Mucus-penetrating nanocarriers

The chapter provides an overview of the different strategies, based on nanotechnology, to overcome one of the main barriers related to the mucosal delivery of biologically active compounds. Therapeutic nanocarriers are largely trapped by the protective mucus layer, limiting their residence time on epithelial surfaces and, therefore, reducing the possibilities for drug absorption or action. Development of mucus-penetrating particles provides a promising tool for overcoming this barrier. For this purpose, different strategies may be envisaged, including a combination of nanocarriers with mucolytic compounds or their coating with hydrophilic agents in order to minimize adhesive interactions with mucus components. Another possibility would be the use of a biomimetic approach similar to those developed by bacteria and virus to reach the epithelium before entry into host mucosal cells.