Au-MP-PEI） were synthesized with in situ synthesis, and observed undera transmission electron microscope （TEM） . The particle size and potential were analyzed. DNA bindingtest was done with magnetic gold nano-particle vector in original nano-vector fluid and nano-vector fluid di-luted one time. Results The magnetic nano-particles wraped by PEI （MP-PEI） were scanned under theTEM after phosphotungstic acid stain, and it was found that every aggregate was formed by several nano-particles ,enveloped by a thin layer of greyblack molecules,with a diameter of about 90 nm,and electronmicroscopic scanning of magnetic gold nano-particle showed more black punctiform particles, synthesizedcolloidal gold. Gel retardation electrophoresis with different concentrations of magnetic gold nano-particlesrevealed that the original fluid of magnetic gold nano-particles could completely bind DNA. Conclusion Anew gene carrier which is uniform particle-size magnetic gold nano-particle is successfully, and gel electro-phoresis proves its complete DNA binding ability as well.