摘要
目的构建特异性结合阿尔茨海默病（AD）病理标志物β淀粉（Aβ）斑块的靶向磁性纳米颗粒，并探究其与A15斑块体外结合的能力。方法采用纳米级锰锌铁氧体Mn0.6Zn0.4Fe2O4，以两亲性星型嵌段共聚物进行包覆，负载Ap特异性探针匹茨堡复合物B（PiB），构建新型靶向Aβ斑块的磁性纳米颗粒MZF—PiB，透射电镜检测其形态，3．0TMRI扫描测量MZF—PiB悬液的T2值，通过计算r2弛豫率评估其超顺磁性，应用人神经母细胞瘤细胞株SH—SY5Y、狗肾上皮细胞株MDCK行细胞毒性实验以评估该纳米颗粒的生物安全性，6月龄AD小鼠脑片免疫组化染色检测其体外结合A8的能力。采用单因素方差分析进行组间比较。结果MZF—PiB纳米颗粒成功构建，透射电镜显示其粒径约100nm，r2弛豫率为163．11mMS^-1；孵育MZF—PiB悬液24h、48h后的SH—SYSY和MDCK细胞与对照组细胞活性相比差异均无统计学意义（F=2．336、2．539、0．293、1．493，均P〉0．05）。体外结合实验显示纳米颗粒可与Aβ斑块特异性结合，被检出斑块最小尺寸为27μm。结论PiB修饰的靶向磁性纳米颗粒有良好的安全性和优良的顺磁性，具有体外检测Aβ斑块的能力和早期诊断AD的潜力。
Objective To construct magnetic nanoparticles targeting β-amyloid （Aβ） plaques, the pathological biomarker of Alzheimer＇s disease （AD） and to study their binding capability in vitro. Methods Superparamagnetic nanoparticles Mn0.6 Zn0.＋ Fe204 （MZF） were coated with amphiphilic star-block eopolymeric micelles and modified with Aβ-specific probe Pittsburgh compound B （PiB） to construct a novel magnetic nanoparticle MZF-PiB, which specifically targeted amyloid plaques. Transmission electron microscope was used to study the morphological features of MZF-PiB. Superparamagnetism of MZF-PIB was assessed by its r2 relaxation rate by using 3.0 T MRI scanner. Cytotoxic test was applied to determine biosafety of MZF-PiB nanoparticles in differentiated human neuroblastoma cells （SH-SYSY） and Madin- Darby canine kidney （MDCK）. In vitro binding tests were conducted via immunohistochemistry on 6-month old AD mice brain sections. Differences of cell viability between groups were compared with one-way analysis of variance. Results MZF-PiB nanoparticles were successfully constructed. Transmission electron microscope images showed that the nanoparticles were about 100 nm in size. The r2 relaxation rate was 163.11 raMS^-1. No differences were found in cell viability of SH-SY5Y and MDCK incubated with MZF-PiB suspension for 24 h or 48 h when compared with those of untreated ceils （ F = 2. 336, 2. 539, 0. 293, 1. 493, all P 〉 0. 05 ）. In vitro binding tests indicated that the MZF-PiB were specifically bound to amyloid plaques. The smallest size of detected plaques was 27 μm. Conclusion PiB-modified nanoparticles targeting Aβ are biologically safe and highly superparamagnetic, possessing the capability to detect amyloid plaques early in vitro and the potential for early diagnosis of AD.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2017年第41期3258-3262,共5页
National Medical Journal of China
基金
国家自然科学基金项目（81571665）
