用于正电子断层扫描成像的^(68)Ga标记PM_(2.5)模拟粒子的制备及其活体示踪

Preparation and in vivo tracing of ^(68)Ga⁃labeled PM_(2.5)mimetic particles for positron emission tomography imaging

将黑色素纳米颗粒(melanin nanoparticle,MNP)经聚乙二醇(polyethylene glycol,PEG)修饰制备得到PEG-MNP,随后通过与放射性的^(68)Ga^(3+)离子螯合,高标记产率地制备得到^(68)Ga-PEG-MNP,标记产物稳定性良好。进一步将^(68)Ga-PEG-MNP通过雾化方式制备得到^(68)Ga-PEG-MNP PM_(2.5)(particulate matter _(2.5),size<_(2.5)μm)模拟颗粒,其经雾化小鼠吸入体内后,通过正电子断层扫描(positron emission tomography,PET)成像对小鼠进行全身显影,结果可见雾化的^(68)Ga-PEG-MNP PM_(2.5)模拟颗粒可由气管向肺部双叶区域扩散,并滞留于肺。体内的PET成像结果与离体放射自显影结果高度一致。

Melanin nanoparticle(MNP)was modified by polyethylene glycols(PEG),and the resulting compound(PEG-MNP)was obtained.The^(68)Ga labeled PEG-MNP was prepared by chelating radioactive^(68)Ga^(3+)ions with high labeling yield(95.6%±1.9%)and radiochemical purity(>95%).The stability of the labeling compound as well.Then^(68)Ga-PEG-MNP for simulating PM_(2.5)particles(particulate matter_(2.5),size<_(2.5)μm)was obtained through nebulization.After inhaling the nebulized particles,whole-body positron emission tomography(PET)in mice was performed.It revealed that nebulized^(68)Ga-PEG-MNP diffused from the trachea to the bilateral lobe area of the lungs and retained in the lungs.Quantification of PET images showed that the uptakes of the trachea and lung were(7.20±2.44)%·g-1,(4.46±1.04)%·g-1,(4.91±2.48)%·g-1,(4.71±2.39)%·g-1,(3.34±1.14)%·g-1,and(17.90±3.75)%·g-1,(18.10±4.52)%·g-1,(19.49±6.11)%·g-1,(19.19±2.83)%·g-1,(20.87±2.40)%·g-1 at 0 min,30 min,1 h,2 h,4 h after administration of the nebulized^(68)Ga-PEG-MNP,respectively.The results were highly consistent with the findings of ex-vivo radiographic autoradiography.