Levina A S, Ismagilova Z R, Repkova M N, Shikina N V, Baĭborodin S I, Shatskaia N V, Zagrebel'nyĭ S N, Zarytova V F
Bioorg Khim. 2013 Jan-Feb;39(1):87-98. doi: 10.1134/s1068162013010068.
Methods of noncovalent immobilization of DNA fragments onto titanium dioxide nanoparticles (TiO2) were developed, which led to TiO2-DNA nanocomposites capable of penetrating through cell membranes. TiO2 nanoparticles of different forms (amorphous, anatase, brookit) with enhanced agglomeration stability were synthesized. The particles were characterized by X-ray diffraction, small angle X-ray scattering, infrared spectroscopy and atomic force microscopy. Three approaches to the preparation of nanocomposites are described: (1) sorption of polylysine-containing oligonucleotides onto TiO2-nanoparticles, (2) the electrostatic binding of oligonucleotides to TiO2 nanoparticles bearing immobilized polylysine, and (3) sorption of oligonucleotides on TiO2 nanoparticles in the presence of cetavlon. All three methods provide an efficient and stable immobilization of DNA fragments onto nanoparticles, which leads to nanocomposites with a density for an oligonucleotide up to 40 nmol/mg. It is shown that DNA fragments in nanocomposites retain their ability to form complementary complexes and can be delivered into cells without transfection agents and other methods of exposure.
开发了将DNA片段非共价固定在二氧化钛纳米颗粒（TiO₂）上的方法，这导致能够穿透细胞膜的TiO₂-DNA纳米复合材料的产生。合成了具有增强团聚稳定性的不同形态（无定形、锐钛矿型、板钛矿型）的TiO₂纳米颗粒。通过X射线衍射、小角X射线散射、红外光谱和原子力显微镜对颗粒进行了表征。描述了制备纳米复合材料的三种方法：（1）将含聚赖氨酸的寡核苷酸吸附到TiO₂纳米颗粒上，（2）寡核苷酸与负载固定化聚赖氨酸的TiO₂纳米颗粒的静电结合，以及（3）在西他氯铵存在下将寡核苷酸吸附到TiO₂纳米颗粒上。所有这三种方法都能将DNA片段有效且稳定地固定在纳米颗粒上，从而得到寡核苷酸密度高达40 nmol/mg的纳米复合材料。结果表明，纳米复合材料中的DNA片段保留了形成互补复合物的能力，并且无需转染剂和其他暴露方法即可递送至细胞中。
