The blood-brain barrier (BBB) is constituted by a specialized vascular endothelium that interacts directly with astrocytes, neurons and pericytes. It protects the brain from the molecules of the systemic circulation but it has to be overcome for the proper treatment of brain cancer, psychiatric disorders or neurodegenerative diseases, which are dramatically increasing as the population ages. In the present work we have revised the current knowledge on the cellular structure of the BBB and the different procedures utilized currently and those proposed to cross it. Chemical modifications of the drugs, such as increasing their lipophilicity, turn them more prone to be internalized in the brain. Other mechanisms are the use of molecular tools to bind the drugs such as small immunoglobulins, liposomes or nanoparticles that will act as Trojan Horses favoring the drug delivery in brain. This fusion of the classical pharmacology with nanotechnology has opened a wide field to many different approaches with promising results to hypothesize that BBB will not be a major problem for the new generation of neuroactive drugs. The present review provides an overview of all state-of-the-art of the BBB structure and function, as well as of the classic strategies and these appeared in recent years to deliver drugs into the brain for the treatment of Central Nervous System (CNS) diseases.

血脑屏障（BBB）由与星形胶质细胞，神经元和周细胞直接相互作用的特殊血管内皮组成。它可以保护大脑免受全身循环分子的侵害，但是对于正确治疗脑癌，精神疾病或神经退行性疾病的人来说，必须克服这一难题，因为人口老龄化正在急剧增加。在目前的工作中，我们已经修订了有关血脑屏障细胞结构的现有知识，以及目前使用的各种程序以及拟通过该程序的程序。药物的化学修饰，例如增加其亲脂性，使它们更易于被大脑内化。其他机制是使用分子工具来结合药物，例如小的免疫球蛋白，脂质体或纳米颗粒将充当特洛伊木马，有利于大脑中的药物输送。经典药理学与纳米技术的这种融合为许多不同的方法开辟了广阔的领域，并有希望的结果证明BBB不会成为新一代神经活性药物的主要问题。本综述概述了BBB结构和功能的所有最新技术，以及经典策略，这些策略近年来出现在将药物输送到大脑中以治疗中枢神经系统（CNS）的过程中）疾病。