Although nanotechnology has been investigated during recent years to increase the bioavailability and therapeutic effects of mucosal administrated drugs, numerous barriers (e.g., pH environment, enzymes and mucus) still limit the delivery efficiency. And the epithelium would also affect the systemic mucosal drug delivery. Amongst all the barriers, the protective mucus has drawn more and more attention, which strongly hinders the accessibility of nanovehicles to epithelium. Therefore, trials to conquer the mucus barrier have been designed using two controversial strategies: mucoadhesion and mucus-penetration. This review summarizes the influence of mucus layer on nanomaterials and introduces the modification strategies by modulating surface properties (i.e., hydrophilicity/hydrophobicity and surface charge) to overcome mucus barriers. Furthermore, it also reviews advanced modification methods to meet the different surface requirements of nanovehicles to overcome mucus and epithelium barriers in systemic mucosal delivery.

尽管近年来已经研究了纳米技术以增加粘膜给药药物的生物利用度和治疗效果，但是许多障碍（例如，pH环境，酶和粘液）仍然限制了递送效率。并且上皮也将影响全身粘膜的药物递送。在所有的障碍中，保护性粘液引起了越来越多的关注，这严重阻碍了纳米载体上皮的可及性。因此，使用两种有争议的策略设计了克服粘液屏障的试验：粘膜粘附和粘液渗透。这篇综述总结了粘液层对纳米材料的影响，并介绍了通过调节表面特性（即亲水性/疏水性和表面电荷）克服粘液屏障的改性策略。此外，