The diagnosis of brain diseases is the first key step in effective treatment. In vivo imaging tracers that effectively cross the blood–brain barrier (BBB) and reach areas of brain dysregulation is one focus of accurate diagnosis. Here, our main objective was to develop an iron-based nanoparticle for dual brain magnetic resonance imaging (MRI) and fluorescence imaging studies. Small sized iron oxide nanoparticles (SIONs) were prepared by a solvothermal method. Angiopep-2 was covalently connected to the surface of SIONs to enhance penetration of the BBB. The photosensitizer (chlorin e6, Ce6) was modified on the surface of SIONs to enhance fluorescence imaging to corroborate MRI results. We found that the resultant SIONs@ANG/Ce6/PEG displayed good biocompatibility and excellent MRI and fluorescence detection. Moreover, dual-modal MR/fluorescence imaging demonstrated that SIONs@ANG/Ce6/PEG had high sensitivity and accuracy in imaging of mouse with brain tumors. This work provides a strategy to design dual-modal contrast agents for diagnosis of brain disease.

中文翻译：

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小型功能化氧化铁纳米粒子，用于双脑磁共振成像和荧光成像

脑疾病的诊断是有效治疗的第一步。体内有效穿越血脑屏障（BBB）并到达大脑失调区域的成像示踪剂是准确诊断的重点之一。在这里，我们的主要目标是开发用于双脑磁共振成像（MRI）和荧光成像研究的铁基纳米颗粒。通过溶剂热法制备了小尺寸的氧化铁纳米颗粒（SIONs）。Angiopep-2共价连接到SIONs的表面，以增强BBB的渗透。对光敏剂（氯霉素e6，Ce6）在SION的表面进行了修饰，以增强荧光成像，从而证实了MRI结果。我们发现，所得的SIONs @ ANG / Ce6 / PEG显示出良好的生物相容性以及出色的MRI和荧光检测。而且，双模态MR /荧光成像表明，SIONs @ ANG / Ce6 / PEG对脑肿瘤小鼠的成像具有很高的灵敏度和准确性。这项工作为设计用于诊断脑疾病的双峰型造影剂提供了一种策略。