超小磁性纳米粒子模拟过氧化物酶用于免疫组化检测

基于磁性纳米粒子的磁性纳米探针已经越来越多地被应用于生物医学检测领域。尺寸是衡量磁性纳米探针的一个重要指标，制备出稳定的超小磁性纳米粒子以及构建功能化的超小磁性纳米探针，对于肿瘤的早期诊断、治疗效果及预后评价将有极其重大的意义。本文采用二巯基丁二酸作为修饰材料，用它取代油酸包裹的四氧化三铁磁性纳米粒子表面的油酸分子，制备出水溶性好、稳定性能高、适合生物医学应用的超小磁性纳米粒子（磁核尺寸仅为5nm左右），并利用尼妥珠单抗，在偶联剂（EDC/NHS）的作用下，构建了一种新型的体外靶向食道癌细胞的超小磁性纳米探针（水动力尺寸小于40nm）。利用这种探针的模拟过氧化物酶特性，我们发展了一种新型的免疫组化检测方法。

YihangWu,Mengjie Song,Zhuang Xin,Xiaoqing Zhang,Yu Zhang,ChunyuWang,Suyi Li and Ning GuUltra-small particles of iron oxide as peroxidase for immunohistochemical,Nanotechnology 22 (2011) 225703

Figure 1. Synthetic procedure for the Ab-DMSA-USPIO probes and their biological application in immunohistochemical staining.

Figure 2. TEM photographs of (a) the OA-USPIO, (b) the DMSA-USPIO.

Figure 6. Hydrodynamic sizes of (a) BSA, (b) the DMSA-USPIO, (c) the Ab-DMSA-USPIO probes blocked by BSA.

Figure 7. UV–vis absorption spectra of (a) the DMSA-USPIO, (b) the Ab-DMSA-USPIO probes unblocked by BSA, (c) the Ab-DMSA-USPIO probes blocked by BSA.

Figure 8. Peroxidase-like activity of (a) the DMSA-USPIO (b) the Ab-DMSA-USPIO probes.

Figure 9. Michaelis constant of DMSA-USPIO (a) with TMB as the substrate, (b) with H2O2 as the substrate.

Figure 10. Immunohistochemistry staining of DAB (a) the Ab-DMSA-USPIO probes, (b) control-1, (c) control-2, (d) control-3.