Dendrimer-based magnetic resonance imaging agents for brain cancer

树型分子的磁共振造影剂在脑肿瘤成像中的应用（英文）

Brain cancer is one of the most lethal and difficult-to-treat cancers because of its physical location and biological barriers. The mainstay of brain cancer treatment is surgical resection, which demands precise imaging for tumor localization and delineation. Thanks to advances in bioimaging, brain cancer can be detected earlier and resected more reliably. Magnetic resonance imaging（MRI） is the most common and preferred method to delineate brain cancer, and a contrast agent is often required to enhance imaging contrast.Dendrimers, a special family of synthetic macromolecules,constitute a particularly appealing platform for constructing MRI contrast agents by virtue of their well-defined three-dimensional structure, tunable nanosize and abundant surface terminals, which allow the accommodation of high payloads and numerous functionalities. Tuning the dendrimer size,branching and surface composition in conjunction with conjugation of MRI functionalities and targeting moieties can alter the relaxivity for MRI, overcome the blood-brain barrier and enhance tumor-specific targeting, hence improving the imaging quality and safety profile for precise and accurate imaging of brain tumors. This short review highlights the recent progress, opportunities and challenges in developing dendrimer-based MRI contrast agents for brain tumor imaging.

脑癌由于其特殊的生理位置和血脑屏障,是一种难以治疗的致命肿瘤.手术切除是目前脑癌的主要治疗手段,然而成功的手术需要精确的肿瘤定位和肿瘤成像以确保完全切除癌细胞并避免伤害正常脑组织.磁共振成像是诊断脑癌最常见的成像方法,但通常需要造影剂来增强成像对比度和精准度.树型分子因其独特的精准三维结构,可调控的纳米尺寸和众多的表面官能团,可作为构建磁共振成像造影剂的优选材料.藉由调整树型分子的尺寸、使用不同的分支结构和表面官能团修饰(包括磁共振成像功能团和脑肿瘤靶向基团),可以改善造影剂的弛豫性,克服血脑屏障并增强肿瘤靶向能力,从而改善成像质量以获得精准的脑瘤成像,并提高造影剂的安全性.本文简要总结了基于树型分子的磁共振成像造影剂在脑癌成像应用中的挑战、最新进展、机遇和未来发展趋势.