The blood-brain barrier prevents passage of large and hydrophilic molecules, undermining efforts to deliver most active molecules, proteins and other macromolecules. To date, nanoparticle-assisted delivery has been extensively studied to overcome this challenge but with limited success. On the other hand, for certain brain therapeutic applications, periphery-confined particles could be of immediate therapeutic usefulness. The modulation of CNS dysfunctions from the peripheral compartment is a promising approach, as it does not involve invasive interventions. From recent studies, three main roles could be identified for periphery-confined particles: brain tissue detoxification via the "sink-effect"; a "circulating drug-reservoir" effect to improve drug delivery to brain tissues, and finally, brain vascular endothelium targeting to diagnose or heal vascular-related dysfunctions. These applications are much easier to implement as they do not involve complex therapeutic and targeting strategies and do not require crossing biological barriers. Micro/nano-devices required for such applications will likely be simpler to synthesize and will involve fewer complex materials. Moreover, peripheral particles are expected to be less prone to neurotoxicity and issues related to their diffusion in confined space.

中文翻译：

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用于神经退行性疾病和毒性管理的外围受限微粒系统：避免血脑屏障挑战。

血脑屏障可防止较大的亲水分子通过，从而破坏了传递最活跃分子，蛋白质和其他大分子的努力。迄今为止，已经广泛研究了纳米粒子辅助递送以克服该挑战，但是成功有限。另一方面，对于某些脑部治疗应用，外围限制的颗粒可能具有直接的治疗作用。来自周围区室的中枢神经系统功能障碍的调节是一种有前途的方法，因为它不涉及侵入性干预。从最近的研究中，可以确定外围受限颗粒的三个主要作用：通过“下沉效应”对脑组织进行排毒；对脑组织进行排毒。改善药物向脑组织的输送的“循环药物储库”效应，最后，靶向脑血管内皮以诊断或治愈与血管相关的功能障碍。这些应用程序更容易实现，因为它们不涉及复杂的治疗和靶向策略，并且不需要跨越生物学障碍。此类应用所需的微型/纳米设备将可能更易于合成，并且涉及的复杂材料也更少。此外，预期外围颗粒不太容易受到神经毒性以及与其在受限空间中扩散有关的问题。