稿件1.重力对金纳米颗粒在生物膜表面吸附影响的荧光研究(修改).doc

重力对金纳米颗粒在生物膜表面吸附影响的荧光研究* 蒋中英1,2?, 薛永培1, 盛洁1, 马淑新1 (1.伊犁师范学院电子与信息工程学院, 伊宁 835000 2. 新疆大学物理科学与技术学院, 乌鲁木齐, 830046) 摘 要：纳米颗粒在生物膜表面的吸附行为是纳米生物技术领域的重要问题. 采用正、倒置实验, 通过荧光显微镜定量研究了重力对金纳米颗粒在支撑磷脂膜表面吸附的影响. 研究发现, 颗粒尺寸决定其在顶或底层支撑膜表面吸附的差异性. 吸附量的差异与颗粒的沉淀速率和扩散速率之比的对数呈线性关系. 粒径小于14 nm时, 不考虑重力在吸附时的影响; 粒径大于176 nm时, 重力在吸附中占主导地位. 为药物载体研究和理解颗粒－生物膜相互作用提供参考. 关键词：支撑膜, 纳米颗粒, 重力, 扩散 中图分类号: 0485 文献标识码: A Effect of gravity on gold nanoparticle adsorption on biomembrane: a fluorescence study* JIANG Zhong-Ying1,2?, XUE Yong-Pei1, SHENG Jie1, MA Su-Xin1 (1. School of Electronic and Information Engineering, Yili Normal University, Yining 835000, China; 2. School of Physics Science and Technology, Xinjiang University, Urumqi 830046, China) Abstract: Adsorption of nanoparticles on biomembrane is one critical problem in bionanotechnology. Using fluorescence microscopy, we studied the effect of gravity on gold nanoparticle adsorption on supported lipid membrane by performing the upright and inverted configuration experiments. It was found that: particle size controls the discrepancy between the adsorption on the membranes at the top and bottom of medium. The adsorption disparity increases linearly with the logarithm of the ratio between the sedimentation and diffusion velocities. Gravity is neglectable in adsorption for nanoparticles less than 14 nm, while it is dominant in adsorption for nanoparticles larger than 176 nm. The study provides references for drug carrier research and the understanding of the nanoparticle-membrane interaction in real life. Keywords: supported lipid membrane, nanoparticle, gravity, diffusion 1 引 言 纳米颗粒在生物制药与疾病检测方向应用前景广阔[1]. 生物膜吸附量是纳米颗粒实际应用的一个关键物理参量, 决定着颗粒的生物相容性[2]、内吞途径[3]和其接触生物膜的物理性质[4]、最终状态[5]等. 由于纳米颗粒的重力一般远小于经典胶体理论中的Derjaguin-Landau-Verwey-Overbeek作用力包括电双层与范德华力 [6,7], 重力对纳米颗粒在生物膜表面吸附的影响长期被认为可忽略[8,9]. 但最近的研究表明, 重力在此吸附过程中发挥了重要的作用. Xia等在细胞实验中观察到, 由于金纳米颗粒在重力下发生沉淀, 处于溶液顶层的细胞颗粒内吞量显著低于底层[6]. Wittmaack等报道, 相于个体金属氧化物纳米颗粒, 颗粒聚集体具有较高的重力沉淀效率, 因而更倾向和溶液底层的细胞作用[2]. 我们之前的研究发现, 流体力学