Central nervous system (CNS) cancers are among the most common and treatment-resistant diseases. The main reason for the low treatment efficiency of the disorders is the barriers against targeted delivery of anticancer agents to the site of interest, including the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB). BBB is a strong biological barrier separating circulating blood from brain extracellular fluid that selectively and actively prevents cytotoxic agents and majority of anticancer drugs from entering the brain. BBB and BBTB are the major impediments against targeted drug delivery into CNS tumors. Nanotechnology and its allied modalities offer interesting and effective delivery strategies to transport drugs across BBB to reach brain tissue. Integrating anticancer drugs into different nanocarriers improves the delivery performance of the resultant compounds across BBB. Surface engineering of nanovehicles using specific ligands, antibodies and proteins enhances the BBB crossing efficacy as well as selective and specific targeting to the target cancerous tissues in CNS tumors. Multifunctional nanoparticles (NPs) have brought revolutionary advances in targeted drug delivery to brain tumors. This study reviews the main anatomical, physiological and biological features of BBB and BBTB in drug delivery and the recent advances in targeting strategies in NPs-based drug delivery for CNS tumors. Moreover, we discuss advances in using specific ligands, antibodies, and surface proteins for designing and engineering of nanocarriers for targeted delivery of anticancer drugs to CNS tumors. Finally, the current clinical applications and the perspectives in the targeted delivery of therapeutic molecules and genes to CNS tumors are discussed.

中文翻译：

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中枢神经系统癌症中的细胞和分子靶向药物递送：靶向策略的进展。

中枢神经系统 (CNS) 癌症是最常见和最难治疗的疾病之一。这些疾病治疗效率低的主要原因是抗癌药物靶向递送至目标部位的障碍，包括血脑屏障 (BBB) 和血脑肿瘤屏障 (BBTB)。BBB 是一种强大的生物屏障，将循环血液与脑细胞外液分开，可选择性地主动阻止细胞毒剂和大多数抗癌药物进入大脑。BBB 和 BBTB 是靶向药物递送到 CNS 肿瘤的主要障碍。纳米技术及其相关模式提供了有趣且有效的递送策略，可将药物通过 BBB 运送到脑组织。将抗癌药物整合到不同的纳米载体中可以提高所得化合物跨 BBB 的递送性能。使用特定配体、抗体和蛋白质的纳米载体表面工程增强了 BBB 穿越功效以及对 CNS 肿瘤中靶癌组织的选择性和特异性靶向。多功能纳米粒子 (NPs) 为脑肿瘤靶向药物递送带来了革命性的进步。本研究回顾了 BBB 和 BBTB 在药物递送中的主要解剖学、生理学和生物学特征，以及基于 NPs 的 CNS 肿瘤药物递送靶向策略的最新进展。此外，我们讨论了使用特定配体、抗体和表面蛋白来设计和改造纳米载体以将抗癌药物靶向递送至 CNS 肿瘤的进展。最后，