Alzheimer’s disease (AD) is a neurodegenerative disease, and β-amyloid (Aβ) is believed to be a causative factor in AD pathology. The abnormal deposition of Aβ is believed to be responsible for progression of AD. In order to facilitate the imaging of Aβ in vivo, suitable probe molecules with a near-infrared emission wavelength that can penetrate the blood–brain barrier (BBB) were utilized. The commercial fluorescent probe thioflavin-T (ThT) is used to image Aβ; however, because of its short emission wavelength and poor BBB penetration, ThT can only be used in vitro. With this research, based on ThT, we design three fluorescent probes (SZIs) having a longer emission wavelength in order to image Aβ aggregates. SZIs with different numbers of double bonds respond to Aβ aggregates. The SZIs have a structure similar to ThT, and as such, the SZIs are also unable to penetrate the BBB. To deal with the problem, we develop nanocomposites (MSN-Lf@SZIs) to deliver SZIs into the brain of AD mouse and image Aβ successfully. These new nanocomposites are able to deliver the dyes into the brain and facilitate Aβ imaging in vivo.

中文翻译：

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用于体内β-淀粉样蛋白成像的苯并噻唑衍生物封端二氧化硅纳米复合材料

阿尔茨海默病 (AD) 是一种神经退行性疾病，β-淀粉样蛋白 (Aβ) 被认为是 AD 病理的致病因素。Aβ的异常沉积被认为是AD进展的原因。为了促进体内Aβ 的成像，使用了具有可穿透血脑屏障 (BBB) 的近红外发射波长的合适探针分子。使用商业荧光探针硫代黄素-T (ThT) 对 Aβ 进行成像；然而，由于其发射波长短且 BBB 穿透性差，ThT 只能在体外使用. 通过这项研究，我们基于 ThT，设计了三种具有更长发射波长的荧光探针 (SZI)，以对 Aβ 聚集体进行成像。具有不同数量双键的 SZI 对 Aβ 聚集体有反应。SZI 具有类似于 ThT 的结构，因此，SZI 也无法穿透 BBB。为了解决这个问题，我们开发了纳米复合材料 (MSN-Lf@SZIs) 以将 SZI 传递到 AD 小鼠的大脑中并成功地对 Aβ 进行成像。这些新的纳米复合材料能够将染料输送到大脑中并促进体内Aβ 成像。