Advances in cell-penetrating peptide-based nose-to-brain drug delivery systems.

The incidence of brain disorders has gained worldwide attention and the presence of the blood-brain barrier prevents numerous drugs from reaching the targeted brain. The specific physiology of the nasal cavity and the brain provides the feasibility of direct nose-brain delivery, a system that bypasses the blood-brain barrier in a non-invasive manner for brain-targeted drug delivery via intracellular and extracellular mechanisms. The use of CPPs provides further feasibility for naso-brain drug delivery studies, and liposomes, nanopolymer particles, and gels modified with CPPs have demonstrated significant brain-targeting capabilities after nasal delivery. In this paper, the physiology of the nasal cavity and brain, the pathways of naso-brain delivery and the influencing factors are discussed in detail. At the same time, the introduction, classification, mechanism of action and application of CPPs in the nasal-brain delivery system are discussed in detail to provide a theoretical basis for the in-depth study of the application of CPPs in the nasal-brain delivery system.